Allograft Transplants of the Extremities

Number: 0364

Policy

1. Allograft Transplant of the Knee

   Aetna considers allograft transplant of the knee (knee ligaments, osteochondral, and meniscus) medically necessary when selection criteria are met.

   Anterior Cruciate Ligament (ACL), Posterior Cruciate Ligament (PCL), Medial Collateral Ligament, (MCL), and Lateral Collateral Ligament (LCL):

   Aetna considers allografts of the knee ligaments medically necessary as an alternative to autografts for knee ligament reconstruction.

   Osteochondral (Femoral Articulation Only):

   1. Avascular necrosis lesions of the femoral condyle; or
   2. Osteochondral lesions of the distal femur; or
   3. Otherwise healthy, active, non-elderly members who have either failed earlier arthroscopic procedures or are not candidates for such procedures because of the size, shape, or location of the lesion; or
   4. Treatment of a focal lesion on distal femur that meets the following criteria:
      
      
      1. Full-thickness depth (grade 3 or 4) lesion 2 cm or more in diameter by MRI or arthroscopy; and
      2. Surrounded by normal, healthy (non-arthritic) cartilage; and
      3. Causing disabling localized knee pain that is unresponsive to conservative treatment (e.g., medication, physical therapy); and
      4. Normal knee alignment or knee alignment will be surgically corrected (i.e., by osteotomy) at time of allograft; and
      5. Stable and aligned knee with intact meniscus and normal joint space on X-ray (a corrective procedure in combination with, or prior to, chondrocyte implantation may be necessary to ensure stability, alignment and normal weight distribution within the joint); and
      6. The opposing articular surface should be generally free of disease or injury, including no arthritis on the corresponding tibial surface.

   Meniscus:

   1. Degenerative changes must be absent or minimal (Outerbridge grade II or less), and
   2. Knee must be stable prior to surgery or be surgically corrected at the time of the allograft (i.e., intact or reconstructed ACL), and
   3. Members under the age of 55 years, and 
   4. Normal knee alignment or knee alignment will be surgically corrected (i.e., by osteotomy) at time of allograft; and
   5. Pre-operative studies (MRI or previous arthroscopy) reveal absence or near-absence of the meniscus; and
   6. Significant knee pain unresponsive to conservative treatment.

   Aetna considers allograft transplant of the knee experimental and investigational for all other indications because its effectiveness for indications other than the ones listed above has not been established.

2. Osteochondral Allograft of the Talus

   Aetna considers osteochondral allograft of the talus experimental and investigational because there are unanswered questions regarding the clinical outcomes of this approach when compared with ankle arthrodesis, especially in terms of pain, disability, functionality and durability. 

3. Vascularized Bone Graft

   Aetna considers the use of vascularized bone graft for the treatment of avascular necrosis of the talus experimental and investigational because its effectiveness has not been established.

4. Osteochondral Allograft

   Aetna considers osteochondral allograft experimental and investigational for the following:

   1. Individuals who have had a previous total meniscectomy; or
   2. Individuals with a cartilaginous defect associated with osteoarthritis or inflammatory diseases or where an osteoarthritic or inflammatory process significantly and adversely affects the quality of the perilesional cartilage; or
   3. All other indications, including aseptic non-union in the upper extremity, dysplasia epiphysealis hemimelica (Trevor's disease), femoral trochlear dysplasia, ilio-tibial band repair, shoulder instability, tarso-metatarsal arthrodesis, repairing chondral defects/lesions of the ankle, elbow, hip, patella, patello-femoral ligament, and shoulder (e.g., acromio-clavicular (AC) separation, Hill Sachs lesions) because its effectiveness has not been established.

5. Synthetic Resorbable Polymers

   Aetna considers the use of synthetic resorbable polymers (e.g., TruFit Plug, PolyGraft) for osteochondral allografts of the knee and other joints experimental and investigational because its effectiveness has not been established.

6. Fast-Fix Meniscal Repair System

   Aetna considers the Fast-Fix meniscal repair system medically necessary for repair of meniscal tears.

7. Juvenile Cartilage Allograft Tissue Implantation

   Aetna considers juvenile cartilage allograft tissue implantation (e.g., the use of DeNovo ET engineered tissue graft (living cartilage allografts using juvenile chondrocytes) and DeNovo NT tissue graft (particulated juvenile cartilaginous allograft)) for repair of articular cartilage lesions experimental and investigational because its effectiveness has not been established.

8. Manipulated Human Tissue Graft Products

   Aetna considers manipulated (decellularized) human tissue graft products (e.g., Chondrofix osteochondral allograft) experimental and investigational because their clinical value has not been established. 

9. Cartiform Viable Osteochondral Allograft

   Aetna considers Cartiform viable osteochondral allograft experimental and investigational for use in microfracture and other surgery on the knee and other joints (e.g., glenoid, metatarsal phalangeal, and patella-femoral joints) because its effectiveness has not been established.

10. Semitendinosus Allograft for the Treatment of Chronic Ankle Instability

    Aetna considers semitendinosus allograft medically necessary for the treatment of chronic ankle instability if members have failed 6 months of non-operative treatments (including braces, physical therapy (balance and strength exercises), medication and taping).

11. Cryopreserved Arterial Allografts for Critical Limb Ischemia

    Aetna considers cryopreserved arterial allografts experimental and investigational for the treatment of critical limb ischemia because the effectiveness of this approach has not been established.

Background

Repair of knee ligaments refers to surgical treatment of acute injuries (ruptures), whereas primary reconstruction usually refers to surgical intervention of ligamentous laxity (chronic insufficiency) several months following an injury.  Revision reconstruction means corrective surgery when the original reconstruction has failed.  The bulk of the literature on ligamentous reconstruction of the knee deals with the primary reconstruction of the anterior cruciate ligament (ACL).  Generally, there are 3 reconstructive methods for managing ACL insufficiency:

1. intra-articular replacements,
2. extra-articular procedures, and
3. combined procedures. 

The first method is intended to replace the ACL, whereas the second method is intended to tighten the medial or lateral secondary restraints, or both in the third method.  The sources for intra-articular replacements are quadriceps tendon, patellar tendon, hamstring tendons, and iliotibial band or tract.  In particular, the bone-patellar tendon-bone autograft (the central one-third of the patellar tendon and its bony attachments to the patella and tibial tubercle) is the most common operation currently performed for reconstructing the ACL through arthroscopy. 

Allograft, also known as allogeneic graft or homograft, is a graft between individuals of the same species, but of dissimilar genotype.  Allografts may be used as an alternative to autografts for ligament reconstruction or meniscal transplantation of the knee. For tendon allografts, cadaver donors are usually used. Allograft tissue is procured from genetically unrelated cadaver donors and processed, stored and utilized according to U.S. Food and Drug Administration (FDA) and the American Association of Tissue Banks (AATB) standards. The advantages of allografts include no donor site morbidity, shorter surgical time, smaller incisions and greater availability. Allograft transplants are not rejected by the body as with other organ transplants. The donor tissues most commonly used are the patellar and Achilles tendons.  An allograft may be preserved by freeze-drying or deep-freezing and can be sterilized either by sterile procurement with careful donor screening or by secondary sterilization with gaseous ethylene oxide or gamma irradiation.  It is believed that freeze-drying or deep-freezing renders connective tissue allografts less immunogenic by killing the cells and denaturing surface histocompatibility antigens.  However, while some investigators have claimed that freeze-drying of the allograft does not significantly change the mechanical properties of the grafts compared with deep-freezing; others have reported frequent late failures of freeze-dried allograft tissues.  Fideler and co-workers (1994) concluded that a dose of 30,000 or 40,000 gray (3 or 4 megarad) of gamma radiation is necessary for the inactivation of the DNA of the human immunodeficiency virus in frozen bone-patellar ligament-bone allograft harvested from donors infected with the virus.

Knee ligament reconstruction with allograft tendons may be performed for the anterior cruciate ligament (ACL), posterior cruciate ligament, medial or lateral collateral ligaments. These ligaments are strong fibrous bands of tissue that attach to the femur, fibula patella and tibia bones providing strength and stability to the joint. Allografts are commonly used for ACL reconstruction.

Tendon allograft has been used for the repair/reconstruction of the ACL in patients following major knee injury.  The advantages of using these allografts are a more abundant supply of tissue for multiple ligament and revision surgery, a shorter operative time, faster rehabilitation, avoidance of morbidity associated with autograft harvesting, as well as a lower incidence of stiff knee.  On the other hand, the disadvantages in employing allografts are a potentially increased failure rate, a risk of hepatitis or AIDS infection, as well as stimulation of an immune response.

Studies have shown high failure rates with use of allograft for ACL reconstruction (Gorschewsky et al, 2005; Pritchard et al, 1995; Roberts et al, 1991).  Prodromos et al (2007) performed a meta-analysis of autograft and allograft stability data.  Normal stability for all autografts was 72 % versus 59 % for all allografts (p < 0.01).  Abnormal stability was 5 % for all autografts versus 14 % for all allografts (p < 0.01).  Bone-patellar-tendon-bone (BPTB) autograft normal stability was 66 % versus 57 % for BPTB allografts (p < 0.01).  Abnormal BPTB autograft stability was 6 % versus 16 % for BPTB allograft.  Hamstring autograft normal or abnormal stability rates were 77 % and 4 % and were compared to soft tissue allografts as a group which were 64 % and 12 % (p < 0.01).  The investigators reported that allografts had significantly lower normal stability rates than autografts.  The investigators found that allograft abnormal stability rate, which usually represents graft failure, was nearly 3 times higher than that of autografts.  The investigators concluded that autografts are the graft of choice for routine ACL reconstruction with allografts better reserved for multiple ligament-injured knees where extra tissue may be required.

A meta-analysis of patellar autograft versus allograft for ACL reconstruction found better outcomes with autograft (Krych et al, 2008).  The investigators noted, however, that when irradiated and chemically processed allografts are excluded, the outcomes of autograft and allograft are more similar, but without the irradiation or chemical processing of allografts, there is an increased risk of transmission of infection.

A guidelines panel from the Italian National Guidelines System (Romanini et al, 2010) conducted a critical review of the literature of grafts for arthroscopic ACL reconstruction, and found that "[a]utograft shows moderate superiority compared with allograft" and that "[a]vailable evidence allows recommendation of use of autograft over allograft in arthroscopic ACL reconstruction."  The guidelines panel also found that, for autograft, patellar tendon has better performance than hamstring.  The guidelines panel also concluded that "[i]t is also appropriate to consider allograft and artificial ligaments only in very selected cases, discouraging widespread use, given the potential risks and paucity of well-performed, well-designed clinical studies."

Reinhard et al (2010) conducted a systematic review of the evidence for graft selection in ACL reconstruction.  The investigators found limited high-quality evidence comparing autograft to allograft.  Most case series include a smaller number of young patients (i.e., less than 30 years of age) and there have been early reports of unacceptably high failure rates in young patients.  The authors stated that procurement, storage, sterilization, and processing of allografts vary widely within the industry.  The investigators noted that the sterilization process may affect the mechanical characteristics of allografts, and that this process is necessary to decrease viral disease transmission and bacterial infection rate, but it may also adversely affect the quality of the tissue.  The review stated that several techniques have been used for this purpose.  The review found that, although ethylene oxide sterilization does not alter directly the mechanical properties of the graft, it has been shown to cause clinical failure because of persistent synovitis, and therefore is less favorable.  Another sterilization technique involves applying irradiation.  The authors stated that high-dose irradiation (3 Mrad or more) is unacceptable as it severely affects mechanical properties of the tissue.  The authors stated that lower doses of irradiation (2 to 2.5 Mrad) has also been shown in several studies to cause unacceptable inferior clinical outcomes and high failure rates..

Other more recent studies have found lower failure rates with patellar tendon autograft than allograft and/or hamstring autograft (Barrett et al, 2011; Barrett et al, 2010; Mehta et al, 2010).

Dopirak and colleagues (2008) noted that there has been substantial progress in the understanding of the medial patello-femoral ligament during the past 10 years.  This structure is the primary static soft-tissue restraint to lateral patellar displacement.  Substantial alteration of normal patellar tracking occurs after sectioning of the ligament.  Clinical studies have demonstrated the medial patello-femoral ligament is disrupted during acute patellar dislocation.  Recently, several medial patello-femoral ligament-based procedures have been developed for the treatment of patellar instability with good early results.  However, the authors stated that further studies are needed to define the exact role of these procedures in the treatment of patello-femoral instability.

Oro et al (2011) compared operating room time and costs associated with ACL reconstruction with either bone-patellar tendon-bone (BPTB) autograft or BPTB allograft.  The total mean cost per case was 25 % higher in the allograft group compared with the autograft group.  The mean operating room time was only 12 mins greater in autograft cases.  Other studies have found significantly higher costs with use of allograft than autograft in ACL reconstruction, with little differences in operating room costs (Cooper and Kaeding, 2010; Naqda et al, 2010).

There is inadequate evidence that the use of tendon allograft is equally effective as autograft in the primary reconstruction of ACL.  In addition, due to the risk of disease transmission, it should not be used for primary, isolated ACL reconstruction.  Tendon allograft for reconstruction of the ACL should only be employed when an adequate autologous graft is not available for

1. revision surgery (in knees in which a primary reconstruction of the ligament had failed and in which an autograft had already been used) or for
2. primary reconstruction surgery for combined ligament injuries (ACL and either the posterior cruciate ligament, or medial collateral ligament) when an adequate autologous graft is not available.

There are relatively few studies comparing allograft to autograft in posterior cruciate ligament (PCL) reconstruction.  In an evidence review of outcomes of posterior collateral ligament treatment, Hammoud et al (2010) cited evidence of good results with Achilles allograft and hamstring autograft for posterior cruciate ligament reconstruction.  Hermans et al published a 6- to 12-year follow-up (mean 9.1 years) study of single bundle PCL reconstruction.  Twenty-two patients (88 % follow-up) with isolated PCL injuries underwent reconstruction using patellar tendon autograft (n = 9), 4-strand hamstring tendon autograft (n = 7), 2-strand hamstring tendon autograft plus Achilles tendon allograft (n = 8), or Achilles tendon allograft alone (n = 1).  The authors reported that there were no differences between grafts used in mean Lysholm score, Tegner score, or International Knee Documentation Committee (IKDC) rating between the patellar tendon and hamstring tendon reconstructions. 

Osteochondral grafting is performed to treat cartilage damage or defects due to traumatic injury or degenerative conditions (eg, osteochondritis dissecans (OCD), osteonecrosis or osteoarthritis). Osteochondral allograft transplant refers to the replacement of damaged articular cartilage and bone with tissue from a cadaveric donor. These allografts can either be fresh or frozen. Osteochondral allograft transplantation is used predominantly in the treatment of large and deep osteochondral lesions resulting from conditions such as osteochondritis dissecans (OCD), osteonecrosis or traumatic osteochondral fractures.

Manipulated (decellularized) human tissue graft products (e.g., Chondrofix osteochondral allograft) are made of bone and cartilage tissue that is harvested from a cadaveric donor that has been processed to remove blood, cells and fat from the tissue. It is sterilized to kill bacteria and other microorganisms purportedly promotes bone integration and remodeling, while reducing the risk of inflammation in repair of Grade III and Grade IV osteochondral lesions.

Synthetic resorbable polymers (eg, PolyGraft, TruGraft TruFit plugs) are polymer scaffolds that are being proposed for the repair of osteochondral articular cartilage defects. The implant functions as a scaffold for chondral and osteogenic cells with the synthetic polymer being resorbed as the cells produce their normal matrices.

Williams and Gamradt (2008) noted that the creation of cartilage repair tissue relies on the implantation or neosynthesis of cartilage matrix elements.  One cartilage repair strategy involves the implantation of bioabsorbable matrices that immediately fill a chondral or osteochondral defect.  Such matrices support the local migration of chondrogenic or osteogenic cells that ultimately synthesize new ground substance.  One such matrix scaffold, TruFit Plug, a synthetic resorbable biphasic implant, is a promising device for the treatment of osteochondral voids.  The implant is intended to serve as a scaffold for native marrow elements and matrix ingrowth in chondral defect repair.  The device is a resorbable tissue regeneration scaffold made predominantly from polylactide-coglycolide copolymer, calcium sulfate, and polyglycolide.  It is approved in Europe for the treatment of acute focal articular cartilage or osteochondral defects but is approved by the U.S. Food and Drug Administration only for backfill of osteochondral autograft sites.  Pre-clinical studies demonstrated restoration of hyaline-like cartilage in a goat model with subchondral bony incorporation at 12 months.  Early clinical results of patients enrolled in the Hospital for Special Surgery Cartilage Registry have been favorable, with a good safety profile.

Carmont et al (2009) stated that TruFit plugs are synthetic polymer scaffolds that are inserted into an articular surface to provide a stable scaffold to encourage the regeneration of a full thickness of articular cartilage to repair chondral defects.  These researchers reported promising early results for the repair of small articular cartilage defects within the knee.  Others have reported "failures" in which patients have complained of persistent symptoms and joint effusion at 6 months after plug insertion and arthroplasty has been undertaken.  These investigators reported a case of delayed incorporation of an articular cartilage defect of the lateral femoral condyle treated with 3 TruFit plugs.  The patient eventually reported symptom alleviation and resumption of functional activity after 24 months of continued rehabilitation.  The authors recommended that patients with continued symptoms persevere with rehabilitation and allow the regenerating articular cartilage time to mature fully before considering undertaking irreversible arthroplasty procedures.

The clinical value of TruFit Plug for osteochondral allografts of the knee has not been established.

Severe post-traumatic ankle arthritis poses a reconstructive challenge in the young and active patient.  Bipolar fresh osteochondral allograft (BFOA) may represent an intriguing alternative to arthrodesis and prosthetic replacement.  Giannini et al (2010) described a lateral trans-malleolar technique for BFOA, and evaluated the results in a case series.  A total of 32 patients, mean age of 36.8 +/- 8.4 years, affected by ankle arthritis underwent BFOA with a mean follow-up of 31.2 months.  The graft was prepared by specifically designed jigs, including the talus and the tibia with the medial malleolus.  The host surfaces were prepared by the same jigs through a lateral approach.  The graft was placed and fixed with twist-off screws.  Patients were evaluated clinically and radiographically at 2, 4, and 6 months after operation, and at a minimum 24 months follow-up.  A biopsy of the grafted areas was obtained from 7 patients at 1-year follow-up for histological as well as immunohistochemical examination.  Pre-operative American Orthopaedic Foot and Ankle Society (AOFAS) score was 33.1 +/- 10.9 and post-operatively 69.5 +/- 19.4 (p < 0.0005).  Six failures occurred.  Cartilage harvests showed hyaline-like histology with a normal collagen component but low proteoglycan presence and a disorganized structure.  Samples were positive for MMP-1, MMP-13 and Capsase-3.  The authors concluded that the use of BFOA represents an intriguing alternative to arthrodesis or arthroplasty; precise allograft sizing, stable fitting and fixation and delayed weight-bearing were key factors for a successful outcome.  They stated that further research regarding the immunological behavior of transplanted cartilage is needed.

Injury of articular cartilage due to trauma or pathological conditions is a major cause of disability worldwide.  There is extensive ongoing reseach focusing on strategies to repair and replace knee joint cartilage. Juvenile cartilage allograft tissue implantation (eg, DeNovo NT natural tissue graft, DeNovo ET engineered tissue graft) was developed to treat damaged cartilage. The natural tissue graft is an allograft transplantation process that involves transplanting minced juvenile donor cartilage into a cartilage defect using a fibrin adhesive. The engineered tissue is a living tissue graft grown from juvenile chondrocytes. The cells are isolated and expanded in vitro. The expanded cells are cryopreserved in a cell bank from which a large number of grafts can be grown. The cells are applied to defects of the surface joint using a fibrin adhesive.

DeNovo NT Graft has been used to treat focal articular defects in a wide range of anatomical applications (e.g., ankle, elbow, great toe, hip, knee, and shoulder). DeNovo NT Natural Tissue Graft, a human tissue allograft, is an available cartilage repair treatment in the United States.  DeNovo ET Engineered Tissue Graft is undergoing a clinical study as an investigational biological product currently underoing clinical tials.  In contrast to DeNovo ET (engineered tissue), DeNovo NT (natural tissue) is obtained directly from a juvenile allograft donor joint and the cartilage is then aseptically minced and packaged by the tissue processor. The particulated allograft is mixed intra-operatively with fibrin glue before being implanted in the recipient’s prepared articular lesion.  Moreover, there is a lack of evidence regarding the clinical value of DeNovo tissue graft.

Ahmed and Hincke (2010) discussed strategies to repair and replace knee joint cartilage.  Because of inadequacies associated with widely used approaches, the orthopedic community has an increasing tendency to develop biological strategies, which include transplantation of autologous (i.e., mosaicplasty) or allogeneic osteochondral grafts, autologous chondrocytes (autologous chondrocyte transplantation), or tissue-engineered cartilage substitutes.  Tissue-engineered cartilage constructs represent a highly promising treatment option for knee injury as they mimic the biomechanical environment of the native cartilage and have superior integration capabilities.  Currently, a wide range of tissue-engineering-based strategies are established and investigated clinically as an alternative to the routinely used techniques (i.e., knee replacement and autologous chondrocyte transplantation).  Tissue-engineering-based strategies include implantation of autologous chondrocytes in combination with collagen I, collagen I/III (matrix-induced autologous chondrocyte implantation), HYAFF 11 (Hyalograft C), and fibrin glue (Tissucol) or implantation of minced cartilage in combination with copolymers of polyglycolic acid along with polycaprolactone (cartilage autograft implantation system), and fibrin glue (DeNovo NT natural tissue graft).  Tissue-engineered cartilage replacements show better clinical outcomes in the short-term, and with advances that have been made in orthopedics they can be introduced arthroscopically in a minimally invasive fashion.  Thus, the future is bright for this innovative approach to restore function.

Kruse et al (2012) presented the findings of a new technique using DeNovo NT juvenile allograft cartilage implantation introduced into a talar lesion arthroscopically in a single procedure to repair a posterio-medial talar osteochondral defects in a healthy, active 30-year old female.  The patient tolerated the procedure well.  At the 6-month follow-up visit, the patient had returned to full activity, and at 24 months, she remained completely pain-free.  The findings of this case study need to be validated by well-designed studies.

Haene et al (2012) evaluated the intermediate outcomes of fresh osteochondral allografting for osteochondral lesions of the talus with use of validated outcome measures.  A total of 16 patients (17 ankles) received a fresh osteochondral allograft, and all 16 were available for follow-up.  Data were prospectively collected with use of the Ankle Osteoarthritis Scale (AOS), Short Form-36 (SF-36), and American Academy of Orthopaedic Surgeons (AAOS) Foot and Ankle Module outcome measures.  Post-operative AOFAS hind-foot scale scores were also collected.  All 16 patients underwent radiographic and computed tomographic (CT) analyses pre-operatively, and 15 patients had these studies post-operatively.  The average duration of follow-up was 4.1 years.  The latest follow-up CT evaluation identified failure of graft incorporation in 2 of 16 ankles.  Osteolysis, subchondral cysts, and degenerative changes were found in 5, 8, and 7 ankles, respectively.  Five ankles were considered failures, and 2 required a re-operation because of ongoing symptoms.  The AOS Disability and the AAOS Foot and Ankle Core Scale scores significantly improved, but there was no significant change in the AOS Pain, AAOS Foot and Ankle Shoe Comfort Scale, or SF-36 scores.  Overall, 10 patients had a good or excellent result; however, persistent symptoms remained in 6 of these patients; only 4 were symptom-free.  The authors concluded that the use of a fresh osteochondral allograft is a reasonable option for the treatment of large talar osteochondral lesions.  Moreover, they stated that the high re-operation rate (2 of 17) and failure rate (5 of 17) must be taken into consideration when one is choosing this procedure for the management of these lesions.  The findings of this small case-series study need to be validated by well-designed studies with more patients and longer follow-up.

Gross et al (2012) performed a systematic review of clinical outcomes after cartilage restorative and reparative procedures in the glenohumeral joint to

1. identify prognostic factors that predict clinical outcomes,
2. provide treatment recommendations based on the best available evidence, and
3. highlight literature gaps that require future research. 

These investigators searched Medline (1948 to week 1 of February 2012) and Embase (1980 to week 5 of 2012) for studies evaluating the results of arthroscopic debridement, microfracture, osteochondral autograft or allograft transplants, and autologous chondrocyte implantation for glenohumeral chondral lesions.  Other inclusion criteria included minimum 8 months' follow-up.  The Oxford Level of Evidence Guidelines and Grading of Recommendations Assessment, Development and Evaluation (GRADE) recommendations were used to rate the quality of evidence and to make treatment recommendations.  A total of 12 articles met inclusion criteria, which resulted in a total of 315 patients.  Six articles pertained to arthroscopic debridement (n = 249), 3 to microfracture (n = 47), 2 to osteochondral autograft transplantation (n = 15), and 1 to autologous chondrocyte implantation (n = 5).  Whereas most studies reported favorable results, sample heterogeneity and differences in the use of functional and radiographic outcomes precluded a meta-analysis.  Several positive and negative prognostic factors were identified.  All of the eligible studies were observational, retrospective case series without control groups; the quality of evidence available for the use of the afore-mentioned procedures is considered "very low" and "any estimate of effect is very uncertain".  The authors concluded that more research is needed to determine which treatment for chondral pathology in the shoulder provides the best long-term outcomes.  They encouraged centers to establish the necessary alliances to conduct blinded, randomized clinical trials and prospective, comparative cohort studies necessary to rigorously determine which treatments result in the most optimal outcomes.  At this time, high-quality evidence is lacking to make strong recommendations, and decision- making in this patient population is performed on a case-by-case basis.

Farr et al (2012) noted that Cartilage Autograft Implantation System (CAIS; DePuy/Mitek, Raynham, MA) and DeNovo Natural Tissue (NT; ISTO, St. Louis, MO) are novel treatment options for focal articular cartilage defects in the knee.  These methods involve the implantation of particulated articular cartilage from either autograft or juvenile allograft donor, respectively.  In the laboratory and in animal models, both CAIS and DeNovo NT have demonstrated the ability of the transplanted cartilage cells to "escape" from the extracellular matrix, migrate, multiply, and form a new hyaline-like cartilage tissue matrix that integrates with the surrounding host tissue.  In clinical practice, the technique for both CAIS and DeNovo NT is straightforward, requiring only a single surgery to affect cartilage repair.  Clinical experience is limited, with short-term studies demonstrating both procedures to be safe, feasible, and effective, with improvements in subjective patient scores, and with magnetic resonance imaging evidence of good defect fill.  The authors concluded that while these treatment options appear promising, prospective randomized controlled studies are needed to refine the indications and contraindications for both CAIS and DeNovo NT.

Petrera et al (2013) reported their experience with the use of fresh glenoid osteochondral allograft in the treatment of a chronic post-traumatic posterior subluxation of the shoulder associated with glenoid bone loss in a 54-year old recreational football player.  Based on the pathoanatomy of the lesion and availability of a bone bank providing fresh allograft, these researchers opted for an open anatomic reconstruction using a fresh glenoid allograft.  A posterior approach was used; the prepared allograft was placed in the appropriate anatomic position and fixed with 2 small fragment screws with washers.  At 2-year follow-up, the clinical outcome is excellent.  The authors noted that this procedure may represent an effective option for the treatment of chronic posterior shoulder instability due to glenoid bone loss.  However, they stated that the long-term effectiveness and the progression of glenohumeral osteoarthritis need to be evaluated.

DeNovo ET engineered tissue graft (ISTO Technologies, Inc. St. Louis, MO) is a scaffold-free hyaline cartilage implant designed for the repair and regeneration of knee cartilage.  It uses tissue-engineered juvenile cartilage cells applied to defects of the joint surface using a protein-based adhesive.  There is a lack of evidence regarding the clinical value of the DeNovo ET tissue graft.

Meniscal allograft transplantation (MAT) is a surgical technique for restoring knee function in individuals with destroyed or absent menisci. The meniscus (or menisci) refers to the lateral and medial crescent shaped cartilaginous tissues that are located at the junction of the tibia and femur which provide structural integrity to the knee and absorbs shock. Allograft tissue is matched by size to the individual, inserted into the knee joint and anchored to supporting structures by hardware, soft tissue or bony tissue fixation. The procedure may be performed using an arthroscopic approach or by open incision and may be done alone or in tandem with other reconstructive knee procedures.

Vascellari et al (2012) reviewed the published clinical outcomes of meniscal repair using the Fast-Fix device comparing standard rehabilitation program to an accelerated rehabilitation protocol.  A review of the Medline database was performed involving searches for clinical outcomes of all-inside meniscus repair performed with the Fast-Fix device.  Eight studies were identified for inclusion.  On the basis of the clinical outcomes of these studies, there appears to be no notable difference between an accelerated rehabilitation regimen with full weight bearing allowed as soon as tolerated and a standard post-operative rehabilitation program.  Failure rate was 13 % for patients following an accelerated rehabilitation regimen, and 10 % for standard protocol.  Accelerated rehabilitation after all-inside meniscal repair using the Fast-Fix device appears to be safe, and the incidence of re-tears is in line with those reported for standard rehabilitation protocol.

Giza and Howell (2013) noted that OCD of the talus are frequent sequelae of traumatic ankle injuries such as ankle sprains, fractures, and recurrent ankle instability.  Initial management of talus lesions in most cases involves arthroscopy and microfracture/curettage.  Tissue resulting from the microfracture is fibrocartilage.  Clinical improvement in pain is seen in approximately 75 % to 85 % of people in a number of studies with long-term follow-up.  Often, large lesions (greater than 1 cm(2)) or those with cystic changes require secondary procedures such as talus allograft/autograft or autologous chondrocyte implantation.  The use of a juvenile articular chondrocyte allograft is an option for large or refractory lesions and has the advantage of obviating the need for a tibial or fibular osteotomy.  The purpose of this article was to describe a novel arthroscopic surgical technique for transplantation of juvenile chondrocytes as a treatment for talus OCD defects.

Cerrato et al (2013) noted that osteochondral lesions of the talus can present a challenge to the orthopedic surgeon.  Because of its avascular nature, articular cartilage has a poor capacity for self-repair and regeneration.  A wide variety of strategies have been developed to restore the structure and function of injured cartilage.  Surgical strategies range from repair of cartilage through the formation of fibrocartilage to a variety of restorative procedures, including tissue-engineering-based strategies.  A novel treatment option involves the implantation of particulated articular cartilage obtained from a juvenile allograft donor, the DeNovo NT graft.

Coetzee et al (2013) collected clinical outcomes of pain and function in retrospectively and prospectively enrolled patients treated with particulated juvenile cartilage for symptomatic osteochondral lesions in the ankle.  This study collected outcomes and incidence of re-operations in standard clinic patients.  The analysis presented here includes final follow-up to date for 12 males and 11 females representing 24 ankles.  Subjects had an average age at surgery of 35.0 years and an average body mass index of 28 ± 5.8.  Fourteen ankles had failed at least 1 prior bone marrow stimulation procedure.  The average lesion size was 125 ± 75 mm2, and the average depth was 7 ± 5 mm.  In conjunction with the treatment, 9 (38 %) ankles had 1 concomitant procedure and 9 (38%) had more than 1 concomitant procedure.  Clinical evaluations were performed with an average follow-up of 16.2 months.  Average outcome scores at final follow-up were American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale 85 ± 18 with 18 (78 %) ankles demonstrating good to excellent scores, Short-Form 12 Health Survey (SF12) physical composite score 46 ± 10, SF12 mental health composite score 55 ± 7.1, Foot and Ankle Ability Measure (FAAM) activities of daily living 82 ± 14, FAAM Sports 63 ± 27, and 100-mm visual analog scale for pain 24 ± 25.  Outcomes data divided by lesion size demonstrated 92 % (12/13) good to excellent results in lesions 10 mm or larger and those smaller than 15 mm.  To date, 1 partial graft delamination has been reported at 16 months.  The authors concluded that preliminary data from a challenging clinical population with large, symptomatic osteochondral lesions in the ankle suggested that treatment with particulated juvenile cartilage could improve function and decrease pain.  They stated that longer follow-up and additional subjects are needed to evaluate improvement level and ideal patient indications.

The American College of Occupational and Environmental Medicine’s occupational medicine practice guidelines on “Evaluation and management of common health problems and functional recovery in workers” (ACOEM, 2011) and the Work Loss Data Institute’s clinical guidelines on “Ankle & foot (acute & chronic)” (2011) did not mention the use of allograft as a therapeutic tool.

In a review on “Osteochondral lesions of the talus: Aspects of current management”, Hannon et al (2014) states that “Osteochondral lesions (OCLs) occur in up to 70 % of sprains and fractures involving the ankle.  Atraumatic etiologies have also been described.  Techniques such as microfracture, and replacement strategies such as autologous osteochondral transplantation, or autologous chondrocyte implantation are the major forms of surgical treatment”.  This review does not mention the use of allograft as a therapeutic option.  Furthermore, UpToDate reviews on “Clinical features and management of ankle pain in the young athlete” (Chorley and Powers, 2014) “Talus fractures” (Koehler, 2014a) do not mention the use of allograft as a management tool.

UpToDate reviews on “Acromioclavicular joint injuries” (Koehler, 2013a), “Acromioclavicular joint disorders” (Koehler, 2013b), and “Patient information: Acromioclavicular joint injury (shoulder separation) (Beyond the Basics)” (Koehler, 2013c) do NOT mention the use of allograft as a therapeutic option.

Jordan et al (2012) stated that young patients with cartilage defects in the hip present a complex problem for the treating physician with limited treatment modalities available.  Cartilage repair/replacement techniques have shown promising results in other joints, however, the literature regarding the hip joint is limited.  These researchers conducted a systematic review of clinical outcomes following various treatments for chondral lesions of the hip and defined the techniques for the treatment of these cartilage defects.  The full manuscripts of 15 studies were reviewed for this systematic review including case studies, case series, and clinical studies.  A variety of techniques have been reported for the treatment of symptomatic chondral lesions in the hip.  Microfracture, cartilage repair, autologous chondrocyte implantation, mosaicplasty, and osteochondral allografting have all been used in very limited case series.  Although good results have been reported, most studies lack both a control group and a large number of patients.  However, the authors concluded that the reported results in this article provided a good foundation for treatments and stimulant for further study in an inherently difficult to treat young patient population with articular cartilage defects in the hip.

El Bitar et al (2014) noted that management of injuries to the articular cartilage is complex and challenging; it becomes especially problematic in weight-bearing joints such as the hip.  Several causes of articular cartilage damage have been described, including trauma, labral tears, and femoro-acetabular impingement, among others.  Because articular cartilage has little capacity for healing, non-surgical management options are limited.  Surgical options include total hip arthroplasty, microfracture, articular cartilage repair, autologous chondrocyte implantation, mosaicplasty, and osteochondral allograft transplantation.  Advances in hip arthroscopy have broadened the spectrum of tools available for diagnosis and management of chondral damage.  However, the authors concluded that the literature is still not sufficiently robust to draw firm conclusions regarding best practices for chondral defects.  They stated that additional research is needed to expand the knowledge of and develop guidelines for management of chondral injuries of the hip.

Farr et al (2014) evaluated the use of particulated juvenile articular cartilage (DeNovo NT) to treat patients with symptomatic articular cartilage lesions on the femoral condyle or trochlear groove of the knee.  A total of 25 patients were followed pre- and post-operatively through 2 years.  Physical knee examinations, as well as multiple clinical surveys and magnetic resonance imaging (MRI) were performed at baseline and 3, 6, 12 and 24 month intervals.  In some cases, patients voluntarily underwent diagnostic arthroscopic surgery with cartilage biopsy at 2 years post-op to assess the histological appearance of the cartilage repair.  Clinical outcomes demonstrated statistically significant increases at 2 years compared with baseline, with improvement seen as early as 3 months.  MRI results suggested the development of normal cartilage by 2 years.  Histologically, biopsied repair tissue was noted to be composed of a mixture of hyaline and fibrocartilage and there appeared to be excellent integration of the transplanted tissue with the surrounding native articular cartilage.  The authors concluded that particulated juvenile articular cartilage (DeNovo NT) provides for a rapid, safe and effective treatment of cartilage defects with clinical outcomes showing significant improvement over baseline and histologically favorable repair tissue at 2 years.  There are several limitations from a small study without an appropriate surgical control.  For example, the sample size is inadequately powered for anything other than an analysis of safety, only 3 surgeons participated, and the use of a single but experienced radiologist and pathologist prevents intra-rater reliability measurements.  Further studies on this novel approach are needed, owing to the small number of lesions and relatively short follow-up time in this study.

Bisicchia et al (2014) stated that osteochondral lesions of the talus are being recognized as an increasingly common injury.  They are most commonly located postero-medially or antero-laterally, while centrally located lesions are uncommon.  Large osteochondral lesions have significant biomechanical consequences and often require resurfacing with osteochondral autograft transfer, mosaicplasty, autologous chondrocyte implantation (or similar methods) or osteochondral allograft transplantation.  Allograft procedures have become popular due to inherent advantages over other resurfacing techniques.  Cartilage viability is one of the most important factors for successful clinical outcomes after transplantation of osteochondral allografts and is related to storage length and intra-operative factors.  The authors noted that while there is abundant literature about osteochondral allograft transplantation in the knee, there are few papers about this procedure in the talus. 

Gelber et al (2014) noted that treatment of osteochondral lesions of the knee with synthetic scaffolds seems to offer a good surgical option preventing donor site morbidity.  The TruFit^® plug has frequently been shown to not properly incorporate into.  These researchers evaluated the relationship between magnetic resonance imaging (MRI) findings and functional scores of patients with osteochondral lesions of the knee treated with TruFit^®.  Patients were evaluated with Magnetic Resonance Observation of Cartilage Tissue (MOCART) score for MRI assessment of the repair tissue.  KOOS, SF-36 and visual analog scale (VAS) were used for clinical evaluation.  Correlation between size of the treated chondral defect and functional scores was also analyzed.  A total of 57 patients with median follow-up of 44.8 months (range of 24 to 73) were included.  KOOS, SF-36 and VAS improved from a mean 58.5, 53.9 and 8.5 points to a mean 87.4, 86.6 and 1.2 at last follow-up (p < 0.001).  Larger lesions showed less improvement in Knee injury and Osteoarthritis Outcome Score (KOOS) (p = 0.04) and SF-36 (p = 0.029).  Median Tegner values were restored to pre-injury situation (5, range of 2 to 10).  Mean MOCART score was 43.2 ± 16.1.  Although the cartilage layer had good integration, it showed high heterogeneity and no filling of the subchondral bone layer.  The authors concluded that the TruFit^® failed to restore the normal MRI aspect of the subchondral bone and lamina in most cases.  The appearance of the chondral layer in MRI was partially re-established.  This unfavorable MRI appearance did not adversely influence the patient's outcome in the short time and they restored their previous level of activity.  There was an inverse linear relationship between the size of the lesion and the functional scores.

Song and colleagues (2014) stated that there have been no studies evaluating the clinical results after repair of a radial tear in the posterior horn of the lateral meniscus (PHLM) using the FasT-Fix system.  In a case-series study, these researchers evaluated the clinical outcomes after repair of a radial tear in the PHLM using the FasT-Fix system in conjunction with ACL reconstruction.  Between September 2008 and August 2011, a total of 15 radial tears in the PHLM identified during 132 consecutive ACL reconstructions were repaired using the FasT-Fix meniscal repair system.  These investigators classified the radial tears into 3 types according to the tear patterns:

1. simple radial tear,
2. complex radial tear, and
3. radial tear involving the popliteal hiatus.

Post-operative evaluation was performed using the Lysholm knee score and Tegner activity level.  Second-look arthroscopy was performed in all cases.  The mean follow-up period was 24 months.  None of the patients had a history of recurrent effusion, joint line tenderness or a positive McMurray test.  The meniscal repair was considered to have a 100 % clinical success rate.  At the final follow-up, the Lysholm knee score and Tegner activity level were significantly improved compared to the pre-operative values.  On the second-look arthroscopy, repair of radial tears in the PHLM in conjunction with ACL reconstruction using the FasT-Fix device resulted in complete or partial healing in 86.6 % of cases.  The authors concluded that clinical results after meniscal repair of a radial tear in the PHLM by using the FasT-Fix system were satisfactory.  The study only provided Level IV evidence; its main drawbacks were its small sample size (n = 15) and its short-term follow-up (mean of 24 months).

Osteochondral Allograft for Dysplasia Epiphysealis Hemimelica (Trevor's disease)

In a case study, Anthony and Wolf (2015) presented the case of a 5- year old boy with a 2-year history of right knee pain and evidence of dysplasia epiphysealis hemimelica (DEH or Trevor's disease) on imaging who underwent initial arthroscopic resection of his lesion with subsequent recurrence.  The patient then underwent osteochondral allograft (OCA) revision surgery and was asymptomatic at 2-year follow-up with a congruent joint surface.  This was the first reported case of a DEH lesion treated with OCA and also the youngest reported case of OCA placement in the literature.  The authors concluded that OCA may be a viable option in DEH and other deformities of the pediatric knee.  The main drawbacks of this study were that it was a single-case report and short-term follow-up (2 years).

Osteochondral Allograft for Knee Osteoarthritis

Giannini et al (2015) noted that bipolar fresh osteochondral allografts (BFOA) recently became a fascinating option for articular cartilage replacement, in particular in those young patients non-suitable for traditional replacement because of age.  While the use of OCA for the treatment of focal osteochondral lesions in the knee is well-established, their use in the treatment of end-stage arthritis is far more controversial.  These researchers described their experience in a series of 7 patients who underwent a resurfacing of both tibio-femoral and patello-femoral joints by BFOA.  From 2005 to 2007, 7 patients (mean age of 35.2 ± 6.3 years) underwent BFOA for end-stage arthritis of the knee.  Patients were evaluated clinically, radiographically and by CT scan pre-operatively and at established intervals up to the final follow-up.  No intra-operative complications occurred.  Nevertheless, joint laxity and aseptic effusion, along with a progressive chondrolysis, lead to early BFOA failure in 6 patients, which were revised by total knee arthroplasty (TKA) at 19.5 ± 3.9 months follow-up.  Only 1 patient, who received the allograft to convert a knee arthrodesis, gained a satisfactory result at the last follow-up control.  The authors concluded that BFOA in the knee joint still remains an inapplicable option in the treatment of post-traumatic end-stage arthritis of the young patient, due to the high rate of failure.  They stated that further studies are needed to examine the causes of failure and improve the applicability of this method.

Osteochondral Allograft for Patellar Cartilage Injury

In a case-series study, Gracitelli et l (2015) evaluated functional outcomes and survivorship of the grafts among patients who underwent OCA for patellar cartilage injuries.  An institutional review board-approved OCA database was used to identify 27 patients (28 knees) who underwent isolated OCA transplantation of the patella between 1983 and 2010.  All patients had a minimum 2-year follow-up.  The mean age of the patients was 33.7 years (range of 14 to 64); 54 % were female; 26 (92.9 %) knees had previous surgery (mean of 3.2 procedures; range of 1 to 10).  The mean allograft area was 10.1 cm(2) (range of 4.0 to 18.0).  Patients returned for clinical evaluation or were contacted via telephone for follow-up.  The number and type of re-operations were assessed.  Any reoperation resulting in removal of the allograft was considered a failure of the OCA transplantation.  Patients were evaluated pre- and post-operatively using the modified Merle d'Aubigné-Postel (18-point) scale, the International Knee Documentation Committee (IKDC) pain, function, and total scores, and the Knee Society function (KS-F) score.  Patient satisfaction was assessed at latest follow-up.  Seventeen of the 28 knees (60.7 %) had further surgery after the OCA transplantation; 8 of the 28 knees (28.6 %) were considered OCA failures (4 conversions to total knee arthroplasty, 2 conversions to patella-femoral knee arthroplasty, 1 revision OCA, 1 patellectomy).  Patellar allografting survivorship was 78.1 % at 5 and 10 years and 55.8 % at 15 years.  Among the 20 knees (71.4 %) with grafts in-situ, the mean follow-up duration was 9.7 years (range of 1.8 to 30.1).  Pain and function improved from the pre-operative visit to latest follow-up, and 89 % of patients were extremely satisfied or satisfied with the results of the OCA transplantation.  The authors concluded that OCA transplantation was successful as a salvage treatment procedure for cartilage injuries of the patella.  The main drawback of this study was its small sample size (n = 27) and its case-series design.  The level of evidence of this study was 4.  These findings need to be validated in well-designed studies.

Noyes and Barber-Westin (2013) examined if there is an ideal operation for large symptomatic articular cartilage lesions on the undersurface of the patella in young patients.  These researchers performed a systematic search of PubMed to determine the outcome of operations performed for large patellar lesions in young patients.  Inclusionary criteria were English language, original clinical trials published from 1992 to 2012, patellar lesions 4 cm(2) or larger, mean patient age 50 years or younger, and all evidence levels.  Of 991 articles identified, 18 met the inclusionary criteria, encompassing 840 knees in 828 patients.  These included 613 knees that underwent autologous chondrocyte implantation (ACI) (11 studies), 193 knees that had patello-femoral arthroplasty (PFA) (5 studies), and 34 knees that underwent osteochondral allografting (OA) (2 studies).  The mean patient age was 37.2 years and the mean follow-up was 6.2 years.  Long-term follow-up (greater than 10 years) was available in only 4 studies (2 PFA, 1 ACI, 1 OA).  All studies except 1 were Level IV and none was randomized or had a control group.  Twenty-one outcome instruments were used to determine knee function.  When taking into account knees that either failed or had fair/poor function, the percentage of patients who failed to achieve a benefit averaged 22 % after PFA and 53 % after OA and ranged from 8 % to 60 % after ACI.  In addition, all 3 procedures had unacceptable complication and re-operation rates.  The authors concluded that combination of failure rates and fair/poor results indicated that all 3 procedures had unpredictable results.  They stated that that a long-term beneficial effect might not occur in one of 3 ACI and PFA procedures and in 2 of 3 OA procedures.  The authors were unable to determine an ideal surgical procedure to treat large symptomatic patellar lesions in patients 50 years or younger.

Chahal et al (2013) conducted a systematic review of clinical outcomes after osteochondral allograft transplantation in the knee and identified patient-, defect-, and graft-specific prognostic factors.  These investigators searched PubMed, Medline, EMBASE, and the Cochrane Central Register of Controlled Trials.  Studies that evaluated clinical outcomes in adult patients after osteochondral allograft transplantation for chondral defects in the knee were included.  Pooled analyses for pertinent continuous and dichotomous variables were performed where appropriate.  There were 19 eligible studies resulting in a total of 644 knees with a mean follow-up of 58 months (range of 19 to 120).  The overall follow-up rate was 93 % (595 of 644).  The mean age was 37 years (range of 20 to 62), and 303 patients (63 %) were men.  The methods of procurement and storage time included fresh (61 %), prolonged fresh (24 %), and fresh frozen (15 %).  With regard to etiology, the most common indications for transplantation included post-traumatic (38 %), osteochondritis dissecans (30 %), osteonecrosis from all causes (12 %), and idiopathic (11 %); 46 % of patients had concomitant procedures, and the mean defect size across studies was 6.3 cm(2).  The overall satisfaction rate was 86 %; 65 % of patients (72 of 110) showed little to no arthritis at final follow-up.  The reported short-term complication rate was 2.4 %, and the overall failure rate was 18 %.  Heterogeneity in functional outcome measures precluded a meta-analysis; a qualitative synthesis allowed for the identification of several positive and negative prognostic factors.  The authors concluded that osteochondral allograft transplantation for focal and diffuse (single-compartment) chondral defects resulted in predictably favorable outcomes and high satisfaction rates at intermediate follow-up.   Patients with osteochondritis dissecans and traumatic and idiopathic etiologies have more favorable outcomes, as do younger patients with unipolar lesions and short symptom duration.  The authors stated that future studies should include comparative control groups and use established outcome instruments that will allow for pooling of data across studies.  (Level of Evidence: IV)

In a case-series study, Gracitelli et al (2016) evaluated functional outcomes and survivorship of the grafts among patients who underwent osteochondral allograft (OCA) for patellar cartilage injuries.  An institutional review board-approved OCA database was used to identify 27 patients (28 knees) who underwent isolated OCA transplantation of the patella between 1983 and 2010.  All patients had a minimum 2-year follow-up.  The mean age of the patients was 33.7 years (range of 14 to 64); 54 % were female.  Twenty-six (92.9 %) knees had previous surgery (mean of 3.2 procedures; range of 1 to 10).  The mean allograft area was 10.1 cm(2) (range of 4.0 to 18.0).  Patients returned for clinical evaluation or were contacted via telephone for follow-up.  The number and type of re-operations were assessed.  Any re-operation resulting in removal of the allograft was considered a failure of the OCA transplantation.  Patients were evaluated pre- and post-operatively using the modified Merle d'Aubigné-Postel (18-point) scale, the International Knee Documentation Committee (IKDC) pain, function, and total scores, and the Knee Society function (KS-F) score.  Patient satisfaction was assessed at latest follow-up.  Seventeen of the 28 knees (60.7 %) had further surgery after the OCA transplantation; 8 of the 28 knees (28.6 %) were considered OCA failures (4 conversions to total knee arthroplasty, 2 conversions to patella-femoral knee arthroplasty, 1 revision OCA, 1 patellectomy).  Patellar allografting survivorship was 78.1 % at 5 and 10 years and 55.8 % at 15 years.  Among the 20 knees (71.4 %) with grafts in-situ, the mean follow-up duration was 9.7 years (range of 1.8 to 30.1).  Pain and function improved from the pre-operative visit to latest follow-up, and 89 % of patients were extremely satisfied or satisfied with the results of the OCA transplantation.  The authors concluded that OCA transplantation was successful as a salvage treatment procedure for cartilage injuries of the patella.  The main drawback of this study was its small sample size (n = 27) and its case-series design; these findings need to be validated in well-designed studies.

An UpToDate review on “Patella fractures” (Blount, 2016) does not mention osteochondral allograft as a therapeutic option.

Osteochondral Allograft for the Talus

Caravaggi et al (2015) noted that severe ankle arthritis is a life-limiting condition that often requires surgery.  Ankle arthroplasty via artificial or "biological" reconstruction is a viable option in those patients who are not comfortable with arthrodesis.  More functional studies are needed to compare the performance and outcomes of the 2 function-preserving arthroplasties.  In this study, 2 groups of 10 patients affected by severe ankle arthritis were treated either with a 3-component ankle prosthesis or with bipolar fresh OCA transplantation.  Patients were evaluated pre-operatively and at 5-year follow-up.  The American Orthopaedic Foot and Ankle Society score was used for clinical evaluation, and gait analysis for functional assessment.  Activation pattern of lower limb muscles was obtained by surface electromyography (EMG).  In each group, kinematic, kinetic, and EMG data were compared between pre-op and follow-up assessments, and also versus corresponding data from a 20 healthy subject control group.  The median clinical score significantly increased between pre-op and follow-up from 53 to 74.5 in the transplantation and from 28.5 to 80 in the prosthesis group.  Spatio-temporal parameters showed a statistically significant improvement in cadence and cycle time.  Improvement of gait speed was also observed only in the prosthesis group; EMG patterns at follow-up were strongly correlated with the corresponding control data for both groups.  The authors concluded that although no significant amelioration in the joints' range of motion (ROM) was detected in either surgical procedure, preservation of the functional conditions at medium-term, along with significant improvement of the clinical score, may be considered a positive outcome for both techniques.  Long-term outcomes are important in the evaluation of interventions used in the field of orthopedic.

Johnson and Lee (2015) stated that the treatment of ankle arthritis remains controversial.  Ankle cartilage allograft replacement is a novel and complex procedure.  Many clinical studies have shown some level of promise, as well complications.  These investigators performed a systematic review of the clinical outcomes to evaluate the different techniques and clinical outcomes for ankle cartilage allograft replacement.  They performed a review of the published studies using MEDLINE(^®) by way of PubMed(^®) and Google Scholar(^®) from January 2000 through October 2014, ranging from case reports to clinical studies.  The inclusion criteria consisted of ankle cartilage allograft procedures with objective findings and clinical outcome scoring and complication and fusion rates and excluded non-allograft synthetic graft techniques, bone substitutes or expanders, review reports, and technique instructional manuals.  Evidence with the combination of objective findings and clinical outcomes for all 3 type of allograft replacement (osteochondral, unipolar, and bipolar) is lacking.  Several techniques for cartilage fixation have been described, including absorbable and metallic fixation.  Most of the studies reported many occurrences and a variety of complications.  A myriad of techniques for ankle cartilage allograft replacement exists.  The authors concluded that the findings from the present systematic review of the published studies appeared promising; however, the lack of statistical power and inconsistent documentation made it difficult to determine the superiority of any one intervention compared with another for the treatment of ankle arthritis.

Pinski et al (2016) examined the level of evidence and methodological quality of studies reporting surgical treatments for osteochondral lesions of the ankle.  A search was performed using the PubMed/Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane databases for all studies in which the primary objective was to report the outcome after surgical treatment of osteochondral lesions of the ankle.  Studies reporting outcomes of micro-fracture, bone marrow stimulation, autologous osteochondral transplantation, OCA transplantation, and autologous chondrocyte implantation were the focus of this analysis because they are most commonly reported in the literature.  Two independent investigators scored each study from 0 to 100 based on 10 criteria from the modified Coleman Methodology Score (CMS) and assigned a level of evidence using the criteria established by the Journal of Bone and Joint Surgery.  Data were collected on the study type, year of publication, number of surgical procedures, mean follow-up, pre-operative and post-operative American Orthopaedic Foot & Ankle Society score, measures used to assess outcome, geography, institution type, and conflict of interest.  A total of 83 studies reporting the results of 2,382 patients who underwent 2,425 surgical procedures for osteochondral lesions of the ankle met the inclusion criteria; 90 % of studies were of Level IV evidence.  The mean CMS for all scored studies was 53.6 of 100, and 5 areas were identified as methodologically weak:

1. study size,
2. type of study,
3. description of post-operative rehabilitation,
4. procedure for assessing outcome, and
5. description of the selection process.

There was no significant difference between the CMS and the type of surgical technique (p = 0.1411).  A statistically significant patient-weighted correlation was found between the CMS and the level of evidence (r = -0.28, p = 0.0072).  There was no statistically significant patient-weighted correlation found between the CMS and the institution type (r = 0.05, p = 0.6480) or financial conflict of interest (r = -0.16, p = 0.1256).  The authors concluded that most studies assessing the clinical outcomes of cartilage repair of the ankle are of a low level of evidence and of poor methodological quality.

Orr and associates (2017) reported that over a 2-year period, a single surgeon performed 8 structural allograft transfers for treatment of large osteochondral lesions of the talus (OLTs) in an active duty U.S. military population.  Lesion morphology and MRI stage were recorded.  Pre-operative and latest post-operative AOFAS hindfoot-ankle and pain VAS scores were compared.  A total of 8 male service members with mean age of 34.4 years underwent structural allograft transfer for OLTs with mean MRI stage of 4.9 and a mean lesion volume of 2,247.1 mm3.  Pre-operative mean AOFAS hindfoot-ankle score was 49.6, and mean pain VAS score was 6.9.  At mean follow-up of 28.5 months, post-operative mean AOFAS score was 73, and mean pain VAS score was 4.5, representing overall improvements of 47 % and 35 %, respectively; 3 patients were considered treatment failures secondary to continued ankle disability (n = 2) or graft resorption requiring ankle arthrodesis.  The authors concluded that despite modest improvements in short-term functional outcome scores, large osteochondral lesions requiring structural allograft transfer remain difficult to treat, particularly in high-demand patient populations.  They stated that surgeons should counsel patients pre-operatively on realistic expectations for return to function following structural allograft transfer procedures.  Level of Evidence = IV (Retrospective study).

A guideline from the "Clinical Tissue Regeneration" Group of the German Society of Orthopaedics and Traumatology (Aurich et al, 2017) stated that osteochondral lesions (OCL) of the ankle are a common cause of ankle pain.  Although the precise pathophysiology has not been fully elucidated, it can be assumed that a variety of factors are responsible, mainly including traumatic events such as ankle sprains.  Advances in arthroscopy and imaging techniques, in particular MRI, have improved the possibilities for the diagnosis of OCLs of the ankle.  Moreover, these technologies aim at developing new classification systems and modern treatment strategies. These researchers reviewed the literature and provided recommendations on the treatment of OCLs of the ankle.  The review gave a concise overview on the results of clinical studies and discussed advantages and disadvantages of different treatment strategies.  Non-operative treatment showed good results for selected indications in children and adolescents, especially in early stages of OCD.  However, surgical treatment is usually indicated in OCLs in adolescents and adults, depending on the size and location of the lesion.  Various arthroscopic and open procedures are frequently employed, including re-attachment of the fragment, local debridement of the lesion with fragment removal and curettage of the lesion, bone marrow-stimulation by microfracture or microdrilling (antegrade or retrograde), and autologous matrix-induced chondrogenesis (AMIC) -- with or without reconstruction of a subchondral bone defect or cyst by autologous cancellous bone grafting.  Isolated subchondral cysts with an intact cartilage surface can be treated by retrograde drilling and possibly additional retrograde bone grafting.  For larger defects or as salvage procedure, osteochondral cylinder transplantation (OATS or Mosaicplasty) or matrix-induced autologous chondrocyte transplantation (MACT) were recommended.  Transplantation of so-called (osteochondral) mega grafts (e.g., autologous bone grafts or allografts) were used for very large osteochondral defects that cannot be reconstructed otherwise.  Implantation of the so-called "small metal implants" (e.g., HemiCAP Talus) is reserved for selected cases after failed primary reconstruction.  Corrective osteotomies are indicated in accompanying axial mal-alignments.  The authors concluded that there are several different treatment strategies for OCLs, of the ankle, but clinical studies are rare and evidence is limited.  Therefore, interventional studies (e.g., randomized controlled trials [RCTs], observational studies) are needed.

Saltzman and colleague (2017) reported on their institution's early results from juvenile particulate cartilage allograft transplantation of the talus.  Because of the relative rarity of the procedure at the talus, it was decided to provide a comprehensive understanding of the currently available evidence via a 2-part study with

1. a systematic review of the literature, and
2. a retrospective single-center cohort study of the authors' patients, their demographics, and their early outcomes. 

A total of 4 studies were included with 33 ankles with a weighted mean follow-up of 14.3 months.  Only 1 ankle (3.3 %) was converted to a revision open osteochondral allograft with medial malleolar osteotomy at 16 months post-operative; 6 (18.2 %) required non-revision type re-operations at an average of 15 months post-operative.  Six patients with mean age 35.7 ± 14.4 years were evaluated from the authors' institution at mean 13.04 ± 8.35 months' follow-up.  All reported subjective improvements in pain and motion, and functional improvements, although post-operative MRI in 3 patients at time-points between 3 months and 2 years post-operative demonstrated persistent subchondral edema and non-uniform chondral surface in the talus.  There were no intra-operative or post-operative complications, and there have been no re-operations.  The authors concluded that these preliminary data suggested that treatment of large, traumatic or atraumatic, symptomatic osteochondral talar defects with particulated juvenile cartilage transplantation may improve patient subjective complaints of pain and function; systematic review of the available literature highlighted the need for future prospective, larger cohort studies of its use on the talus but suggested similar potential for the technology.

Okeagu and colleagues (2017) stated that OLTs are an increasingly implicated cause of ankle pain and instability.  Several treatment methods exist with varying clinical outcomes.  Due in part to successful OCA in other joints, such as the knee and shoulder, OCA has gained popularity as a therapeutic option, especially in the setting of large lesions.  The clinical outcomes of talar OCA have been inconsistent relative to the positive results observed in other joints.  Current literature regarding OCA failure focuses mainly on 3 factors: the effect of graft storage conditions on chondrocyte viability, graft/lesion size, and operative technique.  Several pre-clinical studies have demonstrated the ability for bone and cartilage tissue to invoke an immune response, and a limited number of clinical studies have suggested that this response may have the potential to influence outcomes after transplantation.  The authors concluded that further research is needed to examine the role of immunological mechanisms as an etiology of OCA failure

TruFit Plug for Repair of Osteochondral Defects

Verhaegen and colleagues (2015) performed a systematic search in 5 databases for clinical trials in which patients were treated with a TruFit plug for osteochondral defects.  Studies had to report clinical, radiological, or histological outcome data.  Quality of the included studies was assessed.  A total of 5 studies described clinical results, all indicating improvement at follow-up of 12 months compared to pre-operative status.  However, 2 studies reporting longer follow-up showed deterioration of early improvement.  Radiological evaluation indicated favorable MRI findings regarding filling of the defect and incorporation with adjacent cartilage at 24 months follow-up, but conflicting evidence existed on the properties of the newly formed overlying cartilage surface.  None of the included studies showed evidence for bone ingrowth.  The few histological data available confirmed these results.  The authors concluded that there are no data available that support superiority or equality of TruFit compared to conservative treatment or mosaicplasty/micro-fracture.  They stated that further investigation is needed to improve synthetic biphasic implants as therapy for osteochondral lesions; RCTs comparing TruFit plugs with an established treatment method are needed before further clinical use can be supported.

In a retrospective, case-series study, Di Cave and colleagues (2017) evaluated the long-term functional and MRI outcomes of the TruFit Plug for the treatment of OLT.  A total of 12 consecutive patients treated from March 2007 to April 2009 for OLT were evaluated.  Clinical examination included the AOFAS ankle score and the VAS for pain.  MRI scans were obtained pre-treatment and at last follow-up.  The MOCART score was used to assess cartilage incorporation.  Mean follow-up was 7.5 years (range of 6.5 to 8.7 years).  The average age was of 38.6 years (range of 22 to 57 years).  The sex ratio between males and females was 3:1 (9 men, 3 women).  The mean AOFAS score improved from a pre-operative score of 47.2 ± 10.7 to 84.4 ± 8 (p < 0.05).  According to the post-operative AOFAS scores, 1 case obtained excellent results, 9 were classified as good, and 2 were fair; VAS score improved from a pre-operative value of 6.9 ± 1.4 points to 1.2 ± 1.1 points at last follow-up (p < 0.05).  The MOCART score for cartilage repair tissue on post-operative MRI averaged 61.1 points (range of 25 to 85 points).  The authors concluded that the long-term results suggested that the technique of Trufit Plug for OLT was safe and demonstrated good post-operative scores including improvement of pain and function, with discordant MRI results.  However, RCTs comparing TruFit Plug with an established treatment method are needed to improve synthetic biphasic implants as therapy for osteochondral lesions.  Level of Evidence = 4.

Osteochondral Allograft for Femoral Trochlear Dysplasia

Vansadia and colleagues (2016) stated that the risk factors for patella-femoral joint instability include laxity of medial patellar restraints, abnormal limb geometry, femoral and tibial mal-rotation, patella alta, and trochlear dysplasia.  Femoral trochlear dysplasia is characterized by a hypoplastic or shallow trochlear groove.  These investigators reported the case of a 31-year old female with trochlear dysplasia and recurrent patella dislocations, laxity of the medial patella-femoral ligament (MPFL), and high-grade chondromalacia of the trochlea and the patella.  Surgical treatment goals were to re-create a trochlear groove, restore bony restraint, and re-align and offload the patella.  First, a triplane tibial tubercle osteotomy (TTO) was performed, and the patella was everted 360° with a subvastus approach.  The MPFL was reconstructed using a gracilis allograft.  A fresh osteochondral allograft transplant trochlea was sized, and a 35-mm diameter graft was transplanted to re-create the groove.  The TTO was secured in a new anterior, medial, and distal position.  The patient was braced for 6 weeks and completed a rehabilitation protocol.  At 9-month follow-up, she had made significant gains in ROM (0° to 140°) and activity compared to her pre-operative status.  She reported no pain or recurrent dislocations.  The authors concluded that this case demonstrated a viable surgical option for treatment of instability resulting from trochlear dysplasia with patella-femoral chondromalacia.  The osteochondral allograft transplantation surgery technique allowed patients to have a stable, pain-free knee joint and participated in activities compared to non-operative management.  However, they noted that the long-term outcomes of this procedure are unknown, and studies are needed.

The investigators noted that no large studies demonstrate long-term outcomes of treating trochlear dysplasia with OATS (Vansadia, eet al., 2016). The investigators cited Brucker and colleagues (2008) showing good outcomes of large-size OATS procedures in the knee femoral condyle. This case series showed that at mean follow-up of 55 months, the Lysholm knee score improved from 62 to 81 (P<0.001), and 90% of patients had high subjective satisfaction rates (citing Brucker, et al., 2008).

Osteochondral Allografts for the Hip

Oladeji and colleagues (2018) stated that articular cartilage lesions of the hip are difficult to effectively treat.  Osteochondral allograft transplantation in the knee has been associated with long-term success, but OCA for the hip has not been extensively studied.  These researchers presented the clinical and radiological outcomes from a cohort of 10 patients treated with fresh OCA transplants for large osteochondral defects of the femoral head and/or acetabulum.  A total of 10 patients who had undergone osteochondral allograft transplantation of the femoral head and/or acetabulum at the authors’ institution between 2013 and 2016 were identified from their Institutional Review Board-approved registry.  Hip disability and Osteoarthritis Outcome Score (HOOS) was used to track patient progress.  Patients with an average clinical follow-up of 1.4 years were included in this study; 4 patients were treated solely with OCA plugs for femoral head defects, while the remaining 6 received femoral OCA plugs and at least 1 concomitant procedure for additional intra-articular pathology; 7 patients (70 %) had successful functional outcomes, while 3 (30 %) had unsuccessful outcomes and were subsequently converted to total hip arthroplasty (THA) 5 to 29 months after OCA.  The authors concluded that OCA transplantation can be an effective treatment strategy for young, healthy individuals with articular cartilage lesions of the hip.  Smoking, avascular necrosis etiology, acetabular involvement and concomitant procedures may be risk factors for unsuccessful outcomes necessitating salvage with THA.  Moreover, they stated that long-term clinical studies to refine indications and determine functional outcomes and survival rates are needed.  The 2 main drawbacks of this study were its small sample size (n = 10) and short-term follow-up (average of 1.4 years).

Fast-Fix Meniscal Repair System

Furumatsu and colleagues (2017) stated that extrusion of the medial meniscus (MM) is associated with knee joint pain in osteoarthritic knees.  The relationships among MM radial/oblique tears, MM extrusion (MME), and the effect of arthroscopic meniscal repair are not established.  These researchers evaluated the effects of arthroscopic all-inside MM repair on MME and the clinical outcomes in patients with radially oriented MM tears and mildly osteoarthritic knees.  A total of 20 patients with a symptomatic radial or oblique tear of the MM posterior segment, MME greater than or equal to 2.5 mm, and mildly osteoarthritic knees were treated using FasT-Fix 360 All-inside Meniscal Suture devices.  These investigators used MRI to measure the patients' MM body width (MMBW), absolute MME, and relative MME.  The Japanese Knee Injury and Osteoarthritis Outcome Score, Lysholm, Tegner, IKDC Subjective Knee Evaluation, and VAS scores were obtained.  Arthroscopic all-inside MM repair prevented increases of absolute and relative MME.  The pre-operative and 3- and 12-month MRI-based MMBW values were similar.  Over a 24-month follow-up after the MM repairs, the clinical scores showed significant improvements.  The authors concluded that these findings suggested that all-inside meniscal repairs would be useful in preventing the progression of MME in patients suffering from symptomatic MM radial/oblique tears associated with mildly osteoarthritic knees.

The authors stated that this study had several drawbacks.  First, the sample size was small (n= 20); further investigations with larger patient numbers are needed.  Second, this study was not a prospective/comparative analysis that included partial meniscectomy or conservative treatment.  Further MRI examinations and clinical assessments based on longer follow-up periods are needed to evaluate the effects of all-inside MM repair on the prevention of the progression of MME and degenerative knee abnormalities.  The identification of these effects will also be useful in understanding whether MME precedes or follows progressive osteoarthritic changes in the knee.

Laurendon and co-workers (2017) noted that repair is indicated for tears in non-degenerative menisci.  The literature reported a 15 % failure rate for all-inside repair.  In a retrospective, cohort study, these researchers determined prognostic factors for failure of all-inside meniscal repair.  This study included 87 meniscal repair procedures, with or without ACL tear.  Lesions were located in red-red or red-white zones.  After freshening, repair comprised an all-inside arthroscopic technique using the FasT-Fix system, with (70.1 %) or without ligament reconstruction; all ACL tears were reconstructed.  Pre-operative data comprised: age, gender, smoking status, sports activity, trauma-to-surgery time, body mass index (BMI), frontal morphotype, and IKDC score.  Intra- and post-operative data comprised: meniscal lesion characteristics, location, number of sutures, type of ACL reconstruction, presence of chondropathy, authorized post-operative ROM, and IKDC score.  Failure was defined by secondary meniscectomy.  At 31 months' follow-up, there were 13 failures (15 %). Mean post-operative IKDC score was 88.19 (range of 64.37 to 98.95).  Bucket-handle lesion (p = 0.006) and BMI greater than 25 (p = 0.014) emerged as significant factors of poor prognosis.  The authors concluded that the present failure rate matched those reported in the literature.  The more extensive the lesion, the higher the risk of failure; high BMI incurred mechanical stresses that increase the risk of failure.  Level of Evidence = 4.

Juvenile Allogenous Articular Cartilage

Ng and Bernhard (2018) stated that particulated juvenile allograft cartilage (PJAC) has significant promise and is currently supported by several studies.  Potential benefits of this new technique include single-stage procedure, simplicity in the surgical technique, implantation of juvenile tissue, and a lack of donor site morbidity.

Desandis and associates (2018) noted that juvenile allogenic chondrocyte implantation (JACI; DeNovo NT Natural Tissue Graft; Zimmer, Warsaw, IN) with autologous bone marrow aspirate concentrate (BMAC) is a relatively new all-arthroscopic procedure for treating critical-size OCLs of the talus.  Few studies have investigated the clinical and radiographic outcomes of this procedure.  These researchers collected the clinical and radiographic outcomes of patients who had undergone JACI-BMAC for talar OCLs to assess treatment efficacy and cartilage repair tissue quality using MRI.  A total of 46 patients with critical-size OCLs (greater than or equal to 6 mm widest diameter) received JACI-BMAC from 2012 to 2014.  These investigators performed a retrospective medical record review and assessed the functional outcomes pre- and post-operatively using the Foot and Ankle Outcome Score (FAOS) and SF12-item general health questionnaire.  MRI was performed pre-operatively and at 12 and 24 months post-operatively.  Cartilage morphology was evaluated on post-operative MRI scans using the MOCART score. The pre- to post-operative changes and relationships between outcomes and lesion size, bone grafting, lesion location, instability, hypertrophy, and MOCART scores were analyzed.  Overall, the mean questionnaire scores improved significantly, with almost every FAOS subscale showing significant improvement post-operatively.  Concurrent instability resulted in more changes that were statistically significant.  The use of bone grafting and the presence of hypertrophy did not result in statistically significant changes in the outcomes.  Factors associated with outcomes were lesion size and hypertrophy.  Increasing lesion size was associated with decreased FAOS quality of life (QOL) subscale and hypertrophy correlating with changes in the pain subscale.  Of the 46 patients, 22 had undergone post-operative MRI scans that were scored.  The average MOCART score was 46.8.  Most patients demonstrated a persistent bone marrow edema pattern and hypertrophy of the reparative cartilage.  The authors concluded that juvenile articular cartilage implantation of the DeNovo NT allograft and BMAC resulted in improved functional outcome scores; however, the reparative tissue still exhibited fibrocartilage composition radiographically.  They stated that further studies are needed to examine the long-term outcomes and determine the superiority of the arthroscopic DeNovo procedure compared with microfracture and other cartilage resurfacing procedures.

Karnovsky and colleagues (2018) compared the functional and radiographic outcomes of patients who received JACI-BMAC for treatment of talar osteochondral lesions with those of patients who underwent microfracture (MF).  A total of 30 patients who underwent MF and 20 who received DeNovo NT for JACI-BMAC treatment between 2006 and 2014 were included.  Additionally, 17 MF patients received supplemental BMAC treatment.  Retrospective chart review was performed and functional outcomes were assessed pre- and post-operatively using the FAOS and VAS.  Post-operative MRIs were reviewed and evaluated using a modified MOCART score.  Average follow-up for functional outcomes was 30.9 months (range of 12 to 79 months).  Radiographically, average follow-up was 28.1 months (range of 12 to 97 months).  Both the MF and JACI-BMAC showed significant pre- to post-operative improvements in all FAOS subscales; VAS also showed improvement in both groups, but only reached a level of statistical significance (p < 0.05) in the MF group.  There were no significant differences in patient reported outcomes between groups.  Average osteochondral lesion diameter was significantly larger in JACI-BMAC patients compared to MF patients, but size difference had no significant impact on outcomes.  Both groups produced reparative tissue that exhibited a fibrocartilage composition.  The JACI-BMAC group had more patients with hypertrophy exhibited on MRI than the MF group (p = 0.009).  The authors concluded that JACI-BMAC and MF resulted in improved functional outcomes.  However, while the majority of patients improved, functional outcomes and quality of repair tissue were still not normal.  Based on these findings, lesions repaired with DeNovo NT allograft still appeared fibrocartilaginous on MRI and did not result in significant functional gains as compared to MF.

Cartiform Cryo-Preserved Osteochondral Allograft for Knee Surgery

Cartiform viable osteochondral allograft is composed of viable chondrocytes, chondrogenic growth factors, and extra-cellular matrix (ECM) proteins.  While maintaining an intact cartilage structure, the bony portion of Cartiform viable osteochondral allograft is reduced and the graft is porated to offer unique handling characteristics and simple fixation techniques.  Cartiform viable osteochondral allograft supposedly combines the safety and success of fresh osteochondral allografts with ease of use by being trimmable and flexible to match any lesion size and contour.  Cartiform viable osteochondral allograft is readily available and is stored at -80 degrees C.

Geraghty and colleagues (2015) described the design and characterization of a novel, cryopreserved, viable osteochondral allograft (CVOCA), along with evidence that the CVOCA could improve outcomes of marrow stimulation for articular cartilage repair.  These researchers carried out histological staining to examine the CVOCA tissue architecture; CVOCAs were tested for the presence of ECM proteins and chondrogenic growth factors using enzyme-linked immunosorbent assay (ELISA).  Cell viability and composition were examined via live/dead staining, fluorescence-activated cell sorting (FACS) analysis, and immunofluorescence staining.  FACS analysis and a tumor necrosis factor-alpha (TNF-α) secretion bioassay were used to confirm the lack of immunogenic cells.  Effects of the CVOCA on mesenchymal stem cells (MSCs) were tested using in-vitro migration and chondrogenesis assays.  The ability of the CVOCA to augment marrow stimulation in-vivo was evaluated in a goat model.  A method of tissue processing and preservation was developed resulting in a CVOCA with pores and minimal bone.  The pores were found to increase the flexibility of the CVOCA and enhance growth factor release.  Histological staining revealed that all 3 zones of hyaline cartilage were preserved within the CVOCA.  Chondrogenic growth factors (TGF-β1, TGF-β3, BMP-2, BMP-4, BMP-7, bFGF, IGF-1) and ECM proteins (type II collagen, hyaluronan) were retained within the CVOCA, and their sustained release in culture was observed (TGF β1, TGF-β2, aggrecan).  The cells within the CVOCA were confirmed to be chondrocytes and remained viable and functional post-thaw.  Immunogenicity testing confirmed the absence of immunogenic cells.  The CVOCA induced MSC migration and chondrogenesis in-vitro.  Experimental results using devitalized flash frozen osteochondral allografts revealed the importance of preserving all components of articular cartilage in the CVOCA.  Goats treated with the CVOCA and marrow stimulation exhibited better repair compared to goats treated with marrow stimulation alone.  The authors concluded that the CVOCA retained viable chondrocytes, chondrogenic growth factors, and ECM proteins within the intact architecture of native hyaline cartilage.  The CVOCA promoted MSC migration and chondrogenesis following marrow stimulation, improving articular cartilage repair.

Hoffman and associates (2015) stated that marrow stimulation is often used for the treatment of focal chondral defects of the knee.  However, marrow stimulation typically results in fibrocartilage repair tissue rather than healthy hyaline cartilage, which, over time, predisposes the repair to failure.  Recently, a cryopreserved viable chondral allograft was developed to augment marrow stimulation.  The chondral allograft is comprised of native viable chondrocytes, chondrogenic growth factors, and ECM proteins within the superficial, transitional, and radial zones of hyaline cartilage.  Thus, host MSCs that infiltrate the graft from the underlying bone marrow following marrow stimulation are provided with the optimal micro-environment to undergo chondrogenesis.  These investigators described treatment of a trochlear defect with marrow stimulation augmented with this novel chondral allograft, along with 9-month post-operative histological results.  At 9 months, the patient showed complete resolution of pain and improvement in function, and the repair tissue consisted of 85 % hyaline cartilage.  For comparison, a biopsy obtained from a patient 8.2 months after treatment with marrow stimulation alone contained only 5 % hyaline cartilage.  The authors concluded that these findings suggested that augmenting marrow stimulation with the viable chondral allograft could eliminate pain and improve outcomes, compared with marrow stimulation alone.  These researchers noted that a multi-center study is underway to review the results of a greater patient population to fully understand and characterize outcomes following this treatment.

Woodmass and colleagues (2017) stated that isolated cartilage defects can lead to significant pain and disability, prompting the development of a number of options for restorative treatment.  Each method has advantages and limitations, and no single technique has gained widespread use.  These researchers presented a technique for implantation of a cryo-preserved osteochondral allograft (Cartiform) for the treatment of full-thickness cartilage defects.  Cartiform is a cryopreserved osteochondral allograft composed of chondrocytes, chondrogenic growth factors, and extracellular matrix proteins.  This implant allows for regenerative treatment of full-thickness cartilage lesions in a single surgical procedure.  This was a single-case study.  The authors noted that in-vivo and in-vitro results were promising; potential disadvantages of Cartiform include implant cost, size restrictions (single implant limits to a 2-cm diameter defect), inability to fill/restore large osseous defects, and theoretical risks with allograft tissue of disease transmission.

Mirzayan and associates (2018) noted that glenoid chondral injuries constitute challenging injuries to treat because of the limited access and the limited options and evidence available for their resolution.  In this technical note, these researchers described the procedure, pearls, and pitfalls of implantation of a cryo-preserved osteochondral allograft (Cartiform) for the treatment of full-thickness cartilage defects of the shoulder.  Cartiform is composed of chondrocytes, chondrogenic growth factors, and extra-cellular matrix proteins that can be implanted through a single-stage procedure.  There is a potential risk of disease transmission from an allograft.  The graft is soft and malleable; thus, sutures can potentially pull through the graft if pulled under tension.  These investigators recommended placing the sutures in the 2nd hole from the periphery of the graft to minimize suture cutting through.  The graft is obtained from the knee of a donor; therefore, the cartilage will be thicker than the native glenoid articular cartilage.  This did not appear to be clinically significant.  The authors concluded that further clinical research is needed to elucidate the outcomes and optimal fixation of cryo-preserved osteochondral allografts in the shoulder.

Vangsness and co-workers (2018) stated that restoration and repair of articular cartilage injuries remain a challenge for orthopedic surgeons.  The standard 1st-line treatment of articular cartilage lesions is marrow stimulation; however, this procedure can often result in the generation of fibrous repair cartilage rather than the biomechanically superior hyaline cartilage.  Marrow stimulation is also often limited to smaller lesions, less than 2 cm2.  Larger lesions may require implantation of a fresh osteochondal allograft, though a short shelf-life, size-matched donor requirements, potential challenges of bone healing, limited availability, and the relatively high price limit the wide use of this therapeutic approach.  These investigators presented a straight-forward, single-stage surgical technique of a novel reparative and restorative approach for articular cartilage repair with the implantation of a CVOCA.  The CVOCA contains full-thickness articular cartilage and a thin layer of subchondral bone, and maintains the intact native cartilage architecture with viable chondrocytes, growth factors, and extra-cellular matrix proteins to promote articular cartilage repair.  They reported the results of a retrospective case series of 3 patients who presented with articular cartilage lesions more than 2 cm2 and were treated with the CVOCA using the presented surgical technique.  Patients were followed-up to 2 years after implantation of the CVOCA and all 3 patients had satisfactory outcomes without adverse events (AEs).  These researchers stated that RCTs are needed for evaluation of CVOCA safety, efficacy, and long-term outcomes.

Cartiform Cryo-Preserved Osteochondral Allograft for Other Joints

Weber and Wrotslavsky (2019) noted that few reports in the literature have described the use of an osteochondral allograft for the treatment of articular cartilage damage of the 1st metatarsal phalangeal joint.  These researchers presented the clinical outcomes and detailed surgical technique of 4 cases in which they used a CVOCA for full cartilage replacement of the 1st metatarsal head to address degenerative articular cartilage damage.  At 10 to 22 months of follow-up, patients reported clinical improvement, with VAS pain-scale scores decreasing from an average of 8.0 to 0 post-operatively, and ROM improvement from an average of 4.3 degrees to 58.3 degrees dorsiflexion.  Radiographic improvement was also observed, with an increase in average joint space from 1.1 mm, 1.5 mm, and 2.2 mm from medial to lateral on dorsoplantar views pre-operatively, to 3.1 mm, 2.8 mm, and 3.1 mm 15 months post-operatively, respectively.  The authors concluded that these results suggested that CVOCA is a desirable therapeutic option for end-stage degenerative joint disease of the 1st metatarsal phalangeal joint. 

Cryopreserved Arterial Allografts for Critical Limb Ischemia

Almasri and associates (2018) stated that the optimal strategy for re-vascularization in infra-inguinal chronic limb-threatening ischemia (CLTI) remains debatable.  Comparative trials are scarce, and daily decisions are often made using anecdotal or low-quality evidence.  These investigators searched multiple databases through May 7, 2017 for prospective studies with at least 1-year follow-up that evaluated patient-relevant outcomes of infra-inguinal re-vascularization procedures in adults with CLTI.  Independent pairs of reviewers selected articles and extracted dats.  Random-effects meta-analysis was used to pool outcomes across studies.  These researchers included 44 studies that enrolled 8,602 patients.  Peri-procedural outcomes (mortality, amputation, major adverse cardiac events) were similar across treatment modalities.  Overall, patients with infra-popliteal disease had higher patency rates of great saphenous vein graft at 1 and 2 years (primary: 87 %, 78 %; secondary: 94 %, 87 %, respectively) compared with all other interventions.  Prosthetic bypass outcomes were notably inferior to vein bypass in terms of amputation and patency outcomes, especially for below knee targets at 2 years and beyond.  Drug-eluting stents demonstrated improved patency over bare-metal stents in infra-popliteal arteries (primary patency: 73 % versus 50 % at 1 year), and was at least comparable to balloon angioplasty (66 % primary patency).  Survival, major amputation, and amputation-free survival at 2 years were broadly similar between endovascular interventions and vein bypass, with prosthetic bypass having higher rates of limb loss.  Overall, the included studies were at moderate- to high-risk of bias and the quality of evidence was low.  The authors concluded that there are major limitations in the current state of evidence guiding treatment decisions in CLTI, particularly for severe anatomic patterns of disease treated via endovascular means.  Peri-procedural (30-day) mortality, amputation, and major adverse cardiac events are broadly similar across modalities.  Patency rates were highest for saphenous vein bypass, whereas both patency and limb salvage were markedly inferior for prosthetic grafting to below the knee targets.  Among endovascular interventions, percutaneous transluminal angioplasty and drug-eluting stents appeared comparable for focal infra-popliteal disease, although no studies included long segment tibial lesions.  Heterogeneity in patient risk, severity of limb threat, and anatomy treated rendered direct comparison of outcomes from the current literature challenging.  These researchers stated that future studies should incorporate both limb severity and anatomic staging to best guide clinical decision-making in CLTI.

Masmejan and colleagues (2019) noted that in critical limb ischemia (CLI), current guidelines recommend re-vascularization whenever possible, preferentially through endovascular means.  However, in the case of long occlusions or failed endovascular attempts, distal bypasses still have a place.  Single segment great saphenous vein (GSV), which provides the best conduit, is often not available and currently there is no consensus about the best alternative graft.  From January 2006 to December 2015, a total of 42 cryopreserved arterial allografts were used for a distal bypass.  Autologous GSVs or alternative autologous conduits were unavailable for all patients.  The patients were observed for survival, limb salvage, and allograft patency.  The results were analyzed with Kaplan-Meier graphs.  Estimates of secondary patency at 1, 2 and 5 years were 81 %, 73 %, and 57 %, respectively.  Estimates of primary patency rates at 1, 2 and 5 years were 60 %, 56 %, and 26 %, respectively.  Estimates of limb salvage rates at 1, 2 and 5 years were 89 %, 89 %, and 82 %, respectively.  Estimates of survival rates at 1, 2 and 5 years were 92 %, 76 % and 34 %, respectively.  At 30 days, major amputations and major adverse cardiac events were 1 and 0, respectively; 6 major amputations occurred during the long-term follow-up.  The authors concluded that despite a low primary patency rate at 2 years, the secondary patency of arterial allografts was acceptable for distal bypasses.  This suggested that cryopreserved arterial allografts were a suitable alternative for limb saving distal bypasses in the absence of venous conduits, improving limb salvage rates and, possibly, QOL.

Guevara-Noriega and co-workers (2019) stated that re-vascularization is the best alternative to reduce symptoms and to improve the limb salvage rate in patients with CLI.  Alternative grafts as synthetic prostheses and allografts must be considered for patients without a suitable autologous graft.  These researchers examined outcomes of cryopreserved allografts used as a vascular conduit for bypass surgery in the infra-inguinal territory.  They carried out a retrospective analysis (January 1995 to January 2014) of the Registry of vascular and valvular allografts transplant in the autonomous community of Catalonia, Spain to identify patients with CLI who required infra-inguinal bypass with cryopreserved arterial allografts.  Statistical analysis was performed using SPSS, ver. 20, for Mac (Chicago).  A total of 149 patients with CLI (mean age of 70.1 years) were analyzed.  A total of 102 patients (68.5 %) had a grade IV lesion (Fontaine classification).  In the overall follow-up, 24.8 % of patients required a re-intervention.  Overall graft occlusion, infection, and dilation rate were 52.3 %, 6 %, and 5.4 %, respectively.  Overall 30-day mortality was 0.7 %; 5-year primary patency rate and limb salvage rate were 38.6 % and 50.2 %, respectively.  Survival rate at 5 years was 54.2 %.  Major adverse limb event (MALE)-free rate was 21.5 % at 5 years.  Re-vascularization to a distal target vessel was an independent positive predictive risk factor for a lower limb salvage rate and lower primary patency rate.  Dyslipidemia was related to a lower limb salvage rate and represents a risk factor involved in MALEs.  The authors concluded that although arterial allografts appeared to represent a sub-optimal alternative, some selected patients could beneficiate from them.  Moreover, these researchers stated that 5-year results were disappointing, and more studies are needed to determine other predictive factors for better selection of patients.

Semitendinosis Allograft for the Treatment of Chronic Ankle Instability

Miller et al (2013) noted that current operative options for chronic lateral ankle instability (CLAI) include anatomic repairs utilizing existing local tissue and non-anatomic reconstructions sacrificing the peroneus brevis tendon to mechanically stabilize the ankle.  Recent studies have modified these techniques to create an anatomic reconstruction utilizing allograft tendons.  These researchers retrospectively examined the clinical outcomes of a near-anatomic ligament reconstruction utilizing an allograft tendon for recurrent or complex lateral ankle instability.  A total of 28 patients underwent a near-anatomic allograft lateral ankle ligament reconstruction with a semitendinosis allograft for severe or recurrent lateral ankle ligamentous instability, and all of them were available for follow-up at an average 32 months; 12 patients had previously undergone lateral ankle ligament stabilizing surgery, 4 had Ehlers Danlos syndrome with poor local tissue, 5 had greater than 30 degrees of varus angulation of talar tilt, while 12 had associated hind-foot varus requiring concomitant reconstruction.  Patients were assessed pre- and post-operatively for VAS for pain, FAAM, patient satisfaction, radiographic correction, and complications.  Median VAS of pain decreased from 8 before surgery to 1 after surgery (p < 0.001).  Median FAAM score increased from 41.7 to 95.2 after surgery (p < 0.001).  Radiographic comparison demonstrated correction of pre-operative varus mal-alignment in all but 1 patient.  No patients developed subsequent subtalar arthritis or pain; 3 patients had mild persistent instability, all of which was managed non-operatively.  One of the patients with persistent instability also developed chronic regional pain syndrome following surgery.  At final follow-up, 25 of 28 patients rated their satisfaction as good or excellent and 3 as fair.  No patients required revision surgery.  The authors concluded that lateral ligament reconstruction utilizing a near-anatomically placed and tensioned allograft tendon was a viable option in treating recurrent and complex lateral instability.  Not sacrificing the peroneal tendons avoided loss of eversion strength.

Dierckman and Ferkel (2015) noted that the modified Brostrom procedure has been successful for most patients with CLAI; however, a subset of patients has had unsatisfactory outcomes.  For those at risk of failure, anatomic reconstruction of the lateral ankle ligaments using a semitendinosus allograft to augment the modified Brostrom procedure is available.  These investigators reported the findings of anatomic reconstruction of the lateral ankle with a semitendinosus allograft for the treatment of CLAI.  This was a retrospective review of a single surgeon's experience from 2003 to 2011 in performing anatomic lateral ankle ligament reconstruction with a semitendinosus allograft for the treatment of CLAI.  Of 38 patients (40 ankles), 31 (33 ankles; 82 % of patients) returned for final follow-up and constituted the study group.  Pre-operatively, all patients completed the AOFAS ankle-hindfoot score (AHS) and a VAS for pain and underwent plain and stress talar tilt radiographs.  At the most recent follow-up, patients were evaluated by an independent surgeon and completed the post-operative AHS, Foot-Function Index (FFI), VAS for pain, Tegner activity score, and a satisfaction survey.  Patients were evaluated with plain and stress talar tilt and anterior drawer radiographs.  At a mean follow-up of 38 ± 30 months (range of 24 to 107 months), 100 % of patients were completely satisfied with the procedure.  AHS values significantly improved from a mean of 60.3 ± 14.4 to 87.5 ± 9.3 (p < 0.0001); VAS pain scores significantly decreased from 7.3 ± 1.3 to 1.9 ± 1.8 (p < 0.0001); 22 of 31 patients (71 %) either returned to or were 1 level below their previous pre-operative or pre-injury Tegner activity level.  No patients developed arthritic changes beyond grade I on plain radiographs.  On stress radiographs, the mean talar tilt decreased from 14.3° ± 5.4° to 3.1° ± 2.4°.  The mean post-operative anterior tibiotalar translation was 1.8 ± 1.1 mm, with no patients having greater than 5 mm of translation.  The authors concluded that anatomic lateral ankle ligament reconstruction with a semitendinosus allograft for the treatment of CLAI led to high patient satisfaction, decreased pain, a stable ankle without arthritic changes, and significantly improved function.

Cao et al (2018) stated that a key point to surgical treatment of CLAI is choosing a suitable surgical procedure.  In a meta-analysis, these researchers compared different surgical techniques for management of CLAI.  They searched the Cochrane Library, Medline, and Embase.  All identified RCTs and quasi-RCTs of operative treatment for CLAI were included.  Two review authors independently extracted data from each study and assessed risk of bias.  Where appropriate, results of comparable studies were pooled.  A total of 7 RCTs were included for analysis.  They fell in 5 clearly distinct groups.  One study comparing 2 different kinds of non-anatomic reconstruction procedures (dynamic and static tenodesis) found 2 clinical outcomes favoring static tenodesis: better clinical satisfaction and fewer subsequent sprains.  Two studies compared non-anatomic reconstruction versus anatomic repairment.  In one study, nerve damage was more frequent in non-anatomic reconstruction group; the other one reported that radiological measurement of ankle laxity showed that non-anatomic reconstruction provided higher reduction of talar tilt angle.  Two studies comparing 2 anatomic repairment surgical techniques (trans-osseous suture versus imbrication) showed no significant difference in any clinical outcome at the follow-up except operation time.  One study compared 2 different anatomic repairment techniques.  They found that the double anchor technique was superior with respect to the reduction of talar tilt than single anchor technique.  One study compared an anatomic reconstruction procedure with a modified Brostrom technique.  Primary reconstruction combined with ligament advanced reinforcement system resulted in better patient-scored clinical outcome, at 2 years post-surgery, than the modified Brostrom procedure.  The authors concluded that there were limited evidence to support any one surgical technique over another surgical technique for CLAI, but based on the evidence, these researchers could still render several conclusions: There were limitations to the use of dynamic tenodesis, which obtained poor clinical satisfaction and more subsequent sprains; non-anatomic reconstruction abnormally increased inversion stiffness at the subtalar level as compare with anatomic repairment; multiple types of modified Brostrom procedures could acquire good clinical results; and anatomic reconstruction was a better procedure for some specific patients.

Osteochondral Allograft for the Treatment of Aseptic Non-Union in the Upper Extremity

Rollo and colleagues (2020) stated that non-union in forearm fractures is an uncommon challenging clinical condition for orthopedic surgeons.  The complex anatomy and biomechanics of the upper limb make this surgery very demanding.  The accurate restoration of the normal anatomy is mandatory to obtain bone healing.  Infections and important bone loss further reduce the therapeutic success.  The use of bone graft in atrophic non-union may significantly reduce the bone healing time with good clinical results.  These researchers compared fresh-frozen bone (FFB) allograft and autograft in the treatment of forearm aseptic non-union.  Inclusion criteria were patients aged between 18 to 75 years old with forearm aseptic shaft non-union treated with plating and bone grafting.  They retrospectively examined minimum 12-month follow-up with standard X-rays and clinical outcomes.  All non-unions were classified according Association for the Study and Application of the Method of Ilizarov (ASAMI) classification for long bones.  The sample size was divided in 2 groups: patients treated with FFB allograft (Allograft group) and patients treated with iliac crest autograft (Autograft group).  The mean patient age was 33.58 ± 16.72 (18 to 75) years old in the Allograft group and 33.28 ± 17.24 (18 to 75) in the Autograft group.  The mean follow-up was 62.6 months (± 12.3, range of 12 to 160) in the Allograft group and 64.4 (± 12.4; 12 to 160) in the Autograft group.  The mean bone union time after the surgery was 101.6 (± 14.6; 82 to 156) days in the Allograft group, while 117.6 (± 14.6; 90 to 180) days for the Autograft group.  The Radiographic Union Score was 26.8 (± 2.2; range of 24.3 to 30) in the Allograft group versus 26.9 (± 2.8; range of 24.1 to 30) in the Autograft group.  A correlation between clinical and radiographic outcomes was found (Cohen κ: 0.86 ± 0.11 in the Allograft group; Cohen κ: 0.85 ± 0.10 in the Autograft group, p = 0.051).  The pre-operative surgical planning was essential to apply this technique: the adequate cortical graft length was the key point to gain adequate implant stability.  A meticulous surgical technique was mandatory to obtain good clinical and radiological outcomes.  The study reported a good reliability of FFB allograft for large non-union bone defects.  The authors concluded that this technique may represent a feasible alternative to bone transport or amputation, as it allowed the return to daily life activities.  Moreover, these researchers stated that further studies are needed to evaluate the long-term clinical results of this surgical procedure.

Furthermore, an UpToDate review on “Surgical reconstruction of the upper extremity” (Chung and Yoneda, 2021) does not mention allograft as a management tool.

Appendix

The Outerbridge classification system facilitates an objective description of chondral damage in the knee. Classifications are from a grade 0 to grade IV:

• Grade 0: normal cartilage
• Grade I: cartilage with swelling and softening
• Grade II: partial thickness defect with fissures on the surface that do not reach subchondral bone or exceed 1.5 cm in diameter
• Grade III: fissuring to the level of subchondral bone in an area with a diameter greater than 1.5 cm
• Grade IV: exposed subchondral bone.

Table: CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
Information in the [brackets] below has been added for clarification purposes.   Codes requiring a 7th character are represented by "+":
CPT codes covered if selection criteria are met:
20932 - 20934	Allograft, includes templating, cutting, placement and internal fixation, when performed
Allograft transplant of the knee ligaments:
CPT codes covered if selection criteria are met:
27427	Ligamentous reconstruction (augmentation), knee; extra-articular
27428	intra-articular (open)
27429	intra-articular (open) and extra-articular
29888	Arthroscopically aided anterior cruciate ligament repair/augmentation or reconstruction
29889	Arthroscopically aided posterior cruciate ligament repair/augmentation or reconstruction
ICD-10 codes covered if selection criteria are met:
M22.2X1 - M22.3X9	Patellofemoral disorders and other derangements of patella [including lateral, medial, anterior and posterior ligaments]
M22.8X1 - M22.8X9	Other disorders of patella [including lateral, medial, anterior and posterior ligaments]
M23.50 - M23.52	Chronic instability of knee [including lateral, medial, anterior and posterior ligaments]
M23.601 - M23.8X9	Other spontaneous disruption of ligament(s) of knee and other internal derangements of knee [including lateral, medial, anterior and posterior ligaments]
M76.50 - M76.52	Patellar tendinitis
Allograft transplant of the knee, osteochondral:
CPT codes covered if selection criteria are met:
27415	Osteochondral allograft, knee, open
29867	Arthroscopy, knee, surgical; osteochondral allograft(s) (e.g., mosaicplasty)
Other CPT codes related to the CPB:
29870 - 29889	Arthroscopy, knee
73721 - 73723	Magnetic resonance (eg, proton) imaging, any joint of lower extremity
ICD-10 codes covered if selection criteria are met:
M87.051 - M87.059	Idiopathic aseptic necrosis of femur
M87.151 - M87.159	Osteonecrosis due to drugs, femur
M87.251 - M87.256	Osteonecrosis due to previous trauma, femur
M87.351 - M87.353	Other secondary osteonecrosis, femur
M87.851 - M87.859	Other osteonecrosis, right femur
M93.961 - M93.969	Osteochondropathy, unspecified lower leg [osteochondral lesions of the distal femur]
ICD-10 codes not covered for indications listed in the CPB:
M17.0 - M17.9	Osteoarthritis of knee
Q68.2	Congenital deformity of knee [femoral trochlear dysplasia]
Q74.1	Congenital malformation of knee [femoral trochlear dysplasia]
Allograft transplant of the knee, meniscus:
CPT codes covered if selection criteria are met:
29868	Arthroscopy, knee, surgical; meniscal transplantation (includes arthrotomy for meniscal insertion), medial or lateral
Other CPT codes related to the CPB:
27427 - 27429	Ligamentous reconstruction (augmentation), knee
29870 - 29889	Arthroscopy, knee
73721 - 73723	Magnetic resonance (e.g., proton) imaging
ICD-10 codes covered if selection criteria are met:
M23.200 - M23.369	Derangement of medial and lateral meniscus
Q68.6	Discoid meniscus
S83.200+	Tear of unspecified meniscus, current injury
S83.211+ - S83.249+	Tear of medial meniscus, current injury
S83.251+ - S83.289+	Tear of lateral meniscus, current injury
S83.30X+ - S83.32X+	Tear of articular cartilage of knee, current
Semitendinosus allograft of ankle:
CPT codes covered if selection criteria are met:
27695	Repair, primary, disrupted ligament, ankle; collateral
27696	both collateral ligaments
27698	Repair, secondary, disrupted ligament, ankle, collateral
ICD-10 codes covered if selection criteria are met:
M25.371 - M25.373	Other instability, ankle
Osteochondral allograft of talus:
CPT codes not covered for indications listed in the CPB:
20962	Bone graft with microvascular anastomosis; other than fibula, iliac crest, or metatarsal
28103	Excision or currettage of bone cyst or benign tumor, talus or calcaneus; with allograft
Other CPT codes related to the CPB:
28705 - 28725	Arthrodesis; pantalar; triple; or subtalar
ICD-10 codes not covered for indications listed in the CPB:
M87.071 - M87.076	Idiopathic aseptic necrosis of ankle and foot [talus]
M87.171 - M87.176	Osteonecrosis due to drugs, ankle and foot [talus] [avascular necrosis of bone]
M87.271 - M87.276	Osteonecrosis due to previous trauma, ankle and foot [talus] [avascular necrosis of bone]
M87.371 - M87.376	Other secondary osteonecrosis, ankle and foot [talus] [avascular necrosis of bone]
M87.871 - M87.876	Other osteonecrosis, ankle and foot [talus] [avascular necrosis of bone]
Osteochondral allograft of tarsal-metatarsal:
CPT codes not covered for indications listed in the CPB:
20957	Bone graft with microvascular anastomosis; metatarsal
28107	Excision or curettage of bone cyst or benign tumor, tarsal or metatarsal, except talus or calcaneus; with allograft
Other CPT codes related to the CPB:
28730 - 28735	Tarso-metatarsal arthrodesis
Osteochondral allograft other than knee, talus or tarsal-metatarsal:
Osteochondral allograft of shoulder or hip, upper extremity-no specific code:
ICD-10 codes not covered for indications listed in the CPB:
M89.9	Disorder of bone, unspecified [chondral lesions of the hip]
M94.9	Disorder of cartilage, unspecified [chondral lesions of the hip]
M95.8	Other specified acquired deformities of musculoskeletal system [chondral defects of the hip]
S42.001A - S42.92XS	Fracture of shoulder and upper arm
S43.101+ - S43.109+	Unspecified dislocation of acromioclavicular joint [acromio-clavicular (AC) separation]
S52.001A - S52.92XS	Fracture of forearm
S62.001A - S62.92XS	Fracture at wrist and hand level
DeNovo ET engineered tissue graft and DeNovo NT tissue graft, TruFit Plug (a synthetic resorbable biphasic implant), PolyGraft, Chondrofix for osteochondral allografts of the knee:
Fast-Fix meniscal repair system:
No specific code
ICD-10 codes not covered for indications listed in the CPB:
S83.200+	Tear of unspecified meniscus, current injury
S83.211+ - S83.249+	Tear of medial meniscus, current injury
S83.251+ - S83.289+	Tear of lateral meniscus, current injury
S83.30X+ - S83.32X+	Tear of articular cartilage of knee, current
Cartiform viable osteochondral allograft:
HCPCS codes not covered for indications listed in the CPB:
Cartiform - no specific code:
Cryopreserved arterial allografts:
CPT codes not covered for indications listed in the CPB:
Cryopreserved arterial allografts - no specific code
ICD-10 codes not covered for indications listed in the CPB:
M62.20 - M62.28	Nontraumatic ischemic infarction of muscle

The above policy is based on the following references: