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Background
Scoliosis may be classified as functional or structural. Functional scoliosis may be transient or fairly persistent, but is not associated with any structural alterations. Structural scoliosis involves a fixed lateral curve with rotation, and is associated with many conditions including neuropathic diseases/disorders such as cerebral palsy, poliomyelitis, and muscular dystrophy; congenital causes such as failure of formation or segmentation, and myelomeningocele; traumatic causes such as fracture or dislocation (non-paralytic) and post-radiation; soft tissue contractures such as post-empyema and burns; osteochondrodystrophies such as achondroplasia and spondyloepiphyseal dysplasia; tumor; and rheumatoid disease. However, the most common type of structural scoliosis is idiopathic scoliosis. Although idiopathic scoliosis is thought to have a genetic predisposition, its exact cause is still unknown.
Idiopathic scoliosis can be further divided into 3 categories: (i) infantile (0 to 3 years of age), (ii) juvenile (3 to 10 years of age), and (iii) adolescent (over 10 years of age but before maturity). Idiopathic scoliosis most frequently affects young girls. The spinal curvature that persists after skeletal maturity is termed adult scoliosis.
The traditional treatment for adolescent idiopathic scoliosis is the use of a supportive brace, (e.g., the Milwaukee brace, the Boston brace). Torso exercises to increase muscle strength should be used in conjunction with braces. Since bracing is restrictive and must be worn 23 hours a day for up to several years, non-compliance has been estimated to be 20 to 50 % (Moe and Kettelson, 1970). Additionally, this method is associated with side effects such as anxiety, depression, and sleep disturbance. Another non-invasive method to straighten abnormal lateral curvature is surface electrical muscle stimulation. In this approach, muscles on one side of the spine are stimulated electrically (direct or alternating current, not high-voltage galvanic current) to contract and pull the vertebrae into a more normal position. Surface electrical muscle stimulation is usually applied for 8 to 10 hours during sleep. Treatment is terminated when patients reach skeletal maturity and structural stability. It is postulated that electro-muscular stimulation in the scoliotics may produce changes in muscle structure resulting in more fatigue-resistant muscles which increase the ability for postural stabilizing muscle activity in the spine (Grimby et al, 1985). Advantages of surface electrical muscle stimulation include freedom from bracing, the need for only part-time therapy, and an improvement of self-image in the affected adolescents. In severe cases, spinal fusion with instrumentation is effective in halting progression of the curve(s).
Surface electrical muscle stimulation has been shown to be effective in reversing or arresting progression of spinal curvatures in adolescents with idiopathic scoliosis. Brown et al (1984) reported the findings of a multi-center study on the use of night-time lateral electrical surface stimulation (LESS) for the treatment of juvenile or adolescent idiopathic scoliotics (484 girls and 64 boys, mean ages of 12.8 and 13.9 years, respectively). Only individuals with rapidly progressing scoliosis and at least 1 year of growth remaining were selected for this trial. The mean treatment time was 12 months, and the longest follow-up was 51 months. During the initial 6 months of therapy, a pre-treatment curvature progression rate of 1 degree/month was reversed to a reduction rate of 0.5 degree/month. Overall, 395 (72 %) patients had either reduced or stabilized their scoliosis. Seventy-one (13 %) patients had experienced temporary progression with subsequent stabilization and treatment continuation, while 82 (15 %) patients dropped out because of progression of their conditions. The major problem with LESS was skin irritation. The authors concluded that LESS treatment is a viable alternative to bracing for patients with idiopathic scoliosis.
Dutro and Keene (1985) performed a literature review on surface electrical muscle stimulation in the treatment of progressive adolescent idiopathic scoliosis. Patient selection criteria for studies reviewed were as follows: (i) Cobb angle of 25 to 45 degrees as indicated by radiographic studies, (ii) documented history of progression, (iii) minimum of 50 % correction on forced lateral bending, and (iv) minimum of 1 year of bone growth remaining. The authors concluded that electro-muscular stimulation is equally effective as bracing in treating progressive adolescent idiopathic scoliosis -- progression was arrested in 60 to 84 % of treated curves. For juvenile scoliosis, if treatment begins early enough and progression is not too severe, a curve cannot only be arrested, but reversed. Surface electro-muscular stimulation can also be employed to halt progression while patients await surgery.
A prospective study by the Scoliosis Research Society (Nachemson & Peterson, 1995) found electrical stimulation to be less effective than bracing and no more effective than observation in idiopathic scoliosis. In this study, 286 girls who had adolescent idiopathic scoliosis, a thoracic or thoracolumbar curve of 25 to 35 degrees, and a mean age of 12 years and seven months (range, 10 to 15 years) were followed to determine the effect of treatment with observation only (129 patients), an underarm plastic brace (111 patients), and nighttime surface electrical stimulation (46 patients). Thirty-nine patients were lost to follow-up, leaving 247 (86 percent) who were followed until maturity or who were dropped from the study because of failure of the assigned treatment. The endpoint of failure of treatment was defined as an increase in the curve of at least 6 degrees, from the time of the first x-fay, on two consecutive x-rays. As determined with use of this endpoint, treatment with a brace failed in seventeen of the 111 patients; observation only, in 58 of the 129 patients; and electrical stimulation, in 22 of the 46 patients. According to survivorship analysis, treatment with a brace was associated with a success rate of 74 percent (95 percent confidence interval, 52 to 84) at four years; observation only, with a success rate of 34 percent (95 percent confidence interval, 16 to 49); and electrical stimulation, with a success rate of 33 percent (95 percent confidence interval, 12 to 60). The 39 patients who were lost to follow-up were included in the survivorship analysis for the time period that they were in the study. Treatment with a brace was successful (p < 0.0001) in preventing six degrees of increase or more until the patients were 16 years old. The investigators noted that, even a worst-case analysis, in which the 23 patients who were dropped from the study after management with a brace were considered to have failed treatment, showed that the brace prevented progression and that this effect was significant (p = 0.0005). The investigators reported that there was no difference in the degree of increase in the curve between the patients who were managed with observation only and those who were managed with electrical stimulation.
The peer-reviewed medical literature suggest that surgery is indicated for growing children whose curve has exceeded 40 degrees; for individuals of any age whose curve is greater than 50 degrees; individuals with scoliosis-related pain that is refractory to conservative treatments; and patients with thoracic lordosis that can't be treated conservatively.
Braces are a primary treatment for idiopathic scoliosis. Standard scoliosis braces include the Milwaukee brace and the Boston brace.
Unlike other commonly used scoliosis braces, such as the Boston brace and the Milwaukee brace, the Charleston brace is worn only at night. Clinical studies have been published that have shown that the Charleston brace compares favorably to the traditional Boston and Milwaukee TLSO braces (Trivedi et al, 2001; Gepstein et al, 2002; Howard et al, 1998). The Charleston brace is especially useful for children with scoliosis who are not compliant with a traditional Boston or Milwaukee TLSO brace or who do not respond well to TLSO braces (Roach, 2002).
The Copes Scoliosis Brace is a custom-fitted polypropene support structure that utilizes air to attain spinal curvature correction. This is achieved through the use of strategically placed pneumatic force vector pads that are adjusted every 4 to 6 weeks during treatment. The brace is generally used for 12 to 36 months in conjunction with hydrotherapy, regular muscle strengthening exercises, as well as chiropractic treatments such as osseous manipulation and muscle stimulation therapy. There is no scientific evidence that the Copes Scoliosis Brace is effective in treating scoliosis. Additionally, there are no published data concerning the long-term effectiveness of this device, the rate of recurrence of scoliosis after patients stop wearing the brace or the number of patients who eventually have to undergo surgical intervention. Furthermore, the Copes Scoliosis Brace is used in conjunction with hydrotherapy, regular muscle strengthening exercises and chiropractic treatments. Thus, it is unclear what role the brace actually plays in the improvement, if any, of the condition.
The Providence Scoliosis System is designed to be worn only at night. It includes pressure sensors to ascertain if sufficient pressure is being administered. There is a lack of scientific evidence to support the effectiveness of the Providence Scoliosis System in treating idiopathic scoliosis, including a lack of direct comparative studies with other bracing systems. The only published peer-reviewed study of the Providence Scoliosis System is the report by d'Amato et al (2001) of their experience with the first consecutive 102 patients with adolescent idiopathic scoliosis who were followed for 2 years after completing treatment. This study reported on the experience of a single investigator group, limiting the generalizability of the findings. Other limitations of this study are the lack of an internal comparison group and limited duration of follow-up.
Yrjonen et al (2006) evaluated the results of treatment of adolescent idiopathic scoliosis (AIS) with the Providence night-time brace at 1.8 years after discontinuation of bracing. A total of 36 female patients with an average Cobb angle of 28.4 degrees and an apex below T-10 were studied prospectively. For comparisons, 36 matched patients treated with the Boston full-time brace were studied retrospectively. With the Providence night brace an average of 92 % for brace correction of the primary curve was achieved and during follow-up progression of the curve greater than 5 degrees occurred in 27 % of the patients. In the control group of the Boston full-time brace patients, brace correction was 50 % and the progression of the major curve occurred in 22 % of the patients. The authors concluded that the Providence night brace may be recommended for the treatment of AIS with curves less than 35 degrees in lumbar and thoracolumbar cases. The major drawbacks of this study were its small sample size and its limited duration of follow-up. Its findings need to be validated by randomized controlled trials with large sample size and long-term follow-up.
There is a lack of scientific evidence in the peer-reviewed published medical literature to support the effectiveness of the SpineCor Scoliosis System in treating idiopathic scoliosis, including insufficient data on its long-term effectiveness and a lack of studies directly comparing the dynamic corrective brace with rigid bracing systems.
In a prospective, observational study, Couillard and colleages (2007) assessed the effectiveness of the Dynamic SpineCor brace for adolescent idiopathic scoliosis in accordance with the standardized criteria proposed by the Scoliosis Research Society Committee on bracing and non-operative management. From 1993 to 2006, 493 patients were treated using the SpineCor brace. A total of 249 patients met the criteria for inclusion, and 79 patients were still actively being treated. Overall, 170 patients have a definitive outcome. All girls were pre-menarchal or less than 1 year post-menarchal. Assessment of brace effectiveness included (i) % of patients who have 5 degrees or less curve progression, and % of patients who have 6 degrees or more progression; (ii) % of patients who have been recommended/undergone surgery before skeletal maturity; (iii) % of patients with curves exceeding 45 degrees at maturity (end of treatment); and (iv) 2-year follow-up beyond maturity to determine the % of patients who subsequently underwent surgery. Successful treatment (correction, greater than 5 degrees, or stabilization, +/- 5 degrees) was achieved in 101 (59.4 %) of the 170 patients from the time of the fitting of the SpineCor brace to the point in which it was discontinued. Thirty-nine immature patients (22.9 %) required surgical fusion while receiving treatment. Two (1.2 %) of 170 patients had curves exceeding 45 degrees at maturity. One mature patient (2.1 %) needed surgery within 2 years of follow-up beyond skeletal maturity. The authors concluded that the SpineCor brace is effective for the treatment of adolescent idiopathic scoliosis. Moreover, positive outcomes are maintained after 2 years because 45 (95.7 %) of 47 patients stabilized or corrected their end of bracing Cobb angle up to 2 years after bracing. The results of this observational study are promising; however the findings need to be validated by future well-designed studies.
Wong and colleagues (2007) stated that the conventional rigid spinal orthosis and the flexible spinal orthosis, SpineCor, have different treatment principles in the management of AIS. These may influence the patients' gait pattern and clinical outcome. In this study, gait analysis on patients with AIS undergoing these 2 orthotic interventions were conducted. The patients' lower limb kinematic and kinetic data during level walking were collected using a motion analysis system and 2 force platforms in 4-test conditions: pre-intervention, having used the orthosis for 1 month and 1 year (in and out of the orthosis). A total of 21 subjects were randomly assigned to the rigid spinal orthosis group (10 subjects) and the SpineCor group (11 subjects). Neither group showed gait asymmetry when comparing the convex and concave sides in the 4-test conditions. However, significant reduction in the range of motion of the pelvis and hip joints in the coronal plane were found. Although patients with AIS undergoing these 2 orthotic interventions showed significant changes in walking pattern within the study period, their long-term effect on gait and function requires further investigation through long-term prospective studies.
The Rosenberger brace is a low-profile, custom-molded thoracolumbosacral orthosis (TLSO) that includes design changes from other TLSOs that are intended to improve compliance and, therefore, outcomes. The Rosenberger low profile orthoses is intended to offer better appearance than the Milwaukee orthosis with its neck ring (Gavin et al, 1986). While the Rosenberger brace was developed in the 1980's, the effectiveness of the brace had never been evaluated in the literature prior to 2004 (Gavin et al, 1986; Grabowski and Gelb, 2005). At that time, Spoonamore et al (2004) assessed the effectiveness of the Rosenberger brace in preventing curve progression in adolescent idiopathic scoliosis (n = 71). The investigators found the brace to have an overall failure rate similar to that of untreated cases from published natural history studies, although subgroups of patients had lower failure rates. These findings suggested the need for further refinement of the indications for the Rosenberger brace.
The Cheneau brace is a thermo-plastic scoliosis brace modeled on a hyper-corrected positive plaster cast of the patient. This is a 3-dimensional (3-D) correctional brace that has significant pressure and expansion areas built into the brace, which provides correction in all 3 anatomical planes. It follows the general correction principle as was written by Dubousset -- detorsion and sagittal plane normalization, which would effect correction of the coronal and transversal planes, resulting in some elongation of the spine, without any significant distraction force. The Rigo System Cheneau (RSC) brace is a scoliosis brace that is based on the original theories of Dr. Cheneau, however Dr. Rigo furthered the designs by combining his new scoliosis classification types, to design the RSC brace also known as El corse de RSC. The brace is manufactured with an Ortholutions CAD CAM technique.
Rigo et al (2002) reported a retrospective series that included 105 idiopathic scoliotic patients treated with a Chêneau brace. With an average age of 12.5 years old and a mean Risser sign of 0.9, the initial major Cobb angle was 36.8 degrees corrected to 25.9 degrees in the brace (31.1 % of the primary correction), and the major torsion angle was 16.8 degrees corrected to 12.9 degrees in the brace (22.2 % of the primary correction). A total of 37 patients have finished the treatment with a mean follow-up of 16.8 months. For this group, the initial Cobb and torsion angles were not significantly changed (36.4 degrees Cobb to 34.1 degrees Cobb at follow-up, and 16.9 degrees Perdriolle to 15.7 degrees Perdriolle at follow-up). The proportion of patients without progression greater than 5 degrees Cobb (n = 20) and with an improved final Cobb angle (n = 10) was greater than failures (n = 7). However, due to the catastrophic nature of some progressions, which generally coincide with a high Cobb angle right from the start, with low primary correction, and with non-compliance, the final Cobb angle showed a slight tendency to decrease but without reaching high significance. These preliminary results demonstrate that the Chêneau brace can effectively prevent the progression of Cobb and torsion angles, even in cases of bad prognosis.
Weiss et al (2006) stated that in patients with idiopathic scoliosis (IS), reduced thoracic kyphosis and reduced lumbar lordosis frequently occur in correlation with the lateral spinal curvature. Normalization of the sagittal profile and hyper-correction of the deviation in frontal and coronal plane are the main issues of the latest concept of bracing. The purpose of this study was to investigate the influence of of sagittal counter forces (SCF) on the scoliotic deformity. A case series of 4 patients with IS treated with 2 braces designed to improve the sagittal profile (Rigo-System-Chêneau-brace and with a sagittal counter force brace, SCF-brace). The short-term effect (30 mins) of both braces was evaluated using surface topography (Formetric surface topography system, Diers International, Wiesbaden). One patient (Cobb angle 92 degrees) showed no short-term correction in the frontal and coronal planes; others (Cobb angles between 39 and 48 degrees) exhibited valuable correction in frontal and coronal planes. There was no short-term correction in the sagittal plane for either brace. The authors concluded that the application of SCF seems to have similar short-term effects as 3-D correction and should be addressed more in future concepts of scoliosis bracing.
Grivas and Kaspiris (2010) stated that there is a lack of a systematic examination of the braces commonly used in Europe. Thus, the objective of this report was the description of the European braces widely used. The history, design rationale, indications, biomechanics, outcomes and comparison between some braces were reported. Chêneau Brace is used in France and other European Countries. There are 2 Cheneau derivatives, namely the RSC brace used in Spain and the ScoliOlogiC "Chêneau light" used in Germany. The Lyonnaise brace is used in France and Italy. The Dynamic Derotating brace is used in Greece. The TriaC brace is used in the Netherlands. The Sforzesco brace based on the SPoRT concept and the Progressive Action Short brace are used in Italy. Correction of spinal deformities is achieved in conservative treatment with passive and active brace mechanisms. The mode of operation of modern braces is in accordance with various principles of correction, namely active or passive extension with the aid of a neck ring and correction by lateral pads, lateral pressure according to 3-point principle, compression, bending the trunk towards the opposite side, active bracing and correction by means of pressure exerted by bands during movement and by means of metallic blades. These preliminary findings of the Rigo-Cheneau brace need to be validated by well-designed studies with long-term outcomes.
The Risser jacket has been used to correct scoliosis for many years. The Research Committee of the American Orthopaedic Association's report on end-result study of the treatment of idiopathic scoliosis (Shands et al, 1941) discussed the use of the Risser jacket to correct the curve prior to fusion in 149 patients. Clinical improvement of the rotation deformity was observed following correction with the Risser jacket in 48 % of the 126 patients on whom these data were available. In addition, the best clinical appearances of the back were obtained in the group treated by correction in the Risser jacket and spine fusion. James (1952) noted that correction of the primary curvature in scoliotic patients is achieved by the use of the Risser turnbuckle jacket, the most effective method yet devised. Furthermore, a review on infantile scoliosis by Lakshmanan and colleagues (2009) stated that management with orthosis is necessary when the curve is considered to be progressive or if a compensatory curve has developed. Various types of orthosis are available for children younger than 3 years. The most commonly used orthoses include the hinged Risser jacket, the Milwaukee brace, and the Boston brace. The brace should be used for 23.5 hours a day and should be removed only for exercises and swimming. It needs to be used until skeletal maturity is attained, because curves usually do not progress after skeletal maturity; however, curves may progress in spite of using a brace.
Negrini and associates (2003) performed a systematic review of the literature to verify the effectiveness of physical exercises in the treatment of AIS. These investigators carried out a search of different databases, and a hand-search of the non-indexed pertinent literature, and found 11 papers: none of the studies was randomized, 6 were prospective, 7 were controlled, and 2 compared their results to historical controls; 1 paper had both a prospective design and a concurrent control group. The methodological quality of the retrieved studies was reviewed and found to be very poor. With one exception, the published studies demonstrated the effectiveness of physical exercises in reducing both the rate of progression and the magnitude of the Cobb angle at the end of treatment. However, being of poor quality, the literature failed to provide solid evidence for or against the efficacy of physical exercises in the treatment of AIS.
Negrini et al (2008) examined if the indication for treatment with specific exercises for AIS has changed in recent years. A bibliographic search with strict inclusion criteria (patients treated exclusively with exercises, outcome Cobb degrees, all study designs) was performed on the main electronic databases and through extensive manual searching. These researchers retrieved 19 studies, including 1 randomized controlled trial (RCT) and 8 controlled studies; 12 studies were prospective. A methodological and clinical evaluation was performed. The 19 papers considered included 1,654 treated patients and 688 controls. The RCT (highest-quality study) compared 2 groups of 40 patients, showing an improvement of curvature in all treated patients after 6 months. These investigators found 3 papers on Scoliosis Intensive Rehabilitation (Schroth), 5 on extrinsic autocorrection-based methods (Schroth, side-shift), 4 on intrinsic autocorrection-based approaches (Lyon and SEAS) and 5 with no autocorrection (3 asymmetric, 2 symmetric exercises). Apart from 1 (no autocorrection, symmetric exercises, very low methodological quality), all studies confirmed the efficacy of exercises in reducing the progression rate (mainly in early puberty) and/or improving the Cobb angles (around the end of growth). Exercises were also shown to be effective in reducing brace prescription. The authors concluded that in 5 years, 8 more papers have been published to the indexed literature coming from throughout the world (Asia, the United States, Eastern Europe) and proving that interest in exercises is not exclusive to Western Europe.
The review by Negrini and colleagues (2008) emphasized a RCT by Wan et al (2005) of exercise in idiopathic scoliosis. The article by Wan et al is in Chinese, but the description of the study by Negrini et al indicated that the study duration was 6 months, raising questions about the durability of results. Subjects in both the exercise group and control group improved from baseline (15 degrees in the exercise group and 7 degrees in the control group), and there is no report whether the differences between the 2 groups at the end of treatment were statistically significant. Furthermore, the Cobb angles at initiation of therapy (25 degrees in the exercise group and 24 degrees in the control group) were within a range for which children are often managed with observation.
Furthermore, the American Academy of Orthopedic Surgeons (2007) stated that exercise programs have not been found to be effective treatments for scoliosis. The National Institute of Arthritis and Musculoskeletal Diseases of the National Institutes of Health (2008) stated that exercise has not been shown to prevent curve progression. Addtionally, Schiller and co-workers (2010) stated that although numerous non-operative methods have been attempted, including exercise, only bracing is effective in preventing curve progression and the subsequent need for surgery.
Spinal Unloading Devices:
In a pilot study, Chromy and colleagues (2006) evaluated potential benefits of axial spinal unloading (LTX 3000 Lumbar Rehabilitation System) over a 3-month period. A total of 5 adolescent girls with scoliosis were enrolled in the study. Three laboratory sessions: (i) initial baseline, (ii) immediately after 3-month treatment period (axial unloading by using LTX 3000 for 2 10-min treatments daily), and (iii) 1-month post-treatment. Initial baseline postural data were obtained from 2 sets of radiographs (standing antero-posterior [AP] and lateral, sitting AP and lateral), back range of motion (ROM) measurements, and numeric pain scales. The following were assessed: static postural changes; potential functional benefits; and therapeutic compliance. All subjects elicited reductions in lumbar Cobb angles immediately after 3 months of treatment; initial average scoliotic curves of 13.7 degrees were reduced 42 % to 8 degrees (alpha = 0.05, p = 0.004). Additionally, such reductions were evident 1 month post-treatment; average original curves were reduced by 27 %. Subjects' ROM and lumbar lengthening were not significantly altered by this therapeutic protocol. Reported subject compliance was high (95 %). The authors concluded that the LTX 3000 is a potential adjunct therapy for the treatment of adolescent scoliosis. The findings of the present study need to be validated by randomized controlled trials with large sample size and long-term follow-up.
Vertebral Body Stapling:
Vertebral body stapling (VBS) is an alternative to bracing or spinal fusion for the treatment of progressive scoliosis. It is believed that for patients with progressive moderate scoliosis who are still growing, intervertebral body stapling of the outer (convex) side of the anterior spine (the side of the spine facing the chest) may keep the curve from progressing. With the convex growth plates held in check, continued development of the inner (concave) growth plates should stabilize the progression and may allow correction of deformity as the subject grows. This approach employs a special metal device that is clamp-shaped at body temperature, but can be straightened when subjected to cold temperatures and inserted into the spine. When warmed up, the staple returns to its clamp shape and supports the spine.
Betz and colleagues (2003) reported the feasibility, safety, and utility of VBS without fusion as an alternative treatment for adolescent idiopathic scoliosis. These researchers retrospectively reviewed 21 patients (27 curves) with adolescent idiopathic scoliosis treated with VBS. Patients were immature as defined by Risser sign less than or equal to 2. The procedure was safe, with no major complications and three minor complications. One patient had an intra-operative segmental vein bleed resulting in an increased estimated blood loss of 1,500 ml as compared to the average estimated blood loss of 247 ml for all patients. One patient had a chylothorax and one pancreatitis. No patient has had a staple dislodge or move during the follow-up period (mean 11 months, range of 3 to 36 months), and no adverse effects specifically from the staples have been identified. Utility (defined as curve stability) was evaluated in 10 patients with stapling with greater than 1-year follow-up (mean of 22.6 months) and pre-operative curve less than 50 degrees. Progression of greater than or equal to 6 degrees or beyond 50 degrees was considered a failure of treatment. Of these 10 patients, 6 (60 %) remained stable or improved and 4 (40 %) progressed. One of 10 (10 %) in the stapling group had progressed beyond 50 degrees and went on to fusion. Six patients required stapling of a second curve, 3 as part of the primary surgery, and 3 as a second stage, because a second untreated curve progressed. The results need to be considered with caution, as the follow-up was short. The authors concluded that the data showed that VBS for the treatment of scoliosis in the adolescent was feasible and safe in this group of 21 patients. In the short-term, stapling appears to have utility in stabilizing curves of progressive adolescent idiopathic scoliosis.
Betz et al (2005) reported the findings of 39 consecutive patients who have had VBS of 52 curves (26 patients with one curve stapled and 13 patients with two curves). For patients who were 8 years or older with less than 50 degrees pre-operative curve and a minimum 1-year follow-up, coronal curve stability was 87 % when defined by progression less than or equal to 10 degrees. Fusion was necessary in 2 patients. No curves less than 30 degrees at the time of stapling progressed greater than or equal to 10 degrees. Major complications occurred in 1 patient (2.6 %, diaphragmatic hernia) and minor complications occurred in 5 patients (13 %). The authors concluded that further follow-up of treated patients and more research into effectiveness and indications are needed.
Cunningham et al (2005) noted that standard interventions for adolescents and adults, including spinal deformity correction and fusion, may not be appropriate for young patients with considerable growth remaining. Alternative surgical options that provide deformity correction and protect the growth remaining in the spine are needed to treat this population of patients. Several groups have reported advances in the field of deformity spine surgery. Updated findings concerning the successful implementation of growing rods have revived this technique as a viable option for preserving near normal growth of the spine. New techniques have also been recently described, including vertebral stapling that produces asymmetric and corrective growth of the concavity of a deformity, and vertical expandable prosthetic titanium rib instrumentation that indirectly corrects spine deformity and protects spine growth remaining to treat an associated thoracic insufficiency syndrome. The authors concluded that new techniques and instrumentation allow the treatment of this challenging patient population to approach the goals of deformity correction and maintenance with preservation of potential growth. Preliminary outcomes from the different techniques are promising, but further investigation, including long-term follow-up, is needed.
In an assessment of VBS for the treatment of idiopathic scoliosis, the Australian Safety and Efficacy Register of New Interventional Procedures - Surgical (2005) concluded that limited evidence exists on the safety and effectiveness of VBS. Current evidence of this procedure is limited to small patient numbers and short-term follow-up. Furthermore, long-term safety and effectiveness data from prospective, RCTs will be needed before VBS can be widely accepted.
Guille et al (2007) stated that the recent investigations of convex anterior VBS have offered promising early results with use of improved implants and techniques. The use of a shape memory alloy staple tailored to the size of the vertebral body, the application of several staples per level, the instrumentation of the Cobb levels of all curves, and the employment of minimally invasive thoracoscopic approaches all offer substantial improvements over previous fusionless techniques. Patient selection may also play a role in the current success of these fusionless treatments, with perhaps the ideal candidates for this intervention possessing smaller and more flexible curves. However, the authors stated that long-term results of the effects on the instrumented motion segments and adjacent spine are not yet available.
In a systematic literature review of non-surgical treatment in adult scoliosis, Everett and Patel (2007) stated that the evidence on the use of chiropractic manipulation for adult scoliosis is very weak.
Hrysomallis and Goodman (2001) noted that exercise has been promoted in an attempt to correct postural deviations, such as excessive lumbar lordosis, scoliosis, kyphosis, and abducted scapulae. One of the assumed causes of these conditions is a weak and lengthened agonist muscle group combined with a strong and tight antagonist muscle group. Strengthening and stretching exercises have been prescribed accordingly. It is implied that strengthening exercises will encourage adaptive shortening of the muscle-tendon length, reposition skeletal segments, and produce static posture realignment. A review of the literature has found a lack of reliable, valid data collected in controlled settings to support the contention that exercise will correct existing postural deviations. Likewise, objective data to indicate that exercise will lead to postural deviations are lacking. It is likely that exercise programs are of insufficient duration and frequency to induce adaptive changes in muscle-tendon length. Additionally, any adaptations from restricted range-of-movement exercise would likely be offset by daily living activities that frequently require the body segments to go through full ranges of motion.
Mooney and Brigham (2003) reported on the use of progressive resistive exercise in adolescents with scoliosis. A total of 20 adolescent patients (18 girls and 2 boys) with scoliosis ranging from 15 degrees to 41 degrees in their major curve were treated with a progressive resistive training program for torso rotation. All patients demonstrated an asymmetry of rotation strength measured on specialized equipment, and surface electrode electromyograms showed inhibition of lumbar paraspinal muscles. Sixteen of 20 patients demonstrated curve reduction, and no patient showed an increase in curve. These results would need to be replicated in a larger trial. The durability and effectiveness compared with bracing would also need to be evaluated.
In a pilot study, McIntire and colleagues (2008) examined treatment of adolescent idiopathic scoliosis with quantified trunk rotational strength training. Patients received a 4-month supervised followed by a 4-month home trunk rotational strength training program. Trunk rotational strength was measured in both directions at 5 positions at baseline, 4 months, and 8 months. Patients were followed clinically. A total of 15 patients (12 females and 3 males), with an average age of 13.9 years and an average main Cobb of 33 degrees were enrolled. At baseline, there was no significant asymmetry. After 4 months of supervised strength training, involving an average of 32 training sessions, each lasting about 25 mins, their strength had significantly increased by 28 % to 50 % (p < 0.005 to p < 0.001). After 4 months of unsupervised home strength training their strengths were unchanged. The 3 patients with baseline curves of 50 to 60 degrees all had main or compensatory curve progression and 2 had surgery. For patients with 20 to 40-degree curves, survivorship from main curve progression of greater than or equal to 6 degrees was 100 % at 8 months, but decreased to 64 % at 24 months. The authors concluded that quantified trunk rotational strength training significantly increased strength. It was not effective for curves measuring 50 to 60 degrees. It appeared to help stabilize curves in the 20 to 40-degree ranges for 8 months, but not for 24 months. Periodic additional supervised strength training may help the technique to remain effective, although additional experimentation will be necessary to determine this.
Whole Body Vibration:
Li and colleagues (2011) stated that numerical techniques were used to study the vibration response of idiopathic scoliosis patients with single thoracic curve. These researchers analyzed the dynamic characteristics of the idiopathic scoliotic spine under the whole body vibration (WBV) condition. The influence of the upper body mass was also studied. The relationship between the WBV and the spinal disorders has been investigated using finite element method. However, the dynamic response features of the scoliotic spine to the vibration were poorly understood. The resonant frequencies of the scoliotic spine and the effects of the body weight were studied using a finite element model described previously. Modal and harmonic analysis was conducted. The amplitudes of 6 fundamental vertebral movements around the long, coronal and sagittal axis were quantified in the frequency range of 1 to 35 Hz. The vibration-induced rotation amplitudes of the apex of the thoracic deformity were higher than that of the lumbar segments. The apical vertebrae had the greatest rotation amplitudes at 2 and 8 Hz, and the largest lateral translation amplitudes at 16 Hz. Vibration could cause large lateral flexion amplitudes in the apex of the thoracic deformity. The apical vertebrae had the largest side flexion amplitudes at 6 Hz. Increasing upper body mass could not change resonant frequency of vibration-induced lateral translation and rotation around the long axis of the apical vertebrae. The authors concluded that the scoliotic spine is more sensitive to vibration than the normal spine. For a patient with single thoracic curve, long-term WBV may do more harm to the thoracic deformity than to the lower lumbar segments. Axial cyclic loads applied to an already deformed spine may cause further rotational and scoliotic deformity. Patients with idiopathic scoliosis are more likely to suffer from vibration-induced spinal disorders than those by normal persons.
Genetic Tests:
Adolescent idiopathic scoliosis is a lateral spinal curvature observed in children 10 years of age or older, and approximately 100,000 new cases of AIS are diagnosed annually. Of these most are small curvatures of less than 15 to 20 degrees requiring only routine observation for progression. If a curve reaches 20 to 40 degrees, orthotic bracing is used to prevent further progression. If the bracing is unsuccessful and the curve progresses beyond 40 degrees surgical correction may be required. Only about 7 to 10 % of patients require braces and only 1 to 4% require surgery. Patients identified with AIS are periodically monitored for progression of the curve using various methods based on the angular relationships of the vertebrae and assessment of skeletal maturity. Recently a genetically-based test has been developed that is supposed to identify those individuals with the highest risk for curve progression. Those with a low-risk would require less frequent monitoring and x-ray exposure, while those at higher risk would be checked more frequently. The ScoliScore™ AIS Prognostic Test is being offered by Axial Biotech, Inc., and is intended for children between 9 and 13 years of age with a primary diagnosis of AIS and a mild spinal curvature (defined as less than 25 degrees) and who are of Caucasian ethnicity. The test examines a total of 53 genetic markers and converts the result into a risk score using a proprietary software algorithm. A score of 1 to 50 constitutes low-risk for curve progression, 51 to 180 intermediate-risk, and 181 to 200 high-risk.
No articles were found in the peer-reviewed medical literature to independently assess the ScoliScore™ test for analytic validity, clinical validity or clinical utility. A review article by Ogilvie (2010) described how studies of families have been used to determine the inherited nature of AIS. The article declared the test has been validated in Caucasian girls and boys but is not validated in Asians or African-Americans. No details of any clinical trials were discussed. Without clinical trials information in the scientific literature it is not possible to reach conclusions on health outcomes. There is a substantial body of literature addressing evaluation of curve progression by standard methods but none of these studies or reviews mentioned genetic testing. As no articles are currently available in the literature, it is not possible to determine if ScoliScore™ improves net health outcomes. Nor have there been any comparison studies to address whether the use of the genetic test is at least as effective as standard monitoring.
Ward et al (2010) developed and tested the negative predictive value of a prognostic DNA test for AIS and established clinically meaningful endpoints for the test. Logistic regression was used to develop an algorithm to predict spinal curve progression incorporating genotypes for 53 single nucleotide polymorphisms (SNPs) and the patient's presenting spinal curve (Cobb angle). Three cohorts with known AIS outcomes were selected to reflect intended-use populations with various rates of AIS progression: 277 low-risk females representing a screening cohort, 257 females representing higher risk patients followed at referral centers, and 163 high-risk males. DNA was extracted from saliva, and genotypes were determined using TaqMan assays; AIS Prognostic Test scores ranging from 1 to 200 were calculated. Low-risk scores (less than 41) had negative predictive values of 100 %, 99 %, and 97 %, respectively, in the tested populations. In the risk model, these researchers used cut-off scores of 50 and 180 to identify 75% of patients as low-risk (less than 1 % risk of progressing to a surgical curve), 24 % as intermediate-risk, and 1 % as high-risk. The authors concluded that prognostic testing for AIS has the potential to reduce psychological trauma, serial exposure to diagnostic radiation, unnecessary treatments, and direct and indirect costs-of-care related to scoliosis monitoring in low-risk patients. They stated that further improvements in test performance are expected as the optimal markers for each locus are identified and the underlying biologic pathways are better understood. The validity of the test applies only to white AIS patients; versions of the test optimized for AIS patients of other races have yet to be developed.
Liu et al (2010) examined the association between the promoter polymorphisms of matrix metalloproteinase (MMP)-3 (-1171 5A/6A rs3025058) and interleukin (IL)-6 genes (-174G/C rs1800795) and AIS in a Chinese Han population. A total of 487 Chinese girls with AIS and 494 healthy age-matched adolescent girls were recruited consecutively during a 3-year period. Statistical analysis of genotype frequencies between AIS patients and normal controls were performed by Chi-test. In this association study of the MMP-3 polymorphism and the risk of scoliosis, no significant difference was found between cases and controls, both in term of allelic association (6A: 81.2 % in cases versus 81.8 % in controls, 5A: 18.8 % in cases versus 18.2 % in controls, p = 0.745) or genotype association (6A/6A: 65.9 % in cases versus 66.2 % in controls, 5A/6A: 30.6 % in cases versus 31.2 % in controls, and 5A/5A: 3.5 % in cases versus 2.6 % in controls; p = 0.733). Among AIS patients, the maximal Cobb angles were also not different among MMP-3 genotypes (6A/6A: 31.1 degrees +/- 9.7 degrees, 5A/6A: 29.1 degrees +/- 10.5 degrees, and 5A/5A: 29.4 degrees +/- 11.2 degrees; p = 0.392). As for IL-6 polymorphism, -174G/C polymorphism was not found in the Chinese AIS patients, and all 100 AIS patients and 100 normal controls were found to carry the G/G wild type. The authors concluded that these findings did not find any significant association of promoter polymorphisms of the MMP-3 (-1171 5A/6A rs3025058) and IL-6 gene (-174G/C rs1800795) with AIS. The results indicated that the MMP-3 promoter polymorphism is not associated with AIS in the Chinese population. They noted that further studies, however, are needed to rule out the potential association with other promoter polymorphisms in IL-6.
Sharma et al (2011) noted that AIS is an unexplained and common spinal deformity seen in otherwise healthy children. Its pathophysiology is poorly understood despite intensive investigation. Although genetic underpinnings are clear, replicated susceptibility loci that could provide insight into etiology have not been forthcoming. To address these issues, these investigators performed genome-wide association studies (GWAS) of approximately 327,000 SNPs in 419 AIS families. They found strongest evidence of association with chromosome 3p26.3 SNPs in the proximity of the CHL1 gene (p < 8 × 10(-8) for rs1400180). They genotyped additional chromosome 3p26.3 SNPs and tested replication in 2 follow-up case-control cohorts, obtaining strongest results when all 3 cohorts were combined (rs10510181 odds ratio = 1.49, 95 % CI: 1.29 to 1.73, p = 2.58 × 10(-8)), but these were not confirmed in a separate GWAS. CHL1 is of interest, as it encodes an axon guidance protein related to Robo3. Mutations in the Robo3 protein cause horizontal gaze palsy with progressive scoliosis (HGPPS), a rare disease marked by severe scoliosis. Other top associations in the authors' GWAS were with SNPs in the DSCAM gene encoding an axon guidance protein in the same structural class with Chl1 and Robo3. These researchers additionally found AIS associations with loci in CNTNAP2, supporting a previous study linking this gene with AIS. Cntnap2 is also of functional interest, as it interacts directly with L1 and Robo class proteins and participates in axon pathfinding. The authors concluded that these findings suggested the relevance of axon guidance pathways in AIS susceptibility, although these results require further study, particularly given the apparent genetic heterogeneity in this disease.
Huang and colleagues (2011) examined if the matrix metalloproteinase 9 gene (MMP9) polymorphism is associated with the onset or progression of AIS in Chinese Han female. Three SNPs (rs17576, rs2250889, rs1805088) were genotyped through TaqMan-based real-time PCR assay in 190 AIS patients and 190 controls, all of whom were females from Chinese Han population with matched age. Analyses performed included Hardy Weinberg equilibrium test, Pearson chi-square test, Logistic regression analysis, linkage disequilibrium analysis and haplotype analysis. The mean maximum Cobb angles with different genotypes in case-only dataset were also compared. All 3 SNPs have reached Hardy-Weinberg equilibrium in the controls. Genotype and allele frequencies of all SNPs were found similar between cases and controls by Pearson chi-square test and Logistic regression. Genotype-phenotype analysis showed that patients with CC genotype in rs2250889 featured larger maximum Cobb angles. The authors concluded that MMP9 may not be a predisposition gene of AIS in Han female. However, homozygous mutation in rs2250889 can render scoliosis more severe, implying that MMP9 defect may result in deterioration of AIS.
Xu and associates (2011) examined if the predisposition genes previously reported to be associated with the occurrence or curve severity of AIS may play a role in the effectiveness of brace treatment. A total of 312 AIS patients treated with bracing were enrolled in this study. The Cobb angle of the main curve was recorded at the beginning of brace treatment as well as at each follow-up. The patients were divided into 2 groups according to the outcome of brace treatment (success/failure). The failure of brace treatment was defined as a curve progression of more than 5 degrees compared to the initial Cobb angle or surgical intervention because of curve progression. Single nucleotide polymorphism sites in the genes for estrogen receptor α (ERα), estrogen receptor β (ERβ), tryptophan hydroxylase 1 (TPH-1), melatonin receptor 1B (MTNR1B) and matrillin-1 (MATN1), which were previously identified to be predisposition genes for AIS, were selected for genotyping by the PCR-RFLP method. Differences of genotype and allele distribution between the 2 groups were compared by the χ(2) test. A logistic regression analysis was used to figure out the independent predictors of the outcome of brace treatment. There were 90 cases (28.8 %) in the failure group and 222 cases (71.2 %) in the success group. Patients in the failure group were associated with the genotype GA (50.9 versus 17.9 % p < 0.001) and the G allele (27.1 versus 12.0 %, p < 0.001) at SNP rs9340799 of the ERα gene. Similarly, they were also associated with the genotype AT (33.3 versus 13.0 %, p = 0.002) and the A allele (16.7 versus 9.6 %, p = 0.033) at SNP rs10488682 of the TPH-1 gene. For MTNR1B, the difference of genotype distribution between the 2 groups was found to be statistically significant, while the difference of allele distribution between the 2 groups was found to be marginally statistically significant; for the MATN1 and ERβ genes, these investigators found no significant differences of the genotype or allele distribution between the 2 groups. In the logistic regression analysis, ERα and TPH-1 were demonstrated to be independent factors predictive of bracing effectiveness. The authors concluded that ERα and TPH-1 might be potential genetic markers that could predict the outcome of brace treatment. Patients with the G allele at the rs9340799 site of the ERα gene and the A allele at the rs10488682 site of the TPH-1 gene are prone to be resistant to brace treatment.
Miller (2011) stated that idiopathic scoliosis is one of the most common complex genetic disorders of the musculo-skeletal system. The clinical parameters relating to onset, curve progression, and severity in relation to clinical prognosis and current treatment modalities have been defined, but do not address the cause of this disorder. In an effort to define causative genetic elements, multiple studies have delineated potential genetic loci that are statistically related to idiopathic scoliosis in a variety of populations. The question remains how future genetic testing and genomic profiling may be of aid in the therapeutic algorithms related to this disorder.
Thus, it seems that AIS is a complex disorder that result from the interaction of multiple genetic loci and the environment, however, the details of these interactions are unclear. Furthermore, an UpToDate review on "Treatment and prognosis of adolescent idiopathic scoliosis" (Scherl, 2012) does not mention the use of genetic testing.
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