Foot Orthotics

Number: 0451

Policy

Note: Most Aetna plans exclude coverage of orthopedic shoes, foot orthotics or other supportive devices of the feet, except under the following conditions:

1. This exclusion does not apply to such a shoe if it is an integral part of a leg brace and its expense is included as part of the cost of the brace.  See section below on therapeutic shoes as integral parts of a leg brace.  
2. This exclusion does not apply to therapeutic shoes furnished to selected diabetic members in Aetna’s HMO plans and selected diabetic members of other Aetna plans where state diabetic mandates apply.  See section below on therapeutic shoes for diabetes for details.  
3. This exclusion does not apply to rehabilitative foot orthotics that are prescribed as part of post-surgical or post-traumatic casting care.  
4. This exclusion does not apply to prosthetic shoes.  See section below on prosthetic shoes for details.  

This policy is consistent with CMS guidelines.  Please check benefit plan descriptions for details.  For plans that do not exclude coverage of orthopedic shoes, foot orthotics, or other supportive devices of the feet, see section "Plans that do not exclude foot orthotics" below:

Therapeutic Shoes as Integral Parts of a Leg Brace

Note: Even under plans that exclude coverage of foot orthotics, Aetna covers therapeutic shoes if they are an integral part of a covered leg brace and are medically necessary for the proper functioning of the brace.  Oxford shoes are usually covered in these situations.  Other shoes, e.g., high-top, depth inlay or custom-molded for non-diabetic, etc., may also be covered if they are an integral part of a covered leg brace.  Medically necessary heel replacements, sole replacements, and shoe transfers are also covered for therapeutic shoes that are an integral part of a covered leg brace.  Inserts and other shoe modifications of shoes that are an integral part of a leg brace are covered if they are medically necessary for the proper functioning of the brace.  Medically necessary shoe and related modifications, inserts, and heel/sole replacements, are covered when the shoe is an integral part of a leg brace.  A matching shoe, which is not attached to the brace and items related to that shoe, are also covered.

Shoes that are billed separately (i.e., not as part of a brace) will not be covered even if they are later incorporated into a brace.

Therapeutic Shoes for Diabetes

Note on Diabetic Shoe Benefit: Medically necessary foot orthotics may be covered for diabetic members of Aetna HMO plans with a diabetic shoe benefit, and for diabetic members of traditional plans without an exclusion for orthopedic shoes and supportive devices for the feet.

Aetna considers therapeutic shoes (depth or custom-molded) along with inserts medically necessary for members with diabetes mellitus and any of the following complications involving the foot:

1. Foot deformity; or
2. History of pre-ulcerative calluses; or 
3. History of previous ulceration; or
4. Peripheral neuropathy with evidence of callus formation; or
5. Poor circulation; or
6. Previous amputation of the foot or part of the foot.  

Therapeutic shoes and inserts for diabetes are considered experimental and investigational when these criteria are not met.  These criteria are consistent with the Centers for Medicare & Medicaid Services (CMS) guidelines.

One of the following per member per calendar year is considered medically necessary:

1. No more than 1 pair of custom-molded shoes (including inserts provided with the shoes) and 2 additional pairs of inserts; or  
2. No more than 1 pair of depth shoes and 3 pairs of inserts (not including the non-customized removable inserts provided with such shoes).

The following items are considered medically necessary for persons with diabetes who meet the criteria for diabetic shoes listed above:

1. Depth shoes with the following characteristics are considered medically necessary when criteria are met:  

   • Are available in full and half sizes with a minimum of 3 widths so that the sole is graded to the size and width of the upper portions of the shoes according to the American standard sizing schedule or its equivalent.  (The American standard last sizing schedule is the numerical shoe sizing system used for shoes sold in the United States); and 
   • Are made of leather or other suitable material of equal quality; and  
   • Have a full-length, heel-to-toe filler that, when removed, provides a minimum of 3/16th inch of additional depth used to accommodate custom-molded or customized inserts; and 
   • Have some sort of shoe closure.

   This includes a shoe with or without an internally seamless toe.  Depth shoes without these characteristics have no proven value for diabetes.

2. Custom-molded shoes with the following characteristics are considered medically necessary when the member has a foot deformity that can not be accommodated by a depth shoe:  

   • Constructed over a positive model of the member’s foot; and 
   • Have removable inserts that can be altered or replaced as the member’s condition warrants; and 
   • Have some sort of shoe closure; and 
   • Made from leather or other suitable material of equal quality.

   This includes a shoe with or without an internally seamless toe.  Custom-molded shoes without these characteristics have no proven value for diabetes.

3. Modifications of custom-molded and depth shoes: An individual may substitute modifications of custom-molded or depth shoes instead of obtaining a pair of inserts in any combination.  (Note: Payment for the modifications may not exceed the limit set for the inserts for which the individual is entitled).  The following is a list of the most common shoe modifications available, but it is not meant as an exhaustive list of the modifications available for diabetic shoes:

   • Inserts:

     Medically necessary inserts are those that are total contact, multiple densities, removable inlays that are directly molded to the member's foot or a model of the member's foot and are made of a material suitable for the member's condition.

   • Metatarsal bars:

     These are exterior bars that are placed behind the metatarsal heads in order to remove pressure from the metatarsal heads.  The bars are of various shapes, heights, and construction depending on the exact purpose.

   • Offset heels:

     This is a heel flanged at is base either in the middle, to the side, or a combination, that is then extended upward to the shoe in order to stabilize extreme positions of the hind foot.

   • Rigid rocker bottoms:

     These are exterior elevations with apex positions for 51 % to 75 % distance measured from the back end of the heel.  The apex is a narrowed or pointed end of an anatomical structure.  The apex must be positioned behind the metatarsal heads and tapering off sharply to the front tip of the sole.  Apex height helps to eliminate pressure at the metatarsal heads.  The steel in the shoe ensures rigidity.  The heel of the shoe tapers off in the back in order to cause the heel to strike in the middle of the heel.  

   • Roller bottoms (sole or bar):

     These are the same as rocker bottoms, but the heel is tapered from the apex to the front tip of the sole.    

   • Wedges (posting):

     Wedges are either of hind foot, fore foot, or both and may be in the middle or to the side.  The function is to shift or transfer weight upon standing or during ambulation to the opposite side for added support, stabilization, equalized weight distribution, or balance

4. Other medically necessary modifications to diabetic shoes include, but are not limited to:  

   • Flared heels;  
   • Inserts for missing toes; and  
   • Velcro closures.

Deluxe features of therapeutic shoes have no proven value.  A deluxe feature is defined as a feature that does not contribute to the therapeutic function of the shoe.  It may include, but is not limited to style, color, or type of leather.

Aetna considers Orpyx sensory insoles for reduction of diabetic foot ulcer recurrence experimental and investigaional because their effectiveness has not been established.

Note: Coverage is provided for a pair of diabetic shoes even if only 1 foot suffers from diabetic foot disease.

Prosthetic Shoes

Aetna considers shoes that are an integral part of a prosthesis medically necessary for members with a partial foot.  Note: Aetna does not cover stock shoes that are put on over a partial foot or other lower extremity prosthesis.

A prosthetic shoe is a device used when all or a substantial portion of the front part of the foot is missing.  A prosthetic shoe can be considered as a terminal device; i.e., a structural supplement replacing a totally or substantially absent hand or foot.  Terminal devices such as hooks and prosthetic shoes may be considered prosthetics in place of an artificial hand or foot.

Note: Medically necessary prosthetic shoes are covered even under plans that exclude foot orthotics.  The function of a prosthetic shoe is quite distinct from that of excluded orthopedic shoes and supportive foot devices that are used by individuals whose feet, although impaired, are essentially intact.   Please check benefit plan descriptions for details.

Rehabilitative Foot Orthotics Following Surgery or Trauma

Note: Even under plans that exclude coverage of foot orthotics, Aetna covers rehabilitative foot orthotics that are prescribed following foot surgery or trauma when the these rehabilitative foot orthotics are medically necessary as part of their post surgical or casting care.  In these instances, foot orthotics are considered an integral part of the covered surgical procedure or foot trauma repair.  For example, Aetna covers foot orthotics for infants and toddlers who have foot orthotics applied during the rehabilitative period immediately following surgery for congenital foot deformities and are receiving these foot orthotics as part of the post surgery or casting care.

Plans That Do Not Exclude Foot Orthotics

Note: For plans that do not exclude coverage of foot orthotics, Aetna covers foot orthotics when the medical necessity criteria below are met.  Please check benefit plan descriptions.

Foot orthotics are considered medically necessary for members who meet all of the following selection criteria:

1. Member has any of the following conditions:  

   1. Adults (skeletally mature feet)

      • Acute or chronic plantar fasciitis;
      • Acute sport-related injuries (including: diagnoses related to inflammatory problems; e.g., bursitis, tendonitis);
      • Calcaneal bursitis (acute or chronic);
      • Calcaneal spurs (heel spurs);
      • Chronic ankle instability;
      • Conditions related to diabetes (see section above on therapeutic shoes for diabetes for a complete list of medically necessary diagnoses);
      • Inflammatory conditions (i.e., sesamoiditis; submetatarsal bursitis; synovitis; tenosynovitis; synovial cyst; osteomyelitis; and plantar fascial fibromatosis);
      • Medial osteoarthritis of the knee;
      • Musculoskeletal/arthropathic deformities (including: deformities of the joint or skeleton that impairs walking in a normal shoe; e.g., bunions, hallux valgus, talipes deformities, pes deformities, hammertoes, anomalies of toes);
      • Neurologically impaired feet (including: neuroma; tarsal tunnel syndrome; ganglionic cyst; and neuropathies involving the feet, including those associated with peripheral vascular disease, diabetes, carcinoma, drugs, toxins, and chronic renal disease);
      • Vascular conditions (including: ulceration, poor circulation, peripheral vascular disease, Buerger's disease (thromboangiitis obliterans), chronic thrombophlebitis);

      Foot orthotics have no proven value for back pain, knee pain (other than medial osteoarthritis), pes planus (flat feet), pronation, corns and calluses, hip osteoarthritis, and lower leg injuries;

   2. Children (skeletally immature feet)

      • Hallux valgus deformities;
      • In-toe or out-toe gait;
      • Musculoskeletal weakness (e.g., pronation, pes planus);
      • Structural deformities (e.g., tarsal coalitions);
      • Torsional conditions (e.g., metatarsus adductus, tibial torsion, femoral torsion);

   and (for both adults and children)

2. The member must have symptoms associated with the particular foot condition (foot orthotics are not considered medically necessary when the foot condition does not cause symptoms); and   

3. The member has failed to respond to a course of appropriate conservative treatment (e.g., physical therapy, injections, strapping, anti-inflammatory medications). Orthotics should not be considered first line therapy.

Foot orthotics are considered experimental and investigational when these criteria are not met; and for treatment of joint hypermobility syndrome.

The following types of foot orthotics are considered medically necessary for the above listed indications:

1. Shoe modifications to standard non-orthopedic shoes, e.g., rocker soles, shoe buildups, metatarsal bars, shoe stretching, Thomas heels, tongue pads, velcro closures, modified lacers, etc., may be considered medically necessary to compensate for minor foot deformities.  Shoe modifications are medically prescribed alterants to shoes to accommodate minor foot deformities, disabilities, or leg shortening of less than 1.5 inches. 
2. Over-the-counter standard orthopedic Oxford shoes are considered medically necessary when the foot can reasonably be accommodated in this type of shoe.  A standard orthopedic Oxford is a prefabricated shoe that can accommodate an inlay.
3. Inlay shoes are considered medically necessary when shoe modifications will not accommodate the foot deformity and that an insole or additional space is needed.
4. Depth inlay shoes are pre-fabricated shoes with a higher toe box to accommodate for hammer toes and other foot deformities.  These shoes are usually made of plastizote or other pressure absorbing material.  Medically necessary depth inlay shoes (depth shoes) should meet criteria set forth in section above on therapeutic shoes for diabetes.
5. Healing or cast shoes are considered medically necessary when the foot can not be slipped into a standard shoe.  Replacement or repair of healing or cast shoes is usually not medically necessary since this shoe is normally needed for a short period of time.  Spare plastizole healing shoes are not considered medically necessary since these shoes are used for a short duration.
6. Molded shoes are considered medically necessary if no other type or shoe or modification adequately accommodates the foot deformity of condition.
7. Custom-made orthopedic shoes are considered medically necessary when the members needs can not be accommodated by other foot orthotics.  Custom-made orthopedic shoes are considered medically necessary when the severity of the foot condition is such that a lesser means, for example, inlay shoes, shoe modifications, etc., can not adequately compensate for the deformity or there is a leg discrepancy length of at least 1.5 inches or greater.  Custom-made orthopedic shoes are shoes fabricated over special modified lasts in accordance with prescriptions and specifications to accommodate gross or greater foot deformities or shortening of a leg of 1.5 inches or greater.  A last is a form which is shaped like a human foot over which a shoe is manufactured or repaired.  The severity of the foot deformity requires the physical presence of the member for casts, measurements, and trial fittings.
8. Modifications of custom-made/-molded, and depth shoes: An individual may substitute modifications of custom-made/-molded or depth shoes instead of obtaining a pair of inserts in any combination.  (Note: Payment for the modifications may not exceed the limit set for the inserts for which the individual is entitled).  See section on therapeutic shoes for diabetes for description of modifications to custom-molded and depth shoes.

One of the following per member per calendar year is considered medically necessary:

1. No more than 1 pair of custom-molded shoes (including inserts provided with the shoes) and 2 additional pairs of inserts; or 
2. No more than 1 pair of depth shoes and 3 pairs of inserts (not including the non-customized removable inserts provided with such shoes).

Note: Custom molded shoes and shoe modifications are also covered for diabetic patients who meet the criteria set forth in the section "Therapeutic Shoes for Diabetes", above.  For plans that do not exclude coverage of foot orthotics, over the counter orthotics are covered as supplies when medically necessary and prescribed by a physician.  Over-the-counter orthotics are considered medically necessary for short-term use (e.g., for a few weeks to a couple of months) for acute conditions.  They are not considered medically necessary if used to replace custom made orthotics that are for chronic, long-term use, as they would need to be replaced frequently.  Over-the-counter orthotics are not appropriate for children.

Spinal Pelvic Stabilizers (Foot Levelers, Inc.) are specialized custom molded inserts designed to prevent foot injuries and improve foot alignment; these are considered experimental and investigational because their value in treatment of foot disease has not been proven.

Shoe Modifications and Replacements

Medical necessity criteria for replacements of or modifications to existing customized shoes is based on the same criteria noted for the shoe itself.  Replacement of a pair of shoes, or modifications, should be based on necessity (e.g., worn out, loss of effectiveness), not for convenience or style change.  Due to wear and tear with normal use, orthotics may need refurbishing periodically, every 1 or 2 years.  Replacement of orthotics is generally not necessary more often than every 2 years.

Other Medical Necessity Limitations

Orthotic devices made on the same date as an open cutting surgical procedure (e.g., bunionectomy) are not considered medically necessary.  Only 1 orthotic per foot is considered medically necessary.  Separate orthotics for each pair of the member’s shoes are not considered medically necessary.

Apostherapy (Biomechanical Shoe-Like Device)

Aetna considers Apostherapy (biomechanical shoe-like device) for the management of various back, hip, and knee conditions experimental and investigational because its effectiveness has not been established.

UNFO-S (An Adductus-Positioning Device)

Aetna considers UNFO-S (an adductus-positioning device) for the management of metatarsus adductus and metatarsus varus experimental and investigaional becasue its effectiveness has not been established.

See also CPB 0565 - Ankle Orthoses, Ankle-Foot Orthoses (AFOs), and Knee-Ankle-Foot Orthoses (KAFOs).

Background

The terms used to describe orthotics were very confusing; often, clinicians used different terms to describe even the most basic device.  Devices or parts of orthoses were given names that might describe their purpose, the body part to which they were applied, the inventor of the device, or where they were developed.

To minimize confusion, a system of standard terminology has been developed.  The system uses the first letter of each joint that the orthosis crosses in correct sequence, with the letter "O" for orthosis at the end.  Thus, the more common orthoses would be named AFO (ankle-foot orthosis), KAFO (knee-ankle-foot orthosis), and KO (knee orthosis).  A properly written orthotic prescription does not just state the name of the orthosis; it also is necessary to state the desired function to be obtained, the specific material from which the device is to be made, and the specific design and construction that is to be employed.

Foot orthotics may be accommodative or functional.  Accommodative foot orthoses are custom or non-custom inlays fabricated for the purpose of providing relief from callosities and pressure points, and maintaining the integrity of the longitudinal arch and/or the metatarsal heads.  Functional foot orthoses are foot plates fabricated from plaster molds of the feet or electronic (computer) imaging in a semi-weight bearing or non-weight bearing, neutral position, with corrections built in to prevent abnormal compensation during the gait cycle.

Orthopedic shoes are shoes used to prevent or correct disorders of the bones, joints, muscles, ligaments and cartilage of the legs and feet. Custom-made orthopedic shoes are shoes fabricated over special modified lasts in accordance with prescriptions and specifications to accommodate gross or greater foot deformities or shortening of a leg at least 1 and 1/2 inches or greater.  Custom-made orthopedic shoes may be necessary when a physician or podiatrist determines that the severity of the foot condition is such that a lesser means (e.g., inlay shoes, shoe modifications, etc.) can not adequately compensate for the deformity or there is a leg discrepancy length at least of 1 and 1/2 inches in length or greater.  Initial custom-made orthopedic shoes, lasts, and patterns normally are obtained when the severity of the foot disability requires the physical presence of the member for casts, measurements, and possible trial fittings.

A shoe modification is a medically prescribed alteration(s) to a shoe(s) to accommodate minor foot deformities, disabilities, or leg shortening of less than 1 and 1/2 inches.  Shoe modifications (e.g., rocker soles, shoe buildups, metatarsal bars, shoe stretching, Thomas heels, tongue pads, velcro closures, modified lacers, etc.) may be applied to personally purchased shoes, upon medical determination of need, to compensate for minor foot deformities.

Depth inlay shoes are pre-fabricated shoes with a higher toe box to accommodate for hammer toes and other deformities.  This shoe may also accommodate the insertion of special inserts.  These shoes are traditionally made of plastizote or other pressure absorbent material.  Inlay shoes may be necessary after it has been determined that shoe modifications will not accommodate the foot deformity and that an insole or additional space is necessary.

Healing shoes are pre-fabricated shoes with a higher toe box to accommodate for hammer toes and other deformities.  This shoe may also accommodate the insertion of special inserts.  Healing and/or cast shoes may be necessary when the foot can not be slipped into a standard shoe.

Patterns are cardboard tracing (templates) comprising the shoe's upper and innersole components.

A last is a form which is shaped like the human foot over which a shoe is manufactured or repaired.

A standard orthopedic Oxford is a pre-fabricated shoes that can accommodate an inlay (e.g., dress, casual, and athletic shoes).  Over the counter (OTC) standard orthopedic Oxford (dress, casual, athletic) should be used when a foot can be reasonably accommodated in this type of shoe.

Orthotic Shoes or Orthopedic Shoes

Special shoes for certain unusual or abnormal foot conditions, to improve comfort and function.  They are created mostly for recreational use and for pathologic foot conditions.  This definition includes high-quarter shoes, or chukka boots, which cover the medial malleoli.

Reese Orthopedic Shoe is a canvas and wooden sole shoe used post-operatively to reduce motion in joints of the foot.  This shoe is also known as a Darby Shoe.

Clawson Rocker Shoes serve as a walking aid for patients with multiple sclerosis.

Straight Last Shoes serve as a corrective splint for metatarsus adductus.

Modifications of Stock Shoes

Shoe modifications can be classified as internal (i.e., those that are inserted into the inner surface of the shoe or sandwiched between shoe components) or external (i.e., those that are attached to the sole or heel).

Internal shoe modifications:

Inner shoe corrections include steel shanks, cookies (i.e., scaphoid and metatarsal pads), interior heel lifts and wedges, extended or reinforced heel counters, and protective metal toe boxes.

Shoe wedge is any device, generally constructed of leather that is placed on the side of the walking surface of a shoe or within the shoe construction itself, and not in direct contact with the foot.  The purpose of a shoe wedge is to re-distribute the flow of weight through the foot.

First Metatarsal Head is a wedge that extends on the medial side of the shoe from the breast of the heel to the first metatarsal head.

Full Lateral is a wedge on the outer side of the shoe; extending from the heel to the tip of the shoe.

Full Medial is a wedge on the medial (inner) side of the shoe, extending from the heel to the tip of the shoe.

Lateral Dutchman is a wedge that is placed on the lateral (outside) margin of the sole of the shoe.

Medial Dutchman is a wedge that is placed on the medial (inner) side of the sole of the shoe.

Medial Tip is a wedge placed on the medial (inner) side of the tip of the sole of the shoe.

Flanges or flare outs are 0.25-inch wide medial or lateral extensions of the sole or heel that provide rotatory stability.  A lateral flange provides a lever-arm, which ensures a foot flat in the presence of excessive inversion or varus deformity.  Such small lateral flanges are seen on most commercially available runner' shoes.

Elevations (i.e., lifts) are elevations of the sole or heel prescribed for leg length discrepancies.  Elevations of greater than 0.25 inches are placed externally.

Bars are a build-up on the exterior of the sole of the shoe (usually made of leather or rubber) to control distribution of weight to the foot.

Metatarsal bar is made of leather or rubber, and may be attached transversely to the outer sole immediately proximal to the metatarsal heads to relieve pressure on them and to reduce pain.

Kidney is a kidney-shaped metatarsal bar.

Rocker bar is placed similarly to the metatarsal bar, but extends distally beyond the metatarsal heads.  It relieves pressure on the metatarsal heads, and also reduces metatarsal phalangeal flexion on push-off by providing a smooth plantar roll to toe-off.

Denver bar is placed under the metatarsal bones to support the transverse arch extending from the metatarsal heads anteriorly to the tarsal metatarsal joints posteriorly.

Anterior heel is a bar that is effective in providing a broad distribution of weight.  The device consists of a leather raise extending from the front part of the shank where it meets the sole backward to half the distance of the shank.

Comma is a bar put on a shoe behind the metatarsal heads; it has the shape of a comma.  The posterior and lateral side of the bar is thicker and is positioned under the middle of the shank of the shoe.

Mayo is a bar cemented to the sole of the shoe proximal to the forefoot treading surface.

Thomas is a metatarsal bar 3/4" wide by 2/8" to 3/8" thick; the bar is skived thin at the posterior end and applied on the exterior of the sole of the shoe behind the metatarsal heads.  This provides for the relief of pressure off of the metatarsal heads.

External Heel Modifications

See heel elevations, wedges, and flanges under internal shoe modifications.

The heel of a shoe may vary in size, shape, height and construction.

The Thomas heel or the orthopedic heel is similar in design and material to the regular flat heel but has an anteriomedial extension to provide additional longitudinal arch support.  This extension may be of variable length, depending on the extent of the support required, and its effect may be augmented further by a medial wedge or a Thomas heel wedge.

Reverse Thomas heel is an antero-lateral extension to support a weak lateral longitudinal arch.

Heel cushion (e.g., the solid ankle cushion (SACH) heel) is made of compressible resilient materials, usually in conjunction with a rocker bar for cushioning effect on heel strike.

Extended is a heel with an anterior extension on the medial side.

Flared is a heel flared on either the medial, lateral, or posterior sides, or any combination of sides, allowing for a wider base to the heel to control the distribution of body weight to the foot and its gravitational center.

Wedge is a wedge of leather or other material added as an exterior or interior modification at the heel; to assist in balance or stabilization of the foot.  See section on wedges above.

Splints (Mechanical Bars)

Splints are mechanical devices applied to special shoes, comprised of an attachment of a stationary or movable adjustable bar between the shoes to control the position and the motion of the feet while standing and walking for the purpose of correcting foot deformities.

Brachman Splint is a movable bar attached to the shoes that permits reciprocal motion of the feet.

Dennis-Brown Bar is a non-movable or stationary bar attached to the shoes.

Filauer Bar is similar to a Dennis-Brown bar; the difference is that it has an adjustment that allows for an internal or external rotational position of the foot.

Friedman Bar is a leather rectangular bar that is attached to the back of the heels of the shoes to control in-toeing or out-toeing.

Gottler Splint is a device applied to a special shoe to prevent the forefoot from in-toeing (adducting).

Night Splint is an established therapeutic option for plantar fasciitis.

Plates

Plates are rigid type foot orthotics used for correction, stabilization and gait training of the foot.

Whitman's is a rigid appliance, made of stainless steel or plastic that acts as an action brace.  The appliance has a medial flange and lateral clip; no heel seat.  It extends distally to the first metatarsal head only and then laterally to the base of the 5th metatarsal.

Reverse Whitman's are the same as Whitman's; the difference is that an extension of metal or plastic goes to the fifth metatarsal head, instead of the first metatarsal head.

Robert's is a rigid appliance, usually metal or plastic, with a medial flange and lateral clip and heel seat.  The plate extends distally to all metatarsal heads.  Shaeffer is a custom-made rigid orthotic to stabilize the foot.

Foot Orthoses

Orthotics are mechanical devices which are placed in a shoe (shoe inserts) to assist in restoring or maintaining normal alignment of the foot, relieve stress from strained or injured soft tissues, bony prominences, deformed bones and joints, and inflamed or chronic bursae (e.g., arch supports).  Removable foot supports are placed inside the shoe to manage different foot symptoms and deformities.  The devices can be made of several different types of materials and are usually designed to the measurement, plaster models and patterns of the foot and leg.  They may be available commercially or may be custom-made.  The usual indications for foot orthoses are to relieve pressure on areas that are painful, ulcerated, scarred, or callused, to support weak or flat longitudinal or transverse foot arches, and to control foot positions and thus affect the alignment of other lower limb joints.  All are concerned with improving foot function, controlling foot motion, reducing shock absorption and minimizing stress forces that could ultimately cause foot deformity and pain.

Soft or flexible foot orthoses are made from soft compressible materials, such as leather, cork, rubber, soft plastics, or plastic foam (Spenco, PPT, Pelite).  Many of these are commercially available and used for simple problems.  Soft orthotics help to absorb shock, increase balance, and take pressure off uncomfortable or sore spots.  Soft foot orthoses are worn against the sole of the foot and are usually fabricated in full length from heel to toe with increased thickness where weight bearing is indicated and relief where no or little pressure should occur.  Plastic foam orthoses are available in different density and thickness and are commonly used for ischemic, insensitive, ulcerated, and arthritic feet.  The advantage of any soft orthotic is that it may be easily adjusted to changing weight-bearing forces.  The disadvantage is that it must be replaced more often than rigid orthotics.  A soft orthotic is particularly effective for diabetes, the arthritides and for grossly deformed feet where there is the loss of protective fatty tissue on the side of the foot. Soft orthotics are also widely used in the care of healing ulcers in the insensitive foot.

Semi-rigid and rigid orthoses come in a variety of materials such as leather, cork, and metals, but most commonly they are made of solid plastics, which allow minimal flexibility.  These orthoses generally extend from the posterior end of the heel to the metatarsal heads (i.e., 3/4 length), and may have medial or lateral flanges.  They are molded to provide support under the longitudinal arch and metatarsal area and to provide relief for painful or irritated areas.  The most rigid foot orthoses (e.g., Whitman, Mayer, and Shaffer plates; Boston arch supports) are made of metal, usually steel or duralumin, and are covered with leather.

Rigid orthotics are designed to control function.  They are made of a firm material such as plastic, leather, fiberglass or acrylic polymer.  The finished device normally extends along the sole of the heel to the ball or toes of the foot.  It is worn mostly in closed shoes with a heel height under 2 inches.  Rigid orthotics are chiefly designed to control motion in 2 major foot joints, which lie directly below the ankle joint.  These devices are long-lasting, do not change shape, and are usually unbreakable.  Strains, aches, and pains in the legs, thighs, and lower back may be due to abnormal function of the foot or a slight difference in the length of the legs.  In such cases, orthoses may improve or eliminate these symptoms which at first may seem only remotely connected to foot function.  Molded polypropylene orthoses (foot/ankle/leg) are used to manage spastic and flaccid paralysis due to neurodeformities (e.g., cerebral palsy).

Semi-rigid orthotics provide for dynamic balance of the foot while walking or participating in sports.  Each sport has its own demand and each orthotic needs to be constructed appropriately with the sport and the athlete taken into consideration.  The functional dynamic orthotic helps guide the foot through proper functions, allowing the muscles and tendons to perform more efficiently.  The classic, semi-rigid orthotics constructed using laminations of leather and cork, reinforced by a material called Silastic.  It may also be made of polymer composites.

Strappings, paddings, and appliances may be applied directly to the foot and toes to correct deformities and protect tender areas such as corns, calluses, ulcers, nails, and bony outgrowths from excessive friction or pressure.

Gelis et al (2008) developed clinical practice guidelines for the use of foot orthoses (FO) in the treatment of knee and hip osteoarthritis (OA).  The French Physical Medicine and Rehabilitation Society's methodology, associating a systematic review of the literature, input from everyday clinical practice and external review by a multi-disciplinary expert committee, was employed.  The selected analysis criteria were pain, disability, medications used as well as X-ray evolution of OA.  Recommendations were classified according to the level of proof in grade A, B or C according to the French National Agency for Health Accreditation and Evaluation.  In medial knee OA, foot pronation orthotics – when there are no contraindications – can be proposed for their symptomatic impact, especially in the decrease of non-steroidal anti-inflammatory drugs consumption (grade B).  To this day, there is no evidence of a structural or functional impact on OA (grade B).  Outside of this specific clinical framework, there is no validated indication for prescribing FO in the treatment of knee or hip OA (grade C).  The authors concluded that it is necessary to have further randomized controlled trials (RCTs) to better define the indication of FO (severity of knee OA, genu varum), test the efficacy of other orthoses such as cushioning FO.  The long-term side effects, mainly on the external femoro-tibial compartment could also be assessed.  A medical and economical assessment of FO prescriptions is also quite necessary.

Hume and associates (2008) reviewed the effectiveness of FO for treatment and prevention of lower limb injuries.  Qualifying studies were mainly controlled trials, but some uncontrolled clinical trials of patients with chronic injuries were analyzed separately.  Injuries included plantar fasciitis, tibial stress fractures and patello-femoral pain syndrome; these were included because of the large treatment costs for these frequent injuries in New Zealand.  Outcomes were pain, comfort, function and injury status.  Continuous measures were expressed as standardized differences using baseline between-subject standard deviations, and magnitudes were inferred from the intersection of 90 % confidence intervals (CIs) with thresholds of a modified Cohen scale.  Effects based on frequencies were expressed as hazard ratios and their magnitudes were inferred from intersection of CIs with a novel scale of thresholds.  The effects of FO for treatment of pain or injury prevention were mostly trivial.  Foot orthoses were not effective in treating or preventing patello-femoral pain syndrome.  Some studies showed moderate effects for treatment of plantar fasciitis.  Only a few studies showed moderate or large beneficial effects of FO in preventing injuries.  Customized semi-rigid FO have moderate to large beneficial effects in treating and preventing plantar fasciitis and posterior tibial stress fractures, and small to moderate effects in treating patello-femoral pain syndrome.  Given the limited RCTs or clinical controlled trials available for the injuries of interest, it may be that more or less benefit can be derived from the use of FO, but many studies did not provide enough information for the standardized effect sizes to be calculated.  The authors stated that further research with RCTs is needed to establish the clinical utility of a variety of FO for the treatment and prevention of various lower limb injuries.  In this regard, Vicenzino et al (2008) reported that a single-blinded RCT will be conducted to investigate the clinical efficacy and cost effectiveness of FO in the management of patello-femoral pain syndrome.

Foot Orthoses for the Treatment of Plantar Heel Pain

In a systematic review and meta-analysis, Whittaker and associates (2018) examined the effectiveness of foot orthoses for pain and function in adults with plantar heel pain.  The primary outcome was pain or function categorized by duration of follow-up as short (0 to 6 weeks), medium (7 to 12 weeks) or longer term (13 to 52 weeks).  Data sources included Medline, CINAHL, SPORTDiscus, Embase and the Cochrane Library from inception to June 2017.  Studies must have used a randomized parallel-group design and evaluated foot orthoses for plantar heel pain.  At least 1 outcome measure for pain or function must have been reported.  A total of 19 trials (1,660 participants) were included.  In the short-term, there was very low-quality evidence that foot orthoses did not reduce pain or improve function.  In the medium-term, there was moderate-quality evidence that foot orthoses were more effective than sham foot orthoses at reducing pain (standardized mean difference {SMD] -0.27 (95 % CI: -0.48 to -0.06)).  There was no improvement in function in the medium-term.  In the longer term, there was very low-quality evidence that foot orthoses did not reduce pain or improve function.  A comparison of customized and pre-fabricated foot orthoses showed no difference at any time-point.  The author concluded that this review found moderate-quality evidence that foot orthoses were more effective at reducing pain than sham foot orthoses in the medium-term (from 7 to 12 weeks).  However, the effect size was small, so it was uncertain whether this reduction in pain was clinically important for patients.  No evidence was found that foot orthoses were effective in the short-term or longer-term at reducing pain (including “first step” pain) or improving function.  In addition, this review found no difference between customized and pre-fabricated foot orthoses, or between soft and firm foot orthotic materials, for reducing pain or improving function.  Aside from the findings in the medium-term, the evidence that these conclusions were drawn from was of very low to low quality, so there is the possibility that future trials of a higher quality may change some of the findings of this review.The authors noted that there were several limitations that need to be considered when interpreting the findings.  There was a lack of data relating to short-term or longer-term findings (time-points before 6 weeks and after 12 weeks).  Only 3 trials reported data that could be included in a meta-analysis in the short-term, and only 2 trials reported data in the longer-term.  In addition, incomplete reporting in the included trials resulted in down-graded evidence quality and also reduced the potential data available for meta-analyses.  GRADE has highlighted that the evidence for the effectiveness of foot orthoses for PHP ranged between very low and moderate quality for the most important outcomes reported in this review.  Furthermore, there was considerable intervention variability, as none of the included trials evaluated the same foot orthosis.  Because of this, a wide variety of materials, arch contours, methods of casting and prescription have been evaluated.  This may result in heterogeneity when comparing studies, leading to reduced effect sizes and limited evidence regarding which design characteristics of a foot orthosis are most effective.In a systematic review and meta-analysis, Rasenberg and colleagues (2018) examined the effects of different orthoses on pain, function and self-reported recovery in patients with plantar heel pain (PHP) and compared them with other conservative interventions.  A systematic literature search was conducted in Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, CINAHL and Google Scholar up to January 2017; RCTs comparing foot orthoses with a control (defined as no intervention, sham or other type of conservative treatment) reporting on pain, function or self-reported recovery in patients with PHP were selected for analysis.  A total of 20 studies investigating 8 different types of foot orthoses were included in the review.  Most studies were of high quality.  Pooled data from 6 studies showed no difference between pre-fabricated orthoses and sham orthoses for pain at short-term (MD of 0.26 (95 % CI: -0.09 to 0.60)).  No difference was found between sham orthoses and custom orthoses for pain at short-term (MD 0.22 (95 % CI: -0.05 to 0.50)), nor was there a difference between pre-fabricated orthoses and custom orthoses for pain at short-term (MD 0.03 (95 % CI: -0.15 to 0.22)).  For the majority of other interventions, no significant differences were found.  The authors concluded that foot orthoses were not superior for improving pain and function compared with sham or other conservative treatment in patients with PHP.Furthermore, an UpToDate review on “Plantar fasciitis” (Buchbinder, 2018) states that “The efficacy of foot orthoses remains controversial, and there are considerable variations in the prescribing habits of podiatrists, orthopedists, and prosthetists”.

Foot Orthotics for Joint Hypermobility Syndrome

McDermott and colleagues (2018) stated that joint hypermobility syndrome (JHS) in children, presents with increased joint range of motion (ROM) and can lead to altered gait strategies and reduced dynamic balance.  Despite limited evidence foot orthoses are sometimes prescribed to patients with JHS with the aim to improve the stability of their gait pattern and theoretically reduce associated symptoms of fatigue and joint pain.  These researchers analyzed the immediate effects of “off the shelf'” orthoses on temporo-spatial parameters of gait and dynamic balance in this cohort.  A total of 21 patients were recruited for the study (13 female) with a median age of 10 years (IRQ = 4.12).  Each patient had their gait analyzed using the GAITRite walkway in their own footwear and immediately after being prescribed the orthoses.  Gait was tested at both the patients' preferred speed and when asked to walk slower to challenge their dynamic balance.  Gait appeared more synchronized, with a reduction in step length and width variability, when participants were provided with orthotics.  The variation was greatest when participants were asked to walk slower.  Double stance was significantly less at slower speeds when orthotics were added (1.61 %, 95 % CI: 0.34 to 2.89, p = 0.015). The authors concluded that the findings of this study indicated that orthotics had a definite immediate influence on gait patterns in patients with JHS.  Moreover, they stated that future studies should investigate the long-term effects of orthotics in this population and include outcome measures for symptoms such as pain.

Low Back Pain

Papuga and Cambron (2016) evaluated the literature on the use of foot orthotics for low back pain (LBP) and made specific recommendations for future research. Database searches were conducted using PubMed, EBSCO, GALE, Google Scholar, and clinicaltrials.gov.  The biomedical literature was reviewed to determine the current state of knowledge on the benefits of foot orthotics for LBP related to biomechanical mechanisms and clinical outcomes.  It may be argued that foot orthotics are experimental, investigational, or unproven for LBP due to lack of sufficient evidence for their clinical effectiveness.  This conclusion is based upon lack of high quality RCTs.  However, there is extensive research on biomechanical mechanisms underlying the benefits of orthotics that may be used to address this gap.  Additionally, promising pilot studies are beginning to emerge in the literature and ongoing large-scale RCTs are addressing effects of foot orthotics on chronic LBP.  The authors concluded that based upon the critical evaluation of the current research on foot orthotics related to biomechanical mechanisms and clinical outcomes, recommendations for future research to address the evidence-practice gaps on the use of foot orthotics for LBP were presented.

Chronic Ankle Instability

Gabriner and colleagues (2015) stated that chronic ankle instability (CAI) is a condition commonly experienced by physically active individuals. It has been suggested that foot orthotics may increase a CAI patient's postural control.  These investigators reviewed the evidence to examine if an orthotic intervention will help improve postural control.  The literature was searched for studies of level 2 evidence or higher that investigated the effects of foot orthotics on postural control in patients with CAI.  The search of the literature produced 5 possible studies for inclusion; 2 studies met the inclusion criteria and were included – 1 RCT and 1 outcomes study were included.  Foot orthotics appeared to be effective at improving postural control in patients with CAI.  The authors concluded that there is moderate evidence to support the use of foot orthotics in the treatment of CAI to help improve postural control.  They noted that the Centre of Evidence Based Medicine recommended a grade of B for level 2 evidence with consistent findings.

Furthermore, an UpToDate review on “Ankle sprain” (Maughan, 2016) states that “Options for primary or secondary prevention of ankle injuries include external ankle supports (e.g., semi-rigid orthoses, lace up supports, and high-top shoes), taping, stretching, strengthening, and proprioceptive ankle training using a wobble board and other techniques”.

Ankle-Foot Orthoses

Ankle-foot orthoses are most commonly prescribed for muscle weakness affecting the ankle and subtalar joints, such as weakness of the dorsi and plantar flexors, invertors, and evertors.  Ankle-foot orthoses can also be prescribed for prevention or correction of deformities of the foot and ankle and reduction of weight-bearing forces.  In addition to having mechanical effects on the ankle, the AFOs may affect the stability of the knee by varying the degree of plantar or dorsiflexion at the ankle.  An ankle fixed in dorsiflexion will provide a flexion force at the knee and thus may help to prevent genu recurvatum; a fixed plantarflexion will provide an extension force that may help to support a weak knee during the stance phase of gait.  Although traditional metal orthoses still are prescribed, plastic ankle-foot orthoses are more common.  Inexpensive, ready to use AFOs are widely available and useful for minor or temporary deficits, but custom-made orthoses are indicated for more severe and permanent deficits.  Plastic AFOs are worn inside the shoe and consist of the footplate, an upright component, and a Velcro calf strap.  The upright components on plastic AFOs vary in design, depending on the desired function, but usually these extend from the footplate without a joint mechanism to the upper calf approximately 1 to 2 inches below the head of the fibula.

Metal AFOs usually have both medial and lateral uprights with an ankle joint mechanism.  The uprights are attached to the shoe by a stirrup and secured to the calf by a padded leather-covered calf band, leather strap, and a buckle.  Sturdy shoes, such as orthopedic shoes, are required for metal orthoses.  The stirrups usually are attached directly to the shoe between the sole and heel, although the footplate inside the shoe occasionally is used.  The upper end of the stirrup connects with the uprights at the ankle joint.  The solid stirrup is used most commonly and provides the most rigid and least bulky shoe attachment.  The split stirrup allows transfer of the orthosis to any shoe with a flat caliper insertion.  Knee-ankle-foot orthoses: Knee-ankle-foot orthoses are prescribed to provide knee stability for weight bearing in the presence of severe lower limb weakness due to upper or lower motor neuron disease.

Figueiredo et al (2008) performed a literature review evaluating the quality of current research on the influence of AFOs on gait in children with cerebral palsy (CP).  Two between-group and 18 within-group studies met the inclusion criteria indicating a low level of evidence.  Between-group studies each scored "4" on the PEDro Scale, and 17 within-group studies scored "3" and 1 scored "2", indicating low quality.  Standard terminology for AFOs was not used and only 6 studies described functional status using appropriate instruments.  The authors concluded that studies using high quality methods are still needed to support evidence-based decisions regarding the use of AFOs for this population.

Hip-Knee-Ankle-Foot Orthoses

Hip-knee-ankle-foot orthoses consist of the same components as described for the standard AFOs and KAFOs, with the addition of an attached lockable hip joint and a pelvic band to control movements at the anatomic hip joint.

Fracture Orthoses

Latex Shield is a protective shield made to the plaster model of a patient's toe or part of the foot.  The materials used are latex, rubber paddings and nylon or chamois.  It is used to protect a deformity from pressure.

Lateral Wedge Insoles for Knee Osteoarthritis

In a randomized study, Toda and Tsukimura (2006) evaluated the effect of wearing a lateral wedged insole with a subtalar strap for 2 years in patients with OA varus deformity of the knee (knee OA).  A total of 61 female outpatients with knee OA who completed a prior 6-month study were asked to wear their respective insoles continuously as treatment during the course of the 2-year study.  The femoro-tibial angle (FTA) was assessed by standing radiographs obtained while the subjects were barefoot and the Lequesne index of the knee OA at 2 years was compared with those at baseline in each insole group.  A total of 13 patients (21.3 %) did not want to wear the insole continuously and 5 (8.2 %) withdrew for other reasons.  The 42 remaining patients who completed the 2-year study were evaluated.  At the 2-year assessment, participants wearing the subtalar strapped insole (n = 21) demonstrated significantly decreased FTA (p = 0.015), and significantly improved Lequesne index (p = 0.031) in comparison with their baseline assessments.  These significant differences were not found in the group with the traditional shoe inserted wedged insole (n = 21).  The authors concluded that only those subjects using the subtalar strapped insole demonstrated significant change in the FTA in comparison with the baseline assessments.  If the insole with a subtalar strap maintains FTA for more than 2 years, it may restrict the progression of degenerative articular cartilage lesions of knee OA.

Shimada et al (2006) examined the effects of lateral wedged insoles on knee kinetics and kinematics during walking, according to radiographic severity of medial compartment knee OA.  A total of 46 medial compartment knees with OA of 23 patients with bilateral disease and 38 knees of 19 age-matched healthy subjects as controls were included in this study.  These investigators measured the peak external adduction moment at the knee during the stance phase of gait and the first acceleration peak after heel strike at the lateral side of the femoral condyles.  Kellgren and Lawrence grading system was used for radiographical assessment of OA severity.  The mean value of peak external adduction moment of the knee was higher in OA knees than the control.  Application of lateral wedged insoles significantly reduced the peak external adduction moment in Kellgren-Lawrence grades I and II knee OA patients.  The first acceleration peak value after heel strike in these patients was relatively high compared with the control.  Application of lateral wedged insoles significantly reduced the first acceleration peak in Kellgren-Lawrence grades I and II knee OA patients.  The authors concluded that the kinetic and kinematic effects of wearing of lateral wedged insoles were significant in Kellgren-Lawrence grades I and II knee OA.  The results support the recommendation of use of lateral wedged insoles for patients with early and mild knee OA.

Kuroyanagi et al (2007) compared the use of 2 lateral wedged insoles (one with, and the other without subtalar strapping) in patients with medial knee OA.  A total of 21 patients (aged 58 to 83 years, mean 7of 2) with medial knee OA were enrolled.  Thirty-seven knees in the patients were divided into 3 groups based on the Kellgren and Lawrence OA grading system; grades 2 (n = 20), 3 (n = 11), and 4 (n = 6).  Subjects were tested during walking barefoot and during walking with a silicon rubber lateral wedged insole with elevation of 10 mm attached to a barefoot.  Gait analysis was performed on a 10-m walkway for each subject under 3 different walking conditions:

1. barefoot,
2. wearing a conventional insole, and
3. a subtalar strapping insole. 

Peak knee varus moment during gait was measured under each condition, and compared between the 3 conditions and between the OA grades.  On the whole (n = 37), the peak varus moment was significantly reduced by wearing either of the insoles, compared to walking barefoot.  The reduction was more obvious with the strapping insole (-13 %, p < 0.01), compared with the conventional insole (-8 %, p < 0.05).  In moderate OA patients (grades 2 and 3), the moments were significantly lower with the strapping insole, compared with the conventional insole (p = 0.0048 and 0.005, respectively).  However, no significant difference was detected in severe OA patients (grade 4) between the 2 types of insoles (p = 0.4).  The authors concluded that both lateral wedged insoles significantly reduced the peak medial compartment load during gait.  The subtalar strapping insole had a greater effect than the conventional insole, particularly in patients with moderate medial knee OA.

A guideline on OA of the knee published by the Singapore Ministry of Health (2007) stated that lateral wedge insoles (tilt angle of 8.5 to 11 degrees) should be used to provide pain relief for patients with OA of the knee with medial OA symptoms.

Apostherapy (Biomechanical Shoe-Like Device)

Rosen (2009) stated that AposTherapy is a non-invasive, biomechanical therapy that is intended to rehabilitate the pathological gait patterns of patients with knee osteo-arthritis (OA).  It is performed in the patient's own environment and during daily activities.  The therapy is based on a unique technology that enables manipulation of the center of pressure under the foot which thereby modifies the moments acting on the joints of the lower extremity, pelvis and spine.  Throughout therapy the patients are carefully monitored for changes in gait, pain and function.

Bar-Ziv et al (2010) examined the effect of treatment with a novel biomechanical device on the level of pain and function in patients with knee osteoarthritis (OA).  Patients with bilateral knee OA were enrolled to active and control groups.  Patients were evaluated at baseline, at 4 weeks and at the 8-week end-point.  A novel biomechanical device was individually calibrated to patients from the active group.  Patients from the control group received an identical foot-worn platform without the biomechanical elements.  Primary outcomes were the Western Ontario and McMaster Osteoarthritis Index (WOMAC) and Aggregated Locomotor Function (ALF) assessments.  There were no baseline differences between the groups.  At 8 weeks, the active group showed a mean improvement of 64.8 % on the WOMAC pain scale, a mean improvement of 62.7 % on the WOMAC function scale, and a mean improvement of 31.4 % on the ALF scale.  The control group demonstrated no improvement in the above parameters.  Significant differences were found between the active and control groups in all the parameters of assessment.  The authors concluded that the biomechanical device and treatment methodology was effective in significantly reducing pain and improving function in knee OA patients.  Moreover, they stated that future studies should examine the long-term effect of the device on patients with medial compartment knee OA and patients with other musculoskeletal pathologies.

The authors noted that this study lacked randomization in the assignment of the patients to control and active groups.  Although both the active and the control group were similar in their characteristics and in the measured variables at baseline, future studies should implement a randomization procedure in assigning patients to control and active groups.  Patients in this study were told not to consume any medications aside from the rescue pills given to them at the start of the study.  This was done in order to evaluate the effectiveness of the device as a stand-alone treatment without the use of any other interventions or medications.  Since the authors could not ask patients to refrain from taking medications for a long period of time, they made the study only 8 weeks.  The control group in this study did not demonstrate any placebo effect.  This may be explained in 2 ways.  First, because according to the protocol the control group was told to walk with the device even while in pain, these researchers assumed that this worsened their symptoms and balanced out any placebo effect.  Second, it may be that any placebo effect only occurred in the first 2 weeks and as a result the first evaluation at 4 weeks did not capture the placebo effect.

Drexler and associates (2012) noted that previous studies have shown that a customized biomechanical therapy can improve symptoms of knee OA.  These studies were small and did not compare the improvements across gender, age, body mass index (BMI) or initial severity of knee OA.  These researchers examined the effect of new biomechanical therapy on the pain, function and quality of life (QOL) of patients with medial compartment knee OA.  A total of 654 patients with medial compartment knee OA were examined before and after 12 weeks of a personalized biomechanical therapy (AposTherapy).  Patients were evaluated using the WOMAC and Short Form 36 (SF-36) Health Survey.  After 12 weeks of treatment, the WOMAC-pain and WOMAC-function subscales were significantly lower compared to baseline (both p ≤ 0.001).  All 8 categories of the SF-36 health survey significantly improved after treatment (all p ≤ 0.001).  Females and younger patients showed greater improvements with therapy.  The authors concluded that patients with medial compartment knee OA treated by AposTherapy for 12 weeks showed statistically and clinically significant improvements in pain, function and QOL; these researchers stated that AposTherapy may be a useful tool for treating patients with medial compartment knee OA.  Moreover, these investigators stated that the success rate of AposTherapy was measured based on the changes in the self-reported questionnaires and showed an overall 80 % of improvement in pain and function after 3 months; however, this clinical value cannot be fully determined by this study and should be further examined in future studies.

The authors stated that this study had several drawbacks.  First, the study lacked a control group.  Second, the study had a short follow-up duration (12 weeks) and as such can only stand as evidence to the short-term effects of this therapy.  The results of this study supported the findings of previous examinations of this therapy; thus, it may be assumed that this therapy has a true impact on the patients rather than a placebo effect or simply part of the natural evolution of the disease.  Nevertheless, future studies should examine the long-term effects of this therapy.  Third, this study did not include radiographic assessment of the patients’ knees.  Radiographic evaluation of structural changes in the knee joint is an integral process in knee OA assessment.  The correlation, however, between structural severity and knee OA symptoms is poor.  The purpose of this study was to examine the clinical effect of this therapy in patients with knee OA; thus, these researchers did not find it relevant to incorporate radiographic evaluation.  Future studies should examine the effect of this therapy on structural changes at the knee joint.  Fourth, the study only examined the effects of AposTherapy on patients with medial compartment knee OA.  These researchers stated that further work is needed to ascertain how AposTherapy affects patients with other types of knee OA.

Bar-Ziv et al (2013) noted that several biomechanics treatments for knee OA have emerged with the goal of reducing pain and improving function.  Through this, researchers have hoped to achieve a transition from the pathological gait patterns to coordinated motor responses.  These researchers determined the long-term effects of a therapy using a biomechanical device in patients with knee OA.  Patients with knee OA were enrolled to active and control groups.  The biomechanical device used in therapy (AposTherapy) was individually calibrated to each patient in the active group.  Patients in the control group received standard treatment.  Outcomes were the WOMAC, ALF, Short Form 36 (SF-36), and Knee Society Score assessments.  The active and control groups were similar at the baseline (group difference in all scores p > 0.05).  The active group showed a larger improvement over time between groups in all 3 WOMAC categories (F = 16.8, 21.7, and 18.1 for pain, stiffness, and function; all p < 0.001), SF-36 Physical Scale (F = 5.8; p = 0.02), Knee Society Knee Score (F = 4.3; p = 0.044 ), and Knee Society Function Score (F = 6.5; p = 0.014 ).  At the 2-year end-point, the active group showed significantly better results (all p ≤ 0.001).  The groups showed a difference of 4.9, 5.6, and 4.7 for the WOMAC pain, stiffness, and function scores, respectively, 10.8 s in ALF score, 30.5 in SF-36 Physical Scale, 16.9 in SF-36 Mental Scale, 17.8 in Knee Society Knee Score, and 25.2 in Knee Society Function Score.  The authors concluded that the biomechanical therapy examined was shown to significantly reduce pain and improve function and QOL of patients with knee OA over the long-term.

The authors stated that there were 2 main drawbacks to the present study.  Firstly, in contrast to their previous study, the present study was unblended, and the 2 groups were not randomized.  Nevertheless, the 2 groups were equal at the baseline in terms of patient characteristics and clinical outcomes.  Secondly, due to the study logistics, the control group could only be asked to arrive for a follow-up exam at 2 years without evaluations before then.  This limited the authors’ knowledge of how this group faired over time.  Moreover, they stated that there were several ways in which the study could have been improved.  The study could have attempted to discontinue treatment with the device to see if the improvements were maintained without therapy.  This addition to the study could allow researchers to determine if and when the therapy can be terminated.  This may test whether the patients acquired a new action that they will maintain on their own or whether the patients need continuous training to maintain their new gait patterns.  The present study could also benefits from spatiotemporal, kinetic, and kinematic gait analyses of the patients over time when the treatment device is removed.  This could help determine which, if any, changes in gait the body's motor learning system is able to acquire from therapy.

In a pilot study, Segal et al (2013) examined the effect of a foot-worn biomechanical device on the clinical measurements and gait patterns of patients with total hip arthroplasty (THA).  A total of 19 patients, up to 3 months post-THA, were enrolled to the study.  Patients underwent a computerized gait analysis to calculate spatiotemporal parameters and completed the WOMAC and the SF-36 health survey.  Patients then began therapy with a non-invasive foot-worn biomechanical device coupled with a treatment methodology (AposTherapy).  Patients received exercise guidelines and used the device daily during their regular activities at their own environment.  Follow-up examinations were conducted after 4, 12, and 26 weeks of therapy.  Repeated measures ANOVA was used to evaluate changes over time.  The clinical significance of the treatment effect was evaluated by computing the Cohen's effect sizes (ES statistic).  After 26 weeks of therapy, a significant improvement was seen in gait velocity (50.3 %), involved step length (22.9 %), and involved single limb support (16.5 %).  Additionally, a significant reduction in pain (85.4 %) and improvement in function (81.1 %) and QOL (52.1 %) were noted.  The authors concluded that the results of this study showed promising outcomes including significant improvements in gait patterns, functional tests, and self-evaluation questionnaires; however, future RCT's are needed.  These RCT's should include a comparison of this therapy modality to other common modalities and also compare this therapy with a group of healthy controls.  This will help determine and relate the improvement to the therapy.

Elbaz et al (2014) stated that previous studies have shown the effect of a unique therapy with a non-invasive biomechanical foot-worn device (AposTherapy) on Caucasian Western population suffering from knee osteoarthritis (OA).  These researchers examined the effect of this therapy on the level of symptoms and gait patterns in a multi-ethnic Singaporean population suffering from knee OA.  A total of 58 patients with bilateral medial compartment knee OA participated in the study.  All patients underwent a computerized gait test and completed 2 self-assessment questionnaires (WOMAC and SF-36).  The biomechanical device was calibrated to each patient, and therapy commenced.  Changes in gait patterns and self-assessment questionnaires were re-assessed after 3 and 6 months of therapy.  A significant improvement was observed in all of the gait parameters following 6 months of therapy.  Specifically, gait velocity increased by 15.9 %, step length increased by 10.3 %, stance phase decreased by 5.9 %, and single limb support phase increased by 2.7 %.  In addition, pain, stiffness and functional limitation significantly decreased by 68.3 %, 66.7 % and 75.6 %, respectively.  SF-36 physical score and mental score also increased significantly following 6 months of therapy (46.1 % and 22.4 %, respectively) (p < 0.05 for all parameters).  The authors concluded that Singaporean population with medial compartment knee OA demonstrated improved gait patterns, reported alleviation in symptoms and improved function and quality of life (QOL) following 6 months of therapy with a unique biomechanical device.

The authors stated that this study had several drawbacks.  First, the study lacked a control group.  A previous study, however, by Bar-Ziv et al (2010) had already demonstrated the positive effect of this therapy compared to a control group in a double-blind study.  Second, this study did not include radiographic assessment of the patients’ knees.  Radiographic evaluation of structural changes in the knee joint is an integral process in knee OA assessment.  The correlation, however, between structural severity and knee OA symptoms is poor.  Third, the study examined patients with medial compartment knee OA; hence, the results were applicable for this type of knee OA.  Furthermore, this study included patients with severe degenerative changes to the knee joint that may have biased the results as other compartments of the knee were also involved.  These investigators stated that future studies should examine the effect of this therapy on structural changes at the knee joint and should also examine the effect of this therapy in patients with lateral/anterior knee OA and in patients with different knee alignment (varus / valgus).  Finally, follow-up period was relatively short (3 to 6 months).  A recent long-term follow-up study by Bar-Ziv et al (2013) demonstrated maintenance of improved symptoms in patients with medial knee OA; however, this should be applied on the Singaporean population and include gait assessment.

In a retrospective analysis, Atoun et al (2016) examined the effect of a non-invasive, home-based biomechanical treatment program for patients with spontaneous osteonecrosis of the knee (SONK).  A total of 17 patients with SONK, confirmed by MRI, participated in this trial.  Patients underwent a spatio-temporal gait analysis and completed the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the Short-Form-36 (SF-36).  Following an initial assessment, patients commenced the biomechanical treatment (AposTherapy).  All patients were re-assessed after 3 and 6 months of treatment.  A significant reduction in pain and improvement in function was observed after 3 months of therapy with additional improvement after 6 months of therapy.  Pain was reduced by 53 % and functional limitation reduced by 43 %.  Furthermore, a significant improvement was also found in the SF-36 subscales, including the summary of physical and mental scores.  Significant improvements were found in most of the gait parameters including a 41 % increase in gait velocity and a 22 % increase in step length.  Patients also demonstrated improvement in limb symmetry, especially by increasing the single limb support of the involved limb.  The authors concluded that applying this therapy allowed patients to be active, while walking more symmetrically and with less pain.  With time, the natural course of the disease alongside the activity of the patients with the unique biomechanical device led to a significant reduction in pain and improved gait patterns.  Thus, these researchers believed AposTherapy should be considered as a therapeutic option for patients with SONK.

The authors stated that this study had several drawbacks.  First, this was a single cohort study with no control group.  The lack of a control group made it difficult to conclude that the treatment was better than other alternatives.  However, this study presented a positive trend and should be considered as an additional non-invasive therapeutic option for patients with SONK.  It should be emphasized that none of the patients needed any surgical intervention during the follow-up period.  These investigators acknowledged that further research is needed and recommended that a future study should examine the effect of treatment for patients with SONK in a randomized controlled trial (RCT).  This will support the preliminary results of the current study.  Second, this was a retrospective analysis of patients seeking treatment at a private clinic.  As such, the study population may have been biased to those who were exposed to this clinic rather than the entire population.  These investigators postulated that this had a minor effect on the results and that the group’s characteristics were good representatives of the population.  Third, this study monitored the changes in objective gait patterns and clinical outcomes.  Having a RCT with an additional MRI assessment of the involved knee after 6 months would have given a clearer picture of the changes in the knee joint over time.

Debbi et al (2019) noted that biomechanics after total knee arthroplasty (TKA) often remain abnormal and may lead to prolonged post-operative recovery.  In a randomized controlled trial (RCT), these researchers examined a biomechanical therapy (the Apos System) following TKA.  This trial included 50 patients after unilateral TKA.  One group underwent a biomechanical therapy in which subjects followed a walking protocol while wearing a foot-worn biomechanical device (BD) that modifies knee biomechanics and the control group followed a similar walking protocol while wearing a foot-worn sham device.  All subjects had standard physical therapy post-operatively as well.  Patients were evaluated throughout the 1st post-operative year with clinical measures and gait analysis.  Improved outcomes were observed in the biomechanical therapy group compared to the control group in pain scores (88 % versus 38 %, p = 0.011), function (86 % versus 21 %, p = 0.001), knee scores (83 % versus 38 %, p = 0.001), and walking distance (109 % versus 47 %, p = 0.001) at 1 year.  The therapy group showed healthier biomechanical gait patterns in both the sagittal and coronal planes at 1 year.  The authors concluded that the use of the Apos System improved outcomes following TKA; and should be considered as an additional therapy post-operatively.

The authors stated that this study had several drawbacks.  The study occurred only over the 1st post-operative year following surgery; thus, long-term differences between the groups are unknown.  The 1st post-operative year was chosen as this is likely the most important time for rehabilitation, before scar tissue forms and gait patterns become set.  Another drawback was inherent in the barefoot gait analysis, which has been shown to be different than shod walking.  Nevertheless, when developing the study protocol, it was found that barefoot gait analysis was the most reliable way of eliminating any confounding variables between groups.  Another drawback was that there was no complete documentation of the type of shoes subjects wore at baseline or whether any of the participants changed their own walking shoes during the study period.  Nevertheless, these investigators did not believe that significant differences in baseline footwear existed between the groups that would have influenced the study results.  Another drawback was the ability to create a perfectly blinded study with devices.  Due to the inherent nature of the device, it was impossible to create an identical control device.  Nevertheless, these researchers attempted to create a sham device that was as similar as possible to the BD.  Monitoring patient compliance was another drawback that should be acknowledged.  Since the intervention was a home-based program carried out during daily activities, measuring usage time/compliance to treatment instructions was challenging.  Nevertheless, patients were asked to complete a usage log, which was confirmed at each follow-up appointment.  Furthermore, as this was a multi-center study with multiple surgeons, there was variability between technique and implant.  There were, however, no significant differences between groups in implant type or significant effect of implant on results.  Finally, while a specific training program was examined in this study, all other therapy programs that apply these principles may potentially be useful as well.

Reichenbach and colleagues (2020) noted that individually calibrated biomechanical footwear therapy may improve pain and physical function in people with symptomatic knee OA; however, the benefits of this therapy are unclear.  In a randomized clinical trial, these researchers examined the effect of a biomechanical footwear therapy versus control footwear over 24 weeks of follow-up.  Subjects (n = 220) with symptomatic, radiologically confirmed knee OA were recruited between April 20, 2015, and January 10, 2017.  The last subject visit occurred on August 15, 2017.  Subjects were randomized to biomechanical footwear involving shoes with individually adjustable external convex pods attached to the outsole (AposTherapy; n = 111) or to control footwear (n = 109) that had visible outsole pods that were not adjustable and did not create a convex walking surface.  The primary outcome was knee pain at 24 weeks of follow-up assessed with the WOMAC pain subscore standardized to range from 0 (no symptoms) to 10 (extreme symptoms).  The secondary outcomes included WOMAC physical function and stiffness subscores and the WOMAC global score, all ranging from 0 (no symptoms) to 10 (extreme symptoms) at 24 weeks of follow-up, and serious AEs.  Among the 220 randomized subjects (mean age of 65.2 years [SD, 9.3 years]; 104 women [47.3 %]), 219 received the allocated treatment and 213 (96.8 %) completed follow-up.  At 24 weeks of follow-up, the mean standardized WOMAC pain subscore improved from 4.3 to 1.3 in the AposTherapy group and from 4.0 to 2.6 in the control footwear group (between-group difference in scores at 24 weeks of follow-up, -1.3 [95 % confidence interval [CI]: -1.8 to -0.9]; p < 0.001).  The results were consistent for WOMAC physical function subscore (between-group difference, -1.1 [95 % CI: -1.5 to -0.7]), WOMAC stiffness subscore (between-group difference, -1.4 [95 % CI: -1.9 to -0.9]), and WOMAC global score (between-group difference, -1.2 [9 5% CI: -1.6 to -0.8]) at 24 weeks of follow-up; 3 serious AEs occurred in the AposTherapy group compared with 9 in the control footwear group (2.7 % versus 8.3 %, respectively); none was related to treatment.  The authors concluded that among subjects with knee pain from OA, use of biomechanical footwear compared with control footwear resulted in an improvement in pain at 24 weeks of follow-up that was statistically significant but of uncertain clinical importance.  These researchers stated that further research is needed to examine long-term safety and efficacy, as well as replication, before reaching conclusions regarding the clinical value of this device.

The authors stated that this study had several drawbacks.  First, there were differences in the appearance of the biomechanical footwear and the control footwear.  To overcome this limitation and minimize the likelihood that subjects would correctly guess that they were not receiving the active intervention, subjects were kept unaware that the control footwear was not expected to have therapeutic benefits.  Subjects were informed in a neutral fashion that 2 different types of footwear were being compared.  The manufacturer’s website described the control footwear as a device with a novel design of the sole, and the subjects randomized to the control group received a simulated calibration that mimicked the actual calibration.  Second, the use of a blinding index to determine the success of blinding was not carried out because such an index assumes indistinguishable interventions.  Third, the self-reported time per day wearing the footwear was longer in the biomechanical footwear group than in the control footwear group.  It was possible that the greater benefit in the biomechanical footwear group was due to longer wear time.  Fourth, analgesic treatment for pain was allowed during the trial; however, the rates of analgesic use did not differ between groups.  Fifth, it was not possible to examine changes in knee adduction moments using 3-dimensional (3D) gait analyses.  Sixth, the trial was conducted at a single center, potentially limiting generalizability.  Seventh, the between-group differences occurred only late during follow-up and were smaller than the observed within-group change from baseline in the control group; thus, the clinical importance of these findings remains uncertain.  Eighth, the findings from this trial were not generalizable to individuals at high risk for falls because they in eligible to participate.  Ninth, the findings were not generalizable to individuals with severe knee pain because they were under-represented in the trial.

Miles and Greene (2020) stated that osteoarthritis (OA) is a major cause of pain and disability worldwide; thus, ways of treating this condition are paramount to a successful health system.  In a retrospective analysis, these investigators examined the changes in spatial-temporal gait parameters and clinical measurements following treatment with a non-invasive foot-worn BD on patients with knee OA within the United Kingdom.  This study was performed on 455 patients with knee OA.  All subjects were evaluated using a computerized gait test and 2 self-assessment questionnaires (Western Ontario and McMaster Osteoarthritis Index [WOMAC] and Short Form 36 [SF-36] Health Survey) at baseline and after 3 and 6 months of treatment.  The BD is a shoe-like device with convex pods under the sole that have the capability of changing foot center of pressure and training neuromuscular control.  The device was individually calibrated for each patient to minimize symptoms while walking and train neuromuscular control.  Subjects used the device for short periods during activities of daily living (ADL).  Repeated measures statistical analyses were carried out to compare differences over time.  After 6 months of treatment significant improvements were observed in all gait parameters (p < 0.01).  Specifically, gait velocity, step length and single limb support of the more symptomatic knee improved by 13 %, 7.8 % and 3 %, respectively.  These were supported by significant improvements in pain, function and quality of life  (QOL)(48.6 %, 45.7 % and 22%, respectively; p < 0.001).  A sub-group analysis revealed no baseline differences between those who were recommended joint replacement and those who were not.  Both groups improved significantly over time (p < 0.05 for all).  The authors concluded that these findings suggested that the personalized biomechanical treatment could improve gait patterns, pain, function and QOL.  It may provide an additional solution to managing United Kingdom patients suffering from knee OA; however, further studies in a controlled setting are needed to examine its clinical effect further.  These researchers stated that the personalized BD appeared to create a comparable response between patients that have already been recommended knee joint replacement surgery and those that have not been recommended; thus, potentially providing an alternative solution for this population.  If these findings can be retained in the longer term, it could hypothetically delay or even avoid the need for surgery in many cases that provides an area for examination in future trials. 

The authors stated that this study had several drawbacks.  First, the study was a retrospective analysis of patients from the centers database and therefore had no control group.  In addition, patients were allowed to continue with traditional care, and these investigators could not determine that other treatment did not affect the results of this study.  Patients were usually characterized with a moderate-severe knee OA and commenced the current treatment after trying traditional care with little to no success.  The treatment was often undertaken as a final attempt to address the condition non-invasively before the need for a surgical intervention.  As a result, these investigators believed most of the clinical effect observed in this study could be attributed to the BD and treatment plan as opposed to any adjunctive or continued treatment modalities.  Potentially, a combined approach of exercise therapy alongside the biomechanical treatment may yield further superior effects compared to the device alone and this should be examined in a controlled setting in the future.  Second, this study had a relatively short follow-up duration of 6 months for this cohort.  Long-term follow-up would give more insight into the lasting effects of the treatment.  However, it reflected previous research on the treatment on different populations with similar improvements in gait and patient reported outcome measures.  Therefore, it could be assumed that the improvements can be maintained with the high compliance rates in the treatment.  Nevertheless, future research should continue to examine the long-term clinical effect of the treatment, in prospective, RCT design while tracking decay rates for joint replacement surgeries.  Promisingly, preliminary data from an RCT on the effect of this treatment displayed comparable improvements to this study (Reichenbach et al, 2020 [which was reviewed in my previous e-mail]) .  Lastly, this study did not monitor the overall activity level of the patients in general and this compliance to the treatment plan in specifics.  These researchers could not confirm the usage time of the device at home other than when the patients returned to the clinic for a follow-up appointment and reported that they have been using the device daily.  Future studies should enforce methods to monitor compliance to the treatment plan at home.

Orpyx Sensory Insoles

The Orpyx Sensory Insoles (SI) technology is FDA-registered and consists of custom insoles that measure and provide real-time feedback on temperature, pressure, and adherence for patients.

Abbott et al (2019) noted that prevention of diabetic foot ulcer recurrence in high risk patients, using current standard of care methods, remains a challenge.  In a prospective, randomized, proof-of-concept study, these researchers hypothesized that an innovative intelligent insole system would be effective in reducing diabetic foot ulcer recurrence in such patients.  Patients with diabetes, and with peripheral neuropathy and a recent history of plantar foot ulceration were recruited from 2 multi-disciplinary out-patient diabetic foot clinics in the United Kingdom, and were randomly assigned to either intervention or control.  All patients received an insole system, which measured plantar pressure continuously during daily life.  The intervention group received audiovisual alerts via a smartwatch linked to the insole system and off-loading instructions when aberrant pressures were detected; the control group did not receive any alerts.  The primary outcome was plantar foot ulcer occurrence within 18 months.  Between March 18, 2014, and December 20, 2016, a total of 90 patients were recruited and consented to the study, and 58 completed the study.  At follow-up, 10 ulcers from 8,638 person-days were recorded in the control group and 4 ulcers from 11,835 person-days in the intervention group: a 71 % reduction in ulcer incidence in the intervention group compared with the control group (incidence rate ratio 0.29, 95 % confidence interval [CI]: 0.09 to 0.93; p = 0.037).  The number of patients who ulcerated was similar between groups (6 of 26 [control group] versus 4 of 32 [intervention group]; p = 0.29); however, individual plantar sites ulcerated more often in the control group (10 of 416) than in the intervention group (4 of 512; p = 0.047).  In an exploratory analysis of good compliers (n = 40), ulcer incidence was reduced by 86 % in the intervention group versus control group (incidence rate ratio 0.14, 95 % CI: 0.03 to 0.63; p = 0.011).  In the exploratory analysis, plantar callus severity (change from baseline to 6 months) was greater in re-ulcerating patients (6.5, inter-quartile range [IQR] 4.0 to 8.3) than non-re-ulcerating patients (2.0, 0.0 to 4.8; p = 0.040).  The authors concluded that to their knowledge, this study was the 1st to show that continuous plantar pressure monitoring and dynamic off-loading guidance, provided by an innovative intelligent insole system, could lead to a reduction in diabetic foot ulcer site recurrence.  Moreover, these researchers recommended that future long-term, randomized controlled trials (RCTs) test the efficacy and cost-effectiveness of this technology in the wider diabetic at-risk neuropathic community for ulcer prevention.

These researchers noted that the intention-to-treat (ITT) analysis was under-powered because of higher than expected attrition rate for patients who consented to study, but withdrew after the wearing-in period, before their baseline visit.  There were 4 main reasons provided for high drop-out before the baseline visit.  The 1st was the broad inclusion criteria used to recruit sufficient patients with previously healed diabetic foot ulcer, because these patients comprise only approximately 3 % of the general diabetes community.  The high prevalence of co-morbidities (coronary artery disease, retinopathy, and nephropathy) in these high-risk patients often resulted in withdrawal because of too many other hospital appointment commitments.  The 2nd reason related to the device proving challenging for some individuals, with patients describing problems engaging with the smartwatch technology.  The device required charging every other day and connecting to the smartwatch each time the shoes were put on (after taking them off).  Variables that might have affected how patients dealt with these challenges (but were not assessed) include cognitive function, eyesight, manual dexterity, and family or friend assistance in trouble-shooting.  Third, some patients' custom-made shoes were too deep to allow the device to fit optimally, and this was a reason for some of the drop-outs observed post-randomization.  Fourth, some patients reported a reluctance to commit to wearing only lace-up or Velcro shoes for up to 18 months, realizing that they would prefer to sometimes wear slip-on shoes or sandals, especially during summer months.  All of these observations should be useful for the future targeting of appropriate cohorts to benefit from using active-feedback insole systems.  The authors stated that limitations of this proof-of-concept study included the continued withdrawal of ITT patients after baseline, with similar reasons to those for pre-baseline withdrawals.  Withdrawing patients in the intervention and control groups used the device for substantial, similar periods.  Interestingly, no-one in the intervention group withdrew because of frequency of the alerts; therefore, the mean 12 (SD 5) self-reported audio-visual alerts received per day over the study period might be considered a tolerable level for successful intervention.  Although the in-shoe system was considered to have a very low risk of potential harm to patients, the lack of an independent data safety monitoring board was a limitation of this study. We recommend that future, long-term studies should use a data safety monitoring board.

UNFO-S: Adductus-Positioning Device

The UNFO-S is an orthopedic device worn below the ankle that supposedly would improve outcomes for metatarsus adductus / varus over traditional serial casting.  The device functions by stabilizing the heel in the heel cage and the rest of the foot in the brace while applying corrective pressures to the mid-foot; thus, re-aligning the malformed pediatric foot.  This is an alternative to serial casting.  There is a lack of evidence regarding the effectiveness of the UNFO-S adductus positioning device.

Lateral Wedge Insoles for the Management of Medial Osteoarthritis of the Knee

Malvankar et al (2012) stated that lateral wedges were originally proposed to manage medial compartment OA of the knee; however, recent reviews suggested that lateral wedges do not affect disease progression.  In a systematic review, these researchers examined the recent literature and defined how effective, if at all, lateral wedges are in the management of medial compartment OA of the knee.  The inclusion criteria were defined as any study published within the past 10 years, using a sample size of at least 20 patients, and examining the effect of insoles or wedges on either unilateral or bilateral knee varus OA.  The standardized keyword term 'lateral*wedge*OR insole*OR orthotic* OR medial compartment OR varus OR osteoarthri* OR knee*' was used.  These investigators identified 10 studies that met the inclusion criteria.  Although there was not enough evidence in the literature to prove that lateral wedge orthotics are an effective treatment for varus OA of the knee, there was some evidence to suggest that they do have some symptomatic effect.  Patients with early OA and higher BMI may benefit to a greater extent than those with a greater extent of degenerative changes and lower BMI.  The literature was unclear as to what the optimal duration for the use of lateral wedges is; but supported the prolonged use of the wedges as the benefits at 1 month were maintained at 1 year.  The authors concluded that future studies should be RCTs with a large sample size with long follow-up, and use objective clinical, biomechanical and radiological outcome measures.

The authors stated that the recent literature on the use of lateral wedges for medial compartment knee OA is insufficient to draw any substantial conclusions.  The studies had some heterogeneity in the results that could be explained by confounding factors that were not controlled.  Some studies used non-steroidal anti-inflammatory drugs (NSAIDs) as an adjunctive therapy, confounding the results.  Objective outcome measures such as the WOMAC score was only used in 3 studies, and the visual analog scale (VAS) in 2.  Although radiographs were used in 4 studies, the correlation between the effectiveness of the wedges and radiographic severity of the OA was only examined in 1 study.  Furthermore, the study samples were small and the follow-ups short.  Only 1 study had control wedges; and failed to confirm that they were made of the same material or similar confirmed material wear.

Penny et al (2013) noted that a conservative management strategy for knee OA is the lateral wedge insole (LWI).  The theoretical basis for this intervention is to correct tibio-femoral malalignment; thus, reducing pain and optimizing function.  In a systematic review, these researchers examined the evidence on the safety and effectiveness of LWI for the treatment for knee OA.  They carried out a systematic review, searching published (Medline, AMED, Embase, CINAHL, Cochrane Library) and unpublished literature from their inception to August 2012; RCTs were included that compared the use of LWI with a neutral insole or control intervention for individuals with medial compartment OA.  Risk of bias and clinical relevance were evaluated, and outcomes were analyzed via meta-analysis.  From a total of 3,105 citations, 10 studies adhered to the a priori eligibility criteria.  These included 1,095 individuals; 535 subjects were allocated to receive LWI insoles compared to 509 in control groups; 8 % of papers were of high quality with low risk of bias.  There was no statistically significant difference between LWI and neutral insoles for pain, function, analgesic requirement, compliance or complications (p ≥ 0.07).  Those who received LWI demonstrated lower NSAIDs requirements (p < 0.001).  The authors concluded that there is limited evidence to support the prescription of LWI to individuals with medial compartment OA to reduce pain and increase function; however, there remains a paucity of evidence to determine whether LWI outcomes differ in subgroups of the patients, such as severe compared to mild OA, obese patients, or whether the angle of LWI is of clinical importance.

Zhang et al (2018) stated that using the LWI is a conservative management strategy for knee OA.  The theoretical basis for this intervention is to correct femoro-tibial angle; thus, reducing pain and optimizing function.  In a systematic review, these researchers examined the evidence on the effectiveness of LWI compared with flat insole for the treatment of knee OA.  They carried out a systematic review searching published (Medline, Embase, CNKI, Cochrane Library, and Web of Science) and unpublished literature from their inception to April 2018; RCTs that compared the use of wedge insole with a flat insole were included.  Risk of bias and clinical relevance were assessed, and outcomes were analyzed via meta-analysis.  From a total of 413 citations, 8 studies adhered to the a priori eligibility criteria.  The WOMAC pain showed non-significant change with the use of wedge insole (SMD = 0.07), and low heterogeneity (I2 = 22 %) and a 95 % CI that crossed zero (95 % CI: -0.09 to 0.24).  The 5 independent trials were not significant in improving pain score (SMD = -0.02, 95 % CI: -0.19 to 0.16).  This review also showed no significance in improving Lequesne index (SMD = -0.27, 95 % CI: -0.72 to 0.19).  The meta-analysis from the 2 independent trials was significant in improving femoro-tibial angle (SMD = -0.41, 95 % CI: -0.73 to -0.09).  The authors concluded that the findings of this meta-analysis suggested that LWI could improve femoro-tibial angle but are of no benefit with pain and functions in knee OA.

Felson et al (2019) stated that LWIs decrease medial knee loading; but trials have shown no effect on pain in medial knee OA.  However, loading effects of insoles are inconsistent, and they could increase patella-femoral loading.  In a randomized clinical trial, these investigators tested the hypothesis that insoles would reduce pain in pre-selected patients.  Among patients with painful medial knee OA, these researchers excluded those with patella-femoral OA and those with a pain rating of less than 4 of a possible 10.  They further excluded subjects who, in a gait analysis using LWIs, did not show at least a 2 % reduction in knee adduction moment (KAM), compared to wearing their shoes and a neutral insole.  These researchers then randomized subjects to LWI versus neutral insole for 8-week periods, separated by an 8-week washout.  The primary outcome measure was knee pain (0 to 10 scale) during the past week, and secondary outcome measures included activity pain and pain rated in the Knee Injury and Osteoarthritis Outcome Score questionnaire.  They carried out mixed model analyses adjusted for baseline pain.  Of 83 participants, 21 (25.3 %) were excluded from analysis because of insufficient reduction in KAM.  In the 62 patients included in analysis, the mean ± SD age was 64.2 ± 9.1 years, and 37.1 % were women; LWIs produced a greater reduction in knee pain than neutral insoles (MD of 0.7 on 0 to 10 scale [95 % CI: 0.1 to 1.2]) (p = 0.02).  Findings for secondary outcome measures were mixed.  The authors concluded that in subjects pre-screened to eliminate those with patella-femoral OA and biomechanical non-responders, LWIs reduced knee pain, but the treatment effect was small and most treated patients did not achieve conventional levels of minimal important response.  They stated that future modifications of the treatment or of the screening strategy might offer greater levels of efficacy.

Chen et al (2019) noted that functional limitations and pain are common presenting complaints for individuals suffering from knee OA; and wedge insole could be used for treatment of knee OA.  These researchers conducted a systematic review and meta-analysis to examine the effectiveness of wedge insole in the treatment of knee OA.  A systematic literature search for studies will be performed in Medline, Embase, the Chinese National Knowledge Infrastructure Database (CNKI), Cochrane Library, Web of Science.  The methodological quality of the included studies will be evaluated by using the risk bias assessment tool of Cochrane.  Funnel plot will be used to assess the reporting bias; and the level of evidence for results will be evaluated by the GRADE method.  Statistical analysis will be performed with Revman 5.3.  This systematic review and meta-analysis will provide a synthesis of evidence for wedge insole on knee OA.  The authors stated that it is unclear if the use of wedge insole could improve the pain and other symptoms of knee OA.  Furthermore, the confusing results of many studies on this topic also hindered the use of insoles in the treatment of knee OA; thus, it is necessary to perform a study to examine the effectiveness of wedge insole therapy for knee OA.  These researchers hoped that the findings of this study would help to form the clinical recommendation for knee OA and to provide more high-level evidence about the application of wedge insole.

In a prospective, randomized, controlled, single-blind clinical trial, Ferreira et al (2021) examined if LWIs adjusted by biomechanical analysis may improve the condition of patients with medial knee OA.  A total of 38 patients with medial knee OA were allocated to either an experimental group (LWIs) or a control group (neutral insoles).  Experimental group (n = 20) received an adjusted LWI of 2, 4, 6, 8, or 10 degrees, after previous biomechanical analysis.  Control group (n = 18) received a neutral insole (0 degrees).  All patients used the insoles for 12 weeks.  Outcome measures included VAS, Knee Injury and Osteoarthritis Outcome Score questionnaire, biomechanical parameters: 1st and 2nd peak of the external KAM and knee adduction angular impulse, and physical performance tests: 30-second sit-to-stand test, the 40-m fast-paced walk test, and the 12-step stair-climb test.  After 12 weeks, between-group differences did not differ significantly for pain intensity (-12.5 mm, (95 % CI: -29.4 to 4.4)), biomechanical parameters (p = 0.05), Knee Injury and Osteoarthritis Outcome Score, and physical performance tests, except on the Knee Injury and Osteoarthritis Outcome Score subscale other symptoms (p = 0.002; 13.8 points, (95 % CI: 5.6 to 22.0)).  The authors concluded that tailored LWIs were no more effective at improving biomechanical or clinically meaningful outcomes than neutral insoles, except on symptoms.  More subjects from the experimental group reported they felt some improvement; however, these effects were minimal and without clinical significance.

Furthermore, an UpToDate review on “Management of knee osteoarthritis” (Deveza and Bennell, 2022) states that “Insoles and other specialized footwear -- There has been an interest in the use of insoles and other specialized footwear in an effort to reduce stress on osteoarthritic knee compartments and potentially slow disease progression.  However, the data in support of these devices suggest limited clinical benefit overall.  Lateral wedge insoles -- Due to the evidence indicating against the use of lateral wedge insoles in medial compartment knee OA, we do not routinely suggest their use.  However, medially wedged insoles for patients with lateral tibiofemoral OA and valgus deformity may be reasonably tried based on limited evidence from one study of significant improvements in pain for these patients.  Nevertheless, there are few studies investigating medial compared with lateral wedge insoles.  Lateral wedge insoles have been shown to modestly reduce the external knee adduction moment and thereby reduce medial knee joint loading. However, compared with control inserts (neutral soles), lateral wedge insoles provided no clinically significant improvement in pain in patients with medial knee OA, as examined in meta-analyses including trials with both neutral and no insole control.  Moreover, a randomized trial including 200 participants with mild to moderate medial knee OA found no differences between full-length lateral wedged insole and flat insole in medial tibial and femoral cartilage volume loss and change in size of bone marrow lesions on magnetic resonance imaging (MRI) over 12 months.  Another randomized trial that involved prescreening to select those patients more likely to respond to insoles (i.e., those who showed a ≥2 percent reduction in the knee adduction moment with insoles and without patellofemoral OA) found that lateral wedge insoles reduced pain more than control insoles.  However, the effect of treatment was small and likely to be of clinical significance in only a minority of patients”.

Appendix

Table: Foot Orthotics Details

Pathology	Shoe Type	Insert Modification (as needed)	Comments
Forefoot deformities: Hallux abducto valgus, hallux varus, hallux rigidus	Standard orthopedic OxfordFootnotes* Oxford style bootFootnotes** Depth shoes Custom molded shoes	Semi-rigid or rigid functional orthosis Additional accommodative padding as needed	The type of shoe and orthotic must be determined based on the severity of the pathology.
Midfoot deformities: Charcot foot	Depth shoe Custom molded Oxford style bootFootnotes**	Semi-rigid or rigid functional orthosis Additional accommodative padding as needed Ankle-foot orthosis or other stabilization and/or immobilization brace	The type of shoe and orthotic must be determined based on the severity of the pathology.
Rearfoot deformities: a. Symptomatic pronation b. Symptomatic supination c. Symptomatic pes cavus d. Heel pain (1) Retrocalcaneal (2) Inferior calcaneal e. Symptomatic equines f. Tarsel coalition g. Ankle instability h. Charcot foot	Standard orthopedic OxfordFootnotes* Oxford style bootFootnotes** Depth shoe Custom molded	Semi-rigid or rigid functional orthosis Additional accommodative padding as needed Ankle-foot orthosis or other stabilization and/or immobilization brace Heel cup	The type of shoe and orthotic must be determined based on the severity of the pathology.
Diabetic neuropathology with no concomitant deformities	Depth shoe	Over the Counter (OTC) OTC Accommodation Orthoses Semi-rigid or rigid functional orthosis Additional accommodative padding as needed	As a preventive measure, this group of patients should be followed on a regular basis for the development of pathology to ensure quick interventions as needed.
Peripheral vascular disease with non- concomitant deformities (arterial or venous)	Depth shoe	OTC OTC Accommodation Orthoses Semi-rigid or rigid functional orthosis Additional accommodative padding as needed	As a preventive measure, this group of patients should be followed on a regular basis for the development of pathology.
Digital and midtarsal amputations	Depth shoe Custom molded	Semi-rigid or rigid functional orthosis Appropriate Filler Additional accommodative padding as needed	As a preventive measure, this group of patients should be followed on a regular basis for the development of pathology.

Adapted from VHA, 2004.

Footnotes* Stock shoes include standard therapeutic Oxford dress, casual or walking/exercise shoes.

Footnotes** Certain conditions and circumstances may require the use of boots that add ankle support.

For limitations on medical necessity frequency of replacement of orthotics, see Medi-Cal. Orthotics and prosthetics. Frequency limits on orthotics. Ortho cd fre 1. Provider Manual. Sacramento, CA: California Department of Health Care Services; August 2010.

Available at: Provider Manuals. Accessed August 15, 2012.

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 "+":
HCPCS codes covered if selection criteria are met:
A5500 - A5507, A5510 - A5514	Diabetic shoes, fitting, and modifications
A9283	Foot pressure off loading/supportive device, any type, each
L3000 - L3031	Foot inserts, removable
L3040 - L3090	Foot arch supports, removable or nonremovable
L3100 - L3170	Repositioning foot orthotics
L3201 - L3265	Orthopedic footwear (shoes, boots, depth inlays)
L3300 - L3485	Shoe modifications (lifts, wedges, heels)
L3500 - L3649	Other orthopedic shoe additions, and transfers
HCPCS codes not covered for indications listed in the CPB:
Apostherapy (biomechanical shoe-like device), orpyx sensory insoles – No specific codes:
A5508	For diabetics only, deluxe feature of off-the-shelf depth-inlay shoe or custom-molded shoe, per shoe
ICD-10 codes covered if selection criteria are met (not all-inclusive):
C40.30 - C40.32	Malignant neoplasm of short bones of lower limb
C47.20 - C47.22, C49.20 - C49.22	Malignant neoplasm of peripheral nerves and connective and soft tissue of lower limb, including hip
C79.51 - C79.52	Secondary malignant neoplasm of bone and bone marrow
D21.20 - D21.22, D36.13	Benign neoplasm of peripheral nerves and connective and other soft tissue, lower limb, including hip [neuroma]
E08.00 - E08.9	Diabetes mellitus due to underlying condition
E10.21 - E10.29, E11.21 - E11.29, E13.21 - E13.29	Diabetes with kidney complications
E10.40 - E10.49, E11.40 - E11.49, E13.40 - E13.49	Diabetes with neurological complications
E10.51 - E10.59, E11.51 - E11.59, E13.51 - E13.59	Diabetes with circulatory complications
E10.610 - E10.618, E11.610 - E11.618, E13.610 - E13.618	Diabetes with other specified complications
E64.3	Sequelae of rickets
G57.00 - G57.93	Mononeuropathies of lower limb
G60.0	Hereditary motor and sensory neuropathy
G60.1	Refsum's disease
G60.3	Idiopathic progressive neuropathy
G60.8	Other hereditary and idiopathic neuropathies
G61.0 - G61.9	Inflammatory polyneuropathy
G62.0 - G62.9	Other and unspecified polyneuropathies
I70.201 - I70.299	Atherosclerosis of native arteries of the extremities
I73.00 - I73.01	Raynaud's syndrome
I73.1	Thromboangiitis obliterans [Buerger's disease]
I73.81	Erythromelalgia
I73.89	Other specified peripheral vascular diseases (e.g., acrocyanosis, acroparesthesia, erythrocyanosis)
I73.9	Peripheral vascular diseases, unspecified
I74.3	Embolism and thrombosis of arteries of the lower extremities
I75.021 - I75.029	Atheroembolism of lower extremity
I80.00 - I80.03	Phlebitis and thrombophlebitis of superficial vessels of lower extremities
I80.10 - I80.13	Phlebitis and thrombophlebitis of femoral vein [deep and superficial]
I80.201 - I80.299	Phlebitis and thrombophlebitis of other and unspecified deep vessels of lower extremities [e.g., femoropopliteal vein, popliteal vein, tibial vein]
I80.3	Phlebitis and thrombophlebitis of lower extremities, unspecified
I82.401 - I82.409	Acute embolism and thrombosis of unspecified deep veins of lower extremity
I83.001 - I83.029	Varicose veins of lower extremities with ulcer
I83.10 - I83.12	Varicose veins of lower extremities with inflammation
I83.201 - I83.229	Varicose veins of lower extremities with both ulcer and inflammation
I83.891 - I83.899	Varicose veins of lower extremities with other complications
L97.101 - L97.929	Non-pressure chronic ulcer of lower limbs, not elsewhere classified
M10.00 - M10.09	Idiopathic gout
M12.271 - M12.279	Villonodular synovitis (pigmented), ankle and foot
M12.571 - M12.579	Traumatic arthropathy, ankle and foot
M12.871 - M12.879	Other specific arthropathies, not elsewhere classified, ankle and foot [contrature of joint]
M17.0 - M17.12	Primary osteoarthritis of knee
M17.2 - M17.5	Post-traumatic osteoarthritis of knee
M17.9	Osteoarthritis of knee, unspecified
M19.071 - M19.072	Primary osteoarthritis ankle and foot
M19.271 - M19.279	Secondary osteoarthritis, ankle and foot
M19.90 - M19.92	Osteoarthritis, unspecified site [ankle and foot]
M20.10 - M20.12	Hallux valgus (acquired)
M20.20 - M20.22	Hallux rigidus
M20.30 - M20.32	Hallux varus (acquired)
M20.40 - M20.42	Other hammer toe(s) (acquired)
M20.5x1 - M20.5x9	Other deformities of toe(s) (acquired)
M20.60 - M20.62	Acquired deformity of toe(s), unspecified
M21.251 - M21.279	Flexion deformity [hip, knee, ankle and toes]
M21.40 - M21.42	Flat foot [pes planus] (acquired), [covered for children only]
M21.611 - M21.629	Other acquired deformities of foot [pronation covered for children only]
M21.751 - M21.769	Unequal leg length (acquired)
M21.861 - M21.869	Other specified acquired deformities of thigh and lower leg
M24.571 - M24.576	Contracture, ankle and foot
M25.371 - M25.373	Other instability, ankle and foot
M25.771 - M25.776	Osteoophyte, ankle and foot
M65.80	Other synovitis and tenosynovitis, unspecified site
M65.871 - M65.879	Other synovitis and tenosynovitis, ankle and foot
M65.9	Synovitis and tenosynovitis, unspecified
M67.471 - M67.479, M71.371 - M71.379	Ganglion and other bursal cyst [ankle and foot]
M72.2 - M72.4	Plantar fascial and pseudosarcomatous fibromatosis
M76.60 - M76.9, M77.9	Enthesopathy of lower limb, excluding foot
M86.071 - M86.079, M86.171 - M86.179, M86.271 - M86.279, M86.371 - M86.379, M86.471 - M86.479, M86.571 - M86.579, M86.9, M90.871 - M90.879	Osteomyelitis, periostitis, and other infections of ankle and foot
N18.1 - N18.9	Chronic kidney disease (CKD)
Numerous options	Other disorders of bone and cartilage [sesamoiditis]
O22.20 - O22.23	Superficial thrombophlebitis in pregnancy
O22.30 - O22.33	Deep phlebothrombosis in pregnancy
O87.1	Deep phlebothrombosis in the puerperium [postpartum]
Q66.3	Other congenital varus deformities of feet
Q66.50 - Q66.52	Congenital pes planus
Q66.6	Other congenital valgus deformities of feet
Q66.80 - Q66.89	Other congenital deformities of feet
Q69.2	Accessory toe(s)
Q70.20 - Q70.23	Fused toes
Q70.30 - Q70.33	Webbed toes
Q74.2	Other congenital malformations of lower limb(s), including pelvic girdle
ICD-10 codes not covered for indications listed in the CPB:
L84	Corns and callosities
M16.0 - M16.12	Osteoarthritis of hip
M16.2 - M16.7	Osteoarthritis, secondary, hip
M16.9	Osteoarthritis of hip, unspecified
M23.00 - M23.92	Internal derangement of knee
M23.8x1 - M23.8x9 M25.261 - M25.269 M25.361 - M25.369	Other internal derangement lower leg
M24.361 - M24.369	Pathological dislocation of knee, not elsewhere classified
M24.461 - M24.469	Recurrent dislocation, knee
M35.7	Hypermobility syndrome
S82.001+ - S82.099+	Fracture of patella
S82.101+ - S82.499+	Fracture of tibia and fibula
S82.51x+ - S82.66+	Fracture medial and lateral malleolus
S82.811+ - S82.92x+	Other fractures of lower leg
S83.101+ - S83.106+	Unspecified subluxation and dislocation of knee
S83.401+ - S83.92x+	Sprains of ligaments of knee
S87.00x+ - S87.82x+ S97.00x+ - S97.82x+	Crushing injury of knee and lower leg, ankle and foot, or toe
S93.01x+ - S93.06x+	Subluxation and dislocation of ankle joint
T24.001+ - T25.799+	Burn and corrosion of lower limb
UNFO-S (an adductus-positioning device):
HCPCS codes not covered for indications listed in the CPB:
K1015	Foot, adductus positioning device, adjustable[UNFO-S (an adductus-positioning device)]
ICD-10 codes not covered for indications listed in the CPB:
Q66.221 – Q66.229	Congenital metatarsus adductus

The above policy is based on the following references: