Lower limb prosthesis is an artificial device that replaces all or a part of the missing extremity. The application of an appropriate prosthesis is designed to regain or maintain function of the limb, and depends on the functional level of the amputee and the expected functional rehabilitation potential.

The microprocessor-controlled prosthetic knee is designed for lower limb amputees and congenital lack of limb. It is equipped with a sensor that controls the hydraulic that adjusts the swing and stability of the knee based on the position of the foot to permit a more natural walking pattern at varying speeds.

Immediate Prostheses

Lower limb prostheses, immediate, may be considered medically necessary for a new or revised amputation when ALL of the following criteria are met:

• The individual has a lower extremity amputation; and
• The immediate prosthesis is provided after surgery, while the surgical incision is still healing; and
• The individual is motivated to ambulate using the prosthesis; and
• The prosthesis is prescribed by an eligible professional provider (i.e., physician with training and expertise in the functional evaluation of individuals with amputations) and fitted/made by an orthotist or prosthetist.

Lower limb prostheses, immediate, are complete and all-inclusive; therefore, additional components, add-ons, upgrades, test sockets, or substitutions of components, etc., are considered not medically necessary.

Immediate lower limb prostheses, not meeting the criteria as indicated in this policy are considered not medically necessary.

Preparatory Prostheses

Lower limb prostheses, preparatory, may be considered medically necessary for a new or revised amputation when ALL of the following criteria are met:

• The individual has had an above or below knee amputation; and
• The preparatory prosthesis is provided to an individual starting a rehabilitation program; and
• The preparatory prosthesis is provided after the surgical incision has healed; and
• The individual is motivated to ambulate using the prosthesis; and
• The preparatory prosthesis is prescribed by an eligible professional provider (i.e., physician with training and expertise in the functional evaluation of individuals with amputations) and fitted/made by an orthotist or prosthetist.

Lower limb prostheses, preparatory, are complete and all-inclusive; therefore, additional components, add-ons, upgrades, adjustments, modifications, or substitutions of components, etc., are considered not medically necessary.

Preparatory lower limb prostheses, not meeting the criteria as indicated in this policy are considered not medically necessary.

Definitive Prostheses

Lower limb prostheses, definitive- initial, may be considered medically necessary when ALL of the following criteria are met: 

·         The individual has had an above or below knee amputation; and

·         The definitive prosthesis is provided to an individual who will be participating in a rehabilitation program appropriate for the individual’s expected functional level; and

·         The definitive prosthesis is provided after the surgical incision is stable (healed); and

·         The definitive prosthesis is provided after the residual limb has matured; and

·         The individual is motivated to ambulate using the prosthesis; and

·         The individual is cognitively capable of using the prosthesis to ambulate effectively at the determined functional level [one (1) – four (4)]; and

·         The individual has sufficient neuromuscular control to effectively and appropriately make use of the definitive prosthesis at the determined functional level [one (1) – four (4)]; and

·         The individual has sufficient cardio-pulmonary capacity to effectively use the definitive prosthesis at the determined functional level [one (1) – four (4)]; and

·         The individual has had an in-person medical evaluation with the ordering physician to establish their overall functional capabilities,

o    NOTE: The ordering physician may delegate this assessment to a licensed/certified medical professional (LCMP) defined as a physical therapist (PT) or occupational therapist (OT), or physician with training and expertise in the functional evaluation of individuals with amputations; and

·      This specialty evaluation must:

o    Evaluate and document the individual’s over-all health status taking into consideration factors related to the amputation and prosthesis use as well the effect of co-morbidities on potential function ; and

o    The evaluation must include a complete physical examination including an objective neuromuscular evaluation, cardio-pulmonary capacity evaluation and cognitive evaluation; and

o    Determine a global activity level as described by the functional level modifiers:

 § Levels zero (0) – four (4) (see Table Attachment); and

·      The individual has had an in-person evaluation by the prosthetist to evaluate prosthetic needs consistent with the overall functional capabilities identified by the medical examination; and

·      The individual is able to ambulate using the device at or above the identified functional level.

Definitive lower limb prostheses, not meeting the criteria as indicated in this policy are considered not medically necessary.

Sockets and Socket Inserts

One (1) socket per individual definitive prosthesis may be considered medically necessary when the prosthesis meets above criteria.

Two (2) test (diagnostic) sockets for an individual definitive prosthesis may be considered medically necessary when the prosthesis meets above criteria.

No more than two (2) of the same socket inserts per individual prosthesis at the same time may be considered medically necessary.

One (1) custom fabricated socket insert may be considered medically necessary when the prosthesis meets the above criteria and the ALL of the following:

• Non-custom socket inserts are unable to provide an adequate interface between the residual limb and socket; and
• A different type of non-custom insert will not compensate for the irregular contours of the limb.

Socket replacements for a definitive prosthesis may be considered medically necessary when the prosthesis meets the above criteria, and EITHER of the following:

• There are changes in the residual limb that cannot be accommodated though the use of socket inserts and/or liners and/or stump stockings, and/or modifications to the existing socket;  or
• When the existing socket is irreparable due to damage or wear.

Suspension Systems

Mechanical

Mechanical suspension systems including, belts, sleeves, straps, socket design features, and pin-locking mechanisms may be considered medically necessary when the prosthesis meets the above criteria, and the individual’s functional level is one (1) - four (4).

Suction

Passive suction systems may be considered medically necessary when the prosthesis meets above criteria, and the individual’s functional level is one (1) – four (4).

Vacuum Suspension System

Vacuum suspension systems (e.g., vacuum-assisted socket system [VASS™]) may be considered medically necessary to control residual limb volume when there is contraindication to or failure of other socket-suspension systems (e.g., mechanical, passive suction) to adequately secure the limb to the prosthesis; and the individual’s functional level is three (3) - four (4).  

Suspension systems for lower limb prostheses, not meeting the criteria as indicated in this policy are considered not medically necessary.

Feet and Ankles

One (1) foot/ankle may be considered medically necessary when a definitive prosthesis meets the above criteria, and the foot/ankle is appropriate for the individual’s functional level [one (1) – four (4)] as indicated below:

• An external-keel solid ankle cushion heel (SACH) foot or single-axis ankle/foot may be considered medically necessary for individuals whose functional level is one (1) or above; or
• A flexible-keel foot or multi-axial ankle/foot may be considered medically necessary for individuals whose functional level is two (2) or above; or
• An energy-storing foot, dynamic response with multi-axial ankle, flex-foot system, flex-walk system or equal, or shank system with vertical loading pylon may be considered medically necessary for individuals whose functional level is three (3) or above; or
• An axial rotation unit may be considered medically necessary for individuals whose functional level is two (2) or above; or
• A partial foot prosthesis may be considered medically necessary for individuals whose functional level is one (1) or above.

Knees

Prosthetic knees may be considered medically necessary, when a definitive prosthesis meets the above criteria, and the type is based upon the functional needs of the individual as indicated below:

• A fluid, pneumatic or electronic knee may be considered medically necessary for individuals whose functional level is three (3) or above.
• A single axis constant friction knee and other basic knee systems may be considered medically necessary for individuals whose functional level is one (1) or above.

Quick change self-aligning units are considered not medically necessary.

Hips

A pneumatic or hydraulic polycentric hip joint may be considered medically necessary when a definitive prosthesis meets the above criteria, and for individuals whose functional level is three (3) or above.

A pneumatic or hydraulic polycentric hip joint for a lower limb prostheses, not meeting the criteria as indicated in this policy is considered not medically necessary.

Additional Criteria

Lower limb prostheses, not meeting the criteria as indicated in this policy is considered not medically necessary.

 All parts of a lower limb prosthesis are considered not medically necessary when any related part is considered not medically necessary.

Lower limb prosthesis is considered not medically necessary for an individual that is at functional level zero (0).

Duplication or upgrade of a functional prosthesis is considered not medically necessary.

Additions/components that are not required for the effective use of the device, or do not serve a functional purpose are considered not medically necessary.

Additions provided for cosmetic reasons are considered not medically necessary.

Prosthetic devices or additions/components not required for participation in normal activities of daily living, including those that are chiefly for convenience, for participation in recreational activities, or that otherwise exceed the medical needs of the amputee (e.g., back-up prosthetic devices, waterproof leg prosthesis [e.g., Water Leg, used for showering, swimming] are considered not medically necessary.

Prosthetic donning sleeve is considered not medically necessary.

Protective outer surface covering systems are considered not medically necessary.

Additions/Accessories

Additions/Accessories may be considered medically necessary when a definitive prosthesis meets the above criteria, and supporting documentation indicates that they aid in, or are essential to, the effective use of the artificial limb, and are appropriate for the individual’s functional level [one (1) – four (4)].

Additions/Accessories not meeting the criteria as indicated in this policy are considered not medically necessary.

Repairs/Replacements

All necessary fitting, adjustments, modifications, replacements, etc., made during the 90 days after provision of a prosthesis are considered inherent to the prosthesis.

Lower limb prostheses replacement during the reasonable useful lifetime (usually based on the manufacturer's recommendation or FDA-approved labeling) may be considered medically necessary when supporting documentation indicates that the item is lost or irreparably damaged (i.e., fire, flood, etc.).

Lower limb prostheses replacement after the reasonable useful lifetime (usually based on the manufacturer's recommendation or FDA-approved labeling) may be considered medically necessary for at least ONE of the following when supporting documentation indicates:

• There is a change in the physiological condition of the individual, and the prosthesis is considered medically necessary; or
• There is irreparable wear of the device or a part of the device, and the prosthesis is considered medically necessary; or
• The condition of the device, or part of the device, requires repairs and the cost of such repairs would be greater than 60% of the cost of a replacement device or the part being replaced, and the prosthesis is considered medically necessary.

Lower limb prostheses repairs may be considered medically necessary for EITHER of the following when supporting documentation indicates they are:

• Required to make the prosthesis functional; or
• In keeping with the manufacturer’s maintenance recommendations: or
• Adjustments are required due to wear and tear.

Repairs/Replacements not meeting the criteria as indicated in this policy are considered not medically necessary.

Pediatric Lower Limb Prostheses

​Pediatric lower limb prostheses may be considered medically necessary for congenital and acquired pediatric limb deficiencies.

Considerations for pediatric lower limb prostheses include:

• Infants who are born with a missing or partial limb, or children who lose a limb through injury or amputation, should be evaluated by a prosthetist as soon as possible.
• It is appropriate for infants and very young children to be fit with a passive prosthesis right away so that the prosthetic limb is incorporated into their developing body image.
• A child is eligible for prosthetics when they are able to stand on their own (approximately 9-12 months of age).
• Components must be evaluated for age-appropriateness, considering comfort, weight, durability, and function.
• A new socket and other prosthetic modifications are required at least once a year for children between the ages of birth to 18 years to allow for normal growth and development.
• Follow-up with a multidisciplinary approach is recommended.

Pediatric lower limb prostheses, not meeting the criteria as indicated in this policy is considered not medically necessary. 

Microprocessor-Controlled Lower Limb Prosthesis

Microprocessor-controlled knee may be considered medically necessary when the following criteria are met:

• Individual’s functional level is three (3) or above, as indicated by modifier K3 or K4; and  
• There is a demonstrated need for long-distance ambulation at variable rates (use of the limb in the home or for basic community ambulation is not sufficient to justify provision of the computerized limb over standard limb applications); or
• There is a demonstrated patient need for regular ambulation on uneven terrain or for regular use on stairs (use of the limb for limited stair climbing in the home or employment environment is not sufficient evidence for prescription of this device over standard prosthetic application); and
• Physical ability includes adequate cardiovascular and pulmonary reserve, for ambulation at faster than normal walking speed; and
• Individual demonstrates adequate cognitive ability to master use and care requirements for the technology; and
• The patient’s medical record must provide clear documentation of the patient’s history, current condition, and expected functional ability to support the need for the technologic or design feature of the microprocessor-controlled knee (This information must be retained in the physician’s or prosthetist’s files, and be available upon request.).

Microprocessor-controlled knee not meeting the criteria as indicated in this policy is considered not medically necessary.

Microprocessor-controlled ankle/foot prosthesis may be considered medically necessary when the individual’s functional level is three (3) or above, as indicated by modifier K3 or K4.

Microprocessor-controlled ankle/foot prosthesis not meeting the criteria as indicated in this policy is considered not medically necessary.

Powered and Programmable Flexion/Extension Assist-Control Prosthetic Knees

Powered and programmable endoskeletal knee-shin system with flexion-extension assist (addition to lower extremity) may be considered medically necessary when ALL of the following criteria are met:

• The individual has a microprocessor (swing and stance phase type) controlled (electronic) knee; and
• Individual’s functional level is three (3), as indicated by modifier K3 (the device is not intended for high impact activity, sports, excessive loading or heavy duty use); and
• Weight is between 110 lbs and 275 lbs; and
• Has a documented comorbidity of the spine and/or sound limb affecting hip extension and/or quadriceps function that impairs K-3 level function with the use of a microprocessor-controlled knee alone; and
• Is able to make use of a product that requires daily charging; and
• Is able to understand and respond to error alerts and alarms indicating problems with the function of the unit.

Powered endoskeletal knee-shin system with flexion-extension assist not meeting the criteria as indicated in this policy is considered not medically necessary.

Power-Assist Ankle-Foot Prosthetic Systems

Powered ankle or foot prostheses are considered experimental/investigational and therefore, non-covered because the safety and/or effectiveness of this service cannot be established by the available published peer-reviewed literature.