This document addresses the use of lower limb prostheses required to replace the function of a lower limb loss due to trauma, disease or a congenital condition.

NOTE: For information addressing microprocessor controlled leg or foot-ankle prosthesis please refer to:

• OR-PR.00003 Microprocessor Controlled Lower Limb Prosthesis

Functional Levels: Throughout this guideline "Functional Levels" are used to guide the appropriateness of lower limb prosthesis.  Provided below are definitions of these levels. Please note that within the functional classification hierarchy, bilateral amputees often cannot be strictly bound by functional level classifications.

Level 0:  Does not have the ability or potential to ambulate or transfer safely with or without assistance and prosthesis does not enhance their quality of life or mobility.
Level 1:  Has the ability or potential to use prosthesis for transfers or ambulation on level surfaces at fixed cadence.  Typical of the limited and unlimited household ambulator.
Level 2:  Has the ability or potential for ambulation with the ability to traverse low-level environmental barriers such as curbs, stairs or uneven surfaces.  Typical of the limited community ambulator.
Level 3:  Has the ability or potential for ambulation with variable cadence.  Typical of the community ambulator who has the ability to traverse most environmental barriers and may have vocational, therapeutic, or exercise activity that demands prosthetic utilization beyond simple locomotion.
Level 4:  Has the ability or potential for prosthetic ambulation that exceeds basic ambulation skills, exhibiting high impact, stress, or energy levels.  Typical of the prosthetic demands of the child, active adult, or athlete.

I.     Lower Limb: Prosthesis Fitting and Selection

Medically Necessary:

A lower limb prosthesis is considered medically necessary when all the following are met and are documented in the medical record:

1. The prosthesis is prescribed by physician; and
2. The member will reach or maintain a defined functional state within a reasonable period of time; and
3. The member needs prosthesis for ambulation; and
4. The member's rehabilitation potential is based on functional levels as outlined above; and
5. The following anatomy-specific criteria apply:
   • Ankles:
     An axial rotation unit is considered medically necessary for individuals whose functional level is 2 or above.
   • Knees:
     Basic lower extremity prostheses include a single axis, constant friction knee.  Prosthetic knees are considered for medical necessity based upon functional classification:
     1. Fluid and pneumatic knees are considered medically necessary for members with a functional Level 3 or above.
     2. Other knee systems are considered medically necessary for members with a functional Level 1 or above.
   • Sockets:
     1. Up to 2 test (diagnostic) sockets for an individual prosthesis are medically necessary without additional documentation.
     2. Socket replacements are considered medically necessary if there is adequate functional documentation of and/or physiological need, including, but not limited to:
        • Changes in the residual limb; or
        • Functional need changes; or
        • Irreparable damage; or
        • Wear/tear due to excessive member weight or prosthetic demands of very active amputees.
   • Feet:
     The treating physician or the prosthetist will make the determination of the type of foot needed for the prosthesis based upon the functional needs of the individual. Basic lower extremity prostheses include a SACH foot. Other prosthetic feet are considered for medical necessity based upon functional classification.
     1. An external keel SACH foot or single axis ankle/foot is considered medically necessary for individuals whose functional level is 1 or above.
     2. A flexible-keel foot or multi-axial ankle/foot is considered medically necessary for individuals whose functional level is 2 or above.
     3. A flex foot system, energy storing foot, multi-axial ankle/foot, dynamic response, or flex-walk system or equal, or shank foot system with vertical loading pylon is considered medically necessary for individuals whose functional level is 3 or above.

Not Medically Necessary: 

A lower limb prosthesis is considered not medically necessary when the above have not been met.

A lower limb prosthesis is considered not medically necessary for individuals with a functional level of 0.

Test (diagnostic) sockets for immediate post-surgical or early fitting prostheses are considered not medically necessary.

More than two test (diagnostic) sockets for an individual prosthesis are considered not medically necessary without additional documentation of need.

More than two of the same socket inserts are considered not medically necessary per individual prosthesis at the same time.

II.  Lower Limb: Accessories, Maintenance, Repairs and Replacement

Medically Necessary: 

Accessories (e.g., stump stocking for the residual limb, harness, etc.) are considered medically necessary when these appliances aid in or are essential to the effective use of the artificial limb.

Repairs to a prosthesis are considered medically necessary when necessary to make the prosthesis functional.

Maintenance that may be necessitated by manufacturer's recommendations or the construction of the prosthesis and must be performed by the prosthetist is considered medically necessary as a repair.

Adjustments to a prosthesis required by wear and tear or change in an individual's condition are considered medically necessary.

Replacement of a prosthesis or prosthetic component is considered medically necessary if the treating physician orders a replacement device or part because of any of the following:

• A change in the physiological condition of the individual; or
• Irreparable wear of the device or a part of the device; or
• The condition of the device, or part of the device, requires repairs and the cost of such repairs would be more than 60% of the cost of a replacement device or of the part being replaced.

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy.  Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

The need for a prosthetic limb is based upon the expectations and judgment of the treating physician or prosthetist regarding the post-treatment expectation of an individual's functional level.  Potential function ability is based upon many factors, factors including, but not limited to, the following:

1. The individual's past history and level of activity (including prior prosthetic use if applicable)
2. The individual's current condition including the status of the residual limb and the nature of other medical problems
3. The individual's desire to ambulate. 

A determination regarding the use or appropriateness of certain components/additions to the prosthesis is also based on the member's potential functional abilities.

Peer Reviewed Publications:

1. Johannesson A, Larsson GU, Oberg T, Atroshi I. Comparison of vacuum-formed removable rigid dressing with conventional rigid dressing after transtibial amputation: similar outcome in a randomized controlled trial involving 27 patients. Acta Orthop. 2008; 79(3):361-369.
2. Leonard JA, Meier RH. Upper and lower extremity prosthetics. In: DeLisa JA, ed, Rehabilitation Medicine: Principles and Practice. 2^nd Ed. Philadelphia, PA: J.B. Lippincott Co. 1993:507, 514-515.

Government Agency, Medical Society, and Other Authoritative Publications:

1. Hofstad C, van der Linde H, van Limbeek J, Postema K. Prescription of prosthetic ankle-foot mechanisms after lower limb amputation. Cochrane Database Syst Rev. 2004;(1):CD003978.
2. National Government Services Jurisdiction A/B. Local Coverage Determination for Lower Limb Prostheses (L27013). Revised 04/15/2011. Available at: http://www.cms.hhs.gov/mcd/index_local_alpha.asp?from=alphalmrp&letter=A. Accessed on August 12, 2011.

Lower Leg
Prosthesis
SACH Foot

The use of specific product names is illustrative only.  It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.