Microprocessor- Controlled Prostheses for the Lower Limb Form

500 EXCHANGE STREET, PROVIDENCE, RI 02903-2699 MEDICAL COVERAGE POLICY | 1 (401) 274-4848 WWW.BCBSRI.COM

EFFECTIVE DATE: 11|01|2025 POLICY LAST REVIEWED: 08|06|2025

OVERVIEW Microprocessor-controlled prostheses use feedback from sensors to adjust joint movement on a real-time as- needed basis. Active joint control is intended to improve safety and function, particularly for patients who can maneuver on uneven terrain and with variable gait.

Note: This policy is applicable for Commercial Products only. For Medicare Advantage Plans, see the applicable policy in the Related Policies section. MEDICAL CRITERIA Medicare Advantage Plans Blue Cross & Blue Shield of Rhode Island (BCBSRI) follows the medical necessity criteria from the Centers for Medicare and Medicaid Services (CMS) National and Local Coverage Determinations (NCD/LCD) for L5615. Please use the online tool for participating providers. See the Related Policies section.

Commercial Products The medical criteria below is only applicable for the following HCPCS code:
 L5615 (for dates of service on or after 1/1/2024)

For all other microprocessor-controlled prostheses for the lower limb HCPCS codes (L5856, L5857, L5858 & L5973), please use the online tool for participating providers. See the Related Policies section.

A microprocessor-controlled knee may be considered medically necessary in individuals with transfemoral amputation who meet the following requirements:  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 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, including adequate cardiovascular and pulmonary reserve, for ambulation at faster than normal walking speed; AND  adequate cognitive ability to master use and care requirements for the technology

Amputees should be evaluated by an independent, qualified professional to determine the most appropriate prosthetic components and control mechanism. A trial period may be indicated to evaluate the tolerability and efficacy of the prosthesis in a real-life setting. Decisions about the potential benefits of microprocessor knees involve multiple factors including activity levels and the patient's physical and cognitive ability. A patient's need for daily ambulation of at least 400 continuous yards, daily and frequent ambulation at variable cadence or on uneven terrain (eg, gravel, grass, curbs), and daily and frequent use of ramps and/or stairs (especially stair descent) should be considered as part of the decision. Typically, the daily and frequent need of 2 or more of these activities would be needed to show benefit.

Individual Selection and Identification Medical Coverage Policy | Microprocessor- Controlled Prostheses for the Lower Limb

500 EXCHANGE STREET, PROVIDENCE, RI 02903-2699 MEDICAL COVERAGE POLICY | 2 (401) 274-4848 WWW.BCBSRI.COM

For individuals in whom the potential benefits of the microprocessor knees are uncertain, individuals may first be fitted with a standard prosthesis to determine their level of function with the standard device.

A. Contraindications for the use of the microprocessor knee should include the following:  Any condition that prevents socket fitting, such as a complicated wound or intractable pain which precludes socket wear  Inability to tolerate the weight of the prosthesis  Medicare level K0-no ability or potential to ambulate or transfer  Medicare level K1-limited ability to transfer or ambulate on level ground at fixed cadence  Medicare level K2-limited community ambulator who does not have the cardiovascular reserve, strength, and balance to improve stability in stance to permit increased independence, less risk of falls, and potential to advance to a less restrictive walking device  Inability to use swing and stance features of the knee unit  Poor balance or ataxia that limits ambulation  Significant hip flexion contracture (>20°)  Significant deformity of remaining limb that would impair the ability to stride  Limited cardiovascular and/or pulmonary reserve or profound weakness  Limited cognitive ability to understand gait sequencing or care requirements  Long-distance or competitive running  Falls outside of recommended weight or height guidelines of the manufacturer  Specific environmental factors such as excessive moisture or dust, or inability to charge the prosthesis  Extremely rural conditions where maintenance ability is limited.

B. Indications for the use of the microprocessor knee should include the following:  Adequate cardiovascular and pulmonary reserve to ambulate at variable cadence  Adequate strength and balance in stride to activate the knee unit  Should not exceed the weight or height restrictions of the device  Adequate cognitive ability to master technology and gait requirements of the device  Hemi-pelvectomy through knee-disarticulation level of amputation, including bilateral; lower- extremity amputees are candidates if they meet functional criteria as listed  The individual is an active walker and requires a device that reduces energy consumption to permit longer distances with less fatigue  Daily activities or job tasks that do not permit full focus of concentration on knee control and stability-such as uneven terrain, ramps, curbs, stairs, repetitive lifting, and/or carrying  Medicare level K2-limited community ambulator, but only if improved stability in stance permits increased independence, less risk of falls, and potential to advance to a less restrictive walking device, and the individual has the cardiovascular reserve, strength, and balance to use the prosthesis. The microprocessor enables fine-tuning and adjustment of the hydraulic mechanism to accommodate the unique motor skills and demands of the functional level K2 ambulator.  Medicare level K3-unlimited community ambulator  Medicare level K4-active adult athlete who needs to function as a K3 level in daily activities  Potential to lessen back pain by providing more secure stance control, using less muscle control to keep the knee stable  Potential to unload and decrease stress on remaining limb  Potential to return to an active lifestyle.

C. Physical and Functional Fitting Criteria for New Amputees:  New amputees may be considered if they meet certain criteria as outlined above  Premorbid and current functional assessment important determinant

500 EXCHANGE STREET, PROVIDENCE, RI 02903-2699 MEDICAL COVERAGE POLICY | 3 (401) 274-4848 WWW.BCBSRI.COM

 Requires stable wound and ability to fit the socket  Immediate postoperative fit is possible  Must have potential to return to an active lifestyle

PRIOR AUTHORIZATION
Prior authorization for microprocessor-controlled prostheses (L5615) for lower limb is required for Medicare Advantage Plans and recommended for Commercial Products.

For all other microprocessor-controlled prostheses for the lower limb HCPCS codes (L5856, L5857, L5858 & L5973), prior authorization is required for Medicare Advantage Plans and recommended for Commercial Products using the medical criteria available in the online authorization tool for participating providers. POLICY STATEMENT Commercial Products A microprocessor-controlled knee in individuals with transfemoral amputation is considered medically necessary when the criteria above are met.

A powered knee is considered not covered for Medicare Advantage Plans and not medically necessary for Commercial Products as the evidence is insufficient to determine that the technology results in an improvement in the net health outcome.
COVERAGE Benefits may vary between groups and contracts. Please refer to the appropriate Benefit Booklet, Evidence of Coverage or Subscriber Agreement for applicable not medically necessary/not covered benefits/coverage. BACKGROUND Lower-Extremity Prosthetics More than 100 different prosthetic ankle-foot and knee designs are currently available. The choice of the most appropriate design may depend on the patient’s underlying activity level. For example, the requirements of a prosthetic knee in elderly, largely homebound individual will differ from those of a younger, active person. Key elements of prosthetic knee design involve providing stability during both the stance and swing phase of the gait. Prosthetic knees vary in their ability to alter the cadence of the gait, or the ability to walk on rough or uneven surfaces. In contrast to more simple prostheses, which are designed to function optimally at 1 walking cadence, fluid and hydraulic-controlled devices are designed to allow amputees to vary their walking speed by matching the movement of the shin portion of the prosthesis to the movement of the upper leg. For example, the rate at which the knee flexes after “toe-off” and then extends before heel strike depends in part on the mechanical characteristics of the prosthetic knee joint. If the resistance to flexion and extension of the joint does not vary with gait speed, the prosthetic knee extends too quickly or too slowly relative to the heel strike if the cadence is altered. When properly controlled, hydraulic or pneumatic swing-phase controls allow the prosthetist to set a pace adjusted to the individual amputee, from very slow to a race-walking pace. Hydraulic prostheses are heavier than other options and require gait training; for these reasons, these prostheses are prescribed for athletic or fit individuals. Other design features include multiple centers of rotation, referred to as “polycentric knees.” The mechanical complexity of these devices allows engineers to optimize selected stance and swing-phase features.

Regulatory Status According to the manufacturers, microprocessor-controlled prostheses are considered a class I device by the FDA and are exempt from 510(k) requirements. This classification does not require submission of clinical data regarding efficacy but only notification of FDA prior to marketing. FDA product codes: ISW, KFX.

For individuals who have a transfemoral amputation who receive a prosthesis with a microprocessor- controlled knee, the evidence includes a number of within-subject comparisons of microprocessor-controlled knees versus non-microprocessor-controlled knee joints and systematic reviews of these studies. Relevant outcomes are functional outcomes, health status measures, and quality of life. For K3- and K4-level

500 EXCHANGE STREET, PROVIDENCE, RI 02903-2699 MEDICAL COVERAGE POLICY | 4 (401) 274-4848 WWW.BCBSRI.COM

amputees, studies have shown an objective improvement in function on some outcome measures, particularly for hill and ramp descent, and strong patient preference for microprocessor-controlled prosthetic knees. Benefits include a more normal gait, increased stability, and a decrease in falls. The evidence in Medicare level K2 ambulators suggests that a prosthesis with stance control only can improve activities that require balance and improve walking in this population. For these reasons, a microprocessor-controlled knee may provide incremental benefit for these individuals. The potential to achieve a higher functional level with a microprocessor-controlled knee includes having the appropriate physical and cognitive ability to use the advanced technology. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have a transfemoral amputation who receive a prosthesis with a powered knee, the evidence includes no data. Relevant outcomes are functional outcomes, health status measures, and quality of life. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

CODING Medicare Advantage Plans The following CPT code(s) are medically necessary for Medicare Advantage Plans when the medical criteria in the in the online authorization tool for participating providers is met: L5615 Addition, endoskeletal knee-shin system, 4 bar linkage or multiaxial, fluid swing and stance phase control

Commercial Products The following HCPCS code(s) is medically necessary for Commercial Products when the medical criteria above has been met: L5615 Addition, endoskeletal knee-shin system, 4 bar linkage or multiaxial, fluid swing and stance phase control

The following HCPCS code(s) are not covered and not medically necessary for
Commercial Products: L5827 Endoskeletal knee-shin system, single axis, electromechanical swing and stance phase control, with or without shock absorption and stance extension damping (New Code Effective 4/1/2025) RELATED POLICIES Prior Authorization via Web-Based Tool for Durable Medical Equipment (DME) Medicare Advantage Plans National and Local Coverage Determinations

PUBLISHED Provider Update, September 2025
Provider Update, June 2025 Provider Update, June 2024 Provider Update, May 2023 Provider Update, November 2022

REFERENCES

1. Flynn K. Short Report: Computerized lower limb prosthesis (VA Technology Assessment Program). No. 2. Boston, MA: Veterans Health Administration; 2000.
2. Thibaut A, Beaudart C, Maertens DE Noordhout B, et al. Impact of microprocessor prosthetic knee on mobility and quality of life in patients with lower limb amputation: a systematic review of the literature. Eur J Phys Rehabil Med. Jun 2022; 58(3): 452-461. PMID 35148043
3. Hahn A, Bueschges S, Prager M, et al. The effect of microprocessor controlled exo-prosthetic knees on limited community ambulators: systematic review and meta-analysis. Disabil Rehabil. Dec 2022; 44(24): 7349-7367. PMID 34694952
4. Morgan SJ, Friedly JL, Nelson IK, et al. The effects of microprocessor prosthetic knee use in early rehabilitation: A pilot randomized controlled trial. PM R. Feb 02 2025. PMID 39895150

500 EXCHANGE STREET, PROVIDENCE, RI 02903-2699 MEDICAL COVERAGE POLICY | 5 (401) 274-4848 WWW.BCBSRI.COM

5. Theeven P, Hemmen B, Rings F, et al. Functional added value of microprocessor-controlled knee joints in daily life performance of Medicare Functional Classification Level-2 amputees. J Rehabil Med. Oct 2011; 43(10): 906-15. PMID 21947182
6. Theeven PJ, Hemmen B, Geers RP, et al. Influence of advanced prosthetic knee joints on perceived performance and everyday life activity level of low-functional persons with a transfemoral amputation or knee disarticulation. J Rehabil Med. May 2012; 44(5): 454-61. PMID 22549656
7. Burnfield JM, Eberly VJ, Gronely JK, et al. Impact of stance phase microprocessor-controlled knee prosthesis on ramp negotiation and community walking function in K2 level transfemoral amputees. Prosthet Orthot Int. Mar 2012; 36(1): 95-104. PMID 22223685
8. Orendurff MS, Segal AD, Klute GK, et al. Gait efficiency using the C-Leg. J Rehabil Res Dev. 2006; 43(2): 239-46. PMID 16847790
9. Klute GK, Berge JS, Orendurff MS, et al. Prosthetic intervention effects on activity of lower- extremity amputees. Arch Phys Med Rehabil. May 2006; 87(5): 717-22. PMID 16635636
10. Williams RM, Turner AP, Orendurff M, et al. Does having a computerized prosthetic knee influence cognitive performance during amputee walking?. Arch Phys Med Rehabil. Jul 2006; 87(7): 989-94. PMID 16813788
11. Hafner BJ, Smith DG. Differences in function and safety between Medicare Functional Classification Level-2 and -3 transfemoral amputees and influence of prosthetic knee joint control. J Rehabil Res Dev. 2009; 46(3): 417-33. PMID 19675993
12. Highsmith MJ, Kahle JT, Miro RM, et al. Ramp descent performance with the C-Leg and interrater reliability of the Hill Assessment Index. Prosthet Orthot Int. Oct 2013; 37(5): 362-8. PMID 23327837
13. Howard CL, Wallace C, Perry B, et al. Comparison of mobility and user satisfaction between a microprocessor knee and a standard prosthetic knee: a summary of seven single-subject trials. Int J Rehabil Res. Mar 2018; 41(1): 63-73. PMID 29293160
14. Hafner BJ, Willingham LL, Buell NC, et al. Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee. Arch Phys Med Rehabil. Feb 2007; 88(2): 207-17. PMID 17270519
15. Kaufman KR, Bernhardt KA, Symms K. Functional assessment and satisfaction of transfemoral amputees with low mobility (FASTK2): A clinical trial of microprocessor-controlled vs. non- microprocessor-controlled knees. Clin Biomech (Bristol). Oct 2018; 58: 116-122. PMID 30077128
16. Kaufman KR, Levine JA, Brey RH, et al. Gait and balance of transfemoral amputees using passive mechanical and microprocessor-controlled prosthetic knees. Gait Posture. Oct 2007; 26(4): 489-93. PMID 17869114
17. Kaufman KR, Levine JA, Brey RH, et al. Energy expenditure and activity of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees. Arch Phys Med Rehabil. Jul 2008; 89(7): 1380-5. PMID 18586142
18. Johansson JL, Sherrill DM, Riley PO, et al. A clinical comparison of variable-damping and mechanically passive prosthetic knee devices. Am J Phys Med Rehabil. Aug 2005; 84(8): 563-75. PMID 16034225
19. Carse B, Scott H, Brady L, et al. Evaluation of gait outcomes for individuals with established unilateral transfemoral amputation following the provision of microprocessor controlled knees in the context of a clinical service. Prosthet Orthot Int. Jun 01 2021; 45(3): 254-261. PMID 34016870
20. Alzeer AM, Bhaskar Raj N, Shahine EM, et al. Impacts of Microprocessor-Controlled Versus Non- microprocessor-Controlled Prosthetic Knee Joints Among Transfemoral Amputees on Functional Outcomes: A Comparative Study. Cureus. Apr 2022; 14(4): e24331. PMID 35607529
21. Hofstad C, Linde H, Limbeek J, et al. Prescription of prosthetic ankle-foot mechanisms after lower limb amputation. Cochrane Database Syst Rev. 2004; 2004(1): CD003978. PMID 14974050
22. Alimusaj M, Fradet L, Braatz F, et al. Kinematics and kinetics with an adaptive ankle foot system during stair ambulation of transtibial amputees. Gait Posture. Oct 2009; 30(3): 356-63. PMID 19616436
23. Fradet L, Alimusaj M, Braatz F, et al. Biomechanical analysis of ramp ambulation of transtibial amputees with an adaptive ankle foot system. Gait Posture. Jun 2010; 32(2): 191-8. PMID 20457526

500 EXCHANGE STREET, PROVIDENCE, RI 02903-2699 MEDICAL COVERAGE POLICY | 6 (401) 274-4848 WWW.BCBSRI.COM

24. Darter BJ, Wilken JM. Energetic consequences of using a prosthesis with adaptive ankle motion during slope walking in persons with a transtibial amputation. Prosthet Orthot Int. Feb 2014; 38(1): 5-11. PMID 23525888
25. Gailey RS, Gaunaurd I, Agrawal V, et al. Application of self-report and performance-based outcome measures to determine functional differences between four categories of prosthetic feet. J Rehabil Res Dev. 2012; 49(4): 597-612. PMID 22773262
26. Delussu AS, Brunelli S, Paradisi F, et al. Assessment of the effects of carbon fiber and bionic foot during overground and treadmill walking in transtibial amputees. Gait Posture. Sep 2013; 38(4): 876-
27. PMID 23702342
28. Thomas-Pohl M, Villa C, Davot J, et al. Microprocessor prosthetic ankles: comparative biomechanical evaluation of people with transtibial traumatic amputation during standing on level ground and slope. Disabil Rehabil Assist Technol. Jan 2021; 16(1): 17-26. PMID 31535903
29. Colas-Ribas C, Martinet N, Audat G, et al. Effects of a microprocessor-controlled ankle-foot unit on energy expenditure, quality of life, and postural stability in persons with transtibial amputation: An unblinded, randomized, controlled, cross-over study. Prosthet Orthot Int. Dec 01 2022; 46(6): 541-
30. PMID 36515900
31. Au S, Berniker M, Herr H. Powered ankle-foot prosthesis to assist level-ground and stair-descent gaits. Neural Netw. May 2008; 21(4): 654-66. PMID 18499394
32. Ferris AE, Aldridge JM, Rábago CA, et al. Evaluation of a powered ankle-foot prosthetic system during walking. Arch Phys Med Rehabil. Nov 2012; 93(11): 1911-8. PMID 22732369
33. Herr HM, Grabowski AM. Bionic ankle-foot prosthesis normalizes walking gait for persons with leg amputation. Proc Biol Sci. Feb 07 2012; 279(1728): 457-64. PMID 21752817
34. Mancinelli C, Patritti BL, Tropea P, et al. Comparing a passive-elastic and a powered prosthesis in transtibial amputees. Annu Int Conf IEEE Eng Med Biol Soc. 2011; 2011: 8255-8. PMID 22256259
35. Cacciola CE, Kannenberg A, Hibler KD, Howell J. Impact of a Powered Prosthetic Ankle-Foot Component on Musculoskeletal Pain in Individuals with Transtibial Amputation: A Real-World Cross-Sectional Study with Concurrent and Recalled Pain and Functional Ratings. J Prosthet Orthot.
36. doi: 10.1097/JPO.0000000000000442.

37. VA/DOD Clinical Practice Guideline, Work Group. VA/DOD Clinical Practice Guideline for Rehabilitation of Individuals With Lower Limb Amputation. U.S. Government Printing Office; 2024:2-162. https://www.healthquality.va.gov/guidelines/Rehab/amp/LLA-CPG_2024- Guidelinefinal20250110.pdf

    i

    This medical policy is made available to you for informational purposes only. It is not a guarantee of payment or a substitute for your medical judgment in the treatment of your patients. Benefits and eligibility are determined by the member's subscriber agreement or member certificate and/or the employer agreement, and those documents will supersede the provisions of this medical policy. For information on member-specific benefits, call the provider call center. If you provide services to a member which are determined to not be medically necessary (or in some cases medically necessary services which are non-covered benefits), you may not charge the member for the services unless you have informed the member and they have agreed in writing in advance to continue with the treatment at their own expense. Please refer to your participation agreement(s) for the applicable provisions. This policy is current at the time of publication; however, medical practices, technology, and knowledge are constantly changing. BCBSRI reserves the right to review and revise this policy for any reason and at any time, with or without notice. Blue Cross & Blue Shield of Rhode Island is an independent licensee of the Blue Cross and Blue Shield Association. CLICK THE ENVELOPE ICON BELOW TO SUBMIT COMMENTS