Microprocessor-Controlled Prostheses for the Lower Limb
DESCRIPTION
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 individuals who have the capability to maneuver on uneven terrain and with a variable gait.
Microprocessor-controlled prosthetic knees have been developed, including the Intelligent Prosthesis, Adaptive, Rheo Knee®, C-Leg®, Genium™ Bionic Prosthetic System, X2, X3, and Seattle Power Knees. These devices are equipped with a sensor that detects when the knee is in full extension and adjusts the swing phase automatically, permitting a more natural walking pattern of varying speeds. The prosthetist can specify several different optimal adjustments that the computer later selects and applies according to the pace of ambulation. Prosthetic knees also vary in their ability to alter the cadence of the gait, or the ability to walk on rough or uneven surfaces.
Microprocessor-controlled ankle-foot prostheses are being developed for transtibial amputees, (e.g., Proprio Foot®, iPED, and the Endolite Elan). With sensors in the feet that determine the direction and speed of the foot’s movement, a microprocessor controls the flexion angle of the ankle, allowing the foot to lift during the swing phase and potentially adjust to changes in force, speed, and terrain during the step phase. The intent of the technology is to make ambulation more efficient and prevent falls.
Currently in development are lower-limb prostheses with power assist that are designed to replace muscle activity. The Power Knee™, which is designed to replace muscle activity of the quadriceps, uses artificial proprioception with sensors to anticipate and respond with the appropriate movement required for the next step. The PowerFoot BiOM® is a myoelectric prosthesis for transtibial amputees that uses muscle activity from the remaining limb for the control of ankle movement. This prosthesis is designed to propel the foot forward as it pushes off the ground during the gait cycle. This technology is proposed to improve efficiency and reduce hip and back problems arising from an unnatural gait with the use of a passive prosthesis.
POLICY
A microprocessor-controlled knee is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
A powered knee is considered investigational.
A microprocessor-controlled or powered foot is considered investigational.
MEDICAL APPROPRIATENESS
A microprocessor-controlled knee in an amputee is considered medically appropriate if ALL of the following are met:
Physical ability, including adequate cardiovascular and pulmonary reserve, for ambulation at faster than normal walking speed
Demonstrated need for long distance ambulation at variable rates or for ambulation on uneven terrain (use of the limb in the home or for basic community ambulation, including negotiation of stairs, is not sufficient to justify provision of the computerized limb over standard limb applications)
Adequate cognitive ability to master use and care requirements for the technology
IMPORTANT REMINDERS
Any specific products referenced in this policy are just examples and are intended for illustrative purposes 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. These examples are contained in the parenthetical e.g. statement.
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits, or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan or government program (e.g., TennCare), the express terms of the health plan or government program will govern.
ADDITIONAL INFORMATION
Medicare uses the following functional ability levels when determining medical necessity:
Level 0. Does not have the ability or potential to ambulate or transfer safely with or without assistance and a prosthesis does not enhance their quality of life or mobility.
Level 1. Has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence. Typical of the limited and unlimited household ambulatory.
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 ambulatory.
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 demand of the child, active adult, or athlete.
The limited evidence available to date does not support an improvement in functional outcomes with a microprocessor-controlled or powered ankle-foot prosthesis compared with a standard prosthesis.
SOURCES
BlueCross BlueShield Association. Evidence Positioning System. (4:2023). Microprocessor-controlled prostheses for the lower limb (1.04.05). Retrieved January 8, 2024 from www.bcbsaoca.com/eps/. (28 articles and/or guidelines reviewed)
CMS.gov: Center for Medicare & Medicaid Services, CGS Administrators, LLC. (2024, January). Lower limb prostheses (LCD ID: L33787). Retrieved January 8, 2024 from http://www.cms.gov.
Darter, B.J., & Wilken, J.M. (2014). Energetic consequences of using a prosthesis with adaptive ankle motion during slope walking in persons with a transtibial amputation. Prosthetics and Orthotics International, 38 (1), 5-11. (Level 3 evidence)
Deems-Dluhy, S., Hoppe-Ludwig, S., Mummidisetty, C.K., Semik, P., Heinemann, A.W., & Jayaraman, A. (2021). Microprocessor controlled knee ankle foot orthosis (KAFO) vs stance control vs locked KAFO: A randomized controlled trial. Archives of Physical Medicine and Rehabilitation, 102 (2), 233-244. Abstract retrieved August 2, 2021 from PubMed database.
Delussu, A., Brunelli, S., Paradisi, F., Iosa, M., Pellegrini, R., Zenardi, D., et al. (2013). Assessment of the effects of carbon fiber and bionic foot during overground and treadmill walking in transtibial amputees. Gait & Posture, e-published ahead of print http://dx.doi.org/10.1016/j.gaitpost.2013.04.009. (Level 4 evidence)
Kannenberg, A., Zacharias, D., & Pröbsting, E. (2014). Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: systematic review. Journal of Rehabilitation Research & Development, 51, (10), 1469-1496. (Level 2 evidence)
Kaufman, K.R., Bernhardt, K.A., & Symms, K. (2018). Functional assessment and satisfaction of transfemoral amputees with low mobility (FASTK2): A clinical trial of microprocessor-controlled vs. non-microprocessor-controlled knees. Clinical Biomechanics, 58, 116-122. Abstract retrieved October 7, 2020 from PubMed database.
Rosenblatt, N., Bauer, A., Rotter, D., & Grabiner, M. (2014). Active dorsiflexing prostheses may reduce trip-related fall risk in people with transtibial amputation. Journal of Rehabilitation Research & Development (JRRD), 51 (8), 1229-1242. (Level 4 evidence)
Struchkov, V. & Buckley, J. (2015). Biomechanics of ramp descent in unilateral trans-tibial amputees: Comparison of a microprocessor controlled foot with conventional ankle–foot mechanisms. Clinical Biomechanics, 32, 164-170. (Level 4 evidence)
Theeven, P., Hemmen, B., Brink, P., Smeets, R., & Seelen, H. (2013). Measures and procedures utilized to determine the added value of microprocessor-controlled prosthetic knee joints: a systematic review. BMC Musculoskeletal Disorders, 14, 333. (Level 1 evidence)
U.S. Food and Drug Administration. (1999, July). Center for Devices and Radiological health. 510(k) Premarket Notification Database. K991590. Retrieved January 24, 2017 from http://www.accessdata.fda.gov.
Webster, J.B., Crunkhorn, A., Sall, J., Highsmith, J., Pruziner, A., & Randolph, B.J. (2019). Clinical practice guidelines for the rehabilitation of lower limb amputation an update from the department of veterans affairs and department of defense. American Journal of Physical Medicine & Rehabilitation, 98 (9), 820-829. (Level 1 evidence)
ORIGINAL EFFECTIVE DATE: 11/13/2010
MOST RECENT REVIEW DATE: 2/8/2024
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Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
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