Lower Extremity Prosthetics Nm Cs

Coverage Summary

This is a New Mexico–specific UnitedHealthcare medical policy (Policy Number: CS361NM.E) effective May 1, 2026, that defines coverage positions for lower extremity prosthetics and references state and non-state clinical criteria. The policy only applies to New Mexico and directs users to the New Mexico Administrative Code (NMAC) § 8.324.5 for state-specific medical necessity clinical coverage criteria and to InterQual® CP: Durable Medical Equipment, Prosthetics, Lower Extremity for non‑state‑specific criteria.

At a technology level the policy takes specific device determinations: bone‑anchored percutaneous limb prostheses (e.g., OPRA) are considered unproven and not medically necessary due to insufficient evidence of efficacy. Microprocessor technologies have mixed determinations: an endoskeletal knee‑shin system with microprocessor control (swing/stance phase) is unproven and not medically necessary for certain low‑function amputees (K1 or K2) and specified amputation levels (e.g., transfemoral/AK, hip disarticulation/hemipelvectomy). A combined microprocessor‑controlled ankle‑foot with power assist is also listed as unproven and not medically necessary for specified amputation levels. The policy includes an extensive list of applicable HCPCS/L‑codes (with L5992 added in the update).

Overall coverage stance is mixed: the policy permits standard lower extremity prostheses where supported by InterQual and state rules, but explicitly designates several advanced technologies (bone‑anchored OPRA, certain microprocessor knee/ankle powered combinations) as unproven/not medically necessary for specified populations.

Medical Necessity & Coverage Criteria

General Coverage / References

Coverage decisions reference state rules and InterQual criteria:

ALL of the following

This Medical Policy only applies to the state of New Mexico.
For medical necessity clinical coverage criteria, refer to New Mexico Administrative Code (NMAC) § 8.324.5: Vision Appliances, Hearing Appliances, Durable Medical Equipment, Oxygen, Medical Supplies, Prosthetics and Orthotics.
For non-state-specific medical necessity clinical coverage criteria, refer to the InterQual® CP: Durable Medical Equipment, Prosthetics, Lower Extremity.

Not Medically Necessary / Unproven

The following prosthetic technologies are considered unproven and not medically necessary due to insufficient evidence of efficacy:

ANY of the following

Bone anchored percutaneous limb prosthesis (OPRA): A bone anchored percutaneous limb prosthesis (e.g., Osseoanchored Prostheses for the Rehabilitation of Amputees (OPRA) Implant System) is unproven and not medically necessary due to insufficient evidence of efficacy.
Microprocessor knee-shin system with swing/stance control
- Microprocessor knee general statement: Endoskeletal knee-shin system with microprocessor control feature (swing/stance phase).
- AND required functional classification: Amputee with functional classification status of K1 or K2.

Documentation and Benefit Determination

Coverage decisions must meet federal, state, or contractual requirements and be supported by medical record documentation:

ALL of the following

Benefit/Legal Determination: Benefit coverage is determined by federal, state, or contractual requirements and applicable laws which may require coverage for a specific service.
Medical records may be requested: Medical records documentation may be required to assess whether the member meets the clinical criteria for coverage but does not guarantee coverage of the services requested.
Documentation must support medical necessity: The patient's medical record must contain documentation that fully supports the medical necessity for the requested services, including but not limited to relevant medical history, physical examination, and results of pertinent diagnostic tests or procedures; documentation should be legible and made available upon request.

Applicable Codes

Applicable HCPCS / L-codes (lower extremity prosthetics and additions)HCPCS

L5000	Partial foot, shoe insert with longitudinal arch, toe filler.
L5010	Partial foot, molded socket, ankle height, with toe filler.
L5020	Partial foot, molded socket, tibial tubercle height, with toe filler.
L5050	Ankle, Symes, molded socket, SACH foot.
L5060	Ankle, Symes, metal frame, molded leather socket, articulated ankle/foot (SACH).
L5100	Below knee (BK), molded socket, shin, SACH foot.
L5105	Below knee (BK), plastic socket, joints and thigh lacer, SACH foot.
L5150	Knee disarticulation (or through knee), molded socket, external knee joints, shin, SACH foot.
L5160	Knee disarticulation (or through knee), molded socket, bent knee configuration, external knee joints, shin, SACH foot.
L5200	Above knee (AK), molded socket, single axis constant friction knee, shin, SACH foot.

1–10 of 143

1/15

Provider Actions & Billing

Documentation Required

Medical records documentation requirement

The patient's medical record must contain documentation that fully supports the medical necessity for the requested prosthetic services. Required documentation includes, but is not limited to, relevant medical history, physical examination, and results of pertinent diagnostic tests or procedures.

History
Physical examination
Pertinent diagnostic tests or procedures

Documentation Required

Reference to external clinical criteria

Providers must reference New Mexico Administrative Code (NMAC) § 8.324.5 for New Mexico‑specific medical necessity clinical coverage criteria. For non‑state‑specific determinations, InterQual® CP: Durable Medical Equipment, Prosthetics, Lower Extremity may be used to support medical necessity reviews; medical records may be requested to assess compliance with these criteria.

Background & Evidence Summary

Lower extremity prostheses are artificial devices intended to restore function and help amputees achieve independence (ambulation on level and uneven surfaces, stairs, ramps, and activities of daily living). The policy notes the most common lower‑limb amputation levels are transtibial (below‑knee, BK) and transfemoral (above‑knee, AK).

The supporting evidence base includes evolving evidence reviews (Hayes) and an ECRI clinical assessment; multiple clinical studies and cohort series have evaluated bone‑anchored percutaneous limb prostheses (e.g., OPRA, POP). These reports document improvements in patient‑reported outcomes for some users but raise substantial safety concerns, notably high infection rates, frequent mechanical complications, and high revision/removal rates, and overall evidence is described as limited in quality and quantity.

Evidence Source	Key Finding
Hayes Evolving Evidence Review (OPRA, 2023; updated 2025)	Found limited/low-quality evidence and no/unclear support for OPRA in transfemoral amputations; high revision and infection rates reported; 2024–25 updates did not change level of support.
ECRI clinical assessment (2022)	Concluded evidence inconclusive for OPRA; low-quality studies report mobility/QOL improvements but frequent serious complications (infections, implant loosening) leaving uncertain risk-benefit balance.
Sinclair et al. (2022) — POP study (n=10)	Prospective FDA IDE single-center study: safety concerns including device removals, infection, periprosthetic fracture; small sample and two device removals during follow-up.
Hagberg et al. (2022) — OPRA 10-year cohort (n=51)	Patient-reported outcomes improved at 10 years, but revision-free survival at 10 years: implant revision 83% (CI 69%-91%), deep infection 65% (CI 49%-77%), mechanical complications 17% (CI 7%-29%); high mechanical complication incidence and notable implant removals.
Hagberg et al. analyses (mechanical complications rates)	Mechanical complications constituted most common serious adverse event (3.9 per 10 person-years); mechanical complications increased in later five years; deep infection incidence ~0.3 per 5 person-years.
Brånemark et al. (2019) / Hagberg et al. (2020) longer cohorts	Long-term cohorts report improved prosthetic use and mobility but frequent superficial and deep infections and numerous mechanical complications requiring hardware replacement; fixture survival maintained but adverse events substantial.
Toderita et al. (2024) & Ranaldi et al. (2023)	Small comparative and case-series data show some gait and Q-TFA score improvements after osseointegration, but studies are small, non-generalizable, and lack long-term outcomes.
Klenow et al. (2024) — Genium MPK RCT	Randomized trial of Genium enhancements: stumble frequency reduced 85% (p=0.008); unilateral group showed reductions in residual limb and low back pain and ADL improvements; sample small and limitations noted.
Morgan et al. (2024) — early rehab MPK pilot RCT	Pilot RCT: MPK users had higher mobility and balance scores (PLSOM p=.01; ABC p=.01) and better return-to-normal-living scores; small sample but favored MPK in early rehab.
AHRQ Lower Limb Prostheses review (2018)	Identified 77 articles; evidence limited by small/nonrandomized studies and lack of long-term US data; insufficient/low evidence on many long-term outcomes.
Hayes Evolving Evidence Review (Powered MPAs, 2022; updates 2023–24)	Minimal support for powered microprocessor prosthetic ankles: small, low-quality, inconsistent studies; 2023–24 updates did not change conclusions.
Kim et al. (2021) randomized trial (BiOM)	Small RCT (n=12) found no significant differences between powered and unpowered prostheses on metabolic cost, activity, or perceived mobility; device issues and small sample limit conclusions.
Brannen et al. (2025) — powered hip prototype	Prototype passed ISO 15032:2000 strength tests and enabled level walking in three able-bodied subjects, but functional testing limited and design limitations noted; early-stage evidence.
Kannenberg et al. (2022) survey on PwrAF users	Cross-sectional survey (n=46 analyzed) reported improvements in pain and mobility among current powered ankle users after recall adjustment, but limitations include recall bias, small and male-only sample, and many former users reverted to passive feet.

Definitions

Activities of Daily Living (ADLs) -> Basic tasks needed for functioning such as bathing, grooming, dressing, toilet use, eating, and ambulation.

Instrumental Activities of Daily Living (IADLs) -> Complex activities related to independent living such as shopping, transportation, meal preparation, housecleaning, managing finances, and managing medications.

CMS Modifiers / Medicare Functional Classification Level (MFCL) / K0–K4 -> A classification of prosthetic functional potential ranging from K0 (no potential) through K4 (high activity/athlete) with described functional examples for each modifier.

Microprocessor Controlled Ankle Foot Prosthesis (MPA) -> A device able to actively change ankle angle and identify slope via microprocessor control and sensors.

Microprocessor Controlled Lower Limb Prostheses / MPK -> Microprocessor‑controlled knees that use sensors to provide dynamic swing/stance resistance and attempt to simulate biological knee function (adjust swing/stance resistance, improve stumble recovery).

Myoelectric Prosthetic -> A prosthesis operated by battery‑powered motors activated by muscle myoelectric potentials.

Prosthesis -> Man‑made substitute for a missing body part intended to restore function.

Prosthetist -> Healthcare professional who makes and fits artificial limbs.

OPRA -> Osseointegrated Prostheses for the Rehabilitation of Amputees implant system (bone‑anchored percutaneous limb prosthesis).

MPA / Powered Microprocessor Prosthetic Ankle / PwrAF -> A powered microprocessor ankle‑foot device intended to improve gait and mobility in transtibial amputees.

Revision History

05/01/2026material_changeLatest

State-specific criteria reference added to Coverage Rationale (material). Detail: Added instruction to refer to the New Mexico Administrative Code (NMAC) § 8.324.5 for medical necessity clinical coverage criteria.

05/01/2026material_change

Medical records documentation requirements clarified (material). Detail: Added language listing required contents of documentation, noting documentation may be requested to assess medical necessity and that documentation does not guarantee coverage.

05/01/2026material_change