A Cost-Benefit Analysis of Osseointegrated Prostheses for Lower Limb Amputees in the US Health Care System.

Abstract

Patients with transfemoral and transtibial amputations generally rely on socket-suspended (SS) prostheses for ambulation. The use of these aids can be complicated by poor fit, leading to tissue damage, pain at the socket-limb interface, and inability to ambulate. Osseointegrated implants (OIs) directly anchor a prosthesis to the patient's residual limb, eliminating these issues. However, they require customized components and additional surgeries. The purpose of this study was to conduct the first cost-benefit analysis of OI prostheses compared to SS prostheses for lower limb amputees in the United States. A retrospective chart review was performed on all patients who received unilateral lower limb OI prostheses at our institution. Costs were calculated in a bottom-up approach using Current Procedural Terminology codes. Utilities and SS prosthesis costs were derived from previous studies. A Monte Carlo model was used to project costs and lifetime quality-adjusted life years for OI and SS prostheses, and the incremental cost-effectiveness ratio (ICER) of OI compared SS prostheses was determined. Twenty-five patients (12 female) were included in the study. The mean follow-up was 17 months postimplantation. The average cost of OI surgery was $54,463. Twenty percent of patients required preimplantation soft tissue revision surgery ($49,191). Complication rates per year and average costs were as follows: soft tissue infection (29%, $435), bone/implant infection (11%, $11,721), neuroma development (14%, $14,659), and mechanical failure (17%, $46,513). The ICER was $44,660. A cost-effectiveness acceptability curve demonstrated that OI was favored over SS in 78% of cases at a willingness-to-pay of $100,000 per quality-adjusted life year. In a 1-way sensitivity analysis, the ICER was most sensitive to the mechanical failure rate, mechanical failure cost, and prior SS prosthesis costs. The model shows that OI prostheses provide a higher quality of life at affordable costs when compared to poorly tolerated SS prostheses in patients with lower limb amputations in the United States. The cost-effectiveness is largely determined by the patient's previous SS prosthesis costs and is limited by the frequency and costs of OI mechanical failure. More research must be done to understand the long-term benefits and risks of OI prostheses.