Science News: PLUS-M Mobility Values of Osseointegration Patients: How Do Osseointegration Limb Replacement Prosthesis Users Compare to Traditional Socket Amputee Prosthesis Users?

Submitted by: Oksana Sayko, MD
Edited by: Rebecca O'Bryan, MD

Citation: Page BJ, Sheridan GA, Greenstein MD, Hoellwarth JS, Reif TJ, Rozbruch SR. PLUS-M Mobility Values of Osseointegration Patients: How Do Osseointegration Limb Replacement Prosthesis Users Compare to Traditional Socket Amputee Prosthesis Users?. Am J Phys Med Rehabil. 2025;104(8):687-692. doi:10.1097/PHM.0000000000002685

Summary:  The primary aim of this study was to compare osseointegration (OI) limb replacement prosthesis users to normative published Prosthetic Limb Users Survey of Mobility (PLUS-M) values for traditional socket prosthesis users. The secondary aim was to investigate whether patient factors were predictive of PLUS-M scores.

Functional mobility of lower extremity prosthesis users is integral for amputee quality of life satisfaction. Additionally, it has been shown that quality of life and satisfaction are strongly related to mobility for patients with a lower limb prosthesis. Validated functional mobility scores help to understand and compare the performance of individual patients and treatment cohorts. The Prosthetic Limb Users Survey of Mobility (PLUS-M) is a validated survey designed specifically to assess lower extremity amputees’ perception of mobility performance and has been used extensively for patients with socket prostheses. Recent studies have reported osseointegration limb replacement surgery (OI-LRS) as an effective alternative to socket prosthesis rehabilitation, conferring patients with improved quality of life, physical health, and function.

Osseointegration (OI) was traditionally indicated for patients with lower extremity amputations with skin and soft-tissue intolerances of socket prostheses, short length and abnormal formation of residual limbs, and nerve pain limiting socket prostheses use. While peripheral vascular disease was initially considered a relative contraindication, a recent case series suggests that OI may be considered a reasonable alternative to a traditional socket prosthesis in a patient with peripheral vascular disease. With increasing research into OI, the indication window continues to expand. Importantly, OI has made it possible for some amputees, who were previously unable, to use a prosthesis.

Design: Retrospective review of all patients who underwent osseointegration maintained in a prospectively maintained registry. All patients (N = 63) were invited to complete a PLUS-M survey. Thirty patients completed the survey (15 femoral osseointegration, 15 tibial osseointegration). Inclusion criteria: unilateral lower extremity OI (femur or tibia), performed at least 1 yr prior, and English-speaking. Exclusion criteria: patients not meeting the anatomic and follow-up criteria or who were not using a prosthesis. To best characterize the mobility of the entire OI cohort, patients were not excluded based on age, etiology, or comorbidities.

Results: The osseointegration limb replacement prosthesis users cohort’s composite median scores and interquartile ranges for the PLUS-M Raw Score, PLUS-M T-score, and PLUS-M percentile score were 57 (46–60), T-score 62.5 (51.275–71.4), and 89.5 (54.95–98.4). PLUS-M T-scores were higher in the osseointegration limb replacement prosthesis users compared with the age and etiology matched literature-reported outcomes in traditional socket prosthesis users for above-knee and below-knee amputees. Tibial osseointegration scores were slightly higher than femur osseointegration scores but did not reach statistical significance. PLUS-M raw (P = 0.047) and PLUS-M percentile scores (P = 0.041) were significantly improved for younger patients at the time index amputation.

The most important finding of this study is that OI patients have better PLUS-MT-scores than age, etiology, and amputation level matched traditional socket patients. Additionally, OI limb replacement prosthesis users demonstrated improved function in PLUS-M Raw Scores and PLUS-M Percentile Scores when they were younger at time of the index amputation.

Conclusions: Osseointegration limb replacement prosthesis users demonstrate improved functional mobility outcome scores relative to traditional socket prosthesis users. PLUS-M functional scores were improved for younger patients at time of index amputation.