Joint Biomechanics In Transfemoral Amputees With A Socket-based Versus Osseointegrated Prosthesis: A Pilot Study

Lower-extremity amputees commonly use socket-based (SO) prostheses. Osseointegration (OI), which anchors the prosthesis abutment directly to the residual bone, may be recommended for SO users facing poor gait outcomes, skin irritation, and an insecure fit. Although OI improves SO users’ gait over time, it is unknown if high-functioning SO users (K-level ≥ 3) without current OI prescriptions exhibit distinct gait outcomes compared to those with OI. Distinct gait outcomes between these groups could inform the potential need for OI in high functioning SO users not currently prescribed it. PURPOSE: Compare joint biomechanics between high functioning (K-level ≥ 3) transfemoral amputees with an SO versus OI prosthesis. METHODS: 2 male, high functioning, unilateral transfemoral amputees with an OI prosthesis (age: 58 ± 14.14 yr, body mass: 128.78 ± 24.34 kg, height: 1.82 ± 0.09 m) and 3 with an SO prosthesis (age: 45.66 ± 18.55 yr, body mass: 93.42 ± 2.97 kg, height: 1.83 ± 0.06 m) volunteered. Stance phase joint biomechanics for the intact limb were calculated using 3D motion capture and force plate data as subjects walked at a self-selected speed along a 15-m level walkway. Sagittal ankle, knee, and hip angle, moment, and power, and frontal knee and hip angle and moment waveforms were compared between groups qualitatively and via 1D statistical parametric mapping with two samples independent t-tests (ɑ ≤ 0.05). RESULTS: Both groups walked at similar speeds. Joint angles, moments, and powers were statistically similar between groups (p > 0.05). Qualitatively, OI users generated less sagittal ankle power and hip moments (Figure 1). CONCLUSIONS: We are recruiting a larger sample that may statistically reveal less ankle and hip mechanical output in OI than high-functioning SO users not currently prescribed OI. If confirmed, these findings suggest the potential for improved gait outcomes like reduced joint loads through OI among high functioning SO users without OI prescriptions.US Department of Defense