Changes In Gait Biomechanics One-year Following Osseointegration In People With Transfemoral Amputation

PURPOSE: People with transfemoral amputation (TFA) who use socket prostheses demonstrate aberrant gait patterns that are linked to high rates of knee and hip osteoarthritis and low-back pain; however, few interventions exist to improve aberrant gait biomechanics and mobility issues for people with TFA. Dissatisfaction with socket prostheses has led to the development of bone-anchored prostheses through osseointegration for people with TFA, eliminating the need for a prosthetic socket. Studies show prosthesis osseointegration improves quality of life and functional capacity, yet it remains unknown if gait patterns improve following osseointegration. The purpose of this case series was to evaluate the longitudinal changes in lower-extremity and trunk joint moments during gait one year after osseointegration compared to pre-osseointegration in people with TFA. METHODS: Knee, hip, and trunk internal moments were evaluated in the amputated and non-amputated limbs during walking at a self-selected speed in four participants pre-osseointegration (with traditional socket prostheses) and one-year after prosthesis osseointegration. Longitudinal changes were quantified using the percent change in peak joint moments between the two time points, and Cohen’s d effect size was used to determine the magnitude of effect of osseointegration on joint moments after one year. RESULTS: Participants demonstrated reduced peak knee extension moment (-43 ± 34%, d = 1.82) in the non-amputated limb post-osseointegration. Participants demonstrated bilateral reduction of peak hip extension moment (amputated: -22 ± 37%, d = 0.86; intact: -29 ± 10%, d = 1.27) and bilateral increase of peak hip abduction moment (amputated: 45 ± 40%, d = 1.20; intact: 23 ± 44%, d = 0.74) post-osseointegration. Participants demonstrated reduced peak trunk extension moment on the amputated side (-31 ± 16%, d = 1.51) and reduced peak trunk lateral flexion moment on the non-amputated side (-22 ± 18%, d = 1.12) post-osseointegration. CONCLUSIONS: Results from this case series suggest osseointegration can improve gait symmetry in people with TFA, potentially due to increased stability and perception of the prosthetic limb following osseointegration.