Changes in lower extremity joint moments one-year following osseointegration in individuals with Transfemoral lower-limb amputation: A case series.

backgroundDissatisfaction with socket prostheses has led to the development of bone-anchored prostheses through osseointegration for people with transfemoral amputation, eliminating the need for a prosthetic socket. Gait deviations of transfemoral prosthesis users may be linked to increased risk of osteoarthritis, and it remains unknown if gait biomechanics change following osseointegration. The purpose of this case series was to evaluate the longitudinal changes in joint kinetics one year post-osseointegration in patients with transfemoral amputation during walking.

methodsKnee, hip, and trunk internal moments were evaluated in the prosthetic and intact limbs during walking at a self-selected speed in four participants pre- and one-year post-osseointegration. Longitudinal changes were quantified using the percent change (%∆) in peak joint moments between the two time points and Cohen's d (d) effect size was used to determine the magnitude of effect on joint moments during walking one year following osseointegration.

findingsParticipants demonstrated increased peak knee extension moment (224 ± 308%∆, d = -1.31) in the prosthetic limb, while demonstrating reduced peak knee extension moment (-43 ± 34%∆, d = 1.82) in the intact limb post-osseointegration. Participants demonstrated bilateral reduction of peak hip extension moment (prosthetic: -22 ± 37%∆, d = 0.86; intact: -29 ± 10%∆, d = 1.27) and bilateral increase of peak hip abduction moment (prosthetic: 45 ± 40%∆, d = 1.20; intact: 23 ± 44%∆, d = 0.74) post-osseointegration. Participants demonstrated reduced peak trunk moments on both the prosthetic (extension: -31 ± 16%∆, d = 1.51; lateral flexion: -21 ± 20%∆, d = 0.63) and intact side (extension: -7 ± 22%∆, d = 0.38; lateral flexion: -22 ± 18%∆, d = 1.12) post-osseointegration.

interpretationThis case series suggests improved gait symmetry in individuals with transfemoral amputation one year following osseointegration, justifying future investigation.