Spatiotemporal and Gait Symmetry Changes Following Osseointegration in Transfemoral Prosthesis Users: A Longitudinal Study

Background/Objectives: Bone-anchored prostheses provide an alternative to socket prostheses, directly connecting the prosthesis to the residual limb via osseointegration. However, limited evidence exists on how spatiotemporal gait parameters and gait symmetry change over time following osseointegration in individuals with unilateral transfemoral amputation. This study aimed to examine changes in spatiotemporal and gait symmetry parameters before osseointegration and at 6 and 12 months post-surgery. Methods: Common spatiotemporal parameters were collected from six individuals with unilateral transfemoral amputation at baseline (with socket prosthesis) and at 6 and 12 months post-osseointegration using a motion analysis system. Group-level differences were assessed using repeated measures ANOVA. Gait symmetry was evaluated using selected spatiotemporal parameters. Results: Following osseointegration, individuals with unilateral transfemoral amputation experienced significant spatiotemporal changes over time. At the group level, walking velocity and stride length decreased at 6 months, with stride length increasing at 12 months. Step width and prosthetic-side step length increased at 12 months relative to 6 months, while intact-side step length decreased. Prosthetic-side toe-off timing was shorter at 12 months. Gait symmetry responses varied individually: some with poor baseline symmetry improved, while those with better baseline symmetry became more asymmetric, indicating heterogeneous outcomes. Conclusions: This study highlights longitudinal changes in gait biomechanics following osseointegration in individuals with unilateral transfemoral amputation. Gait adaptations were highly variable across individuals and time points. Future research should involve larger, more homogeneous samples and incorporate kinetic, muscle activity, and functional outcome measures to better understand the impact of bone-anchored prostheses on gait and mobility.