Characterizing loads at transfemoral osseointegrated implants

Establishing normative and outlying loads on transfemoral osseointegrated devices will assist development of preclinical mechanical testing strategies to inform manufacturers and government regulators. Therefore, force and moment data from osseointegrated transfemoral transcutaneous implants were collated to better understand baseline load levels. Load data were also collected from other devices including transfemoral socket prostheses, instrumented hip stems, instrumented knee devices, instrumented limb salvage femoral endoprostheses, as well as estimated loads on transfemoral prostheses using data from able-bodied subjects. These additional data were assessed for their ability to bolster the limited osseointegrated device data. Several activities of daily living were investigated to characterize normative loading. Falling events were investigated to characterize outlying loads. Results revealed that limited loading data exist for osseointegrated devices. The most often reported activity was level walking. While these normative data may inform fatigue testing, they may not fully characterize fatigue loads during all activities of daily living. Socket prosthetics and able-bodied individuals may provide supplementary data, but significance is limited by sample sizes. Falling data are sparse, and insufficient data exist for characterizing adverse loads on osseointegrated devices. Future data collection should include more activities of daily living and adverse events to better define osseointegrated device loading profiles.