A Scoping Review on Bone Mass Status in Individuals with Transfemoral Amputation

Background: Deterioration of bone mineral density (BMD) in the residual femur after a transfemoral amputation (TFA) has been reported over the past five decades, with various potential explanations described in the literature. BMD loss is a critical risk factor of fracture and hence an important clinical concern for prosthesis users. Objectives: This scoping review audited in vivo imaging studies that focused on BMD in individuals with TFA, with the aim to synthesize the status of knowledge on this topic, report on the mechanisms related to BMD status as hypothesized in the reviewed literature, and review BMD outcomes separately for prosthetic socket and bone-anchored suspension. Methods: Three databases (Scopus, PubMed, and Web of Science) were searched on December 1, 2024. Search keywords covered terms that reference bone mineralization (BMD, osteopenia, and osteoporosis) and TFA. Data were extracted for analysis and grouped according to reported prosthesis suspension for analysis. Results: In total, 244 articles were screened, with 20 ultimately reviewed. Articles were published between 1969 and 2024. Fourteen articles reported the use of socket prosthesis and six used bone-anchored devices. The former group consistently reported BMD loss, while the latter presented maintenance or improvements. The socket prosthesis cohort was younger in age compared to bone anchored (range 24–73 vs. 47–58 years). Proposed reasons for BMD loss included disuse atrophy, bedrest post-surgery, gait asymmetry, and prosthesis influence. Conclusions: Articles reporting BMD status using socket prosthesis consistently reported demineralization despite interventions, with no consensus on the mechanical cause of BMD loss. Further, the bone-anchored group tended to demonstrate improvements in limb loading symmetry during ambulation and higher levels of bone loading compared to prosthetic socket use. Clinical relevance: The residual femur in persons with TFA has demonstrated bone demineralization, which appears to be less prevalent in bone-anchored devices compared to socket use. These findings warrant further analysis of the effects of prosthetic socket use on bone demineralization in persons with TFA.