Degree of Safety Against Falls Provided by 4 Different Prosthetic Knee Types in People With Transfemoral Amputation: A Retrospective Observational Study.

The study is observational, so it cannot prove that fluid-controlled knees cause more falls; the association could be influenced by unmeasured confounders. The findings apply only to the inpatient rehabilitation setting, which has different environmental hazards and patient familiarity levels than the community, so generalizability to daily life is unknown. There was a high proportion of missing data for key variables, including the Barthel Index (37%), cause of amputation (35.7%), and Morse Scale (29.5%), which may affect the validity of some risk factor associations. The sample was heavily skewed toward traumatic amputations (77.4%), which differs from the general population where vascular disease is the leading cause, limiting applicability to vascular amputees. The study did not perform subgroup analyses or test for interactions between patient risk factors and knee type due to sample size limits, so it is unknown if certain patient profiles are more or less protected by specific knee types. Physical performance measures like the 10-meter walk test were excluded from analysis due to missing data rates greater than 50%.

The study was funded by the Istituto Nazionale Assicurazione Infortuni sul Lavoro (INAIL) and the Sant'Anna School of Advanced Studies. Two coauthors, P. Randi and A. Davilli, are employees of the funder (INAIL) and substantially contributed to the study design, data collection, and discussion of results.

Do not conclude that microprocessor knees are definitively safer than fluid-controlled knees for all patients in all settings. This association was found only during inpatient rehabilitation, and the study could not test whether this effect differs for patients with specific clinical profiles or in the community.