Fall incidence and risk factors in patients after total knee arthroplasty

To prospectively investigate the relationship between physical function and falls among elderly patients who underwent total knee arthroplasty (TKA) and to determine the incidence of falls as well as their risk factors.

A total of 108 patients (17 male, 91 female) over 60 years of age who underwent TKA were enrolled and who were living independently in community. 75 patients fulfilled our inclusion criteria and 74 (8 male, 66 female) of them agreed to participate. Baseline assessment (physical examination, physical performance tests, and self-administered questionnaire) were conducted between 6 and 12 months after the last arthroplasty and the follow-up assessment was performed 6 months after the baseline assessment. Monthly pre-stamped postcards were sent to assess the incidence of falls.

Of the 74 patients enrolled, 70 (94.6%) completed a 6-month prospective observation. 23 of 70 patients (32.9%) fell during the observational period. Postoperative range of knee flexion, ranges of knee flexion and extension and ankle plantar flexion were significantly lower in fallers than in non-fallers (P = 0.016, P = 0.037, P = 0.014, respectively). In the multivariate analysis, postoperative range of knee flexion (OR 0.277, 95%CI 0.088-0.869, P = 0.028) and ankle plantar flexion (OR 0.594, 95%CI 0.374-0.945, P = 0.028) were determined to be significant risk factors.

Elderly people who underwent TKA are considered more likely to fall compared with healthy elderly people. For patients with limited knee flexion and ankle plantar flexion, improvement of ROM by exercise therapy and patient education regarding the prevention of falls and fractures are considered necessary.