A comparison of patient-reported and measured range of motion in a cohort of total knee arthroplasty patients.

Range of motion (ROM) is an important component of the assessment of total knee arthroplasty (TKA) outcome. We compared patient-reported versus clinically observed ROM in a prospective cohort. Clinically observed ROM was measured using a goniometer by a trained research assistant. Self-reported ROM was estimated using a set of lateral knee photographs depicting varying levels of flexion and extension. All measures were taken pre-operatively, three, and six months postoperatively. We found statistically significant associations between self-reported ROM and clinically observed ROM for flexion and extension (all P < 0.001). We dichotomized flexion at 90° and found that self-report had a specificity of 94% and sensitivity of 65%. We conclude that patient-reported ROM may be a useful outcome measure for TKA.