Clinical usability, reliability, and repeatability of noncontact scanners in measuring residual limb volume in persons with transtibial amputation

BACKGROUND: In previous studies, noncontact 3D scanners were found to be the most reliable in measuring volume of the residual limb after a transtibial amputation (TTA). Meanwhile newly developed noncontact scanners became available to measure residual limb volume after TTA but should be tested for clinical usability and reliability. OBJECTIVE: To determine the clinical usability, reliability, and repeatability of noncontact scanners in measuring residual limb volume in persons with a TTA. STUDY DESIGN: Original research report; repeated measurements. METHODS: Three noncontact scanners (Rodin4D, Omega Tracer, and Biosculptor) were used to measure the residual limb volume on two occasions by two observers in 30 persons with an unilateral or bilateral TTA. Clinical usability was assessed as scores of the Post-Study System Usability Questionnaire, participant satisfaction (0-10 scale), and time to take the measurement. RESULTS: The usability score of the Omega Scanner 3D (123.4) and Rodin4D (121.3) was significantly better compared with the Biosculptor (117.8). Participant experience was equal for all. The residual variance was 8.4%, where participant and scanning system explained most of the error variance (80.7%). Repeatability coefficients of the systems were 16.5 cc (Omega Scanner 3D), 26.4 cc (Rodin4D), and 32.8 cc (Biosculptor). The time to perform the measurements was significantly longer (+80 seconds) for the Omega Scanner 3D. CONCLUSIONS: For measuring residual limb volume in TT amputees, Omega software (state version 12.2) combined with the Rodin4D scanner was more usable and reliable than the Rodin 4D or Biosculptor systems, when operated by staff with limited experience and training