Variation in results of volume measurements of stumps of lower-limb amputees: a comparison of 4 methods.

Objective: To analyze the reliability of 4 methods (water immersion, computer-aided design [CAD] photometric method, CAD hand scanner, and circumferential measurements) for stump volume measurement in transtibial amputees.

Design: Repeated measurements.

Setting: General community, ambulatory care.

Participants: Transtibial amputees (N=26; mean age ± SD, 58.7±11.0y).

Interventions: Stump volume of patients with an amputation was measured on 2 occasions, each consisting of 2 sessions. In each session, stump volume was measured by 2 observers using each of the 4 methods. Sequence of observers and measurement methods was determined randomly.

Main Outcome Measure: Repeatability coefficients, as a measure for reliability, for each method were calculated, as well as variance components to estimate the influence of measurement conditions on stump volumes measured.

Results: Repeatability coefficients varied from 129mL CAD hand scanner to 158mL CAD photometric method. Error variance contributed 12% to the total variance. Methods contributed 36%, method-amputee and occasion-amputee interactions contributed both 25% to the error variance.

Conclusions: Repeatability coefficient was lowest for the CAD hand scanner, which indicates the best reliability. Substantial differences existed in stump volumes measured between the 4 methods.