Effectiveness of a Modified Icex® Casting Technique Based on Circumferential Change in Residual Limb Volume

Abstract

This article outlines a modified Icex® (Ossur Americas, Foothill Ranch, CA) casting technique and documents statistically significant (p ≤ 0.05) volume changes in circumferential measurements of the residuum after the application of this casting technique. The investigator-proposed hypothesis for this study was that the modified Icex casting technique would achieve sufficient volume reduction to validate the efficacy of using the technique. The investigator retrospectively collected demographic and measurement data of patients with transtibial amputation, from the University of Oklahoma Health Sciences Center in the Orthotic and Prosthetic Section, whose residua were cast using the modified Icex casting technique. The patients were initially identified through a billing code search of all patients treated from January 2001 through December 2008. Seventy-eight patients who underwent a total of 82 transtibial amputations who met the inclusion criteria with sufficient measurement information documented in the chart were included. One patient’s data were excluded because of the extreme brevity of the residuum resulting in insufficient normalized data. All of the patients’ residual limbs (n = 81) were cast for their initial preparatory prosthetic socket. Twenty-four of the original 78 patients were also cast for their first definitive socket during the same period. The subjects included 56 male and 22 female patients with a mean age of 50.6 (20–72) years. The studied population included 44 right and 38 left transtibial residual limbs, with the breakdown of the type of surgical amputation being 33 traditional and 49 osteomyoplastic amputations. Circumferential measurement data were collected for all casting procedures to analyze volume reduction achieved through the application of the casting bladder pressurized to 120 mm Hg. Residual limb circumferential measurement data were normalized to three levels: proximal, middle, and distal for statistical analysis in the Statistical Package for the Social Sciences (SPSS) version 18 (SPSS Inc, 2010).1 Statistical analysis, using a two-way repeated analysis of variance (ANOVA), yielded significant (p < 0.001) volume reduction at all three levels of the residual limb. The reduction in volume is not only scientifically significant but also clinically relevant.