Abstract Title: Transverse Cross Sectional Surface Area And Circularity Consistency For Hands-Off And

Hands-On Casting Of Below Knee Residual Limb Using Mri

Abstract number: 494

Authors: M. Safari, A. Buis, P. Rowe

Presenter: A. Buis

Introduction

Socket fit is the most important characteristic of a prosthesis indicated by amputees (1-3). The consistency of the

final socket fit for an individual amputee is important. The aim of this study was to examine inter- and intra-cast

cross-sectional surface area and circularity consistency of Hands-off and Hands-on casting concepts using MRI.

Methods

Twelve amputee were recruited and the residual limbs were cast four times randomly in a single session, by a

single certified prosthetist, twice for Patellar Tendon Bearing (Hands-on) and twice for ICEROSS pressure casting

(Hands-off) method. After each cast the residual limb was scanned using MRI scanner. Then transverse crosssectional

surface area (CSSA) and cross-sectional circularity (CSC) of residual limb in all slices of all volume

images were automatically calculated. The Intra-class correlation coefficient and t-test were used to analyse the

inter and intra cast difference.

Results

Neither Hands-on nor Hands-off intra-cast CSSA and CSC difference was statically significant except for the

Hands-on CSC of the first slice. Besides, there was a statically significant difference between the Hands-on and

Hands-off in CSSA at the far distal region and in CSC in the proximal region. The Hands-on resulted in a larger

intra-cast CSSA mean difference than the Hands-off. The proximal region in the Hands-on casting showed a larger

CSSA intra-cast mean difference and variability and a larger inter-cast variability. At the distal region, a larger interand

intra-cast CSC mean difference and variability were noticed.

Discussion

Although not statistically significant, the smaller Hands-off CSSA mean difference and could be due to the uniform

force application around the residual limb and the distal traction of the soft tissue in the Hands-off casting by

the casting. The inter and intra cast CSC inconsistency in the far proximal region could be explained by manual

dexterity in the Hand-on method