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