Article

Many studies show good clinical results after proximal row
carpectomy. Some biomechanical consequences are documented, but to our knowledge
muscle moment arm variations have not previously been quantified. METHODS: In
five fresh-frozen wrist, kinematics and tendon excursions were measured using a
3D electrogoniometer and Linear Variable Differential Transformers (SOLARTRON
Inc., AMETEK Advanced Measurement Technology, Inc, 801 South Illinois Avenue, Oak
Ridge, TN 37831-2011, USA), respectively, in three conditions: intact wrist,
after posterior capsulotomy and after proximal row carpectomy. Mean pivot point,
defined as the point whose sum of the squared distances to the helical axes is
minimum, wrist range of motion and mean moment arms were measured during
dorso-palmar flexion, radioulnar deviation and circumduction movements. FINDINGS:
No alteration of the range of motion was observed. On the other hand, the mean
pivot point shifted proximally (6.8-9.1mm) after proximal row carpectomy (p<0.05)
for all motions tested and most muscle moment arms decreased significantly after
proximal row carpectomy. INTERPRETATION: The results of this study allow a better
understanding of the biomechanical effects of this procedure. The important
moment arm reduction and pivot point displacement suggest modifications of joint
biomechanical parameters which could influence the functional outcome of PRC.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS