Biomechanical alterations in the carpal arch and hand muscles after carpal tunnel release: A further approach toward understanding the function of the flexor retinaculum and the cause of postoperative grip weakness
✍ Scribed by Franz K. Fuss; Thomas F. Wagner
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 836 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0897-3806
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✦ Synopsis
The difference between maximal and minimal distance covered (the distance between the trapezium ridge and hamate hook; moment exerted on structures: I Nm) by an intact flexor retinaculum (FR, minimum, 3.3 2 0.1 cm; maximum, 3.7 2 0.2 cm) and the increase in the maximal distance on carpal tunnel release (CTR; increase, I .6 2 0.2 mm) were significant. Under an external supination moment, the distance between the attachment.. of the trapeziopisiform band increased after CTR. Under external pronation and ulnar abduction moments, the distance between the attachment.. of the scaphoideohamate band increased afler CTR. The ClX resulted in an anatomic attachment loss for the following muscles: the superficial head of the flexor pollicis brevis (shortening by -25%. relative to rest length), the ulnar part of the abductor pollicis brevis (with opposition and adductory functions, -20%). the opponens pollicis (-20%), the middle part of the abductor pollicis brevis (-7%), and the oppnens digiti minimi (-10%). Preoperative and postoperative (2-7 weeks after surgery) measurements of the reaction force of the distal phalanx (under isometric thumb opposition and finger 11-IV flexion with extended carpal joint) led to differentiation of three groups: (I) significant strength l m . 4 patient. showed difficulties with grasping, lifting, twisting off lids and caps, screwing, pulling ropes, and pinching; (2) no significant change in force values; and
(3) a significant increase in strength (patients who could grip more firmly).