The Effect of Wrist Position on Finger Tendon Loads Following Pulley Sectioning and Operative Reconstruction
Journal of Hand Surgery Global Online
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© 2019 The Authors Purpose: Postoperative rehabilitation is important for maximizing patient outcomes after surgical pulley reconstruction. The purpose of this study was to identify the optimal wrist position in which rehabilitation should be undertaken to decrease the load on surgically reconstructed pulleys. Methods: We tested 14 digits composed of the index, middle, and ring fingers from 5 cadaveric specimens in a novel in vitro finger motion simulator designed to achieve full finger flexion and extension actively. Servo-motors were used to generate motion through tendons under load or position control while measuring tendon forces, joint range of motion, and tendon excursion. Flexor digitorum profundus (FDP) and flexor digitorum superficialis loads were measured sequentially with native intact pulleys and A2 and A4 pulleys sectioned, and with reconstructed A2 and A4 pulleys. Each condition was tested with the wrist neutral and with 30° wrist flexion or extension. The effect of wrist position on FDP and flexor digitorum superficialis loads under each condition was analyzed using repeated-measures analysis of variance. Results: With pulleys reconstructed, the wrist position had a significant effect on tendon load. The flexed wrist position resulted in a 31% reduction of FDP load compared with the neutral wrist position. Wrist extension also produced an apparent reduction of 14%, although not statistically significant. Conclusions: After pulley repair, placing the wrist in 30° flexion decreased tension in the FDP tendon compared with a neutral wrist. Clinical relevance: This study suggests that rehabilitation should be carried out with the wrist flexed to reduce the load on pulley reconstructions.