Fractional Lengthening of Forearm Flexor Tendons: A Cadaveric Biomechanical Analysis.

Autor:	Do DH; Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX., Heineman N; Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX., Crook JL; Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX; University of Tennessee Health Science Center, Memphis, TN., Ahn J; Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX., Sammer DM; Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX; Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX., Koehler DM; Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX. Electronic address: Daniel.Koehler@UTSouthwestern.edu.
Jazyk:	angličtina
Zdroj:	The Journal of hand surgery [J Hand Surg Am] 2024 May 03. Date of Electronic Publication: 2024 May 03.
DOI:	10.1016/j.jhsa.2024.03.016
Abstrakt:	Purpose: Multiple procedures have been described for wrist and finger flexion contractures and spasticity. Fractional lengthening of forearm flexor tendons involves making parallel transverse tenotomies at the musculotendinous junction to elongate the muscle. Currently, there is limited literature to define the biomechanical consequences of this lengthening technique. Methods: Forty-eight flexor tendons were harvested from eight paired upper limbs including flexor carpi radialis, flexor carpi ulnaris, flexor pollicis longus, and flexor digitorum superficialis tendons. Each tendon that was lengthened was paired with the contralateral tendon as a control. A pair of transverse tenotomies were completed for the fractional lengthening. The first tenotomy was performed at the musculotendinous junction where the tendon narrowed to 75% of its maximal width. The second tenotomy was made 1 cm distal to the first. Tendon length was measured before and after fractional lengthening at a constant resting tension of 1 N. The maximum load at failure of each tendon and the mechanism of failure were each measured and compared with the contralateral side. Results: After fractional lengthening, the mean increase in resting tendon length was 4 mm. When loaded to failure, the mean maximum load of fractionally lengthened tendons was 42% of the mean maximum load of intact tendons. All lengthened tendons failed at the distal tenotomy site. Conclusions: Fractional lengthening resulted in an increase of 3-6 mm (mean: 4 mm) in tendon length at resting tension. There was a significant loss in tensile strength and load to failure following fractional lengthening compared with an intact musculotendinous unit. Clinical Relevance: The reduction in tensile strength following fractional lengthening results in loads at failure that are, in some cases, lower than the estimated forces required to perform basic tasks. Caution during the healing and rehabilitation period is warranted. Competing Interests: Conflicts of Interest No benefits in any form have been received or will be received related directly to this article. (Copyright © 2024 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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