Comparison of Z-Lengthening to Fractional Lengthening of Forearm Flexor Tendons: A Biomechanical Cadaveric Analysis

IF 2.1 2区医学 Q2 ORTHOPEDICS

Journal of Hand Surgery-American Volume Pub Date : 2025-09-01 DOI:10.1016/j.jhsa.2025.05.005

Angel A. Valencia MD , Dang-Huy Do MD , Nathan Heineman MD , Junho Ahn MD , Douglas M. Sammer MD , Daniel M. Koehler MD

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引用次数: 0

Abstract

Purpose

Contractures of the extrinsic forearm flexor units can be surgically treated with various procedures that lengthen the musculotendinous unit. Z-lengthening performed at the tendon level and fractional lengthening (FL) performed at the musculotendinous junction are two common interventions to address contractures. The purpose of this study was to compare the biomechanical properties of flexor tendons undergoing Z-lengthening versus FL.

Methods

Seventy-two flexor tendons were harvested from 12 paired upper extremities, including flexor carpi radialis, flexor carpi ulnaris, flexor pollicis longus, and flexor digitorum superficialis tendons. Tendons for each set of paired upper-extremities were subjected to either FL or Z-lengthening, so that each type of tendon in an upper extremity pair received a different lengthening procedure. Z-lengthened tendons were lengthened 20 mm and repaired with a pair of 2-0 horizontal mattress sutures. For fractionally lengthened tendons, a transverse tenotomy was made at the musculotendinous junction at the level corresponding to 75% of its maximal width, followed by a second tenotomy 1 cm distal to the first. The maximum load at failure and excursion at failure for each tendon type were measured and compared with the contralateral side.

Results

Z-lengthened tendons demonstrated a significantly greater load to failure compared with the fractionally lengthened tendons (24.1 N vs 17.3 N). Maximum tendon excursion at failure was also significantly greater for Z-lengthening compared with FL. Among Z-lengthened tendons, 91% (32/35) failed because of suture pullout.

Conclusions

Z-lengthened forearm flexor tendons had greater overall tensile strength and excursion at failure compared with fractionally lengthened tendons.

Clinical relevance

Surgeons should consider performing Z-lengthening as an alternative method for tendons that are susceptible to failure with FL.

查看原文本刊更多论文

前臂屈肌腱z型延长与分数型延长的比较：生物力学尸体分析。

目的：外源性前臂屈肌单位挛缩可以通过各种延长肌腱肌单位的手术治疗。在肌腱水平进行z轴延长和在肌肉肌腱连接处进行分数延长（FL）是治疗挛缩的两种常见干预措施。本研究的目的是比较进行z型延长和fl型延长的屈肌腱的生物力学特性。方法：从12对上肢取下72根屈肌腱，包括桡腕屈肌、尺腕屈肌、拇长屈肌和指浅屈肌肌腱。每组成对上肢的肌腱进行FL或z延长，以便上肢成对的每种肌腱接受不同的延长程序。将z型延长肌腱延长20mm，采用一对2-0水平床垫缝合线修复。对于部分延长的肌腱，在其最大宽度的75%处进行横向肌腱切断术，然后在第一次肌腱远端1cm处进行第二次肌腱切断术。测量了每种肌腱类型在破坏时的最大载荷和破坏时的偏移量，并与对侧进行了比较。结果：与部分延长的肌腱相比，z轴延长的肌腱表现出更大的破坏负荷（24.1 N vs 17.3 N）。与FL相比，z轴延长失败时的最大肌腱偏移也明显更大。在z轴延长的肌腱中，91%（32/35）因缝线拔出而失败。结论：与部分延长的肌腱相比，z延长的前臂屈肌腱具有更大的整体抗拉强度和失效时的偏移。临床相关性：外科医生应考虑将z轴延长作为易患FL的肌腱的替代方法。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Hand Surgery-American Volume 医学-外科

CiteScore

3.20

自引率

10.50%

发文量

402

审稿时长

12 weeks

期刊介绍： The Journal of Hand Surgery publishes original, peer-reviewed articles related to the pathophysiology, diagnosis, and treatment of diseases and conditions of the upper extremity; these include both clinical and basic science studies, along with case reports. Special features include Review Articles (including Current Concepts and The Hand Surgery Landscape), Reviews of Books and Media, and Letters to the Editor.