Flowable Extracellular Matrix Hydrogel to Prevent Adhesion Formation Following Flexor Tendon Repair: A Preclinical Study.

Abstract

<h4>Background</h4>Adhesion formation following flexor tendon repair remains a significant clinical challenge, often necessitating reoperation and leading to suboptimal outcomes. Current adhesion barrier technologies have limited efficacy and usability.<h4>Methods</h4>A flowable extracellular matrix (ECM) hydrogel and ECM mesh were evaluated in a preclinical rabbit model of flexor tendon repair. Range of motion (ROM), adhesion scoring, and rupture strength were measured. Safety and overapplication effects were assessed in cadaveric tendon models. Histologic analysis evaluated inflammation.<h4>Results</h4>The ECM hydrogel and mesh reduced adhesions and improved ROM compared to saline controls. ROM in treated tendons ranged from 70.4°±17.7° (3:1 Gel) to 69.8°±8.3° (1:1 Gel), significantly higher than controls (50.7°±17.7°; p<0.05). Adhesion scores improved across treated groups, with 1:1 Gel achieving the best results (5.2±1.8 vs. control 8.0±1.5; p<0.05). Histology suggested reduced sustained inflammation in treated groups. No impact on rupture strength was observed, confirming mechanical safety.<h4>Conclusions</h4>Flowable ECM hydrogel and ECM mesh significantly reduce adhesions and preserve tendon mechanics after flexor tendon repair. The hydrogel's flowable form offers superior ease of application, addressing unmet clinical needs.