In Vitro Biomechanical Testing of Equine Metacarpophalangeal Collateral Ligaments and Collateral Ligaments Repair Using Suture Anchors.

Abstract

Background The disruption of equine metacarpophalangeal (MCPCL) and metatarsophalangeal collateral ligament (MTPCL) occurs as a result of traumatic events and it has been associated with guarded to poor prognosis for the return to athletic performance before the injury. Rupture of the MCPCL induces joint laxity which can, directly and indirectly, lead to a cartilage damage of the metacarpophalangeal joint (MCPJ). The literature describes several methods of the surgical management of those injuries, including the suture anchors. However, the knowledge about their biomechanical performance in the equine MCPCL repair model is lacking. This study describes the method of suture anchor placement within the metacarpal bone as well as reveals data of the biomechanical testing. The first objective was to perform bending tests on equine metacarpophalangeal joints with intact metacarpophalangeal collateral ligaments. The second objective was to perform similar tests on the metacarpophalangeal joints, having completely severed metacarpophalangeal collateral ligaments which were reattached to the suture anchors. Results The results of the biomechanical testing of 50 specimens showed that the suture anchor repairs obtained 15% of the intact metacarpophalangeal collateral ligaments’ maximum load, 34% of their bending stiffness, 14% of their load at maximum flexure extension, and 82% of the maximal flexure extension. The suture anchor placement within the bone can be performed quick and in the feasible way. The results of the biomechanical testing did not vary significantly between the tested types of the suture anchors used in this study. Conclusions The repairs with the suture anchors achieved lower biomechanical testing results compared with the intact metacarpophalangeal collateral ligaments; however, the anatomical position of the joint could be easily restored with the repair. The use of anchors may anatomically restore the ligament and provide additional mechanical support for the injured metacarpophalangeal collateral ligaments.