Ulnar collateral ligament strain of the thumb metacarpophalangeal joint: biomechanical comparison of two postoperative immobilization techniques

ConclusionsWhile immobilized, valgus thumb force, as opposed to MP flexion, is a likely contributor to UCL strain during simulated pinch representing noncompliance during the postoperative period. Supplemental thumb MP pin fixation more effectively protects the UCL from valgus strain. UCL shortening with FPL loading likely represents paradoxical MP extension due to flexion of the distal phalanx against the distal splint, suggesting attempted thumb flexion with splint immobilization alone does not jeopardize UCL repair.Clinical RelevanceThis study provides a foundation to aid clinical decision-making after UCL repair. It reinforces the practice of surgeons who routinely pin their MP joints, but also brings to attention that the use of temporary MP pin fixation may be considered in difficult cases, such as those with potential noncompliance or tenuous repair.
Source: Hand - Category: Surgery Source Type: research