Generalized ligamentous laxity as a predisposing factor for primary traumatic anterior shoulder dislocation

HypothesisThe purpose of this study was to determine whether generalized ligamentous laxity and increased shoulder external rotation represent predisposing factors for primary traumatic anterior shoulder dislocation in young, active patients. We hypothesized that generalized ligamentous laxity and increased shoulder external rotation would be more common in individuals with first-time traumatic shoulder dislocations compared with controls.Materials and methodsThis retrospective case-control study examined hyperlaxity and shoulder external rotation >85° in 57 consecutive individuals (age <30 years) who sustained a primary traumatic anterior shoulder dislocation between 2003 and 2006. The Hospital Del Mar Criteria (battery of 10 clinical examination maneuvers) was used to measure generalized ligamentous laxity, which was determined to be present by overall scores exceeding 4/10 for men or 5/10 for women. The control group comprised 92 age-matched university students without a history of shoulder dislocation or anterior cruciate ligament injury.ResultsGeneralized ligamentous laxity was present in 33.3% of the cases compared with 15.2% of controls (P = .014). Increased contralateral shoulder external rotation (>85°) was observed in 38.6% of the study group compared with 22.8% of controls (P = .043). Men who had dislocated their shoulder were 6.8 times more likely to demonstrate generalized ligamentous laxity and increased shoulder external rotation compared with age and sex matched controls (P = .003).DiscussionIdentifying hyperlax individuals may allow for shoulder-specific proprioceptive training.ConclusionGeneralized joint laxity and increased external rotation in the contralateral shoulder were more common in patients who had sustained a primary shoulder dislocation.