Frequency and Characteristics of Posterior Labral Injuries in Operative Acetabular Fractures Treated Through a Posterior Approach: A Prospective Observational Study

Abstract

OBJECTIVES: The association between labral injuries and acetabular fractures is unknown. This study aimed to identify the frequency and characteristics of labral injuries in operatively treated acetabular fractures that cannot be identified on preoperative imaging. METHODS:   Design: Prospective observational cohort. Setting: Level I trauma center. Patient Selection Criteria: Adult patients with an acetabular fracture operatively treated through a posterior approach. Outcome Measures and Comparisons: The frequency and characteristics of labral injuries. RESULTS: Fifty-three of 71 acetabular fractures (75%; 95% confidence interval, 63%–83%) demonstrated a labral injury visible via the posterior approach. Posterior labral injuries occurred in 89% of operative acetabular fracture patterns involving the posterior wall and most commonly represent a detachment of the posteroinferior labrum (n = 39, 75%). Fractures with a labral injury were more likely to have gluteus minimus damage (93% vs. 61%, P = 0.02), femoral head lesions (38% vs. 17%, P = 0.03), joint capsule detachment (60% vs. 33%, P = 0.05), and fracture patterns involving the posterior wall (89% vs. 50%, P = 0.05). CONCLUSIONS: This study describes the high rate (89%) of posterior labral injuries in posterior wall fractures, the most common injury pattern being a detachment of the posteroinferior labrum. Labral injuries in acetabular fractures may have important clinical implications and this study is the first to identify the frequency and characteristics of these injuries. Further studies should assess the relationship between labral injuries, treatment strategies, and the progression to post-traumatic osteoarthritis. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.