Comparative Analysis of Labral Repair Characteristics in Patients Treated for Anterior versus Posterior Instability.

Background: Direct comparisons of the demographic and clinical risk factors between patients with anterior and posterior glenohumeral instability are uncommon. Purpose: To identify and compare demographic, clinical, and perioperative variables in patients receiving arthroscopic labral repair for anterior and posterior shoulder instability. Study Design: Case series; Level of evidence, 4. Methods: A retrospective chart review was performed for patients who underwent primary arthroscopy for shoulder instability by 7 surgeons at a single institution between 2012 and 2020, excluding revision surgeries and multidirectional instability patients. Demographics, radiological findings, and intraoperative data were collected. Patients with anterior instability (AI) were compared to those with posterior instability (PI) by number of dislocation events (0, 1, 2, or >2), chief complaint (dislocation event and direction, subluxation, or pain), and concomitant intraoperative procedures. A subgroup analysis was performed of patients with documented dislocations. Statistical analysis included the Student Results: A total of 482 shoulders met the inclusion criteria. Overall, 80% (384/482) of the patients were evaluated with AI and 20% (98/482) with PI. The PI group demonstrated a greater mean BMI compared with the AI group (28 ± 7 vs 26 ± 6; Conclusion: Patients arthroscopically treated for AI undergo concomitant posterior labral repair at rates similar to those with PI requiring concomitant anterior labral repair. This finding suggests that tear extension occurs at similar rates in patients with AI and those with PI. Additionally, patients with AI requiring labral repair are more likely to experience multiple dislocation events as opposed to patients with PI who present with pain and subluxation.