Influence of Glenoid Defect Size and Bone Fragment Size on the Clinical Outcome After Arthroscopic Bankart Repair in Male Collision/Contact Athletes.

Background: The usefulness of arthroscopic Bankart repair for collision/contact athletes has varied in previous reports. Purpose: To investigate the influence of glenoid rim morphologic characteristics on the clinical outcome after arthroscopic Bankart repair without additional reinforcement procedures in male collision/contact athletes, including athletes with a large glenoid defect. Study Design: Case-control study; Level of evidence, 3. Methods: Eighty-six athletes (93 shoulders) followed for a minimum of 2 years were retrospectively investigated. The sports were rugby (36 shoulders), American football (29 shoulders), and other collision/contact sports (28 shoulders). Preoperative glenoid defect size, bone fragment size, and bone union after bony Bankart repair were investigated regarding factors influencing postoperative recurrence. Postoperative changes in glenoid defect size and bone fragment size were investigated as well as their influence on the clinical outcome. Results: Postoperative recurrence of instability was noted in 22 shoulders (23.7%). The recurrence rate was 33.3% in rugby, 17.2% in American football, and 17.9% in other collision/contact sports. The recurrence rate was only 7.1% in 28 shoulders without a preoperative glenoid defect, but it increased to 43.8% in 16 shoulders that did not have a bone fragment even though there was a preoperative glenoid defect. Additionally, the recurrence rate was 7.7% in 26 shoulders with bone union after arthroscopic bony Bankart repair but rose to 45% in 20 shoulders without bone union. In the shoulders with bone union, the mean bone fragment size increased from 8.2% preoperatively to 15.2% postoperatively, while the mean glenoid defect size decreased from 18.0% to 2.8%, respectively. The recurrence rate was 8.3% in shoulders with a final glenoid defect 5% or less versus 38.1% in shoulders with a defect greater than 5%. While the recurrence rate was low among athletes other than rugby players with a final defect of 10% or less, it was low in only the rugby players with a defect of 0%. Conclusion: In male collision/contact athletes, while the overall clinical outcome was unsatisfactory, a favorable outcome was achieved in athletes without a preoperative glenoid defect and athletes with bone union. The glenoid defect decreased in size postoperatively due to remodeling of the united bone fragment, and the recurrence rate was low when the final glenoid defect size was 5% or less.