Arthroscopic Posterior Bankart Repair: Risk Factors for Recurrence of Instability

Abstract

Background:

The high rates of failures and reoperations (up to 50%) after arthroscopic posterior Bankart repair (APBR) remain a concern.

Purpose:

To evaluate mid- to long-term follow-up outcomes of APBR in patients with unidirectional, recurrent posterior shoulder instability and to identify risk factors for failure.

Study Design:

Case series; Level of evidence, 4.

Methods:

A single-center, retrospective study was conducted that included all consecutive athletes with unidirectional recurrent posterior shoulder instability operated on between 2006 and 2022. Patients with voluntary instability or previous failed instability repair were excluded. The posterior labrum was reattached using a minimum of 4 suture anchors, and a posteroinferior capsular shift was systematically performed. The mean follow-up was 11 years (range, 2-18 years). At final follow-up, the investigators evaluated persistent pain, apprehension, recurrence of instability (recurrent episode of either true dislocation or subluxation), range of motion, return to sport, and satisfaction. Revision surgeries and reoperations were also recorded.

Results:

The study included 44 athletes (45 shoulders). Patients were predominantly males (96%) and had a mean age of 28 years at surgery, and half (51%) practiced a contact or collision sport. Recurrence of posterior instability occurred in 22% (10/45): 2 patients sustained frank posterior dislocations, 6 reported recurrent subluxations, and 2 had a single episode of subluxation. Of the 10 patients with recurrence of instability, only 2 were reoperated (revision rate 4%); the 8 remaining patients declined any additional surgery. The presence of posterior glenoid bone erosion (9 patients) was associated with a higher risk of postoperative recurrent dislocation or subluxation (P = .024). By contrast, the presence of a posterior glenoid fracture (6 patients) was not a risk factor for postoperative recurrence of instability. Other potential prognostic factors (young age, contact sport, voluntary instability that became involuntary, or reproducible instability) were not found to be significant in the present series. At 1-year follow-up, 75% returned to the same level of sports.

Conclusion:

In patients with recurrent posterior instability, the presence of posterior glenoid erosion was the main risk factor for failure after APBR. By contrast, a posterior bony Bankart lesion did not represent a contraindication to arthroscopic stabilization using suture anchor fixation.