Does an "Off-Track" Hill-Sachs Lesion That Is Misclassified as "Non-Engaging" Affect Outcomes From Bankart Repair Alone Compared With Bankart Repair Combined With Remplissage?

Abstract

Purpose: To determine how intraoperative assessment (engagement test) may affect recurrent dislocation rate and to compare the clinical outcomes, recurrence rates, and presence of on-/off-track conditions between cases that received arthroscopic Bankart repair alone (nonengaged Hill-Sachs lesion) and Bankart repair with remplissage (engaged Hill-Sachs lesion).

Methods: We retrospectively reviewed 213 patients who underwent arthroscopic Bankart repair alone (186 patients with nonengaging lesions, group A) or with remplissage (27 patients with engaging lesion, group B) for recurrent anterior shoulder instability with <25% glenoid bone defect. The presence of an engaging Hill-Sachs lesion was determined during arthroscopic evaluation. On-track or off-track lesions were assessed retrospectively from preoperative 3-dimensional (3D) computed tomography (CT).

Results: Mean glenoid bone defect was 13.7% in group A and 20.7% in group B (P < .001). Off-track lesions were identified in 8.1% (15/186) and 100% (27/27) in group B. At the final follow-up (minimum 2 years; mean follow-up periods after surgery of 50.1 months in group A and 47.7 months in group B), there were no significant differences in shoulder functional scores and recurrence rates between groups, despite improvement after surgery. In the off-track lesion (group A-1: nonengaging but off-track lesion), recurrence instability occurred in 9 patients (60%, 9/15). Also, comparing group A-1 and group B, we noted significant differences in shoulder functional scores and recurrence rates (P < .001).

Conclusion: Of 186 patients, 8.1% with nonengaging Hill-Sachs lesions during direct arthroscopic examination under anesthesia actually demonstrated off-track lesions on preoperative 3D CT scans retrospectively, with 60% experiencing recurrent instability. Intraoperative manual assessment for Hill-Sachs engagement was inferior to 3D CT scan in establishing the presence of off-track defects.

Level of evidence: III, retrospective comparative study.