Surgical treatment of significant glenoid bone defects and associated humeral avulsions of glenohumeral ligament (HAGL) lesions in anterior shoulder instability

Combined occurrence of humeral avulsion of glenohumeral ligament (HAGL) lesion and a significant glenoid bone defect is an unusual and previously undescribed association in traumatic anterior shoulder instability. The purpose of this study was (1) to report a retrospective case series of seven anterior bony instability patients who were diagnosed with this unusual association and (2) to evaluate the results of a modified Latarjet procedure and simultaneous HAGL repair using a new subscapularis-sparing approach. A retrospective review of the records of 64 anterior shoulder instability patients who underwent bony stabilization surgery was performed, and patients who underwent a combined reconstruction for significant glenohumeral bone defects (glenoid loss > 20 %) and an associated HAGL lesion were identified. Pre- and postoperative follow-up clinical parameters and functional scores were documented (Oxford shoulder instability score [OSIS], Western Ontario shoulder instability index [WOSI]), Rowe score). Radiological assessment included measurement of the glenoid bone defect (CT scan) and evaluation of soft tissue lesions (MR arthrogram). Radiological and arthroscopic evaluation confirmed the combined lesion complex in 7 (11 %) patients. Follow-up evaluation (mean 20.6 months) suggested an excellent outcome (Rowe score: median 95, range 95-100); a statistically significant improvement was seen in the follow-up OSIS (median 12, range 12-14, p = 0.018) and WOSI score (median 28, range 17-102, p = 0.018) as compared to the preoperative score (median OSIS 50, range 32-53; median WOSI 1,084, range 919-1,195). Clinical tests for subscapularis function revealed a functional subscapularis muscle; no significant differences were detected in pre- versus postoperative internal rotation strength and in the operated versus normal contralateral shoulder (ns). The dual-window subscapularis-sparing approach provided adequate exposure for combined reconstruction of the humeral and glenoid lesions, and no complications were encountered. Significant glenoid defects are associated with HAGL lesions in approximately 1/10th of patients with bony instability. Combined reconstruction of these lesions via a subscapularis-sparing approach results in an excellent outcome and significant improvement in functional scores at a medium-term follow-up. Therapeutic study, Level IV.