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

Abstract

Purpose: 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.

Methods: 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).

Results: 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.

Conclusions: 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.

Level of evidence: Therapeutic study, Level IV.