Treatment And Results Of Combined Mild Bone Loss Instability With The Modified Laterjet

Abstract

Objectives:Recurrent anterior glenohumeral dislocation in the setting of an engaging Hill-Sachs lesion is high. The Latarjet procedure has been well-described for restoring glenohumeral stability in patients with over 25% glenoid bone loss. However, the treatment for patients with combined humeral head and mild (<25%) glenoid bone loss remains unclear. We report on the outcomes of the modified Latarjet for this population.Methods:Modified Latarjet was performed in twenty three patients with recurrent anterior shoulder instability, engaging Hill-Sachs by exam confirmed with arthroscopy, and less than 25% anterior glenoid bone loss. The mean follow-up was 3.5 years. All patients were assessed for their risk of recurrence using the Instability Severity Index Score (ISIS), had pre-operative 3D imaging to assess humeral and glenoid bone loss. Single Assessment Numeric Evaluation (SANE), Western Ontario Shoulder Instability Index (WOSI), recurrence rate, radiographs, range of motion and dynamometer strength were used to assess outcomes.Results:Average pre-operative instability severity index score was 6.2 (range 4-9). Pre-operative glenoid bone loss averaged 15.1% (range 5-25%). The humeral defect averaged 40.4% in width and 13.7% in depth on axial computed tomography scan, with an average Hill-Sachs angle of 28°. The mean WOSI index was 457 of 2100 (range 0-1398). The mean SANE score was 81.2 (range 60-100). Five out of ten competitive athletes returned to play for at least one season. There were no recurrent dislocation and three patients had a single episode of recurrent subluxation. Loss of external rotation at the side averaged 8°, and there was no significant loss of abduction. Subscapularis, abduction and external rotation strength averaged greater than 85% of the contralateral shoulder. Fourteen patients on average had 1.4 (range 1-4) previous open or arthroscopic stabilization procedures prior to the Latarjet, nine others had Latarjet done primarily. WOSI scores correlated directly with number of previous surgery (r=0.81, p=0.02). Average WOSI score was 239 (range 0-510) in primary Latarjet, 495 (range 42-1024) in patients with one previous stabilization procedure, and 674 (range 192-1398) in patients with two or more previous stabilization procedures (ANOVA p<0.001). There were three deep infections, two graft fractures, two painful hardware, one broken screw with graft malunion, and one radiographic graft nonunion. All infections, malunion and nonunion occurred in patients with failed previous stabilization procedures. No long-term nerve palsies were found. Resorption of the graft at the superior screw was seen in 28% of patients.Conclusion:The modified Latarjet is a reasonable choice for the treatment of an engaging Hill-Sachs lesion with concomitant mild anterior glenoid bone loss in this very demanding group of patients. However, the complication rate is significant.