Mid-term Functional Outcomes of Open Congruent Arc Latarjet for Recurrent Anterior Shoulder Instability: A Retrospective Cohort Study

Introduction: Recurrent anterior shoulder instability with significant glenoid bone loss is associated with high failure after isolated soft-tissue repair. The open Latarjet procedure with congruent arc modification improves graft coverage and glenoid arc restoration, but mid-term clinical data are limited. Materials and Methods: This retrospective cohort included patients who underwent open Latarjet with congruent arc modification between January 2015 and December 2020. Eligibility criteria were ≥3 anterior dislocations, ≥15% glenoid bone loss, and ≥24 months of follow-up. Functional outcomes (Western Ontario Shoulder Instability Index [WOSI], Rowe), range of motion, complications, and graft union on computed tomography (CT) were assessed. Kaplan–Meier survival analysis estimated recurrence-free survival. Results: A total of 80 patients (62 males, 18 females; mean age 28.5 ± 6.4 years) were analyzed with a mean follow-up of 4.5 ± 1.2 years. WOSI improved from 46.7 ± 12.3 to 79.4 ± 15.8 (P < 0.001), and Rowe from 32.5 ± 9.6 to 85.6 ± 10.7 (P < 0.001), both exceeding minimal clinically important difference thresholds. Forward flexion (+15°) and abduction (+20°) improved significantly, whereas external rotation showed a mild, non-significant reduction (–10°, P = 0.079). Complications occurred in 12.5%, mainly graft non-union (5%). CT confirmed graft union in 95%. Kaplan–Meier analysis showed 97.5% recurrence-free survival at 5 years. Conclusion: Open Latarjet with congruent arc modification provides clinically meaningful functional improvement, reliable graft union, and durable mid-term stability in recurrent anterior instability with glenoid bone loss. Keywords: Latarjet, congruent arc, shoulder instability, glenoid bone loss, functional outcomes.