Arthroscopic selective approach to dynamic posterior shoulder instability: long-term follow-up insights.

Background: The objective of this study is to evaluate the outcomes of arthroscopic capsulolabral repair in patients with structural dynamic posterior instability (Moroder classification B2), analyzing factors associated with inferior clinical outcomes or recurrence. The primary hypothesis is that this surgical approach in patients without static structural changes such as excessive glenoid retroversion or dysplastic glenoids will result in satisfactory clinical outcomes and low failure rates.

Methods: We conducted observational retrospective analysis in patients diagnosed with posterior structural dynamic instability who underwent arthroscopic capsulolabral repair. Demographic, clinical, and radiologic characteristics were registered, as well as patient-reported outcomes, satisfaction, complications, and failure, with a minimum 2-year follow-up. The association between these outcomes and preoperative factors was investigated.

Results: 21 patients were included, with an average age of 38.1 years (range: 27-51 years) and a mean follow-up of 68.7 months (range: 24-127 months). At the final follow-up, the degree of instability was 0 in 19 (90.5%) patients. The overall outcome assessment demonstrated a mean Subjective Shoulder Value score of 82.3 (±15.2), a mean Western Ontario Shoulder Instability score of 460.1 (±471), and a mean Rowe score of 91.5 (±13). Furthermore, a significant portion of patients returned to sport: 71.4% at any level and 57.1% at the previous level, and 71.4% reported satisfaction with treatment, whereas 5 (23.8%) patients had criteria for failure.

Conclusion: Arthroscopic capsulolabral repair in selected patients with type B2 posterior shoulder instability without static posterior findings yielded satisfactory clinical outcomes and low failure rates.