Arthroscopic double bone block augmentation is a salvage procedure for anterior and posterior shoulder instability secondary to glenoid bone loss.

PURPOSE: The aim of this study was to describe a one-step arthroscopic anterior and posterior bone block augmentation technique for bidirectional shoulder instability and to present preliminary results.
METHODS: Seven consecutive patients who underwent a concomitant anterior and posterior bone block procedure between 2007 and 2015 were retrospectively reviewed. Clinical scores, return to sport rate, and complications were assessed. Radiological outcome, with CT scan at 6 months and plain radiographs at final follow-up were reviewed. Patient reported functional outcomes were also assessed via phone or email interview.
RESULTS: Seven consecutive patients were included in the study with a median age at surgery of 27 years. Median clinical and radiological follow-up was 7 months (4-72 months). Walch-Duplay score and Rowe scores were improved. Four patients were able to return to sport. One patient experienced recurrent dislocation, and one subjective instability/subluxation without confirmed recurrence. CT scan showed union in all cases, with one case of anterior bone block osteolysis and one case of partial posterior bone block osteolysis. Radiographs showed no detectable progression of osteoarthritis using the Samilson and Prieto classification. At final follow-up the median WOSI score was 187 (100-1140).
CONCLUSIONS: An all-arthroscopic technique for the treatment of combined anterior and posterior glenoid bone loss as a cause of shoulder instability can provide fair to good clinical outcomes, with a low incidence of intra-operative complications. The rate of failure in our series remains higher than that seen in primary stabilization procedures. As such we consider this largely as a salvage procedure for cases in which alternative treatments have failed or are unlikely to succeed. LEVEL OF EVIDENCE: IV.