Poster 165: Non-Rigid Fixation Results in Higher Failure Rates Following Arthroscopic Glenoid Reconstruction

OBJECTIVES: It has previously been established that screw fixation results in better outcomes than button fixation for arthroscopic anatomic glenoid reconstruction (AAGR) with frozen allograft. There has been considerable debate on the causes for the higher dislocation rates with non-rigid fixation. The purpose of this study was to evaluate which factors may affect failure rates for AAGR with non-rigid fixation. METHODS: This was a retrospective review of patients who had AAGR using non-rigid fixation that were age-, gender-, and followup-matched with screw fixation patients. Arthroscopic videos were used to evaluate surgical factors including graft placement, fixation quality, tensioning, graft contact, soft tissue quality, quality of soft tissue repair, presence of Hill-Sachs, and addition of Remplissage. Patient demographic factors (age, gender, medical history etc) were also assessed. XRays and CTs were used to evaluate graft union, screw and button angle, graft remodeling, and button pull through. RESULTS: A total of 36 patients were included in our study who had AAGR between 2014 and 2019 (18 non-rigid fixation matched to 18 screw fixation). Seven patients who had non-rigid fixation had a dislocation requiring reoperation. Of these, 4/7 had poor anterior soft tissue. All but one patient had excellent soft tissue repair and balance at end of surgery. All seven patients had complete graft resorption compared with those did not fail who had a normal post-operative glenoid A-P dimension. CONCLUSIONS: In our case series, AAGR with non-rigid fixation had high rate of recurrent dislocation. These failed patients had appropriate surgical factors that were equivalent between dislocated patients and successful patients. The failure rate was not correlated with surgical technique, patient or radiographic factors but rather only fixation type. Further study is needed to evaluate fixation methods and to assess whether type of graft impacts these clinical outcomes.