Screw Fixation has Better Outcomes, Lower Incidence of Re-dislocation and Lower Bone Resorption than Button Fixation for Arthroscopic Anatomic Glenoid Reconstruction with Distal Tibia Allograft: A Matched Cohort Analysis

To compare the clinical outcomes between patients who received arthroscopic anatomic glenoid reconstruction (AAGR) using distal tibia allograft with button fixation versus screw fixation. A retrospective chart review was conducted for all patients who underwent AAGR with button or screw fixation between 2012 and 2021. Patients were matched at a 1:1 ratio based on sex, type of surgery, and time since surgery. All patients who were included had a minimum clinical follow-up of two years. Study outcomes compared Western Ontario Shoulder Instability (WOSI) Index scores, recurrence of instability, incidence of revision surgeries, and CT readings. 44 patients were included with 22 patients in each group. The pre-operative glenoid bone loss was 22.57 ± 8.06% in the screw group and 22.92 ± 8.84% in the button group (p = 0.898). Both groups demonstrated a significant improvement in WOSI from pre-operative to latest follow-up, however patients in the screw group demonstrated significantly better WOSI scores at both two-year (p = 0.003) and latest follow-up (p = 0.019) compared to the button group. Recurrent dislocation was observed in 9 patients (40.9%), all of whom underwent button fixation (p < 0.001). Two patients in the screw group experienced hardware complications (p = 0.488). Individuals who underwent button fixation were significantly more likely to undergo a revision surgery for recurrent instability (p = 0.011). Individuals in the button group demonstrated a significantly smaller mean graft AP diameter postoperatively (p < 0.001). AAGR with both screw fixation results in significantly improved WOSI scores at minimum two-year follow-up. Button fixation has a significantly higher incidence of re-dislocation. Radiographic findings suggest that on average, button fixation results in higher grade bone resorption and subsequently smaller post-operative glenoid AP width than screw fixation. Level III, retrospective comparative case series.