Arthroscopic double-button Latarjet: two-thirds of bone block healed at 90 days

Purpose The aim of this study was to evaluate the union rate and risk factors for delayed union in the early postoperative period after an arthroscopic Latarjet with double-button fixation. Method In a retrospective study, postoperative CT scans at 3 months were analysed following an arthroscopic Latarjet with double-button fixation used to treat anterior shoulder instability. Healing of the bone block, its position in the sagittal and coronal planes, and the contact area graft/scapula were analysed. Results Ninety-eight CT scans (98 patients) were included. The rate of healing at 3 months was 63/98 (64%) and four grafts clearly migrated. The position was perfectly flush to the glenoid rim in 67% and under the equator in 96%. The mean contact graft/scapula area was 135 mm 2 (4-420). In multivariate analysis, the risk of non-union at 3 months was associated with tobacco consumption (p = 0.001, aOR = 12.17 95% CI [2.62-56.49]), absence of preoperative glenoid bone defect (p = 0.003, aOR = 8.06 95% CI [2.06-31.56]), and a contact area graft/scapula less than 120 mm 2 (p = 0.010, aOR = 5.25 95% CI [1.50-18.40]). Among 31 non-united grafts, 93% definitively healed on CT scan at 1 year, leaving an overall rate of 93% of united grafts at last follow-up. Conclusions The rate of union at 3 months after an arthroscopic Latarjet with double-button fixation was 64%, reaching 93% at 1 year. This procedure should be carefully indicated in case of tobacco use or instability without glenoid bone defect, especially when the shoulder is exposed to high-energy trauma in the early phase after surgery.