[An arthroscopic "inlay" Bristow procedure with suture button fixation: Surgical technique and radiology evaluation]

To introduce an arthroscopic "inlay" Bristow procedure based on the Mortise-Tenon joint structure concept using suture button fixation, and to evaluate its clinical and radiology results postoperatively with a minimal 3-year follow-up.

A total of 56 patients who received arthroscopic "inlay" Bristow procedure with suture button fixation between June 2015 to June 2016 were eventually enrolled in this study. Radiological assessment on the 3D CT scan was performed preoperatively, immediately after operation, and postoperatively at the end of 3 months, 6 months and the final follow-up. Complications postoperatively were also recorded.

A total of 56 patients were finally included in this study. The mean follow-up time was (36.1±3.7) months. Coracoid grafts (middle point) were positioned at about 4 o'clock (123.8°±12.3°) in the En-face view. In the axial view, 95% (53/56) of the grafts positioning were measured as flush, 5% (3/56) as medial. Bone union rate was 96.4% at the final follow-up. At the end of 3 months, 6 months, and the final follow-up, the length of the coracoid graft was 96.9%±4.9%, 91.9%±6.2%, and 91.6%±6.6% of the immediate postoperative length, respectively. Compared with the immediate postoperative length, the length measured at the end of 3 months shortened not significantly (t=2.12, P > 0.05). The coracoid graft shortened more pronouncedly 6 months postoperatively (t=4.98, P < 0.05) and then remained almost constant over time (t=-0.75, P > 0.05), with all grafted coracoid graft retaining more than 90% of their initial length by the 3-year follow-up. And new bone formation at the junction between the coracoid graft and glenoid neck in the axial view were obviously noted in 25 cases. The quantitative evaluation showed that the glenoid area in En-face view was significantly increased at the final follow-up than that immediately after surgery [(9.72±1.22) cm² vs. (9.42±1.11) cm²]. No degenerative changes were noted on CT images in all the patients at the final follow-up.

This study reported a series of "inlay" Bristow procedure with suture button fixation for recurrent shoulder dislocation, providing satisfactory union rate and excellent graft positioning. And using suture button fixation instead of screw can reduce osteolysis and complications related to hardware implantation. Moreover, the bone remodeling between the coracoid process and glenoid could be beneficial to restoring the anterior stability of shoulder joint in a long term follow-up.