PURPOSE OF THE STUDY Irreparable rotator cuff tear continues to be a point of discussion. Several surgical techniques have been proposed so far. None of them, however, can be considered the method of choice. This study presents the first clinical results of superior capsule reconstruction (SCR) using the DX Reinforcement Matrix. MATERIAL AND METHODS The evaluation included patients with the minimum follow-up of 6 months. The follow-up period in these patients was 1 year (6-18 months) on average. The active (AROM) and passive (PROM) ranges of motion were assessed-anterior flexion, abduction, external rotation and external rotation at 90° abduction. The patients were assessed using clinical scores before and after the surgery-pain assessment scale (VAS), UCLA (University of California at Los Angeles) Shoulder Rating Scale and ASES (American Shoulder and Elbow Surgeons) Shoulder Score. RESULTS In the period from October 2016 to October 2018, a total of 20 SCRs were performed. The mean age of patients was 61 years. Nine patients were clinically assessed, with the mean follow-up of 1 year. The mean UCLA Shoulder Score was 10 points preoperatively. Postoperatively, the values went up to 29 points on average. The reported ASES score was 23.8 points preoperatively. Postoperatively, the mean score was 73.2 points. The VAS subjective pain score ranged around 7 points before the surgery. After the surgery, the mean VAS score was 2 points. The mean active shoulder flexion was 74° preoperatively and 161° postoperatively. The mean active abduction was 74° preoperatively and 161° postoperatively. The mean active external rotation of the shoulder joint was 20° preoperatively and 56° postoperatively. The mean active external rotation at 90° abduction was 21° preoperatively and 82° postoperatively. The changes in all the followed-up mean parameters of UCLA, ASES, VAS, AROM and PROM reported by our group show a relatively high level of substantive significance. DISCUSSION Results of arthroscopic superior capsule reconstruction using the DX Reinforcement Matrix have not been published in literature so far. Compared to the results for fascia lata published in literature, our results are slightly worse. By contrast, our results are similar to those achieved by human dermal allograft. CONCLUSIONS Arthroscopic superior capsule reconstruction currently appears to be the method of choice in unreconstructed supraspinatus and infraspinatus tear. Our group of patients shows that early clinical outcomes of SCR using xenograft are very promising. A significant pain relief and a considerable improvement in the range of motion of the operated shoulder joint were observed. No complication specifically associated with the use of xenograft has been reported as yet. A longer follow-up period and assessment of a larger group of patients will be necessary to confirm the success of this surgical procedure. Key words: massive rotator cuff tears; irreparable rotator cuff tears; superior capsular reconstruction; xenograft; DX Reinforcement Matrix.

Ortopedická klinika Lékařské fakulty Univerzity Palackého v Olomouci a Fakultní nemocnice Olomouc

Arthroscopic superior capsule reconstruction using the DX Reinforcement Matrix in patients with irreparable rotator cuff tears - pilot data