A Clinical Research on Arthroscopic Repair of Massive-large Rotator Cuff Tears With a Novel Inner Fixation Technique

The purpose of this study is to compare a novel double row technique with suture bridge double row technique in the arthroscopic repair of massive-large rotator cuff tears clinically. The study is designed as a randomized controlled trial. A total of 52 participants with large - massive rotator cuff tears will be prospectively enrolled and randomly divided into 2 groups according to the applied repairing technique: novel double row technique group and suture bridge double row technique group.

The investigators prospectively enrolled participants who met the following inclusion criteria: preoperative magnetic resonance imaging (MRI) diagnosis of a large - massive sized rotator cuff tear (>3cm), which was confirmed during operation; chronic tear; older than 17 years and younger than 75 years; without surgical contraindications and willing to participate. The investigators excluded patients with poor quality rotator cuff and irreparable tear; severe glenohumeral arthritis; previous shoulder surgery; accompanied by dislocation or fracture of shoulder; refusal to participate.

Each participant, assigned using a randomization table, was assessed by a clinical researcher, who was blinded to the grouping, at the following time points: preoperatively; 3, 6, 12 and 24 months postoperatively. The visual analog scale (VAS) for pain, active and passive ROM, and functional scores were assessed at each time point. The functional scores including the Constant score, American Shoulder and Elbow Surgeons (ASES) score, and University of California Los Angeles shoulder score (UCLA). Anatomic healing was evaluated using MRI at 3, 6, 12 and 24 months postoperatively. An experienced musculoskeletal radiologist interpreted the MRI and determined the healing failure rate. On the basis of the MRI findings, type IV or V of the Sugaya classification was regarded as healing failure.

Based on the previous study, the retear rate of large to massive rotator cuff tears treated with suture bridge double row technique was assumed to be 28.3%. Based on the investigators' previous clinical data on large to massive rotator cuff tears, it is assumed that the retear rate of large to massive rotator cuff tears treated with novel double row technique is 1.0%.

Differences in primary end points between the two groups were analyzed using chi-square tests. Set α=0.05, power is 0.80, the sample ratio of the two groups was 1:1. The sample size was estimated with PASS 15.0. A total of 46 patients, with 23 in each group, had sufficient power to detect statistical differences between groups. In consideration of the uncertainty of the effect and the possible loss of follow-up, the design effect was assumed to 10%. Therefore, the total sample size of this study should be more than 46÷90%≈51. To facilitate randomization, the sample size was determined to be 52 patients, with 26 patients in each group.