Shoulder evaluation with isokinetic strength testing after arthroscopic rotator cuff repairs

Hypothesis

The purpose of this study was to evaluate, with isokinetic testing, the recovery of strength in patients with rotator cuff tears treated with two different arthroscopic repair techniques.

Materials and methods

From September 2004 to September 2006, patients with a full-thickness supraspinatus tear were randomized to two different groups. Patients in group 1 underwent side-to-side repair with permanent sutures, whereas those in group 2 underwent tendon-to-bone fixation with 1 metal suture anchor loaded with double sutures. The same independent examiner evaluated the outcomes using the Constant score and isokinetic strength testing preoperatively and at 3, 6, and 12 months postoperatively. Data analysis was also performed in three subgroups: small, medium, and large tears.

Results

Constant scores improved from preoperatively to 12 months postoperatively. In group 1, the mean Constant score was 32 points before surgery and 78 points at 12 months postoperatively. In group 2, the mean Constant score was 30 points before surgery and 88 points at 12 months after surgery. Strength increased gradually during the first postoperative year. In group 1, preoperative mean peak torque was 34% and 39% in internal rotation and external rotation, respectively. After repair, it decreased to 17% and 21%, respectively, at 12 months. In group 2, preoperative mean peak torque was 32% and 37% in internal rotation and external rotation, respectively; after surgery, it decreased to 9% and 12%, respectively, at 12 months. Data analysis showed that the difference in improvement in Constant scores and in strength recovery from preoperatively to postoperatively in groups 1 and 2 was statistically significant (p < .05).

Conclusion

We showed a strength difference between patients with side-to-side repairs and those with tendon-to-bone repairs.

Level of evidence

Level 1; Prospective randomized study.

Keywords: Rotator cuff, rotator cuff tear, rotator cuff repair, Constant score