The post-operative isokinetic strength of the shoulder and arthrogram were evaluated in eighteen patients who had a repair of a full thickness cuff tear. Arthrography was performed in all patients at six months after operation and the isokinetic strength was evaluated at one year after operation using Myolet (Kawasaki Heavy Industry, Ltd.) The post-operative arthrograms revealed that the only four shoulders (22%) were intact. Other than that, five (28%) shoulders had either intratendinous leakage of the contrast medium or a pinhole tear, and nine shoulders (50%) had obvious leakage of the contrast medium into the subacromial bursa namely a residual defect. The mean peak torque was 97%/89%,102%/89% of the uninvolved shoulder in adduction/abduction at 60°/sec and 120°/sec respectively, and 87%/91% in internal/external rotation at 60°/sec. Recovery of strength correlated primarily with the size of the tear and not with the watertightness of the repaired cuff.
Postoperative muscle strength of the shoulder is one of the most i mportant factors for good clinical results of a rotator cuff repair. This study, however, did not show a significant relation between the status of a repaired rotator cuff and the strength of the shoulder suggesting that a watertight repair of the rotator cuff tear may not be necessary for the recovery of isokinetic strength of the shoulder.
