Isokinetic strength of the shoulder after repair of a torn rotator cuff.

The strength of the shoulder was measured isokinetically in forty patients who had undergone surgical repair of a torn rotator cuff. Thirty-three patients were tested six months postoperatively and twenty-four, after a year. There was an increase in strength between the two intervals (p less than 0.05) for abduction measured at 180 degrees per second, external rotation measured at 60 and 180 degrees per second, and flexion measured at 60 degrees per second. On the average, strength reached 80 per cent of normal in abduction and 90 per cent of normal in external rotation at one year postoperatively. Strength of forward flexion reached 75 per cent of normal. In seventeen patients with paired data (recorded at both six and twelve months), an increase in strength (p less than 0.05) was found for each motion and speed that was tested. Patients who had a small tear scored higher than those who had a large tear, but not to a significant degree. Whether the operation was done on the dominant extremity or on the non-dominant one did not appear to affect the results, nor did the timing of the repair after injury.