To clarify the short-term results of conservative treatment for symptomatic full-thickness tears of the rotator cuff.

Between September 1996 and August 1999, 107 shoulders of 105 patients were diagnosed as full-thickness tears of the rotator cuff by MRI or arthrography at our institute. All patients were treated conservatively and only 3 shoulders underwent surgery because of persistent pain after 6 months of conservative treatment. Among 104 shoulders treated conservatively for more than 12 months, 102 shoulders of 100 patients were followed up with an average follow-up period of 33 months. Two patients were excluded: one had died and the other had been lost at the time of follow up. Among 102 shoulders, 56 shoulders of 56 patients were assessed by direct examination, and 44 shoulders of 46 patients were interviewed by telephone. There were 54 males and 46 females with an average of 64 years (44–80). The Shoulder Functional Evaluation by the Japanese Orthopaedic Association (JOA score) was used for assessment (full score = 75 points)

The overall JOA score improved significantly from 41.3 points (initial) to 63.5 points (follow-up) (p< .01). Satisfactory results (> - 60 points) were obtained in 71%. The pain score (full score = 30 points) improved from 8.3 points (initial) to 24.7 points (follow-up) (p< .01). At follow-up, 49% had no pain and 88% did not need any medication. The range of motion, abduction strength, and activities of daily living improved significantly (p< .01). Angle of external rotation at initial examination was positively correlated with the JOA score at follow-up (r=0.373, p> .01).

Short-term outcome of conservative treatment for symptomatic full-thickness tears of the rotator cuff was satisfactory in 71% of the patients.

We measured the isokinetic strength of abduction, adduction, internal rotation, and external rotation in ten patients with full-thickness tears of the supraspinatus and ten with partial-thickness tears. The measurements were repeated after intra-articular or intrabursal injection of local anaesthetic.

Pain blocks produced significant increases in strength in both full and partial-thickness tears. After the block, the strength in full-thickness tears compared with the opposite side was 67% to 81% in abduction and 67% to 78% in external rotation, both significantly smaller than those on the uninvolved side (p = 0.0064, p = 0.0170). In partial-thickness tears the strength after the block ranged from 82% to 111%, with no significant differences between the involved and uninvolved sides.

The decreases in strength of 19% to 33% in abduction and 22% to 33% in external rotation after full-thickness tears appear to represent the contribution of supraspinatus to the strength of the shoulder.