抄録
The purpose of this study was to examine the relationship between synovitis and shoulder pain in rotator cuff tear. Seventy six patients with rotator cuff tear were the candidates. Subacromial synovium around the greater tuberosity and glenohumeral synovium from the rotator interval to the subscapularis bursa were harvested for specimens during operation. The degree of preoperative shoulder pain was measured with a visual analogue scale (VAS: 0 as no pain,5 as moderate and 10 as severe). For the control specimens, subacromial synoviums were obtained from patients with anterior instability of the shoulder who had exhibited no signs of subacromial impingement. All specimens were obtained with patient's informed consent. The amount of substance P in the subacromial bursa (SAB) was examined by radioimmunoassay. The mRNA expression levels of inflammatory cytokines (interleukinl- and its naturally occurring antagonists) in the SAB and glenohumeral joint (GHJ) were analyzed with RT-PCR methods. Thirty-seven patients were divided into two groups: 19 patients with nonperforated rotator cuff tears (partial-thickness tear and subacromial bursitis)and 18 patients with perforated cuff tears (a full-thickness tear). The VAS showed significantly greater pain in the nonperforated cuff tear than in the perforated cuff. Consistent with these results, the amount of substance P in the SAB was significantly greater in the former group than in the latter one. In the remaining thirty-nine patients, the mRNA expression levels of the cytokines were analyzed. The expression level of cytokinemRNAs in the SAB were significantly correlated with the degree of shoulder pain, by contrast in the GHJ, inversely correlated with the pain. Subacromial synovitis is correlated with the degree of shoulder pain in a rotator cuff tear. By contrast, glenohumeral synovitis appears less to contribute to the generation of shoulder pain.