Background: Night pain is a vexing symptom in rotator cuff tear (RCT) patients. Under arthroscopic rotator cuff repair, we found hyperemic synovitis around the rotator interval or capsule surfaces in severe night pain patients. Therefore, we hypothesized blood flow of the feeding artery toward the capsule was increased in the night pain patients with RCT. The purpose of this study was to evaluate the blood flow around the shoulder using Doppler ultrasonography (US).
Methods: From August 2010 to April 2011, a consecutive series of 28 patients with RCT with night pain were evaluated using Doppler US. Blood flow of the anterior humeral circumflex artery (AHCA) and the brachial artery (BA) were evaluated on both peak systolic velocity (PSV) and resistance index (RI) by pulse Doppler US. Concurrently, we also investigated 15 normal shoulders, 5 RCT without night pain, and 9 impingement shoulders as the control groups. PSV and RI on the affected side were compared with the unaffected side.
Results: PSV and RI of the BA showed no differences between the affected and unaffected side in all groups, however PSV of the AHCA was significantly higher (p<0.0001) in the affected side of the night pain groups. Furthermore, RI of the AHCA was significantly lower (p<0.05) in the affected side of the night pain groups.
Conclusion: We found that the increasing PSV and decreasing RI of the AHCA was observed in the night pain groups. These results should be an important condition for the pathogenesis of night pain in RCT patients.
