Blood flow in the anterior humeral circumflex artery reflects synovial inflammation of the shoulder joint in rotator cuff tears

BACKGROUND: An association has been reported between rotator cuff tear and inflammation. We hypothesized that blood flow in the anterior humeral circumflex artery would reflect synovial inflammation in the shoulder. This study aimed to clarify the association of blood flow in the anterior humeral circumflex artery with synovial inflammation and shoulder pain in patients with rotator cuff tears. METHODS: In this prospective, cross-sectional study, tissue samples from the synovium in the rotator interval were obtained from 33 patients undergoing arthroscopic rotator cuff repair. Reverse transcription-polymerase chain reaction and real-time polymerase chain reaction were performed to determine the messenger RNA expression of inflammatory mediators, growth factors, and matrix metalloproteinases. Additional tissue samples were fixed for histologic evaluation. Before surgery, we measured the peak systolic velocity in the anterior humeral circumflex artery using pulse Doppler ultrasonography. RESULTS: The peak systolic velocity in the anterior humeral circumflex artery was positively correlated with the messenger RNA expression of interleukin 1β, interleukin 8, and matrix metalloproteinase 3 genes (r = 0.49, P = .004; r = 0.55, P = .001; and r = 0.39, P = .026, respectively), as well as histologic synovitis scores (r = 0.48, P = .005). Additionally, it was significantly higher in patients with resting pain than in those without resting pain (P = .048). CONCLUSION: The peak systolic velocity in the anterior humeral circumflex artery is associated with the severity of synovial inflammation. Our results suggest that assessing the peak systolic velocity in the anterior humeral circumflex artery is useful for evaluating the severity of synovial inflammation.