Patterns of vascular and anatomical response after rotator cuff repair

Background: It has been assumed that a robust vascular response at the tendon to bone interface during rotator cuff repairs is an integral part to the healing process. There are few studies that have explored this in an in-vivo prospective fashion. Purpose: To prospectively characterize vascular and anatomical patterns in repaired rotator cuff tendons using Power Doppler sonography in a double-blinded fashion. Study Design: Case control study; Level of evidence, 3. Methods: Fifty patients undergoing rotator cuff repair were enrolled: 28 mini-open, 14 open, and 8 arthroscopic repairs; 20 patients were controls. Patients underwent Power Doppler sonography at 6 weeks, 3 months, and 6 months postoperatively. Power Doppler sonography analysis examined 6 areas of the rotator cuff repair: discretely marginated intrasubstance, partial-thickness defects, full-thickness defects, focal thinning of repair, presence of bursal or joint fluid, and location of anchors. A subjective scoring system assessed blood flow in each region. Results: There was a predictable, significant decrease in vascular scores after rotator cuff repair over time. The mean vascular score was 11.6 at 6 weeks, 8.3 at 3 months, 7.0 at 6 months, and 2.4 for controls. There was a significant difference (P < .05) in vascular recruitment scores between each time period, with the most robust flow at the peritendinous region. The lowest vascular score was at the anchor site or cancellous trough. Forty-eight percent of the patients had a rotator cuff repair defect postoperatively. These findings did not correlate with functional assessment and outcome at 6 months. There was no significant difference in vascular scores between the defect and no-defect groups. Mean University of California, Los Angeles; L'Insalata; and American Shoulder and Elbow Surgeons scores at 6 months were 28.6, 86.3, and 81.5, respectively. Thirty-three percent of asymptomatic controls had a rotator cuff tear that averaged 7.6 x 7.1 mm. Conclusion: The robust vascular response dropped with time, which is not seen in asymptomatic shoulders. Nearly half of the patients demonstrated persistent rotator cuff defects after rotator cuff repair that did not correlate with functional outcome and physical findings at 6 months.