Repaired Supraspinatus Tendons in Clinically Improving Patients: Early Postoperative Findings and Interval Changes on MRI

OBJECTIVE To demonstrate and further determine the incidences of repaired supraspinatus tendons on early postoperative magnetic resonance imaging (MRI) findings in clinically improving patients and to evaluate interval changes on follow-up MRIs. MATERIALS AND METHODS Fifty patients, who showed symptomatic and functional improvements after supraspinatus tendon repair surgery and who underwent postoperative MRI twice with a time interval, were included. The first and the second postoperative MRIs were obtained a mean of 4.4 and 11.5 months after surgery, respectively. The signal intensity (SI) patterns of the repaired tendon on T2-weighted images from the first MRI were classified into three types of heterogeneous high SI with fluid-like bright high foci (type I), heterogeneous high SI without fluid-like bright high foci (type II), and heterogeneous or homogeneous low SI (type III). Interval changes in the SI pattern, tendon thickness, and rotator cuff interval thickness between the two postoperative MRIs were evaluated. RESULTS The SI patterns on the first MRI were type I or II in 45 tendons (90%) and type III in five (10%). SI decreased significantly on the second MRI (p < 0.050). The mean thickness of repaired tendons and rotator cuff intervals also decreased significantly (p < 0.050). CONCLUSION Repaired supraspinatus tendons exhibited high SI in 90% of clinically improving patients on MRI performed during the early postsurgical period. The increased SI and thickness of the repaired tendon decreased on the later MRI, suggesting a gradual healing process rather than a retear.