Tendon Healing Progression Evaluated With Magnetic Resonance Imaging Signal Intensity and Its Correlation With Clinical Outcomes Within 1 Year After Rotator Cuff Repair With the Suture-Bridge Technique

Abstract

Background: After a rotator cuff (RC) is repaired, its signal intensity (SI) on magnetic resonance imaging (MRI) gradually changes to normal and could reflect the degree of RC healing. Nevertheless, it remains unclear how long it takes for SI to recover to normal and whether the SI progression correlates with clinical outcomes after RC repair (RCR). Purpose: To serially evaluate the SIs of the repaired RC tendon on MRI and the postoperative clinical outcomes and then analyze the correlation between them. Study Design: Case series; Level of evidence, 4. Methods: This study prospectively included 25 patients who underwent arthroscopic RCR with the suture-bridge technique between June 2016 and July 2017. Twenty-three patients accepted full follow-ups at 1, 3, 6, 9, and 12 months. Before surgery and at each follow-up, visual analog scale (VAS) for pain and 4 functional scores were evaluated: Constant-Murley score, American Shoulder and Elbow Surgeons shoulder evaluation form, modified University of California at Los Angeles score, and Fudan University shoulder score. The patients underwent MRI examinations at every follow-up. The values of the signal/noise quotient at the distal (SNQd) and proximal (SNQp) areas were calculated to evaluate the SI of the repaired tendon. The correlations of clinical outcomes with SNQd and SNQp values were analyzed, and subgroup analyses were performed. Results: Overall, the mean postoperative VAS score significantly decreased at postoperative 1 month ( P < .001), and the functional scores were all significantly higher than the preoperative values at 6 months (all P < .001). SNQd and SNQp values were both significantly higher than normal at 1 and 3 months (all P < .001) and reduced to normal after 9 and 6 months, respectively. Correlation analyses showed that the SNQp value significantly correlated with VAS score (positive) and all functional scores (negative) at 1 and 3 months postoperatively. Further comparison indicated that the patients with VAS score >3 had higher SNQp values than patients with VAS score ≤3 at 1 and 3 months postoperatively (both P = .01). Conclusion: After RCR with the suture-bridge technique, it took longer for SI to become relatively normal than it did to have a significant clinical improvement. Early after surgery (1-3 months), worse clinical outcome correlated with higher SI on proximal cuff tendon.