Retear rate in the late postoperative period after arthroscopic rotator cuff repair.

BACKGROUND

Few clinical studies have evaluated the integrity of repaired tendons and identified the timing of retears through the use of serial imaging.

HYPOTHESIS

Retears after arthroscopic rotator cuff repair are uncommon in the late postoperative period (after 3 months).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Among 221 arthroscopic rotator cuff repairs that were performed at a single hospital between May 2010 and February 2012, 61 were involved in this study. Rotator cuff tears consisted of 12 small, 31 medium, 8 large, and 6 massive rotator cuff tears. Additionally, 4 isolated subscapularis tears were included. For clinical evaluation, all patients were assessed both preoperatively and postoperatively by use of the University of California-Los Angeles Shoulder Rating Scale, absolute and relative Constant scores, and American Shoulder and Elbow Surgeons score; active range of motion was assessed as well. For radiological evaluation, all 61 patients had a magnetic resonance imaging (MRI) evaluation at 3 months postoperatively. Among them, 23 patients were evaluated for repaired tendon integrity on postoperative MRI at a minimum of 1 year after surgery (mean, 14.1 months; range, 12-19 months), and results were classified according to the Sugaya classification: type I, sufficient thickness with homogeneously low intensity on each image; type II, sufficient thickness, partial high-intensity area; type III, less than half the thickness without discontinuity; type IV, minor discontinuity; and type V, major discontinuity. The remaining 38 patients, who refused to undergo MRI again for financial reasons, were evaluated through ultrasound.

RESULTS

Statistically significant clinical improvements were observed after surgery. The MRI conducted at 3 months postoperatively identified 9 patients with Sugaya type I, 28 patients with type II, and 24 patients with type III repairs. No patients showed Sugaya type IV or V repairs at postoperative 3 months. Thirty-seven patients who had shown Sugaya type I or II repairs on 3-month postoperative MRI had no retear on imaging study at a minimum of 1 year. Of 24 patients who had shown type III repairs on 3-month postoperative MRI, 1 patient exhibited retear (Sugaya type IV) on 1-year postoperative MRI and 3 patients showed full-thickness retear on 1-year postoperative ultrasonography. All 4 of these patients had had large to massive tears preoperatively.

CONCLUSION

Retears occurred infrequently in the late postoperative period (after 3 months) in well-healed tendons that had shown intact cuff repair integrity with sufficient mechanical and biological healing within the first 3 postoperative months.