Summary

Delamination is not associated with rotator cuff re-tear. Preoperative anteroposterior length of rotator cuff tear affects postoperative rotator cuff retear with or without delamination.

Abstract

Introduction

In this study, we investigated the influence of delamination and anteroposterior length (AP length) of rotator cuff tear on postoperative rotator cuff retear.

Materials And Methods

72 shoulders with full-thickness rotator cuff tears of middle size or greater with suture-bridging technique between April 2014 and April 2019 and follow-up of at least 1 year were included. The mean age was 64.6 years, and the mean follow-up period was 18.9 months. Delamination or non-delamination was evaluated using a 30-degree scope from the anterolateral portal in arthroscopic surgery. Among the patients, 24 without delamination received a suture bridging technique, and 48 with delamination received either En masse (n=10) repair or separate double layer repair (n= 38). The retraction grade of the rotator cuff and anteroposterior tear length (AP length) were analyzed. The degree of retraction of the rotator cuff tear was evaluated in the MRI coronal plane and classified as stages 1 to 4. The AP length of the rotator cuff tear was measured from anterior to posterior along the greater tuberosity. The biceps tendon groove was defined as the leading edge of the supraspinatus tendon. There was no difference in maximum coronal length and maximum axial length of the humeral head on reformation CT images between the two groups. The cut-off value of AP length for preoperative MRI of rotator cuff re-tear was assessed using the Receiver Operating Characteristic analysis (ROC analysis).

Results

There were no significant differences in any preoperative factors between the 2 groups except in the stage of retraction. In non-delamination and delamination cohorts, stage of preoperative retraction of the rotator cuff tear was 2.5[2-3]and 3[3-3]respectively(p=0.009),mean AP length of rotator cuff tear measured 27.8 and 27.1 mm respectively(p=0.704), and retear rate was 21 and 14.6% respectively(p=0.518). The retraction stages of the rotator cuff without and with postoperative rotator cuff retear in the non-delamination group were 2 [2-3] and 3 [3-3] (p=0.03), respectively, and in the delamination group was 3 [2-3] and 3 [3-3] (p=0.147), respectively. The preoperative AP length in the non-delamination group was 25.8 and 35.6 mm (p=0.006) for without and with retears, respectively. In contrast, preoperative AP length in the delamination group was 26.2 and 32.6 mm without and with retears, respectively (p=0.033). The AUC value, sensitivity, and specificity for rotator cuff retears were 0.832, 80%, and 90%, respectively, when the cut-off value was 33 mm or longer AP length in the non-delamination group by ROC analysis. In the delamination group, the AUC value, sensitivity, and specificity were 0.739, 57%, and 81%, respectively, when the cut-off value was 34 mm or longer.

Conclusion

Delamination is not associated with rotator cuff re-tear. Preoperative retraction of the rotator cuff tear is associated with postoperative re-tear in the non-delamination group. Preoperative AP length of rotator cuff tear affects postoperative rotator cuff retear with or without delamination.