Summary

Arthroscopic rotator cuff repair with muscle advancement and polyglycolic acid sheet reinforcement had lower failure rate for massive rotator cuff tears. The clinical outcomes of the healed group after surgery were significantly improved, while no significant improvements after surgery were observed in the failed group. Preoperative teres minor atrophy was a risk factor for failure.

Abstract

Introduction

We have been performing ARCR with muscle advancement of the supraspinatus (SSP) and infraspinatus (ISP) and artificial biomaterial reinforcement over the repaired tendon for mRCTs. The purpose of the procedure is to reduce the extracting tension applied to the repairing tendon by the muscle advancement, and to enhance the cuff healing using the polyglycolic acid (PGA) sheet which can potentially serve as a source of rotator cuff regeneration. This time, the failure rate of this procedure was investigated, and the postoperative clinical outcomes were statistically compared between the healing group and the failure group. In addition, multivariate analysis of risk factors causing failure was performed.
Materials & Methods: Eighty-four patients (56 males, 28 females, average age 66.6±8.9 years) who underwent this procedure under the diagnosis of mRCTs, and in which the entire footprint could be covered with the cuff stump with a traction force of 30 N were included in this study. For these cases, each cuff integrity was evaluated by MRI taken 6 months after surgery (Sugaya type IV and V were defined as failure), the failure rate was calculated. Then, the subjects were divided into a healed group (H group) and a failure group (F group) according to the MRI findings. The range of motion, Constant scores, and the isometric muscle strength at the time of preoperative and final follow up were measured for all cases, and statistically compared between the H and F group at the final follow up as well as between pre- and the final follow up in each group. In addition, univariate and multivariate analyses were performed about preoperative conditions and intraoperative findings to identify the risk factors for failure.

Results

Postoperative MRI revealed that 70 cases were healed, and 14 cases were failed, and the failure rate was 16.7%. The clinical outcomes of the H group were significantly improved after surgery except for the internal and external rotation angles, while no significant improvements after surgery were observed in the F group. Comparing the two postoperative groups, all the values were significantly higher in the H group than the F group except for the internal rotation angle. Univariate analyses of risk factor for failure after surgery showed significant differences between the H and F groups in preoperative teres minor (TM) muscle atrophy (p = 0.004), preoperative external rotation angle (p = 0.008), and preoperative isometric external rotation muscle strength (p < 0.001). Multivariate analysis showed a significant difference in preoperative TM muscle atrophy with a 95% confidence interval of 1.04 – 14.46 and an odds ratio of 3.88 (p = 0.04).

Conclusions

This procedure for mRCTs is a useful technique as the failure rate of is 16.7%, which is lower than the previous reports. Since the clinical outcomes were significantly better in the H group than in the F group, complete repair by this procedure should be aimed even for mRCTs. However, when TM muscle atrophy is involved, failure is likely to occur even if this procedure is performed.