Summary

Failure after arthroscopic rotator cuff repair with muscle advancement was likely to occur if the infraspinatus tendon retraction or long head of biceps tendon conditions were more severe for the massive rotator cuff tears although the flexion angles, muscle strengths of all directions, and clinical scores significantly improved even if the repaired tendon healed.

Abstract

Introduction

High failure rates of arthroscopic rotator cuff repair (ARCR) are frequently reported for massive rotator cuff tears (mRCTs). We therefore perform the procedure which we developed: ARCR with supraspinatus (SSP) and infraspinatus (ISP) muscle advancement (MARCR) when more than 30 N is required at the repair site for such mRCTs. The purpose of this study was to evaluate the outcomes of healed and unhealed cases of MARCR.

Methods

We screened 86 MARCR patients (average age: 67.8±8.3 years old) who could be followed up for at least 2 years (average follow-up period: 28.6±13.2 months). MARCR was performed as follows: a 4 cm transverse skin incision was created along the medial border of the scapular spine, and after detaching the trapezius muscles the cuff muscle bellies were released from the scapular body. Then, torn cuff tendon repair was achieved via the suture bridge technique with additional procedures as required [artificial biomaterial (polyglycolic acid sheet) reinforcement, or bone marrow stimulation]. MRI was used at the final follow up to determine the healed and unhealed groups, by evaluating the postoperative cuff integrity, (type IV and V of Sugaya classification was regarded as unhealed). The preoperative conditions and additional procedures, the postoperative ROM, isometric muscle strengths and clinical scores (Constant score, UCLA score), were compared statistically between the two groups. Furthermore, a statistical comparison was made between the 2 groups of the degree of fatty infiltration, based on data from sagittal MRI taken preoperatively and at the final follow up.

Results

At the final follow up, 66 shoulders were successfully healed, with 20 unhealed, amounting to a failure rate of 23.3%. Regarding postoperative outcomes, the clinical scores and the isometric muscle strengths of the internal and external rotation significantly improved after surgery in both groups. The flexion angle and abduction muscle strength significantly improved only in the healed group, and the internal and external rotation angles failed to improve significantly after surgery in either group. When comparing the healed and unhealed groups, all ROM, isometric strengths, and the clinical scores in the healed group were significantly better than in the unhealed group. In spite of no significant differences preoperatively between either group, the postoperative SSP fatty infiltration in the healed group was significantly less.

Conclusion

As the SSP fatty infiltration was more pronounced after surgery, the postoperative flexion angle and abduction muscle strength failed to improve in the unhealed group.