2017 ISAKOS Biennial Congress ePoster #1905

 

Failure of Subscapularis Healing after RTSA Happens Frequently and Is Associated with Decreased Internal Rotation Strength

Vishal M. Mehta, MD, Naperville, IL UNITED STATES
Rachit Shah, BS, Geneva UNITED STATES
Cassie Mandala, PAC, Geneva, IL UNITED STATES

Fox Valley Orthopaedic Institute, Geneva, IL, UNITED STATES

FDA Status Cleared

Summary

This study demonstrates that 40% of subscapularis repairs did not heal after RTSA. Subscapularis failure was associated with internal rotation weakness.

Abstract

Introduction

Reverse Total Shoulder Arthroplasty (RTSA) has emerged as an effective treatment for many types of shoulder pathology. While its popularity has grown, it remains unclear whether subscapularis repair has any impact on the results of this procedure. It also remains unclear how often the repaired subscapularis remains intact after routine repair. The purpose of this study is to determine the rate of subscapularis failure after routine repair during RTSA.

Methods

10 consecutive cases of RTSA performed with a 135 degree, lateralized design were reviewed. All cases were greater than 2 years out from surgery at follow-up. All patients had a repairable subscapularis at the time of surgery and all repairs were performed using a standard tenotomy repaired with figure of eight number 5 Fiberwire sutures. The subscapularis repair was evaluated using ultrasound. Internal rotation strength was determined using a dynamometer and compared to the contralateral shoulder.

Results

4 subscapularis tendons were found to be completely torn (40%). An increase in internal rotation strength was found in the group with intact subscapularis tendons (108% strength of the contralateral shoulder versus 69%, p=.026).

Discussion And Conclusion

The subscapularis frequently does not heal when repaired after RTSA. It is unclear if the high failure rate is associated with the design of the implant. It is possible that a lateralized implant may place more tension on the repaired
subscapularis contributing to failure. In this series, failure to heal was found to be strongly correlated with a decrease in internal rotation strength. Debate over whether to repair the subscapularis during RTSA may be tempered by the fact that many repairs do not heal.