# Longitudinal analysis of rotator cuff repair: joint kinematics and clinical outcomes

## TL;DR

This study tracks shoulder movement and recovery in patients after rotator cuff surgery over two years, finding improved strength and function but some joint changes.

## Contribution

The study provides longitudinal insights into joint kinematics and clinical outcomes after rotator cuff repair, revealing subtle biomechanical changes and healing patterns.

## Key findings

- Surgical rotator cuff repair improved pain and function within the first 3 months.
- Shoulder strength significantly increased at 12 and 24 months post-surgery.
- Subtle changes in joint motion occurred, with a superior shift in the center of contact on the glenoid over time.

## Abstract

Rotator cuff repair is a common surgical procedure, but postoperative outcomes can be highly variable, and postoperative repair tissue healing remains a significant clinical challenge. Furthermore, the biomechanical effects of rotator cuff repair are not fully understood.

Twenty-two participants scheduled for arthroscopic rotator cuff repair were evaluated preoperatively and at 3, 12, and 24 months postsurgery. The following data were recorded at each time point: glenohumeral and scapulothoracic kinematics, shoulder strength, and patient-reported measures of pain and function. Postoperative repair integrity was assessed via magnetic resonance imaging at 3 months and 24 months postsurgery.

At 3 months postsurgery, 5 of 20 patients were identified as having a recurrent tear. An additional 4 patients had a recurrent tear at 24 months postsurgery. The center of contact of the humerus on the glenoid gradually shifted superiorly on the glenoid during the 24 month follow-up period (P < .01). There were subtle changes in scapulothoracic upward rotation at 3 months postsurgery compared to presurgery (P ≤ .01), but these differences did not persist at 12 or 24 months postsurgery. Compared to presurgery, there were significant increases in flexion and internal rotation strength at 12 months postsurgery (P < .01) and significant increases in flexion, abduction, external rotation, and internal rotation strength at 24 months postsurgery (P < .01). Patient-reported measures of pain and function improved significantly over the 24 month follow-up period (P < .01).

Surgical rotator cuff repair was associated with decreased pain and improved subjective assessments of function within the first 3 months after surgery, and increased shoulder strength over 12- 24 months postsurgery. The study also found subtle changes over time in glenohumeral joint and scapulothoracic motion.