Related Experiment Video
Updated: Jul 16, 2025
05:20
Development of a Rabbit Chronic-Like Rotator Cuff Injury Model for Study of Fibrosis and Muscular Fatty Degeneration
Published on: March 31, 2023
1.3K
Structural Musculotendinous Parameters That Predict Failed Tendon Healing After Rotator Cuff Repair
Maurits G L Olthof1, Martin Flück2, Paul Borbas1
1Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
Orthopaedic Journal of Sports Medicine
|September 22, 2023
Summary
Rotator cuff repair failure is linked to shorter tendon length and more hybrid muscle fibers. Fatty infiltration in the infraspinatus muscle also worsens outcomes for patients undergoing rotator cuff surgery.
Area of Science:
- Orthopedic Surgery
- Musculoskeletal Research
- Regenerative Medicine
Background:
- Rotator cuff repair failure presents a significant clinical challenge with high rates of re-tearing.
- Identifying structural predictors of failed healing is crucial for improving patient diagnosis and management.
- Understanding musculotendinous factors can optimize treatment strategies for rotator cuff disease.
Purpose of the Study:
- To identify structural predictors within the musculotendinous unit associated with failed tendon healing after rotator cuff repair.
- To investigate the relationship between preoperative and intraoperative findings and postoperative retear.
- To determine factors influencing clinical outcomes following arthroscopic rotator cuff repair.
Main Methods:
- A cohort of 116 shoulders (115 patients) with supraspinatus tears underwent arthroscopic rotator cuff repair.
- Preoperative MRI and intraoperative biopsies (capsule, tendon, muscle) were analyzed for structural and histological properties.
- Postoperative clinical and MRI assessments at 3 and 12 months evaluated healing and outcomes using regression models.
Main Results:
- Failed tendon repair correlated with older age, shorter supraspinatus (SSP) tendon length, and a higher proportion of myosin heavy chain (MHC)-I/MHC-II hybrid muscle fibers.
- Poorer 12-month clinical outcomes (Constant score) were associated with fatty infiltration of the infraspinatus muscle.
- Increased content of fast MHC-II muscle fibers in the SSP tendon was linked to better clinical results.
Conclusions:
- Decreased tendon length and increased hybrid muscle fiber proportion are independent predictors of rotator cuff retear.
- Clinical outcomes are negatively impacted by tendon retearing and infraspinatus muscle fatty infiltration.
- A higher proportion of fast MHC-II muscle fibers in the supraspinatus muscle correlates with improved clinical outcomes post-repair.
