Year: 2020
Type: dissertation
Abstract: Introduction: Rotator cuff tendon tears (RCT) are the most common soft tissue injuries in the shoulder joint.Various animal models have been described to investigate the rotator cuff, but all translational animal models have inherent weaknesses to examine the physiology of injury and repair of the chronically degenerated rotator cuff.The objective of this study was to evaluate a partial infraspinatus (IF) tendon transection model for chronic RCT and compare the injury characteristics of this model shown in sheep to those characteristics shown in people with severe chronic RCT injuries.It was hypothesized that a partial RCT of the sheep IF tendon would be repairable following a specified healing period and that characteristics of chronic RCT would closely mimic chronic rotator cuff tendinopathy characteristics noted in people.Methods: The right side IF tendons of six sheep were partially detached followed by capping of the detached medial section of the tendon with Gore-Tex TM .Sheep were sacrificed at a 6-week (n=3) and 12-week (n=3) time point.At both time-points, the reattachment of the IF tendon to the humeral footprint was simulated.Tissues were collected from both the detached and attached portions of the IF tendon.Human tissue samples of the supraspinatus tendon were harvested from patients undergoing primary reverse shoulder arthroplasty and served as positive controls of chronic rotator cuff tendinopathy for comparison.Results: Sheep tendons were characterized by a more acute reactive and reparative pathological process when compared to the human tissues, which were more evident within the medial (detached) portion of the tendon.The lateral (attached) portion of the tendon also showed mild changes, which appeared to be more chronic and degenerative in nature when compared to the medial (detached) tendon.These changes in the lateral (attached) tendon were more similar to those observed in the chronic degenerated human tendon.Conclusions: This translational model demonstrated similar histological changes within the tendinous and muscular portions of the sheep IF muscle that were noted in people with chronic rotator cuff tendinopathy.Six weeks post-surgery in sheep was an appropriate time to result in comparable histological findings of chronic rotator cuff tendinopathy to people, and the limited retraction of the detached tendon at that time point allows for anatomically correct reattachment to the humeral footprint.Clinical relevance: This model is translational to the human condition and has potential to have positive impacts on basic science research as well as advanced development of rotator cuff devices or biologics.
Author: R. Hendrickx
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W3065725633