Establishing a Model of Challenged Rotator Cuff Tendon-to-Bone Healing Using Ovariectomized Rats

Peter holding Phosphate Buffered Saline in a lab.




Fairhill Professor of Orthopaedic Surgery and Professor of Bioengineering

Project Summary

Rotator cuff tears affect many individuals and often require surgery to fix. Despite advancements in surgical technique and post-op care, failure of the rotator cuff repair is still common. Pulsed electromagnetic field therapy, a type of non-invasive therapy, has been previously shown to be beneficial for the healing of rotator cuff repairs in a rat model.

However, these studies utilized healthy, young adult rats, which do not replicate the aged human population most affected by rotator cuff injury. Therefore, our lab recently attempted to establish a model more reflective of the population affected by rotator cuff healing. This was done by comparing the rotator cuff repairs of ovariectomized (OVX) rats to regular female rats. Ovariectomy models post-menopausal osteoporotic bone condition reflective of the bone properties of the older human population.

In a first iteration of this study, it was noted that rats ovariectomized at three months of age did not display changes in the bone properties of the humerus until after the rotator cuff injury and repair. We hypothesized that normal bone development occurring in these animals, specifically at the site of rotator cuff repair, may have altered healing of the repair and confounded our results. Therefore, this most recent study utilized older animals that underwent ovariectomy at five months of age, allowing for full bone development to occur prior to initiation of estrogen deficiency.

Through working on this project under Dr. Lou Soslowsky in the McKay Orthopedic Research Laboratory, I have gained invaluable knowledge in the field of orthopedic research and scientific research as a whole. I have gained experience in investigative techniques such as microCT analysis, histology, and ELISAs. Throughout the project, I learned how much forethought and preparation goes into designing and undertaking a research project. It has been a very interesting and enlightening experience to better understand how scientific experiments and research are carried out. Overall, I enjoyed undertaking the project and am thankful to Dr. Soslowsky for his help and direction.