Endothelial Progenitor Cells for Rotator Cuff Healing

The avascular environment at the tendon-bone interface is a major concern for rotator cuff healing, contributing to the high re-tear rate. We hypothesized that better tendon-bone healing would occur with transplantation of endothelial progenitor cells, a population of angiogenic cells, during rotator cuff repair in rats. The surgical procedure involved a unilateral detachment and repair of the supraspinatus tendon in a syngeneic population of Fischer 344 rats. The EPC group received one 106 EPCs and the Fibrin (negative control) group received none. Biomechanical and histological analyses were performed at two, four, and six weeks post mortem. At 6 weeks, there was a statistically significant difference in the tendon attachment strength. While no significant difference was found in histology, the EPC groups showed a trend of increased vascularity. The EPCs provide improvements in tendon-bone attachment 6 weeks after the repair. However, such biomechanical improvement was not detectable via conventional histological methods.M.Sc