The effect of recombinant human platelet-derived growth factor BB-coated sutures on rotator cuff healing in a sheep model.

Abstract

The purpose of this study was to determine whether suture could be coated with recombinant human platelet-derived growth factor BB (rhPDGF-BB) and whether the coated suture would improve histologic scores and biomechanical strength of sheep rotator cuff repairs. FiberWire sutures (Arthrex, Naples, FL) were dip coated in a collagen-rhPDGF-BB solution. Coating was confirmed by use of enzyme-linked immunosorbent assay. Rotator cuff tears were created in 18 sheep. The tendons were wrapped in Gortex (Gore Medical, Flagstaff, AZ) and allowed to scar for 2 weeks. Tendons were then repaired to bone by use of standard anchors loaded with either rhPDGF-BB-coated sutures or uncoated sutures. Gross examination, histologic analysis, and biomechanical testing were performed 6 weeks after repair. Enzyme-linked immunosorbent assay confirmed successful loading of the growth factor onto the sutures. Gross examination showed well-healed tendon-to-bone interfaces in both rhPDGF-BB-augmented repairs and controls. Histologic analysis using a semiquantitative rating scale showed improved tendon-to-bone healing in the rhPDGF-BB-augmented repairs. There was no significant difference in the ultimate load to failure of rhPDGF-BB-augmented rotator cuff repairs compared with standard suture repairs at 6 weeks after repair. We were able to coat No. 2 FiberWire with rhPDGF-BB. At short-term follow-up, rhPDGF-BB-coated sutures enhanced histologic scores of sheep rotator cuff repairs; however, ultimate load to failure was equivalent to standard suture repairs. rhPDGF-BB-coated sutures seem to produce a more histologically normal tendon insertion.