Comparison of the Effect of Intra-Tendon Applications of Recombinant Human Platelet-Derived Growth Factor-BB, Platelet-Rich Plasma, Steroids in a Rat Achilles Tendon Collagenase Model

This study compared the effect of intra-tendon (IT) delivery of recombinant human platelet-derived growth factor-BB (rhPDGF-BB), platelet-rich plasma (PRP) and corticosteroids in a rat tendinopathy model. Seven days after collagenase induction of tendinopathy, a 30-mu l IT injection was administered. Treatments included: saline; 3 mu g rhPDGF-BB; 10 mu g rhPDGF-BB; PRP; and 300 mu g triamcinolone acetonide (TCA). Outcomes were assessed 7 and 21 days after treatment. All groups exhibited good to excellent repair. Relative to saline, cell proliferation increased 65% in the 10 mu g rhPDGF-BB group and decreased 74% in the TCA group; inflammation decreased 65% in the TCA group. At 7 days, maximum load-to-failure was increased in the 3 mu g rhPDGF-BB group relative to saline, PRP, and TCA (p<0.025). On day 21, maximum load-to-rupture was increased in the 10 mu g rhPDGF-BB group relative to saline, PRP, and TCA (p<0.035) and in the 3 mu g rhPDGF-BB group compared to saline and TCA (p<0.027). Stiffness in the 10 mu g rhPDGF-BB group was increased compared to saline, PRP, and TCA (p<0.038). Histology demonstrated similar repair in all groups. PRP and TCA did not improve mechanical properties compared to saline. Injections of rhPDGF-BB increased maximum load-to-failure (3 and 10 mu g) and stiffness (10 mu g) relative to controls and commonly used treatments. (C) 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.