Quantitative assessment of growth factors in reaming aspirate, iliac crest, and platelet preparation

Large bony defects and non-unions are still a complication in trauma and orthopedic surgery. Treatment strategies include the use of autogenous materials (iliac crest), allogenic bone, bone substitutes, and currently stimulation with growth factors such as BMP-2, BMP-7 or the growth factors containing platelet-rich plasma (PRP). Another source of bone graft material might be the cuttings produced during intramedullary reaming. The aim of this study was to compare the quantity of various growth factors found within iliac crest, bony reaming debris, reaming irrigation fluid, and platelet-rich plasma. Iliac crest and reaming debris and irrigation samples were harvested during surgery. PRP was prepared from blood. The growth factors in the bony materials (iliac crest or reaming debris) and of the liquid materials (platelet-poor plasma (PPP), platelet-rich plasma (PRP) or reaming irrigation) were compared. Elevated levels of FGFa, PDGF, IGF-I, TGF-beta1 and BMP-2 were measured in the reaming debris as compared to iliac crest curettings. However, VEGF and FGFb were significantly lower in the reaming debris than from iliac crest samples. In comparing PRP and PPP all detectable growth factors, except IGF-I, were enhanced in the platelet-rich plasma. In the reaming irrigation FGFa (no measurable value in the PRP) and FGFb were higher, but VEGF, PDGF, IGF-I, TGF-beta1 and BMP-2 were lower compared to PRP. BMP-4 was not measurable in any sample. The bony reaming debris is a rich source of growth factors with a content comparable to that from iliac crest. The irrigation fluid from the reaming also contains growth factors.