Non-union site debridement increased the efficacy of rhBMP-2 in a rodent model

In our study we investigated the influence of debridement on bone healing in a rodent critical size defect model with and without rhBMP-2 in fibrin matrix. A total of 58 male Sprague-Dawley rats underwent a first surgical procedure where a femoral osteotomy was performed. In the single step group the defect remained empty and the specimens were collected 4 weeks later. A silicone spacer was implanted to inhibit bone healing within the defect in all the other groups. At 4 weeks the spacer was removed in a second operation with and without debridement of the bone ends and fibrin matrix alone or combined with 10 μg rhBMP-2 were applied. 4 weeks after the primary operation those specimens were collected. All the specimens were evaluated by μCT scans and histological analysis. Debridement of the defect significantly increased bone volume in the animals treated with rhBMP-2. In the control groups without growth factor application the effect of debridement was not significant concerning the union rate and the bone volume. In our experimental setting surgical debridement of the non-union site particularly promoted bone healing in combination with BMP-2 administration in fibrin matrix.