Aim: It is known that high-energy extracorporeal shock waves, focussed to the intact distal rabbit femur, induce periosteal new bone formation within the focus zone. This study was done to investigate whether there is additionally new bone formation outside of the focus zone, i. e., in the proximal femur, 10 days after shock wave application to the distal rabbit femur.
Method: 18 adult Chinchilla-Bastard rabbits were randomly divided into three groups (A, B, C; each n = 6). One distal femur of each animal was focussed for shock wave application with different positive energy flux densities (A 1.2 mJ/mm (2), B 0.9 mJ/mm (2), C sham treatment). Only the proximal femur outside the shock wave focus was investigated. Here periosteal new bone formation was evaluated by fluorescent labelling. The maximum thickness was measured by means of computer-assisted image analysis.
Results: Maximum ventral-periosteal new bone formation outside the shock wave focus was significantly increased in group A compared to group B (p = 0.007) or group C (p = 0.001). In contrast, the maximum ventral-periosteal new bone formation outside the shock wave focus demonstrated no statistically significant difference in group B compared to group C (p = 1.0).
Conclusion: Depending from the amount of positive energy flux density applied to distal rabbit femur a significantly increased ventral-periosteal new bone formation results in the proximal rabbit femur outside the shock wave focus.