Delaying effect of cyclophosphamide on bone fracture healing chemical analyses of rat femora.

Hydroxyproline, calcium and inorganic phosphate contents of osteotomised rat femora were compared with those from rats treated with cyclophosphamide. The treatment consisted of 10 mg/kg/body weight injected intraperitoneally daily for 14 days after (group II) and before (group III) operation. The obtained results indicated a reduction in the hydroxyproline content of the callus and a diminution of the calcium and phosphate deposition upon it, thus inhibiting collagen formation and delaying mineralisation, retarding the healing process of the fraction. The degree of inhibition was decreased when the cyclophosphamide treatment discontinued before osteotomy was performed (group III). We would like to draw attention to these results, and suggest that cyclophosphamide treatment should not coincide with the healing of bone fracture.