Several observational and experimental studies have investigated the potential anabolic effects of statins on undisturbed bone but only a few recent studies have examined the effect of statins on skeletal repair. The goal of the study is to investigate any potential early anabolic effect of the systemic administration of simvastatin in low doses (based on earlier safety and efficacy studies on undisturbed bone) on fracture healing. Fifty-four skeletally mature male New Zealand White rabbits were used for the study. The rabbits were assigned to one of three experimental groups: a control group, and two groups that were orally administrated a diet with 10 and 30 mg/kg/day of simvastatin, respectively. A complete biochemical blood count was performed to exclude drug-induced complications. Half of the animals of each group were sacrificed at 15 days and the other half at 30 days after surgery at which time intervals healing quality was assessed. The bones were subjected to biomechanical testing, histomorphometric analysis and peripheral Quantitative Computed Tomography. In animals received simvastatin of 30 mg/kg/day a significant reduction of BMD, stiffness, and energy absorbed to failure were observed. At 15 days, the amount of cartilaginous callus formation was reduced, and the void space was significantly increased, in the animals of both groups that received simvastatin when compared to the control group (p<
.05). Our results suggest that simvastatin doses of 30mg/ kg/day may have a negative anabolic effect on callus formation in rabbits, whereas doses of 10 mg/kg/day seem not to produce a significant positive or a negative effect, especially at the early stages of fracture remodeling.
We investigated the effect of Platelet Rich Plasma (PRP) in tendon healing. The aim was to assess the effect of an application of PRP on angiogenesis and immunohistochemical expression of TGF-b1 and IGF-I during tendon healing. We used a patellar tendon defect model after resecting its central portion. 48 skeletally mature New Zealand White rabbits were divided into the respective group and each group they were randomised into controls and PRP treated cases. The rabbits were sacrificed at weekly intevals and histological and immunohistological assessments were performed. The results showed a faster healing rate, increased vascularity, and higher expression of the growth factors in the PRP group. We conclude that the mixture of growth factors present in PRP gel improved the rate and quality of tendon healing.