Effects of simvastatin on osseointegration in a canine total hip arthroplasty model: an experimental study

Simvastatin was recently demonstrated to stimulate bone morphogenetic protein-2 expression, leading to bone formation. The present study was designed to evaluate whether simvastatin administered by injection could promote osseointegration in a canine total hip arthroplasty model. Fifteen dogs were divided into 3 groups of 5 dogs each: group 1 (high-dosage simvastatin, 6.0 mg/[kg d]), group 2 (low-dosage simvastatin, 3.0 mg/[kg d]), and a control group (isotonic saline, 3.0 mg/[kg d]). Osseointegration was assessed by using the push-out test, scanning electron microscopy, energy-dispersive spectrometer microanalysis, and histomorphometric examination. The results showed higher mechanical strength, greater area of bone covering the femoral component, and higher bone-implant contact in group 1 than in the other 2 groups. Our findings indicate that simvastatin administered by injection could contribute significantly to osseointegration in a canine total hip arthroplasty model.