[Micro-CT evaluating inhibitory effect of zoledronic acid on polyethylene particle-induced periprosthetic osteolysis model].

OBJECTIVE: To observe inhibitory effect of zoledronic acid on polyethylene particle-induced periprosthetic osteolysis model.

METHODS: Thirty male adult specific-pathogen-free SD rats (weighted 250 to 300 g) were randomly divided into sham group, model group, and zoledronic acid group, 10 in each group. Modeling were building by titanium screws and polyethylene particles implanted into right femur of rats, sham group and model group were performed hypodermic injection by 0.9% saline with 2 ml/kg, zoledronic acid with 0.1 ml/mg were injected into zoledronic acid group, once a week for 8 weeks. After 8 weeks, right femur specimens were drawn and used to san microstructure of femoral cancellous bone in rats model was examined by Micro-CT, and the images were treated with three-dimension reconstruction and analysis software BMD, BV/TV, Tb.N, Tb.Th, SMI, BS/BV, Tb.Sp and Tb.Pf and other parameters include.

RESULTS: According to Micro-CT three-dimensional imaging, BMD in model group was significantly decreased than sham group, bone microstructure damage was serious, bone trabecula changed thinning continuity; while bone microstructure was obviously improved compared with model group and zoledronic acid group. After analyzing Micro-CT parameters of femur microstructure, BMD in model group(0.081±0.020) was significantly decreased than control group(0.160±0.018) and zoledronic acid group(0.125±0.012); BV/TV in model group (10.563±1.070) was obviously lower than control group(27.935±1.834) and zoledronic acid group(14.559±1.258); Tb.N in model group (1.005±0.165) was lower than control group(2.058±0.108) and zoledronic acid group(1.515±0.126); while Tb.Th in model group (0.075±0.016) was decreased than control group(0.158±0.016) and zoledronic acid group(0.124±0.011). Meanwhile, SMI in model group(1.817±0.127) was significantly higher than control group(1.104±0.120) and zoledronic acid group(1.547±0.122); BS/BV in model group(35.784±1.650) was higher than control group(21.506±2.771) and zoledronic acid group(30.399±2.730); Tb.Sp in model group(0.735±0.107) was higher than control group(0.423±0.057) and zoledronic acid group(0.577±0.082), TB.Pf in model group(9.088±1.283) was higher than control group(2.447±0.703) and zoledronic acid group(5.862±1.042).

CONCLUSIONS: Zoledronic acid could change bone microstructure of rats to inhibit polyethylene particle-induced bone solution, which provides a scientific basis for prevent bone solution by zoledronic acid as a therapeutic intervention.