福善美对腰椎内固定术后防止椎弓根螺钉松动的作用

The function of preventing pedicle screw loosening by using Fosamax after lumbar fixation surgery

目的探讨福善美(阿仑膦酸钠)对提高50岁以上行腰椎内固定手术患者术后椎体骨密度的作用。方法将50例行腰椎椎弓根螺钉内固定的老年腰椎退变性疾病患者随机分为A(福善美组)、B(对照组)两组,A组患者口服70 mg/周的福善美6个月,而对照组不给药,两组均在手术前1周内和术后6个月行腰椎后前位双能X线骨密度测定,测定椎体包括L1S1椎体,以BMD表示骨密度值,取一节行椎弓根螺钉内固定的椎体作为研究对象,对该椎体手术前后的BMD进行测定、比较,评价两组患者手术前、后椎体骨密度的差别。结果手术前A组与B组患者椎体BMD无显著性差异(P=0.841),手术后A组患者骨密度值高于B组,其差异有显著性(P=0.005)。A组患者术后骨密度值高于手术前的测定值,术后骨密度值显著高于术前水平(P<0.001),而B组患者中术后骨密度值低于术前水平(P<0.001)。结论对于行腰椎椎弓根螺钉内固定术的老年患者(年龄>50周岁),服用福善美可明显提高其椎体骨密度,从而可能达到防止椎弓根螺钉松动的目的 。

Objective To investigate the function of Fosamax（Alendronate）in improving bone mineral density（BMD）after lumbar fixation surgery in senile patients with the age over 50 years.Methods Fifty senile patients with lumbar degenerative disease who had lumbar fixation surgery were randomly divided into group A（the alendronate group）and B（the control group）.Both of the two groups underwent the measurement of BMD including L1S1 vertebraes before surgery.Then,group A took Fosamax for six months after surgery while group B didn＇t.Two groups underwent the dual-energy-X-ray measurement of BMD again after surgery for six months.Took one of the vertebrae which had pedicle screw as study object and compared this vertebrae＇s BMD before and after surgery,then,evaluated the difference between group A and B.Results There was no significant difference between group A and B before surgery（P=0.841）,but after surgery the BMD of group A was hyper than group B,and showed significant difference（P=0.005）.In group A,the postoperative BMD was hyper than preoperative with significant difference（P〈0.001）,while in group B,the BMD of postoperative was lower than preoperative（P〈0.001）.Conclusion Taking Fosamax can significantly improve the BMD of vertebraes for senile patients who had lumbar fixation surgery（over 50 years old）,which makes the objective of preventing pedicle screw loosening possible.