中文摘要：

目的探讨骨密度（bonemineraldensity，BMD）对微创腰椎后路减压椎间植骨融合内固定（posteriorlumbarinterbodyfusion，PLIF）术中出血量的影响。方法回顾性分析2005至2010年问61例单节段微创PLIF手术患者的病历资料。采集患者年龄、性别、BMD、体重指数、手术时间、术中和术后出血量、术前常规实验室检查等数据。按BMD将患者分为骨量正常、骨量减少两组，独立样本t检验和χ2检验比较两组手术出血量及其他参数；分析所有患者术中出血量与其他因素的相关性，独立样本t检验分析性别对术中出血量的影响；在此基础上，采用多元线性逐步回归分析本研究条件下术中出血量的相关性因素。结果骨量正常组38例，术中出血量为（346．41±199．53）ml；骨量减少组23例，术中出血量为（552．62±300．21）ml，差异有统计学意义。相关性分析显示术中出血量与BMD呈负相关（r=-0．37，P=-0．035），与手术时间呈正相关（r=0．34，P=0．008），与其他因素无相关性；独立样本t检验显示术中出血量在男女性别组间的差异无统计学意义。多元线性逐步回归分析显示，术中出血量=-0．63xBMD＋1．46x手术时间。结论BMD是预测腰椎PLIF术中出血量的重要因素之一。

英文摘要：

Objective To investigate the correlation between intra-operative estimated blood loss （EBL） and bone mineral density （BMD） during minimally invasive posterior lumbar interbody fusion （PLIF）. Methods In this retrospective case control study, 61 consecutive patients suffering from mono-segment low back disorders were treated by minimally invasive PLIF from 2005 to 2010. The patients parameters includ- ing age, gender, operation time （OT）, BMD, EBL, prothrombin time were collected. According to BMD of the lumbar spine, all the patients were divided into two groups： the normal group and the osteopenia group. The differences of the EBL and other parameters between the two groups were analyzed by student＇s t test and Pearson＇s Chi-square test. Besides, the correlation between intra-operative EBL and each of the other param- eters except for gender were analyzed among all the patients. To detect the relationship between intra-opera- rive EBL and gender, patients were divided by gender and the intra-operative EBL of two groups were exam- ined by student＇s t test. Finally, a probable model about intra-operative EBL and the other parameters was proposed using stepwise linear regression analysis. Results The average intra-operative EBL of the normal group and the osteopenia group were （346.41±199.53） ml and （552.62±300.21） ml, respectively. The differ- ence was significant. However, the other parameters including post-operative EBL had no significant differ- ences between two groups. A negative correlation between intra-operative EBL and BMD （r=-0.37, P=0.035） and a positive correlation between intra-operative EBL and OT （r=0.34, P=0.008） were found. But none of the other parameters was correlated with intra-operative EBL. The similar result was observed by the step- wise linear regression analysis. Intra-operative EBL was influenced by BMD and OT under the control of this research, and the relationship might be formulated with the equation, EBL=-0.63×BMD＋1.46xOT. Conclu- sion BM