目的 系统评价阿司匹林预防骨科大手术后静脉血栓栓塞症的有效性及安全性。方法 检索PubMed，Embase和Cochrane图书馆，收集阿司匹林预防围手术期静脉血栓栓塞症的随机对照研究（RCT）及队列研究，提取资料并评价质量后，采用RevMan 5.3软件进行Meta分析。结果 共纳入7项RCT和5项回顾性队列研究。与空白对照组相比，阿司匹林能降低术后深静脉血栓形成率[RR=0.69，95%CI（0.54，0.89），P=0.004]及肺栓塞发生率[RR=0.60，95%CI（0.43，0.84），P=0.003]。与低分子肝素□LMWH□相比，阿司匹林的术后深静脉血栓形成率、肺栓塞发生率、血红蛋白下降量分别为[RR=1.06，95%CI（0.96，1.17），P=0.22]，[RR=1.04，95%CI（0.93，1.18），P=0.48]以及[MD=-7.61，95%CI（-11.73，-3.49），P=0.000 3]。结论 与空白对照组相比，阿司匹林能降低骨科大手术后静脉血栓栓塞症的发生率；与LMWH相比，在术后静脉血栓栓塞症发生率方面没有差异，血红蛋白下降量低于LMWH；阿司匹林与空白对照、LMWH的其他并发症比较没有差异。

Objective To systematically review the efficacy and safety of aspirin for preventing venous thromboembolism (VTE) after major orthopedic surgery. Methods Retrieved from PubMed, Embase and Cochrane Library, randomized controlled trials (RCT) and cohort studies about aspirin used in major orthopedic surgery were collected. Meta-analysis was performed by using Rev Man 5.3 software after data extraction and quality evaluation. Results Totally seven RCTs and five cohort studies were included. Compared with control group, aspirin reduced the incidence of deep vein thrombosis (DVT)[RR=0.69, 95%CI(0.54, 0.89), P=0.004] and pulmonary embolism(PE)[RR=0.60, 95%CI(0.43, 0.84), P=0.003]. Compared with low molecular weight heparin (LMWH), the incidence of DVT, PE and hemoglobin drop were[RR=1.06, 95%CI(0.96, 1.17), P=0.22],[RR=1.04, 95%CI(0.93, 1.18), P=0.48] and[MD=-7.61, 95%CI(-11.73, -3.49), P=0.000 3] respectively in aspirin group. Conclusions Compared with control, aspirin could reduce VTE incidence after major orthopedic surgery. There were no significant differences in VTE incidence between aspirin and LMWH, but hemoglobin drop were lower in aspirin group. For other complications, there were no significant differences between aspirin and control/LMWH.