体重指数及年龄对人工关节置换术后下肢深静脉血栓形成的影响

INFLUENCE OF BODY MASS INDEX AND AGE ON DEEP VEIN THROMBOSIS AFTER TOTAL HIP AND KNEE ARTHROPLASTY

目的探讨体重指数及年龄对人工关节置换术后下肢深静脉血栓形成(deepveinthrombosis,DVT)的影响。方法采用病例对照研究,分析2004年4月～2004年8月符合纳入条件行髋、膝人工关节置换术的95例患者的临床资料。其中男27例,女68例。年龄23～78岁,平均60岁。体重指数(bodymassindex,BMI)14.34～40.39kg/m2,平均25.88kg/m2。人工髋关节置换43例48髋,人工膝关节置换52例80膝。患者按WHOBMI标准分层,即:非肥胖BMI≤25.00kg/m2、超重BMI25.01～27.00kg/m2、肥胖BMI27.01～30.00kg/m2、病理性肥胖BMI>30.00kg/m2,以及按年龄分为≤40岁、41～60岁、61～70岁、>70岁4层,研究其与关节置换术后DVT的相关性。患者术前及术后7～10d均行低分子肝素抗凝预防术后DVT,并于术后7～10d采用彩色多普勒检查双下肢深静脉血流通畅情况及DVT发生率。结果术后45例患者发生DVT,发生率为47.4%,近端DVT发生率为3.2%。DVT组BMI为27.50±3.18kg/m2,高于无DVT组(24.42±4.51kg/m2),差异有统计学意义(P<0.05);分层后,BMI>25kg/m2的患者发生DVT的风险是BMI≤25kg/m2患者的2.24倍(P<0.05);BMI按WHO标准进行分层后,超重、肥胖及病理性肥胖的患者发生DVT的风险分别是非肥胖患者的7.04、4.80及9.60倍,差异均有统计学意义(P<0.05),肥胖患者发生DVT的风险比其他两层患者低,而病理性肥胖患者发生DVT的风险最高。DVT组年龄为65.24±6.98岁,高于无DVT组(54.84±15.11岁),差异有统计学意义(P<0.05)。41～60岁、61～70岁及>70岁组患者发生DVT的风险分别是年龄≤40岁患者的24.0、38.2及24.4倍,差异均有统计学意义(P<0.05)。结论肥胖(BMI>25kg/m2)及高龄(年龄>40岁)是影响人工关节置换术后DVT形成的高危因素,其中61～70岁的患者发生DVT的风险最高。肥胖、高龄患者行人工关节置换术时应予足够预防性抗凝治疗,术后严密观察双下肢情况,必要时行超声或静脉造影检查,防止发生致命性肺栓塞。

Objective To analyze the influence of the body mass index （BMI） and age on deep vein thrombosis （DVT） after the total hip arthroplasty（THA） or total knee arthroplasty（TKA） in Chinese patients who received prophylactic treatment for DVT. Methods We used a randomized clinical case-control study. From April 2004 to August 2004, we performed THA and TKA for 95 patients （128 hips and knees）. There were 27 men and 68 women with an average age of 60 years （range, 23-78） at surgery, and with an average BMI of 25.88 kg/m^2（range, 14.34- 40. 39） before surgery. All the patients were given low-molecular-weight heparin for 7-10 days pre- and postoperatively to prevent DVT. Color Doppler ultrasonography was used to detect DVT of bilateral lower extremities in all the patients before operation and 7-10 days after operation. The patients were divided into 4 groups according to their BMI ：the non- obese group （BMI≤25.00 kg/m^2）, the overweight group （BMI, 25.01-27.00 kg/m^2）, the obese group （BMI, 27.01-30.00 kg/m^2）,and the morbidly obese group （BMI〉30.00 kg/m^2）; and they were also divided into 4 groups according to their ages （≤40, 41-60, 61-70, 〉70 yr） so as to analyze the influence of the BMI and age on DVT. Results The total incidence of DVT in all the patients was 47.4% （45/95） and the incidence of proximal DVT was 3.2%. Forty-five patients had DVT and 50 patients had no DVT. The average BMI of the patients with DVT was significantly higher than that of the patients with no DVT （P〈0.05）. The overweight, obese, and morbidly obese patients had an odds ratio of 7.04, 4.8, and 9.6 for DVT compared with the non-obese patients （P〈0.05）; but the obese group had a less risk than the other 2 groups. The 41-60, 61-70, and 〉70-year-old patients had an odds ratio of 24.0, 38.2, and 24.4 for DVT compared with the ≤40-year-old patients （P〈0. 05）. Conclusion Obesity （BMI〉 25 kg/m^2） and an increasing age （〉40 yr） are identified as statistically significant risk factors for DVT after THA or TKA, and patients aged 61-70 years are more likely to have DVT than the other patients. We should pay more attention to those obesity and aged patients when they are undergoing the total joint replacement, and we should give them enough prophylaxis and closely observe the symptoms in their bilateral lower extremities after operation, taking uhrasonography or venography to check DVT if necessary, so that we can give them prompt treatment and prevent fatal pulmonary thromboembolism.