体质量指数对全膝关节置换术后远期翻修率影响的研究

The study of the effect of body mass index on long-term revision rate after total knee arthroplasty

目的探究患者体质量指数(body mass index,BMI)对全膝关节置换术(total knee arthroplasty,TKA)后远期翻修率的影响。方法回顾性分析2002年1月~2005年12月间于本院行初次TKA的患者713例,根据BMI不同水平将患者分为3组,体重正常组(BMI<25 kg/m^2)、超重组(25 kg/m^2≤BMI<30 kg/m^2)和肥胖组(BMI≥30 kg/m^2),分析3组患者TKA术后早期(5年内)和远期(超过5年)行人工关节翻修术的原因,并比较3组患者早期和远期翻修率的差异,及远期行人工关节翻修术风险差异。结果患者TKA术后早期(5年内)行翻修手术的原因主要为感染,远期(超过5年)行翻修手术的原因主要为假体无菌性松动和假体磨损或断裂;TKA术后5年,3组患者翻修率差异没有统计学意义(肥胖组7.6%,正常体重组3.9%,超重组3.6%,P=0.1060);TKA术后10年,肥胖组患者翻修率为15.1%,显著高于正常体重组和超重组(分别为6.5%和7.6%,P=0.0048)。肥胖组患者TKA术后10年行翻修手术的风险是体重正常组的1.84倍(OR=1.84,95%CI为1.59~2.13),超重组与体重正常组风险差异无统计学意义(OR=1.14,95%CI为0.63~1.91)。结论 BMI水平和TKA术后远期翻修手术风险相关,患者TKA术前或术后减重可能会降低远期行翻修手术的风险。

Objective To explore the influence of body mass index on long-term revision of patients who had received total knee arthroplasty（TKA）. Methods A retrospective study was carried out for the patients who received primary TKA in our hospital from January 2002 to December 2005. A total of 713 patients were recruited to this study. The patients were divided into three groups：normal weight（BMI 25 kg/m^2）,overweight（25 kg/m^2≤ BMI 30 kg/m^2）and obese（BMI ≥ 30 kg/m^2）. Statistical analysis was conducted to investigate the motive for early revision TKA and long-term revision TKA,and the differences of the revision rate and risk of revision TKA among the three groups was examined. Results Infection was the main motive for early revision TKA,and prosthetic damage or fracture and aseptic loosening were the main motives for long-term revision TKA. The percentage of primary TKA revisions at 5 years was 7.6% for the obese group,3.9% for the normal weight group and 3.6% for the overweight group,and there was no significant difference between the three groups（P=0.1060）. The percentage of primary TKA revisions at 10 years was 15.1% for the obese group,6.5% for the normal weight group and 7.6% for the overweight group,and the difference between the three groups was statistically significant（P=0.0048）. Ten years after the primary TKA,obese patients had an 84% increase（OR=1.84,95%CI,1.59-2.13）in the risk of revision versus the normal weight patients;overweight patients had a 14% increase（OR=1.14,95%CI,0.63-1.91）in the risk of revision versus the normal weight patients. Conclusion Patient BMI level is associated with the long-term revision rate after TKA. Losing weight before or after TKA may decrease the long-term revision rate.