股骨近端防旋髓内钉固定治疗股骨反转子间骨折内固定失败的危险因素分析

Risk factors for failed internal fixation with proximal femoral nail antirotation for reverse intertrochanteric hip fractures

目的探讨股骨近端防旋髓内钉(PFNA)固定治疗股骨反转子间骨折内固定失败的危险因素。方法回顾性分析2006年1月至2018年1月期间北京大学第三医院创伤骨科采用PFNA固定治疗的45例股骨反转子间骨折患者资料。男19例,女26例;年龄为19~97岁,平均71.9岁。骨折AO分型:31-A3.1型7例,31-A3.2型4例,31-A3.3型34例。根据末次随访时X线片判断骨折愈合情况,记录内固定失败患者与内固定未失败患者的性别、年龄、体重指数、致伤原因、美国麻醉医师协会分级、骨折AO分型、主要骨折线形态、复位方法、骨折复位质量、外侧壁状态及尖顶距等。先采用单因素分析筛选P<0.05的因素,再采用多因素logistic回归分析确定主要的独立危险因素。结果45例患者术后获12~62个月(平均28.4个月)随访。共有6例(13.3%)患者发生内固定失败:3例螺旋刀片切入,2例主钉断裂,1例螺旋刀片切出。单因素分析结果显示:内固定失败患者与未失败患者在骨折复位质量和主要骨折线形态方面差异有统计学意义(P<0.05)。多因素logistic回归分析结果显示骨折复位质量差(OR=30.809,95%CI:1.052~902.298,P=0.047)和主要骨折线为横形(OR=25.639,95%CI:1.636~401.917,P=0.021)是内固定失败的独立危险因素。结论骨折复位质量差和主要骨折线为横形是PFNA固定治疗股骨反转子间骨折内固定失败的危险因素。

Objective To identify the risk factors for failure of internal fixation with proximal femoral nail antirotation(PFNA)for reverse intertrochanteric hip fractures.Methods A retrospective study was conducted of the 45 patients with reverse intertrochanteric hip fracture who had been treated with PFNA fixation from January 2006 through January 2018 at the Department of Traumatic Orthopaedics,The Third Affiliated Hospital to Peking University.They were 19 males and 26 females,aged from 19 to 97 years(average,71.9 years).According to the AO/OTA classification,there were 7 cases of type 31-A3.1,4 cases of type 31-A3.2 and 34 cases of type 31-A3.3.Fracture healing was judged according to the X-ray at the time of last follow-up.The patients were assigned into a healed group and a failed group.The 2 groups were compared in terms of gender,age,body mass index(BMI),mechanism of injury,AO classification,type of main fracture line,reduction method,reduction quality,status of lateral femoral wall and tip-apex distance.A multivariate logistic regression model was designed to analyse the dependent variable'implant failure’with a set of independent variables as risk factors.Results The 45 patients were followed up for 12 to 62 months(average,28.4 months).Implant failure was observed in a total of 6 patients(13.3%),3 of whom had helical blade perforation,2 main screw breakage,and one cut-out of helical blade.The single factor analysis revealed significant differences in reduction quality and type of main fracture line between the patients with successful fixation and those with failed fixation(P<0.05).The multiple logistic regression analysis identified poor reduction quality(OR=30.809,95%CI:1.052~902.298,P=0.047)and a transverse fracture line(OR=25.639,95%CI:1.636~401.917,P=0.021)as risk factors for implant failure.Conclusion Poor reduction quality and a transverse fracture line may be predictors of implant failure in reverse intertrochanteric hip fractures treated with PFNA fixation.