股骨粗隆间骨折PFNA内固定失效的危险因素分析

Analysis of risk factors of failure in femoral intertrochanteric fracture patients treated with PFNA

目的分析导致股骨粗隆间骨折PFNA内固定失效的危险因素。方法回顾性分析自2010-01—2013-10诊治并获得完整随访的股骨粗隆间骨折157例,按照内固定失效与否分为A（内固定失效组）、B（内固定成功组）2组。观察指标：外侧壁厚度、外侧壁分型、尖顶距（TAD）、螺旋刀片头所在区域、正侧位X线片上远近端皮质对位差。结果 157例获得平均14.6（12～18）个月随访,24例（15.3%）出现内固定失效。11例髋内翻,2例退钉,2例内固定切割,18例复位丢失,4例股骨颈短缩。A组外侧壁厚度小于B组,差异有统计学意义（P〈0.05）。A组TAD〉30 mm者比例明显高于B组,差异有统计学意义（χ2=11.386,P=0.003）。2组螺旋刀片头所在区域及正侧位X线片上远近端皮质对位差比较差异无统计学意义（P〉0.05）。A组Ⅱ、Ⅲ型外侧壁骨折占87.5%,而B组仅为36.1%,差异有统计学意义（χ2=32.305,P=0.001）。结论PFNA内固定治疗股骨粗隆间骨折时,股骨近端外侧壁的厚度过小,Ⅱ、Ⅲ型不稳定外侧壁骨折,以及TAD〉30 mm可能是发生内固定失效的危险因素。

Objective To investigate the risk factors of failure in femoral intertrochanteric fractures treated with proximal femoral nail anti-rotation（PFNA）. Methods The material of 157 patients with intertrochanteric fracture who accepted fixation with PFNA were abstracted from Jan. 2010 to Oct. 2013 in Affiliated Hospital of Jiangsu university. Patients who failed to be followed up were excluded. Cases were divided into group A and group B. PFNA fixation failed in group A, and completed successfully in group B. The following indexes were measured： thickness of lateral wall, type of lateral wall, tip apex distance（TAD）, region of spiral blade, positional alignment of the cortex. Results The follow up averaged 14.6 months（12-18 months）in 157 cases. Internal fixation failure occurred in 24 cases, failure rate of treating intertrochanteric fracture with PFNA was15.3%. The pattern of failure of internal fixation include hip varus deformity in 11 cases, screw with drawal in 2 cases, cutout of the lag screw from the femoral head in 2 cases, loss of reduction in 18 cases and femoral neck shortening in 4 cases.Lateral thickness in group A was thinner than that in group B. Ratio of case with longer TAD（〉30 mm） was higher in group A compared with that in group B（χ2=11.386,P =0.003）. Position of the spiral blade and positional alignment of the cortex in these two groups had no significant differences. Type II and Ⅲ of the lateral wall in group A accounted for 87.5%, while there was only 36.1% in group B（χ2=32.305,P =0.001）. Conclusion Thickness of lateral wall of proximal femur, and type II and III of lateral wall which are unstable, and TAD〉30 mm may be the risk factors of femoral intertrochanteric fracture fixed with PFNA.