PFNA治疗股骨粗隆间骨折内固定失败的多因素分析

Multivariate analysis of internal fixation failure risk factors of PFNA for femoral intertrochanteric fractures

目的探讨股骨近端防旋髓内钉(PFNA)内固定治疗股骨粗隆间骨折术后发生内固定失败的相关危险因素,为临床内固定选择、手术技术改进提供依据。方法回顾性分析自2010-01—2015-03采用PFNA内固定治疗的291例股骨粗隆间骨折的临床资料。测量并收集其影像学指标,包括:术前股骨近端外侧壁厚度、尖顶距(TAD)、断端正位对位差、侧位对位差、髓内钉顶点位置和外侧壁分型。同时记录患者的Singh指数和AO/OTA分型。建立Logistic回归模型,分析易导致内固定失败的危险因素。结果 291例中49例出现内固定失败。单因素分析显示:外侧壁厚度、TAD、外侧壁分型和AO/OTA分型与内固定失败相关(P<0.05),而性别、年龄、断端正侧位对位差、髓内钉顶点位置和Singh指数与内固定失败无关(P>0.05)。Logistic回归分析提示:TAD、外侧壁分型和骨折稳定性是内固定失败的危险因素(P<0.05)。结论TAD过大,脆弱的外侧壁及不稳定骨折是PFNA治疗股骨粗隆间骨折术后内固定失败的危险因素,需谨慎使用,使用后需延缓下地负重时间。

Objective To explore the internal fixation failure risk factors of proximal femoral nail anti-rotation （PFNA） for femoral intertrochanteric fracture and to provide the basis for improving surgical techniques and choosing internal fixation. Methods A total of 291 intertrochanteric fracture patients who received PFNA fixation from January 2010 to March 2015 in one institution with average 13-month follow-up were retrospectively evaluated. The radiological parameters were measured including： thickness of proximal lateral wall, tip-apex distance, the gap of cortical bone alignment in AP and lateral X-ray radiograph, region of spiral blade and type of lateral wall. Singh index and AO/OTA type were also recorded. Logistic regression model was established to analyze the key factors causing fixation failure. Results Forty nine cases from 291 cases showed internal fixation failures. The internal fixation failure was directly related with large TAD, fragile lateral wall, thinner lateral wall and unstable fracture type （P 〈0.05）, but not with gender, age, the gap of cortical bone alignment in AP and lateral X-ray radiograph, region of spinal blade and Singh index （P 〉0.05）. Multiple logistic regression suggested that large TAD, fragile lateral wall type and unstable fracture pattern were independent risk factors of implant failure （P 〈0.05）. Conclusion For femoral intertrochanteric fracture patients treated with PFNA, internal fixation failure may occur. The risk factors include overlong TAD, fragile lateral wall and unstable fracture type. PFNA should be used cautiously in those with the hazard factors, and weightbearing ambulation must be delayed.