老年骨质疏松性粗隆间骨折动力髋内固定危险因素分析

Retrospective study of risk factors related to failure of dynamic hip screw fixation for intertrochanteric fracture in the elderly with osteoporosis

目的 对导致老年骨质疏松性粗隆间骨折动力髋内固定失败的危险因素进行回顾性分析.方法 对2002年1月至2007年12月间110例接受切开复位,135°动力髋螺钉（DHS）内固定且病历资料完整的股骨粗隆间骨折患者进行回顾性分析.男性29例,女性81例;年龄55～87岁,平均77.4岁.采用Evans骨折分型：Type Ⅰ-1型8例,Type Ⅰ-2 19例,Type Ⅰ-3 35例,Type Ⅰ-4型47例,Type Ⅱ 1例.采用Singh分级评定骨的质量：其中Ⅵ级4例,Ⅴ级31例,Ⅳ级52例,Ⅲ级23例.采用尖顶距（tip-apix distance, TAD）评价拉力螺钉在股骨头的位置.选择年龄、骨质疏松程度、骨折类型、复位稳定性、内固定的植入位置作为分析变量,采用t检验及χ2检验对危险因素进行分析.结果 所有患者获得3.0～24.0个月（平均12.4个月）随访,14例患者内固定失败.内固定失败组平均年龄77.4岁（63～87岁）,较骨折愈合组年长8.9岁（P=0.04）.骨质疏松轻重程度以及TAD值大小间均存在明显统计学意义（P=0.01）.骨折稳定与否以及后内侧骨皮质对合情况是否良好均有统计学意义（P〈0.05）.良好复位与功能复位之间无统计学意义（P=0.06）.结论 年龄、骨折类型、骨骼质量、内固定的植入位置（TAD）以及内侧骨皮质复位质量是导致内固定失败的危险因素.功能复位并不增加内固定失败的风险.对于高龄、严重骨质疏松的不稳定骨折不宜应用动力髋内固定.对于采用动力髋内固定的一般患者应力求使TAD值〈25,功能复位即可,但应力求使后内侧骨皮质良好复位.

Objective To evaluate the risk factors leading to the failure of dynamic hip screw fixation for senile intertrochantcric fracture in the elderly with various osteoporosis. Methods 110 osteoporotic patients with an intertrochanteric fracture were treated with a 135° sliding compression hip screw in the period from 2002 to 2007, including 29 males and 81 females, with age range from 55 to 87 （average 77.4）. The fractures were classified on preoperative radiographs according to the Evans classification system. The detailed status of the fracture were as follows： Type Ⅰ -1 8 cases, Type Ⅰ -2 19 cases, Type Ⅰ -3 35 cases, Type Ⅰ -4 47 cases, Type Ⅱ 1 case. The bone quality was classified by Singh rating system： Type Ⅵ 4 cases, Type Ⅴ 31 cases, Type Ⅳ 52 cases, Type Ⅲ 23 cases. Tip-apix distance （TAD） was used to assess the position of placmnent of lag screw. Five possible factors （age, Singh＇s index, reduction states, type of fractures, implant placement ） were analyzed to this investigation. Results All eases were followed up for 3 to 24 months （average 12.4 mouths） and 14 cases got fixation failure. Comparing the two groups, the group of failed cases were 77.4 years old （in range from 63 to 87） averagely, which is averagely 8.9 years older than the cured group （ P = 0.04）. The difference between the degree of osteoporosis and the magnitude of TAD（ P = 0.01 ）is of significance in statistics science. The results also showed that the difference between significant difference between the degree of osteoporosis and the magnitude of TAD type of fractures and the cortical contact medially and posteriorly（ P 〈 0.05）is of significance in statistics science. However, there was no significance in statistics science between the two groups in anatomical reduction or functional reduction （ P = 0.06）. Conclusion Five variables were noted to have statistical relations to the failure of dynamic hip screw fixation. Functional reduction did not increase the risk of internal fixation. Dynamic hip screw shouht not be the first choice for the elder cases who have unstable fractures combined with severe osteoporosis. As to the application of dynamic hip screw fixation, the TAD value should not be higher than 25 mm for the general patients. It might be inadvisable to overemphasize anatomical reduction, but an anatomical reduction with posteromedial apposition is necessary.