“尖顶距”值与拉力螺钉切出股骨头关系的临床回顾性研究

The association between the“Tip-Apex Distance”value and cut-out of the lag screw from the femoral head:a clinical retrospective study

目的验证“尖顶距(TAD)”值与拉力螺钉切出股骨头的关系,并分析其它因素对该并发症的影响。方法2002年1月～2004年12月,对106例接受切开复位,135°动力髋螺钉(DHS)固定且病历资料完整的股骨转子间骨折患者进行回顾性分析。男65例,女41例；年龄20～83岁,平均52．4岁。Evans骨折分型：Ⅱ型19例,Ⅲ型25例,Ⅳ型32例,Ⅴ型29例,R型1例。采用Singh分级评定骨的质量：其中Ⅵ级44例,Ⅴ级34例,Ⅳ级23例,Ⅲ级5例。根据Baumgaertner等提出的预测拉力螺钉切出股骨头的“TAD”预测值25mm分组。A组：“TAD”值＜25 mm 59例,B组：“TAD”值＞25 mm 47例。结果所有患者获得4．5～28．0个月(平均14．45个月)随访。3例患者并发拉力螺钉切出股骨头。其中“TAD”值＞30 mm 15例,拉力螺钉切出1例；“TAD”值＞40mm 7例,拉力螺钉切出2例(P=0．000)。拉力螺钉切出股骨头的3例患者平均年龄为78．7岁(75～83岁),超出骨折顺利愈合的103例患者的平均年龄27．1岁(P=0．000)。拉力螺钉切出股骨头的3例患者,均见于不稳定性股骨转子间骨折,其中EvansⅤ型2例和R型1例。骨折复位质量：优43例,良47例,中9例(拉力螺钉切出股骨头1例),差7例(拉力螺钉切出股骨头2例)。结论拉力螺钉切出股骨头受患者年龄、骨折类型以及骨折复位稳定性等多因素影响,但是“TAD”值越高,拉力螺钉切出股骨头的危险性越大。

Objective To confirm the association between the ＂Tip-Apex Distance （TAD）＂ and cut-out of the lag screw from the femoral head, and to analyze other factors leading to the cut-out. Methods The complete radiographic and clinical data of 106 patients with femoral intertrochanteric fractures were available for this study. They were 65 men and 41 women, with an average age of 52. 4 years （range, 20 to 83 years）. According to Evans classification, 19 cases belonged to type Ⅱ, 25 to type Ⅲ, 32 to type Ⅳ, 29 to type Ⅴ, and one to type R. The bone quality was classified by Singh rating system： 44 cases were rated as type Ⅵ, 34 as type Ⅴ, 23 as type Ⅳ and five as type HI. They were treated with open reduction and fixation with 135° dynamic hip screw （DHS）. According to the finding of Baumgaertner that ＂TAD＂ beyond 25 mm would greatly increase the risk of cut-out, the patients could be divided into two groups： 59 eases with ＂TAD＂ less than 25 mm and 47 greater than 25 mm. Results The mean duration of follow-ups was 14.45 months （range, 4.5 to 28. 0 months）. Of the 15 eases whose ＂TAD＂ was more than 30 mm, one had the cut-out. Of the seven eases whose ＂TAD＂ was more than 40 mm, two had the cut-out （ P = 0. 000）. The average age of the three patients was 78.7 years （range： 75 to 83 years） and 27. 1 years older than that of the 103 patients whose fracture healed （ P = 0. 000） . They belonged to the unstable intertroehanterle fracture of the femur （two to Evans type Ⅴ and one to type R）. The reduction was assessed as excellent in 43 cases, good in 47 eases, fair in nine eases （of whom one had the cut-out）, poor in seven eases （of whom two had the cut-out） . Conclusions The cut-out of the lag screw from the femoral head can be caused by age, fracture type and stability of reduction and ＂TAD＂. The greater the ＂TAD＂ value, the greater possibility of cut-out.