股骨转子下骨折内固定失败原因分析

The reasons of internal fixation failure for subtrochanteric fractures of the femur

目的分析股骨转子下骨折内固定失败的原因,提出避免并发症的方法。方法1993年1月至2004年1月,收治股骨转子下骨折内固定失败患者39例,男34例,女5例;年龄21～65岁,平均37岁。致伤原因:骑自行车摔伤3例,步行摔伤1例,车祸伤28例,高处坠落伤7例。骨折类型:Sein-sheimerⅡA型5例,ⅡB型2例,ⅡC型1例,ⅢA型18例,ⅢB型1例,Ⅳ型3例,Ⅴ型9例。原手术方式包括切开复位钢丝捆扎固定1例,切开复位梅花钉加钢丝捆扎固定13例,闭合复位Russell-Taylor重建钉固定1例,切开复位135°动力髋螺钉固定6例,切开复位钢板固定18例。术后8周内失败2例,8周至6个月失败26例,超过6个月失败11例。内固定失败形式包括骨折内翻畸形35例、拉力螺钉切出股骨头2例、股骨干过度内移2例。内固定失败原因是术中骨折未解剖复位、内固定不坚强、过早完全负重以及拉力螺钉位置不良。结果对骨折内固定进行翻修,切开复位梅花钉固定2例,交锁髓内钉固定23例,135°动力髋螺钉固定6例,钢板固定4例,人工关节置换4例。随访19～37个月,平均23个月。骨折愈合时间11～13个月,平均11.5个月。结论由于偏心负载,股骨转子下区可以产生很高的弯曲负荷。采用髓外内固定时,术中应重建股骨内侧皮质稳定性并植骨。

Objective To analyze the reasons of internal fixation failure for subtrochanteric fractures of the femur and indicate the methods for avoiding the complications. Methods Thirty-nine patients with internal fixation failure for subtrochanteric fractures of the femur were treated from January 1993 to January 2004. There are 34 males and 5 females with an average age of 37 years （range from 21 to 65 years）. The causes of injury included falls from bicycle in 3 cases, pedestrain injury in 1 case, traffic accident in 28 cases and falls from heights in 7 cases. The pattern of the fractures included Seinsheimer Ⅱ A type in 5 cases, liB type in 2 cases, liC type in 1 case,IliA type in 18 cases, ⅢB type in 1 case,Ⅳ type in 3 cases, V type in 9 cases. The initial operation included open reduction and fixed with cerelage wires in 1 case, open reduction and fixed with Kuntscher nail and cerclage wire in 13 cases, closed reduction and fixed with Russell-Taylor reconstruction nail in 1 case, open reduction and fixed with 135° DHS in 6 cases, open reduction and fixed with plate in 18 cases. Two cases failed in 8 weeks postoperation, 26 cases failed in 6 months postoperation and 11 cases failed over 6 months. The pattern of failure of internal fixation include varus deformity of fracture in 35 cases, cutout of the lag screw from the femoral head in 2 cases and over medial migration of the distal femoral shaft in 2 cases. The reasons of internal fixation failure were nonanatomically reduction of fractures, unrigid interal fixation, over early weight bearing and poor placement of lag screw. Resuits The internal fixtion of fractures were revised, including open reduction and fixed with kuntscher nail in 2 cases, fixed with interlocking nail in 23 cases, fixed with 135° DHS in 6 cases, fix with plate in 4 cases, total hip replacement in 4 cases. The mean duration of follow up was 23 months （range from 19 to 37 months）. The average time of fracture healing was 11.5 months （range from 11 to 13 months）. Conclusion There are higher bending loads at the subtrochanteric area of the femur due to the eccentric loading. If extramedullary implant is selected, the stability at the medial cortex of the femur must be reconstructed intra- operatively and bone grafting is required.