动力髋螺钉移位－一例罕见病例

dr.qinan

B. George, F.R. Hashmi, K.J. Barlas*, C.P. Grant
Diana Princess of Wales Hospital, Northern Lincolnshire & Goole Hospitals NHS trust, Scartho Road, Grimsby, UK
We report the case of a 79-year-old woman who had a dynamic hip screw migration into the pelvis after dynamic hip screw osteosynthesis for a pertro-canteric fracture. This kind of complication is very rare and to date we have not found any reported case in literature but with increasing prevalence of osteoporosis, aging population and increasing number of hip fracture fixed with dynamic hip screw there is always a possibility of this type of complication.
我们报道一例79岁老年妇女因经大转子骨折行动力髋螺钉固定后螺钉移位至骨盆的病例。这例病例非常罕见并且尚未见有文献报道类似病例。但是随着骨质疏松症发病率的增加、人口老龄化以及髋部骨折采用动力髋螺钉固定病例数量的增加，因此还是可能再出现类似的病例，本病例可作为一个借鉴。
Case report病例报道
A 79-year-old lady presented to accident and emer¬gency with a complaint of pain in left hip after a fall from stairs. X-rays revealed a basal fracture at the left neck of femur. It was fixed with dynamic hip screw next day (Fig. 1). One week post-operatively she complained of severe pain in the operated hip on weight bearing.
1名79岁的老年妇女因从楼梯上跌落致左髋部疼痛急诊入院。X线显示为左股骨颈基底部骨折，手术采用动力髋螺钉固定（图1）。术后负重1周，老人主诉左髋疼痛加剧。

X-rays of hip showed cut out of dynamic hip screw (Fig. 2). This was revised with another dynamic hip screw 2 weeks after initial operation. She had phy¬siotherapy and mobilisation in ward for 2 weeks and sent home with an out patient appointment. She attended out patients twice without any complaints but 5 months after her second operation she com¬plained of pain in her hip and groin. An X-ray of pelvis revealed dynamic hip screw migration through the acetabulum and half of it lying in pelvis (Fig. 3).
X线检查显示动力髋螺钉穿透进入髋关节（图2）。初次手术2周后患者接受了翻修手术。术后在医院监护病房接受理疗及运动疗法2周，2周后出院。期间患者进行了2次复诊，未发现异常情况，直到2次手术后5个月，患者来院主诉髋部和腹股沟部疼痛。骨盆X线检查显示螺钉穿透髋臼，螺钉的一半都进入了盆腔（图3）。



The lag screw was removed with no evidence of trauma to bladder or any other pelvic structures at the time or after surgery and remaining part of the head was removed. Eight months later she was able to walk with the help of Zimmer frame and shoe raise.
手术去除拉力螺钉，术中及术后均未发现膀胱及其他盆腔脏器损伤的证据。8个月后患者在助行器和增高鞋的辅助下可以自行行走。
Discussion讨论
Peritrochanteric fracture represents a significant risk in every age group but especially in advanced years when they represent a risk to life. Dynamic hip screw is widely used for fixation of such fractures. It utilises controlled impaction during weight-bearing to stabilise the fracture and facilitate healing. However, the functional results following fixation of intertrochanteric fractures with a dynamic hip screw in osteoporotic bone are sometimes unsatis¬factory because of failure of the fixation or failure to reestablish acceptable hip biomechanics. A com¬plication rate of up to 38.6%1,2,4 has been reported including guide wire penetration into the acetabulum,3 infection, deep vein thrombosis, malunion, delayed healing, non-union, disengagement of lag screw from side plate, metal fractures, and cut out of lag screw. Increasing patient age, an unstable fracture, a poor reduction, and use of high angle (1508) side plate also were associated with a sig¬nificant increased risk of failure due to cut out.5,6,7
转子周围骨折在每一个年龄组都可能发生，但随着年龄的增加，其带来的危险也随之增加。动力髋螺钉是治疗此类骨折最常用的固定器械。它利用负重状态下控制性的骨折加压稳定骨折并促进愈合。但是，由于固定失效或者固定后的生物力学强度无法满足要求，骨质疏松的转子间骨折采用动力髋螺钉固定的功能结果并不理想。并发症的发生率高达38.6%【1、2、4】，包括导针穿透髋臼【3】、感染、深部静脉血栓形成、骨不连、延迟愈合、畸形愈合、拉力螺钉同钢板分离以及拉力螺钉穿透。高龄、骨折不稳定、复位不良以及使用高度数的钢板都可能增加螺钉穿透的风险【5、6、7】。
As it is mentioned in many studies that one major advantage of the backward sliding mechanism of lag screw is controlled compression of fracture with weight bearing which helps in healing of fracture.
正如多数研究所提到的拉力螺钉的一个主要优点是反向滑动机制，能在负重条件下对骨折施加控制性加压，促进骨折的愈合。
In our case report it was forward gliding move¬ment with penetration of the pelvis. As in our patient there was history of previous cut out of lag screw so we recommend the use of locking screw after dynamic hip screw fixation which prevent forward migration away from the plate but allow controlled backward impaction of the fracture.
在我们报道的病例中前向的滑动穿透进入骨盆。由于这例病例之前曾有拉力螺钉穿透，因此我们推荐在动力髋螺钉固定后使用锁定钢板，这样可以阻止螺钉的前向运动并允许骨折端的控制性反向滑动加压。
References
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7. Wu CC, Smith CH. Biomechanical analysis of the dynamic hip screw in treatment of intertrochanteric fractures. Arch Orthop Trauma Surg 1991;110:307—10.
（from dxy）