【专题文献】之人工髋关节置换——下肢假体周围骨折的处理

higher in revision surgery.

The post-operative incidence of periprosthetic fractures in primary total hip arthroplasties (THA) has been reported by the Mayo clinic registry as 1.1% of total hip replacements done between 1969 and 1999).

体周围骨折可以分为术中和术后。术中骨折通常由插入假体到股骨或胫骨引起。其发病率因不同的内固定方法而不同。在股骨，非骨水泥型假体有更高的风险，Berry等报道其发病率在骨水泥型假体时0.3%，在非骨水泥型假体时为5.4%。在翻修手术时，其发病率显著增高。

由梅奥医院登记处报道的在初次全髋置换时术后假体周围骨折发生率，自1969－1999年完成的全髋置换术，其PPF发生率为1.1%。

Aetiology

According to the Swedish Hip registry, trauma accounts for 75% of all PPFs.5 The majority are low velocity falls from a standing or sitting position. There are numerous possible risk factors for periprosthetic fractures; while patients with long standing THA are probably at higher risk of developing periprosthetic fracture but there are many possible confounders for this variable including the increased age of this patient group, other co-morbidities, poor bone stock and osteoporosis. Tsiridis6 suggests that female gender is associated with increased risk of PPF which is supported by various studies, and is probably related to the increased prevalence of osteoporosis in females. Beals and Tower reported that 38% of PPF in their study were associated with previous osteoporotic vertebral or metaphyseal fractures. However, the most common cause of PPF in older implants is osteolysis.7,8 The terms osteolysis and aseptic loosening are often used interchangeably and are essentially in reference to a common pathway. Osteolysis is believed be caused by the host s response to particulate wear debris associated with cement failure and subsequent loosening of the prosthesis. The choice of implant, cementation technique (or un-cemented) and operative technique are therefore directly related to the processes which are most likely to be important risk factors for late periprosthetic fracture.

病因 根据瑞典髋关节登记中心，创伤占所有假体周围骨折的75%。主要是从站位或坐位时低速跌倒。对于假体周围骨折有很多可能的风险因素，当病人长时站立时，全髋关节可能有较高的风险发生假体周围骨折，但对此变量有很多干扰因素，包括该组病例的年龄增加，其他基础疾病，骨量较差和骨质疏松。Tsiridis发现女性病人和增高的PPF风险有关，这被很多研究所证实，并且可能和女性的骨质疏松患并率增加有关。Beals和Tower在他们的研究中报道38%的PPF和之前的骨质疏松性椎体或干骺端骨折有关。然而，在较老的假体，PPF最常见的病因为骨溶解。骨溶解和无菌性松动，这两个名词常常互相替换，本质是参考一个共同路径。骨溶解相信是由于宿主对骨水泥失败相关的磨损微粒的反应和随之的假体松动而引起的。假体选择，骨水泥技术（或非骨水泥技术）和手术技术，因此和此过程直接相关，这可能是后期假体周围骨折的最重要的风险因素。

The original diagnosis is relevant to the risk of periprosthetic fracture; rheumatoid arthritis has been shown to be a risk factor for PPF by both the Finnish and Swedish Registries.9 Fractures of the proximal femur treated by arthroplasty are at higher risk for sustaining periprosthetic fracture; osteoporotic fractures of the neck of femur are regarded as pathological fractures and the ongoing pathological process is likely to be responsible for the increased incidence of PPF which increases with age, and from the index operation.10,11 Lindahl, based on the Swedish Registry, shows that initially PPF is the third commonest reason for revision, but from four years onwards, it is the second commonest reason.12

原始诊断和假体周围骨折的风险有关。类风湿性关节炎在荷兰和瑞典的登记中心都显示出是一个PPF的风险因素。股骨近端骨折，使用关节置换治疗的，有更高的PPF风险。股骨颈的骨质疏松性骨折被看成是病理性骨折，其进展的病理学过程，可能是PPF发病率增加的原因，而PPF的发病率随病人年龄而增加。依据瑞典登记中心，Lindahl发现首次PPF是翻修术的第三位常见原因，但是在之前四年，PPF是第二位常见原因。

Classification of periprosthetic fractures around the hip

While classification is essential to aid communication and for research, it is of most use to assist management. Numerous classification systems have been devised. Most, like Parrish (Table 1), classify the fracture according to its location. While simple and straightforward it does not help in deciding the correct treatment.

髋周假体周围骨折的分类

为了交流和研究，分类是必须的，它对于促进治疗帮助最大。己发明许多不同的分类系统，像Parrish系统（表1）一样，大多数系统依据骨折位置进行分类。由于简单和直接，此种方式并不能在决定正确的治疗方案上起到帮助。