University of Heidelberg, Department of Orthopaedic Surgery, Heidelberg, Germany.
Med Sci Monit. 2009 Nov;15(11):BR307-12.
A periprosthetic femoral fracture after total hip arthroplasty is a serious but uncommon complication, and therefore difficult to analyze clinically in scientifically and statistically valid study samples. With the aim of preventing these fractures the purpose of this study was to investigate potential risk factors associated with cementless hip arthroplasty in a standardized laboratory setup. Additionally, we aimed to clarify if the treatment with a cementless hip stem is fraught with higher risk of periprosthetic fracture for older patients compared to younger patients.
MATERIAL/METHODS: A biomechanical setup was developed to provide analysis on sixteen femoral specimens of different age. A cementless hip stem was implanted into the specimens and loads - representing hip contact forces - were applied under standardized conditions until fracture occurred. The femurs were divided into two age groups (<70 and >or=77 years of age).
The elderly specimens fractured at significantly lower maximum forces (<70: Fmax=5,308N; >or=77: Fmax=2,519N; p<0.01). Maximum fracture loads were found to correlate strongly with age (p=0.01), BMD (e.g. for the Ward's triangle: p<0.01) and BMI (p=0.04).
In patients with advanced age treated with cementless hip stems the risk of suffering a periprosthetic fracture is significantly higher. It increases in patients with an age of 80 years or older, a Ward's triangle BMD below 0.500 g/cm2 and a BMI >33 kg/m2. Whereas one single factor must not be viewed as an exclusion criterion for a cementless hip stem treatment, cumulation of these factors should alert the orthopaedic surgeon.
全髋关节置换术后股骨假体周围骨折是一种严重但不常见的并发症，因此难以在科学和统计学上有效的研究样本中进行临床分析。本研究旨在通过标准化实验室设置研究与非骨水泥髋关节置换术相关的潜在危险因素，目的是预防这些骨折。此外，我们旨在明确与年轻患者相比，非骨水泥髋关节柄治疗是否会使老年患者发生假体周围骨折的风险更高。
材料/方法：开发了一种生物力学设置，以对 16 个不同年龄的股骨标本进行分析。将非骨水泥髋关节柄植入标本中，并在标准化条件下施加代表髋关节接触力的载荷，直到发生骨折。将股骨分为两个年龄组（<70 岁和≥77 岁）。
老年标本的最大力明显较低（<70：Fmax=5308N；≥77：Fmax=2519N；p<0.01）。最大骨折载荷与年龄（p=0.01）、BMD（例如 Ward 三角区：p<0.01）和 BMI（p=0.04）呈强相关。
在接受非骨水泥髋关节柄治疗的高龄患者中，发生假体周围骨折的风险显著增加。在年龄 80 岁或以上、Ward 三角区 BMD 低于 0.500g/cm2 和 BMI>33kg/m2 的患者中，风险增加。虽然不能将单个因素视为非骨水泥髋关节柄治疗的排除标准，但这些因素的累积应引起骨科医生的警惕。
