Orthopedic and Traumatology Clinic, University Hospital of Parma, Parma, Italy.
Orthopedic and Traumatology Clinic, University Hospital of Parma, Parma, Italy.
Injury. 2019 Aug;50 Suppl 4:S21-S25. doi: 10.1016/j.injury.2018.11.057. Epub 2019 Mar 19.
Femoral neck fractures are the most frequent fractures in the elderly and hemiarthroplasty is the treatment of choice. The objective of this study is to identify predictive factors of acetabular erosion after bipolar hemiarthroplasty in a mobile independent population during a follow-up of ten years.
This multicenter study started in 1997 ending in 2007. Data were prospectively collected and retrospectively analyzed. Inclusion criteria were: age > 60 and < 85 years, BMI < 35, normal Abbreviated MiniMental Test score, ability to walk 0.8 km and live independently, non-pathological fracture, hip with no or minimal osteoarthritic changes, and availability of clinical and radiological follow-up. For each Patient were recorded: demographic data, comorbidities, time from fracture to surgery, characteristics of the implant, duration of surgery. Patients included underwent clinical and radiological follow-up at a minimum of ten years.
Overall, 209 Patients met inclusion criteria. A press-fit implant was performed in 172 subjects; in contrast a cemented prosthesis was implanted in 37 patients. Nineteen patients underwent implant revision to total hip arthroplasty for acetabular erosion and pain. Classification of X-ray using Baker criteria showed a grade 0 in 54.5%, a grade 1 in 19.6%, a grade 2 in 18.1% and a grade 3 in 7.6%. Multivariate analysis revealed that the size of the femoral head (FH) was the only predictive factor of a higher risk of acetabular erosion. The Kaplan-Meier survival curve verified the risk of implant revision in Group 1 (FH sized > 48 mm) and Group 2 (FH sized < 48 mm). The probability of implant revision for acetabular erosion at ten years from surgery were 5.5% in Group 1 and 15.6% in Group 2.
In bipolar hemiarthroplasty smaller head size lead to a polar wear implying a higher risk of acetabular erosion and migration; in our population this risk was consistent with the use of implant head < 48 mm diameter. Considering the absolute risk of a smaller FH size, the surgeon must evaluate the accuracy of measurement of the caliber, since as reported in previous studies, it can significantly underestimate the size.
股骨颈骨折是老年人最常见的骨折类型，半髋关节置换术是首选治疗方法。本研究的目的是在十年的随访中，确定活动能力独立的人群中，在接受双极半髋关节置换术后发生髋臼侵蚀的预测因素。
这项多中心研究始于 1997 年，结束于 2007 年。数据是前瞻性收集和回顾性分析的。纳入标准为：年龄>60 岁且<85 岁，BMI<35，简易精神状态检查评分正常，能够行走 0.8 公里并独立生活，无病理性骨折，髋部无或仅有轻微骨关节炎改变，且有临床和影像学随访。每位患者均记录：人口统计学数据、合并症、骨折至手术时间、植入物特征、手术时间。所有患者均接受至少十年的临床和影像学随访。
总体而言，209 例患者符合纳入标准。172 例患者行压配式植入物，37 例患者行骨水泥型假体植入。19 例患者因髋臼侵蚀和疼痛行植入物翻修行全髋关节置换术。采用 Baker 标准对 X 射线进行分类，结果显示 0 级 54.5%，1 级 19.6%，2 级 18.1%，3 级 7.6%。多变量分析显示，股骨头（FH）大小是髋臼侵蚀发生风险较高的唯一预测因素。Kaplan-Meier 生存曲线证实了第 1 组（FH 大小>48mm）和第 2 组（FH 大小<48mm）的翻修风险。术后十年，第 1 组（FH 大小>48mm）和第 2 组（FH 大小<48mm）的髋臼磨损翻修概率分别为 5.5%和 15.6%。
在双极半髋关节置换术中，较小的股骨头尺寸会导致极磨损，从而增加髋臼侵蚀和迁移的风险；在我们的人群中，这种风险与使用<48mm 直径的植入物头一致。考虑到较小 FH 尺寸的绝对风险，外科医生必须评估口径测量的准确性，因为正如之前的研究报道，它可能会显著低估尺寸。
