Division of Orthopaedics, Department of Surgery, Dalhousie University and QEII Health Sciences Centre, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada; School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada.
Division of Orthopaedics, Department of Surgery, Dalhousie University and QEII Health Sciences Centre, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada.
J Arthroplasty. 2020 Apr;35(4):1109-1116. doi: 10.1016/j.arth.2019.11.010. Epub 2019 Nov 14.
The anatomic dual mobility (ADM) acetabular component was introduced because of previously described low dislocation rates for this type of construct. The shape of the anatomic cup and the motion of polyethylene liner may have implications for acetabular cup fixation and polyethylene liner wear; therefore, the purpose of this study was to assess the migration patterns and wear rates of the ADM component using radiostereometric analysis.
Uncemented ADM acetabular components were implanted in 27 patients. Radiostereometric analysis exams were taken at 6 follow-up visits over 3 years. Proximal translation and sagittal rotation of the cup and polyethylene total wear and wear rates were calculated. Oxford 12 Hip scores and satisfaction were recorded.
Mean proximal translation was below the 0.2 mm threshold at 2 years associated with acceptable long-term survivorship (0.16 mm [standard deviation {SD} 0.31] at 3 years). Mean sagittal rotation was 0.29 degrees (SD 1.03) and was greater in female subjects (P < .001). Following bedding-in, the annual wear rate was 0.02 mm/y, below the 0.1 mm/y threshold. There was no association between cup migration and polyethylene wear. Patient satisfaction at 3 years was 96%. Mean Oxford 12 Hip scores improved from 21 (SD 7) preoperatively to 43 (SD 7) 3 years postoperatively.
The ADM cup demonstrated stable migration at 3 years indicating low risk for aseptic loosening. Bedding-in in the first year was followed by low annual wear rates. These finding suggest no increased risk of the dual mobility and anatomic design on fixation or wear.
解剖双动（ADM）髋臼组件的引入是因为之前描述过这种类型的结构具有较低的脱位率。解剖杯的形状和聚乙烯衬垫的运动可能对髋臼杯固定和聚乙烯衬垫磨损有影响；因此，本研究的目的是使用放射立体测量分析评估 ADM 组件的迁移模式和磨损率。
在 27 名患者中植入非骨水泥 ADM 髋臼组件。在 3 年内的 6 次随访中进行放射立体测量分析检查。计算髋臼杯和聚乙烯总磨损的近侧平移和矢状旋转以及磨损率。记录牛津 12 髋评分和满意度。
平均近侧平移在 2 年时低于 0.2 毫米的阈值，与可接受的长期存活率相关（3 年时为 0.16 毫米[标准差 0.31]）。平均矢状旋转为 0.29 度（标准差 1.03），女性受试者的旋转更大（P<.001）。在磨合后，年磨损率为 0.02 毫米/年，低于 0.1 毫米/年的阈值。髋臼杯的迁移与聚乙烯的磨损之间没有关联。3 年后患者满意度为 96%。术前平均牛津 12 髋评分为 21（标准差 7），术后 3 年为 43（标准差 7）。
ADM 杯在 3 年内表现出稳定的迁移，表明无菌性松动的风险较低。在第一年的磨合后，出现了低的年磨损率。这些发现表明，双动和解剖设计不会增加固定或磨损的风险。
