Department of Orthopaedic Surgery, Beaumont Health, Royal Oak, MI.
Department of Orthopaedic Research, Beaumont Health, Royal Oak, MI.
J Arthroplasty. 2019 Jun;34(6):1273-1278. doi: 10.1016/j.arth.2019.02.008. Epub 2019 Feb 14.
Dual-mobility (DM) total hip arthroplasty (THA) systems are designed to increase stability while potentially avoiding problems associated with large femoral heads. Complications of these systems are not yet fully understood. This study aims at characterizing in vivo performance of DM hip systems and assessing modes of clinical failure.
Under an institutional review board-approved implant retrieval protocol, 18 DM THA systems from 17 patients were included. Implants were graded at the head-neck junction for fretting and corrosion based on the system of Goldberg et al. Components were also macroscopically examined for different damage modes. Demographics and surgical data were collected from medical records, and radiographs were assessed for component positioning. Data were analyzed through Spearman rank-order correlation and Mann-Whitney U-tests, with α = 0.05.
The average length of implantation was 13.4 months with mild to moderate fretting corrosion damage. Polyethylene (PE) liners exhibited edge deformation, scratching, and pitting damage. Metallic components exhibited burnishing and scratching damage. Summed fretting and corrosion scores were strongly correlated (ρ = 0.967, P < .0001). Summed corrosion score was moderately correlated with presence of embedding on the PE liner (ρ = 0.690, P = .017). PE liner abrasion and edge deformation of the femoral stem taper were moderately positively correlated (ρ = 0.690, P = .017). Fretting and corrosion damage were not significantly correlated with patient demographics or radiographic positioning of implants. There were no differences in scores between modular and monoblock designs.
These findings demonstrate that dual-mobility THA systems may be susceptible to the same fretting and corrosion damage observed in traditional modular THA systems. Future studies are needed to confirm these results and clinical significance.
双动（DM）全髋关节置换（THA）系统旨在增加稳定性，同时避免与大股骨头相关的问题。这些系统的并发症尚未完全了解。本研究旨在描述 DM 髋关节系统的体内性能，并评估临床失效模式。
根据机构审查委员会批准的植入物检索协议，纳入了 17 名患者的 18 例 DM THA 系统。根据 Goldberg 等人的系统，对股骨头颈交界处的植入物进行了微动和腐蚀的分级。还对组件进行了宏观检查，以确定不同的损坏模式。从病历中收集人口统计学和手术数据，并评估 X 射线片的组件定位。使用 Spearman 等级相关和 Mann-Whitney U 检验进行数据分析，α=0.05。
平均植入时间为 13.4 个月，微动腐蚀损伤程度为轻度至中度。聚乙烯（PE）衬垫出现边缘变形、划痕和点蚀损伤。金属部件出现抛光和划痕损伤。总的微动和腐蚀评分呈强相关（ρ=0.967，P<.0001）。总的腐蚀评分与 PE 衬垫上的嵌入物存在中度相关（ρ=0.690，P=0.017）。PE 衬垫磨损和股骨柄锥形边缘变形中度正相关（ρ=0.690，P=0.017）。微动和腐蚀损伤与患者人口统计学或植入物的影像学定位无显著相关性。模块式和整体式设计的评分无差异。
这些发现表明，双动 THA 系统可能容易受到与传统模块化 THA 系统相同的微动和腐蚀损伤的影响。需要进一步的研究来证实这些结果和临床意义。
