Department of Orthopedic Surgery, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-Ku, Tokyo, 160-0023, Japan.
Department of Bone and Joint Biomaterial Research, Tokyo Medical University, Tokyo, Japan.
J Orthop Surg Res. 2023 Feb 28;18(1):147. doi: 10.1186/s13018-023-03634-7.
Adverse local tissue reactions have been problematic as an implant-related complication in total hip arthroplasty (THA). Despite the absence of significant metal wear and corrosion, granulomatous pseudotumor has been reported to be caused by polyethylene wear. We performed a long-term follow-up study investigating the relationship between polyethylene wear and pseudotumor formation in THA.
This study included 57 patients (64 hips) that underwent primary THA with metal-on-polyethylene or ceramic-on-polyethylene bearing over a minimum follow-up of 15 years. They were stratified into pseudotumor and non-pseudotumor groups and their linear wear rates of polyethylene liner and serum cobalt (Co) and chromium (Cr) ion levels were compared. Pseudotumor was diagnosed on metal artifact reduction sequence-MRI according to its composition and wall thickness using the Hauptfleisch classification.
The incidence of pseudotumor was 34% (22/64 hips) at the mean follow-up of 16.9 years. Metal ion levels did not differ between the pseudotumor and non-pseudotumor groups, and none of the patients exceeded the Co/Cr ratio of 2.0 μg/L. Moreover, the wear rate in the pseudotumor group was 1.8 times greater than in the non-pseudotumor group (0.14 vs. 0.08 mm/year, P < 0.001). According to an analysis of the receiver operating characteristic curves, the cutoff level of the wear rate to discriminate between pseudotumor and non-pseudotumor patients at 15 years was 0.11 mm/year (area under the curve = 91%; sensitivity = 95%; specificity = 78%; accuracy = 87%).
Our results might provide new insights into excessive polyethylene wear potentially leading to the future development of both pseudotumor and osteolysis. Further studies are needed to clarify the direct relationship between polyethylene wear and pseudotumor and the mutual effects of osteolysis and pseudotumor in particle reactions.
在全髋关节置换术（THA）中，作为一种与植入物相关的并发症，不良的局部组织反应一直是个问题。尽管没有明显的金属磨损和腐蚀，但据报道，聚乙烯磨损会导致肉芽肿性假瘤。我们进行了一项长期随访研究，调查 THA 中聚乙烯磨损与假瘤形成之间的关系。
本研究纳入了 57 例（64 髋）接受金属对聚乙烯或陶瓷对聚乙烯轴承的初次 THA 患者，随访时间至少 15 年。根据 Hauptfleisch 分类，根据其组成和壁厚，使用金属伪影减少序列-MRI 将他们分为假瘤组和非假瘤组，并比较聚乙烯衬垫的线性磨损率和血清钴（Co）和铬（Cr）离子水平。假瘤的诊断依据是 MRI 上的金属伪影减少序列，根据其组成和壁厚，采用 Hauptfleisch 分类。
在平均 16.9 年的随访中，假瘤的发生率为 34%（22/64 髋）。假瘤组和非假瘤组的金属离子水平无差异，且均未超过 Co/Cr 比值 2.0μg/L。此外，假瘤组的磨损率是无假瘤组的 1.8 倍（0.14 比 0.08mm/年，P<0.001）。根据受试者工作特征曲线分析，15 年时区分假瘤和非假瘤患者的磨损率临界值为 0.11mm/年（曲线下面积为 91%；敏感性为 95%；特异性为 78%；准确性为 87%）。
我们的结果可能为聚乙烯过度磨损可能导致未来假瘤和骨溶解的发展提供新的见解。需要进一步研究以阐明聚乙烯磨损与假瘤之间的直接关系以及骨溶解和假瘤在颗粒反应中的相互作用。
