Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; AutoRSA Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Aarhus, Denmark.
Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; AutoRSA Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Aarhus, Denmark; Department of Orthopeadics, University Clinic for Hand, Hip and Knee Surgery, Hospital Unit West, Holstebro, Denmark.
Knee. 2021 Mar;29:486-499. doi: 10.1016/j.knee.2021.02.033. Epub 2021 Mar 18.
A modular polyethylene (PE) inlay in total knee arthroplasty (TKA) may wear on both sides. PE particles may induce osteolysis, which can lead to implant loosening. The aim of this study was to determine if PE wear in monobloc TKA differs from that ofmodular TKA at 60-month follow-up.
In a prospective, patient-blinded trial, 50 patients were randomized to hybrid TKA surgery with either acementless high-porosity trabecular-metal tibial component with a monobloc UHMWPE inlay (MONO-TM) or a cementless low-porosity screw-augmented titanium fiber-mesh tibial component with a modular UHMWPE inlay (MODULAR-FM). Radiostereometry was used to measure PE wear and tibial component migration.
At 60-monthfollow-up, mean PE wear of the medial compartment was 0.24 mm and 0.61 mm and mean PE wear of the lateral compartment was 0.31 mm and 0.82 mm for the MONO-TM and the MODULAR-FM groups, respectively (p < 0.01). The PE wear-rate was 0.05 mm (95% CI 0.03-0.08) in the MONO-TM group and 0.14 mm (95% CI 0.12-0.17) in the MODULAR-FM group (p < 0.01). Total translation at 60 months was mean 0.30 mm (95% CI 0.10-0.51) less (p < 0.01) for MONO-TM compared with MODULAR-FM tibial components. The majority of tibial components were stable (<0.2 mm MTPM) from 12 to 24-month and 24 to 60-month follow-up.
At mid-term follow-up, monobloc PE inlay wear was approximately 40% of that of the modular PE inlay wear, which suggest that back-side wear of modular PE inlays is a significant contributor of PE wear in hybrid TKA.
全膝关节置换术中的模块化聚乙烯（PE）嵌体可能会在两侧磨损。PE 颗粒可能会引起骨溶解，从而导致植入物松动。本研究旨在确定在 60 个月的随访中，单体式 TKA 中的 PE 磨损是否与模块化 TKA 中的磨损不同。
在一项前瞻性、患者盲法试验中，50 名患者被随机分为接受混合 TKA 手术的两组，一组为无骨水泥高孔隙率多孔金属胫骨组件与单体式超高分子量聚乙烯（UHMWPE）嵌体（MONO-TM），另一组为无骨水泥低孔隙率螺钉增强钛纤维网胫骨组件与模块化 UHMWPE 嵌体（MODULAR-FM）。放射立体测量术用于测量 PE 磨损和胫骨组件迁移。
在 60 个月的随访中，MONO-TM 和 MODULAR-FM 组的内侧间室平均 PE 磨损分别为 0.24mm 和 0.61mm，外侧间室平均 PE 磨损分别为 0.31mm 和 0.82mm（p<0.01）。MONO-TM 组的 PE 磨损率为 0.05mm（95%CI 0.03-0.08），MODULAR-FM 组为 0.14mm（95%CI 0.12-0.17）（p<0.01）。与 MODULAR-FM 胫骨组件相比，MONO-TM 胫骨组件在 60 个月时的总平移减少了 0.30mm（95%CI 0.10-0.51）（p<0.01）。从 12 个月到 24 个月和 24 个月到 60 个月的随访中，大多数胫骨组件均稳定（<0.2mm MTPM）。
在中期随访中，单体式 PE 嵌体的磨损约为模块化 PE 嵌体磨损的 40%，这表明模块化 PE 嵌体的背面磨损是混合 TKA 中 PE 磨损的一个重要因素。
