Department of Orthopaedic Surgery, International University of Health and Welfare Mita Hospital, 1-4-3 Mita, Minato-ku, Tokyo 108-8329, Japan; Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare, 852, Hatakeda, Narita City, Chiba 286-8520, Japan; Department of Orthopaedic Surgery, NHO Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8902, Japan.
Department of Orthopaedic Surgery, International University of Health and Welfare Mita Hospital, 1-4-3 Mita, Minato-ku, Tokyo 108-8329, Japan; Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare, 852, Hatakeda, Narita City, Chiba 286-8520, Japan.
J ISAKOS. 2024 Aug;9(4):609-614. doi: 10.1016/j.jisako.2024.05.015. Epub 2024 May 31.
Cement penetration (CP) plays a key role in implant stability for cemented total knee arthroplasty (TKA), and the radiolucent line (RLL) >2 mm is a preliminary sign for loosening of components. However, the direct relationship between CP and the frequency of RLL >2 mm is unclear, and the best cut-off value for CP to prevent RLL >2 mm also remains unclear. This study aimed to investigate this relationship between CP and RLL and to determine the clinical cut-off value for tibial CP in patients 2 years after TKA.
This retrospective study investigated 157 knees from 123 patients with osteoarthritis who underwent cemented TKA. The CP and RLL immediately after TKA and the RLL 2 years after TKA were measured for the medial, lateral, anterior, and posterior tibial baseplate zones. Receiver operating characteristic (ROC) curves were constructed to determine the best cut-off values for CP.
RLL >2 mm was not observed just after TKA. An RLL >2 mm was observed in any tibial baseplate zone in 22 knees from 20 patients (RLL+ group) and was not observed in the remaining (RLL- group) 2 years after TKA. The mean CP for all zones was significantly higher in the RLL- group (2.5 ± 1.1 mm) than in the RLL+ group (1.7 ± 0.6 mm; P < 0.001). An RLL >2 mm was seen in 21 knees in the medial zone, 9 knees in the lateral zone, 8 knees in the anterior zone, and 3 knees in the posterior zone. CP values with RLL >2 mm were significantly lower than those without the RLL at the medial, anterior, and posterior tibial baseplate zones. The best cut-off values from the ROC curve of CP in each zone were between 1.1 mm and 2.1 mm.
The depth of the CP directly affects the incidence of an RLL >2 mm. The best cut-off value for tibial CP to prevent an RLL >2 mm is 2.1 mm.
水泥渗透（CP）在骨水泥固定全膝关节置换术（TKA）的稳定性中起着关键作用，>2mm 的射线可透线（RLL）是组件松动的初步迹象。然而，CP 与 RLL>2mm 的直接关系尚不清楚，CP 预防 RLL>2mm 的最佳截止值也不清楚。本研究旨在探讨 CP 与 RLL 之间的这种关系，并确定 TKA 后 2 年时胫骨 CP 的临床截止值。
本回顾性研究调查了 123 例骨关节炎患者的 157 膝，这些患者接受了骨水泥固定的 TKA。在 TKA 后立即和 2 年后测量了内侧、外侧、前侧和后侧胫骨基板区域的 CP 和 RLL。构建了接收者操作特征（ROC）曲线，以确定 CP 的最佳截止值。
TKA 后即刻并未观察到 RLL>2mm。在 20 例患者的 22 膝（RLL+组）中，任何胫骨基板区域均观察到 RLL>2mm，而在其余 2 年后（RLL-组）均未观察到 RLL>2mm。所有区域的 CP 平均值在 RLL-组（2.5±1.1mm）明显高于 RLL+组（1.7±0.6mm；P<0.001）。内侧区域有 21 个膝关节、外侧区域有 9 个膝关节、前侧区域有 8 个膝关节、后侧区域有 3 个膝关节观察到 RLL>2mm。在胫骨基板的内侧、前侧和后侧区域，出现 RLL>2mm 的 CP 值明显低于未出现 RLL 的 CP 值。ROC 曲线中每个区域 CP 的最佳截止值在 1.1mm 到 2.1mm 之间。
CP 的深度直接影响 RLL>2mm 的发生率。预防 RLL>2mm 的胫骨 CP 最佳截止值为 2.1mm。
