Hijikata Hiroki, Mochizuki Tomoharu, Maeda Keisuku, Tanifuji Osamu, Omori Go, Yamamoto Noriaki, Kawashima Hiroyuki
Division of Orthopaedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medicine and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan.
Department of Orthopaedic Surgery, Niigata Rehabilitation Hospital, Niigata, Japan.
J Orthop Surg Res. 2025 Mar 29;20(1):326. doi: 10.1186/s13018-025-05741-z.
The purpose of this study was to compare three-dimensional (3D) and two-dimensional (2D) evaluation of the stress X-rays following total knee arthroplasty (TKA).
This prospective study analyzed 51 consecutive rTKAs (four males and 44 females, both aged 74 ± 6 years). Postoperative varus/valgus stress X-rays were taken at maximum manual varus/valgus stress during knee extension under anesthesia, and were analyzed three-dimensionally using a 3D-2D image matching technique with 3D bone and component models. The 3D models of the femur and tibia, along with component-bone constructs, were reconstructed from CT data using 3D modeling software. The 2D evaluation of varus/valgus stress X-rays were carried out directly on the stress X-rays. The varus/valgus angle (VV angle) between components, Medial joint opening (MJO) and lateral joint opening (LJO) were assessed under conditions of no stress, valgus stress, and varus stress.
The VV angles under no stress, valgus stress, and varus stress in 3D and 2D evaluation were 3.6 ± 1.1 / 3.6 ± 1.1°, -0.6 ± 1.6 / -0.6 ± 1.6°, 7.1 ± 1.9 / 6.8 ± 2.5°, respectively. The MJO in the non-stress condition and under valgus stress in 3D and 2D evaluation were 0.0 ± 0.5 / -1.8 ± 0.8 mm,1.4 ± 1.0 / -0.2 ± 1.4 mm, and the LJO in the non-stress condition and under varus stress in 3D and 2D evaluation were 0.9 ± 1.0 / -0.6 ± 1.0 mm, 3.5 ± 1.9 / 2.1 ± 1.9 mm, respectively.
This prospective study revealed that the 3D evaluation of varus/valgus stress X-rays following total knee arthroplasty is equivalent to 2D evaluation in VV angles, whereas different from 2Devaluation in MJO and LJO.
本研究旨在比较全膝关节置换术（TKA）后应力X线片的三维（3D）和二维（2D）评估。
这项前瞻性研究分析了51例连续的初次全膝关节置换术（rTKA）患者（4例男性和44例女性，年龄均为74±6岁）。在麻醉下膝关节伸直时施加最大手动内翻/外翻应力，拍摄术后内翻/外翻应力X线片，并使用3D骨和假体模型的3D-2D图像匹配技术进行三维分析。使用3D建模软件从CT数据重建股骨和胫骨的3D模型以及假体-骨结构。在内翻/外翻应力X线片上直接进行二维评估。在无应力、外翻应力和内翻应力条件下评估假体之间的内翻/外翻角度（VV角）、内侧关节开口（MJO）和外侧关节开口（LJO）。
3D和2D评估中，无应力、外翻应力和内翻应力下的VV角分别为3.6±1.1 / 3.6±1.1°、-0.6±1.6 / -0.6±1.6°、7.1±1.9 / 6.8±2.5°。3D和2D评估中，无应力条件下和外翻应力下的MJO分别为0.0±0.5 / -1.8±0.8 mm、1.4±1.0 / -0.2±1.4 mm，3D和2D评估中，无应力条件下和内翻应力下的LJO分别为0.9±1.0 / -0.6±1.0 mm、3.5±1.9 / 2.1±1.9 mm。
这项前瞻性研究表明，全膝关节置换术后内翻/外翻应力X线片的三维评估在VV角方面与二维评估相当，而在MJO和LJO方面与二维评估不同。
