Yang Hong Yeol, Ayob Khairul Anwar, Jeong Hwi Woo, Seon Jong Keun
Department of Orthopaedic Surgery, Chonnam National University Hwasun Hospital, College of Medicine, Chonnam National University, 322, Seoyang-ro, Hwasun, Chonnam, 58128, Republic of Korea.
Department of Orthopaedic Surgery, National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Sci Rep. 2025 Mar 24;15(1):10099. doi: 10.1038/s41598-025-93542-z.
Assessment of lower limb coronal plane alignment is crucial in surgical planning of total knee arthroplasty (TKA) and is commonly performed with full-length weight-bearing radiographs (FLWBR). The aim of this study was to determine discrepancies in coronal limb alignment as assessed by conventional FLWBR versus non-weight-bearing computed tomography (CT) modalities in robotic arm-assisted TKA. We retrospectively analyzed 100 consecutive patients with osteoarthritic knees who underwent robotic arm-assisted TKA with preoperative FLWBR and CT assessments of knee alignment. The mechanical axes of the Mako system were established in accordance with the Mako TKA Surgical Guide. The following parameters were compared between the two imaging modalities: (1) mechanical hip-knee-ankle angle (mHKA), (2) medial proximal tibial angle (MPTA), (3) lateral distal femoral angle (LDFA), (4) arithmetic hip-knee-ankle angle (aHKA), (5) joint line obliquity (JLO), and (6) proportion of the Coronal Plane Alignment of the Knee (CPAK) types. Regression analyses were performed to identify potential factors associated with discrepancies in measurements of coronal alignment between these two imaging modalities. There were significant differences in terms of the mHKA between preoperative CT and FLWBR (CT vs. FLWBR, 7.0° vs. 8.5°; p < 0.001), which may be attributed to the extent of the weight-bearing condition. The CT measurements with the Mako system demonstrated a lower (more varus) MPTA than the FLWBR measurements (CT vs. FLWBR, 83.7° vs. 85.2°; p < 0.001). Furthermore, there were also significant differences between the CT and FLWBR measurements in terms of the aHKA (- 4.7° vs. - 3.7°; p = 0.028) and JLO (172.2° vs. 174.2°; p < 0.001). There were significant differences of proportion of CPAK types between the two imaging modalities; however, the most common category was type I in both imaging modalities. Multivariate analyses showed that greater preoperative mHKA and posterior tibial slope were associated with the discrepancy in the MPTA measurements between the two imaging modalities. There were discrepancies in coronal alignment between preoperative FLWBR and non-weight-bearing CT using the Mako system. When compared with conventional FLWBR, the Mako system tended to overestimate the magnitude of tibial varus deformity in the knee joint.
在全膝关节置换术（TKA）的手术规划中，评估下肢冠状面排列至关重要，通常通过全长负重X线片（FLWBR）来进行。本研究的目的是确定在机器人手臂辅助TKA中，传统FLWBR与非负重计算机断层扫描（CT）模式评估的冠状面肢体排列差异。我们回顾性分析了100例连续的骨关节炎膝关节患者，这些患者接受了机器人手臂辅助TKA，并在术前进行了FLWBR和膝关节排列的CT评估。Mako系统的机械轴根据Mako TKA手术指南确定。比较了两种成像模式之间的以下参数：（1）机械髋-膝-踝角（mHKA），（2）胫骨近端内侧角（MPTA），（3）股骨远端外侧角（LDFA），（4）算术髋-膝-踝角（aHKA），（5）关节线倾斜度（JLO），以及（6）膝关节冠状面排列（CPAK）类型的比例。进行回归分析以确定与这两种成像模式之间冠状面排列测量差异相关的潜在因素。术前CT和FLWBR之间的mHKA存在显著差异（CT与FLWBR，7.0°对8.5°；p < 0.001），这可能归因于负重情况的程度。使用Mako系统的CT测量显示MPTA低于FLWBR测量（CT与FLWBR，83.7°对85.2°；p < 0.001）。此外，CT和FLWBR测量在aHKA（-4.7°对-3.7°；p = 0.028）和JLO（172.2°对174.2°；p < 0.001）方面也存在显著差异。两种成像模式之间CPAK类型的比例存在显著差异；然而，两种成像模式中最常见的类别都是I型。多变量分析表明，术前更大的mHKA和胫骨后倾与两种成像模式之间MPTA测量的差异相关。术前FLWBR和使用Mako系统的非负重CT之间在冠状面排列上存在差异。与传统FLWBR相比，Mako系统倾向于高估膝关节胫骨内翻畸形的程度。
