Asada Shigeki, Inoue Shinji, Tsukamoto Ichiro, Mori Shigeshi, Akagi Masao
Department of Orthopaedic Surgery, Faculty of Medicine, Kindai University, Osaka, Japan.
Department of Orthopaedic Surgery, Faculty of Medicine, Kindai University, Osaka, Japan.
Knee. 2019 Mar;26(2):410-415. doi: 10.1016/j.knee.2018.12.013. Epub 2019 Jan 26.
The native knee joint line is varus relative to the tibia and remains parallel to the floor during gait even with varus lower-limb alignment. We investigated the desired degree of frontal obliquity for positioning the tibial component during unicompartmental knee arthroplasty (UKA).
We retrospectively analyzed full-leg, standing, hip to ankle digital radiographs from 107 osteoarthritic knees. We measured the hip-knee-ankle (HKA) angle, the tibial joint-line orientation angle (JLOA), which indicates the angle of the joint line (tibial component) relative to the floor, and the medial proximal tibial angle (MPTA), which is the angle of the joint line (tibial component) relative to the tibial mechanical axis, before and after UKA in the coronal plane.
The preoperative HKA angle (mean 7.3°, standard deviation (SD) 3.0) was significantly higher than the postoperative HKA angle (mean 3.4°, SD 3.0, P < 0.0001). The preoperative MPTA (mean 4.8°, SD 2.1) did not significantly differ from the postoperative MPTA (mean 4.5°, SD 3.0, P = 0.47). The mean postoperative JLOA was parallel to the floor (JLOA; 0.2°, SD 3.6).
When the tibial component is positioned along the natural joint slope restoring pre-disease alignment of the overall lower limb in the coronal plane, the tibial component was positioned parallel to the floor. When UKA is indicated for the medial osteoarthritis patient, the surgeon should install the tibial component four to five degrees varus to the tibial mechanical axis to maintain joint-line parallelism.
相对于胫骨，正常膝关节的关节线呈内翻，即使下肢呈内翻对线，在步态过程中关节线仍与地面平行。我们研究了单髁膝关节置换术（UKA）中胫骨假体定位所需的额状面倾斜度。
我们回顾性分析了107例骨关节炎膝关节的全腿站立位髋关节至踝关节数字X线片。我们在冠状面测量了UKA术前和术后的髋-膝-踝（HKA）角、胫骨关节线方向角（JLOA）（该角度表示关节线（胫骨假体）相对于地面的角度）以及胫骨近端内侧角（MPTA）（该角度是关节线（胫骨假体）相对于胫骨机械轴的角度）。
术前HKA角（平均7.3°，标准差（SD）3.0）显著高于术后HKA角（平均3.4°，SD 3.0，P < 0.0001）。术前MPTA（平均4.8°，SD 2.1）与术后MPTA（平均4.5°，SD 3.0，P = 0.47）无显著差异。术后JLOA的平均值与地面平行（JLOA；0.2°，SD 3.6）。
当胫骨假体沿自然关节坡度定位以恢复冠状面整体下肢疾病前的对线时，胫骨假体与地面平行。当为内侧骨关节炎患者进行UKA时，外科医生应将胫骨假体相对于胫骨机械轴内翻4至5度以保持关节线平行。
