Tomite Takenori, Saito Hidetomo, Kijima Hiroaki, Saito Kimio, Tazawa Hiroshi, Ishikawa Noriyuki, Miyakoshi Naohisa, Shimada Yoichi
Department of Orthopedic Surgery, Akita Red Cross Hospital, Kamikitate Sarutaazanaeshirosawa 222-1, Akita City, Akita, 018-1495, Japan.
Akita Sports, Arthroscopy, and Knee Group (ASAKG), Hondou 1-1-1, Akita City, Akita, 010-8543, Japan.
J Orthop. 2018 Dec 6;16(1):25-30. doi: 10.1016/j.jor.2018.11.005. eCollection 2019 Jan-Feb.
Sagittal alignment of the tibia following total knee arthroplasty (TKA) can affect various factors, such as durability, range of motion, stability, and even kinematics. The aim of the present study was to investigate whether taking plain preoperative lateral leg X-ray images to plan the posterior tibial slope can give an insert placement with more accurate sagittal alignment.
A total of 100 patients who underwent total TKA with posterior-stabilized prostheses. were divided into a group of 50 cases in which the posterior tibial slope was determined intra-operatively with only the fibular axis as the landmark, and a group of 50 cases in which determination of the posterior tibial slope was planned preoperatively with reference to preoperative lateral leg images. For the posterior slope, tibial cutting was performed with the posterior slope built into the bone cutting guide of the insert as the target. The angle of the fibular axis and the posterior slope of the tibial insert were measured on the postoperative lateral leg X-ray image, and the difference from the target angle was examined in the two groups.
In the group in which only the fibular axis was used for reference, the mean deviation from the target was 3.96°, while in the group in which planning was carried out preoperatively using lateral leg X-ray images, the mean deviation was 1.59° (P < 0.05).
Drawing up a preoperative plan using lateral leg X-ray images gives a useful landmark at low cost for accurate determination of TKA posterior tibial slope.
全膝关节置换术（TKA）后胫骨矢状位对线可影响多种因素，如假体耐用性、活动范围、稳定性甚至运动学。本研究的目的是调查术前拍摄小腿侧位X线片以规划胫骨后倾坡度是否能使假体植入时矢状位对线更准确。
共有100例行后稳定型假体全膝关节置换术的患者。分为两组，一组50例，术中仅以腓骨轴线为标志确定胫骨后倾坡度；另一组50例，术前参考小腿侧位X线片规划胫骨后倾坡度的确定。对于后倾坡度，以植入物截骨导向器内置的后倾坡度为目标进行胫骨截骨。在术后小腿侧位X线片上测量腓骨轴线角度和胫骨植入物后倾坡度，并比较两组与目标角度的差异。
仅以腓骨轴线为参考的组，与目标值的平均偏差为3.96°，而术前使用小腿侧位X线片进行规划的组，平均偏差为1.59°（P<0.05）。
利用小腿侧位X线片制定术前计划，能以低成本提供有用的标志，用于准确确定TKA胫骨后倾坡度。
