Dept. of Orthopaedic Surgery, Kantonsspital Liestal, Rheinstrasse 26, 4410 Liestal, Switzerland.
Foot Ankle Int. 2011 Mar;32(3):288-93. doi: 10.3113/FAI.2011.0288.
The aim of this study was to describe the difference between the medial distal tibial angle (MDTA) when measured on whole lower limb radiographs and mortise radiographs of the ankle.
A total of 48 legs were included of 24 healthy volunteers. Standard radiographs were obtained of the whole lower leg. Mortise radiographs were obtained of the ankle. The MDTA was measured on the digitized radiographs by three orthopaedic residents, one orthopaedic surgeon and one biomechanical movement scientist. For each leg, the angles measured from the two images were compared. The inter-observer reliability of each method was calculated.
The MDTA as measured on whole lower leg images (94.6 ± 2.6 degrees) was significantly different compared with the angle measured on mortise ankle images (92.1 ± 2.2 degrees) (p < 0.01). The mean measurement difference between observers was less than 1 degree. Reliability of the measurements was good with a high association (κ = 0.85) between observers for the angles measured on the whole lower leg images and also a high association (κ = 0.83) between the observers for the mortise ankle image measurements.
The MDTA is not the same on whole lower leg images and mortise views of the ankle. There was an excellent interobserver reliability for the angles measured.
Foot and ankle surgeons should take this into account when planning coronal deformity correction of the distal tibia. We believe whole lower leg images should be used to assess the medial distal tibial angle.
本研究旨在描述在下肢全长片和踝关节正位片上测量的胫骨远端内翻角（MDTA）之间的差异。
共纳入 24 名健康志愿者的 48 条腿。对整个小腿进行标准 X 线检查。对踝关节进行正位 X 线检查。由三位骨科住院医师、一位骨科医生和一位生物力学运动科学家对数字化 X 线片上的 MDTA 进行测量。比较每条腿两种图像测量的角度。计算每种方法的观察者间可靠性。
在下肢全长片上测量的 MDTA（94.6±2.6 度）与在踝关节正位片上测量的角度（92.1±2.2 度）有显著差异（p<0.01）。观察者之间的平均测量差异小于 1 度。对全长片上测量的角度，观察者之间的可靠性较好，关联度较高（κ=0.85），对踝关节正位片上测量的角度，观察者之间的关联度也较高（κ=0.83）。
MDTA 在下肢全长片和踝关节正位片上并不相同。测量角度的观察者间可靠性很好。
足踝外科医生在计划胫骨远端冠状面畸形矫正时应考虑到这一点。我们认为应使用下肢全长片来评估胫骨远端内翻角。
