Jordan C, Mirzabeigi E, Williams S
Rancho Los Amigos Medical Center, Downey, California, USA.
J Orthop Trauma. 1999 Jan;13(1):47-50. doi: 10.1097/00005131-199901000-00011.
This study was designed to determine the angle off the perpendicular to the lateral calcaneal wall at which a screw would need to be angled to avoid entering the subtalar joint medially. It also determined the distance inferior to the articular surface at which a screw would need to be placed to avoid that penetration if the screw was placed perpendicular to the lateral calcaneal wall.
Eight specimens were dissected and the calcaneus was removed. The measurements were taken from portions of the subtalar joint.
To avoid medial penetration, a screw at the anterior portion of the posterior facet would need to be angled 5 degrees plantar medially or placed 1.5 millimeters below the edge of the articular surface. In the midportion, placements are 20 degrees or 10 millimeters; posteriorly, placements are 32 degrees or 15 millimeters.
This study shows that using a lateral approach, it is possible to position internal fixation screws without disrupting the articular surfaces of the medial subtalar joint.
本研究旨在确定与跟骨外侧壁垂线所成的角度，即螺钉需倾斜的角度，以避免螺钉向内进入距下关节。同时，还确定了如果螺钉垂直于跟骨外侧壁放置，为避免穿透关节面，螺钉需放置在关节面下方的距离。
解剖8个标本并取出跟骨。测量取自距下关节部分。
为避免向内穿透，后关节面后部的螺钉需向足底内侧倾斜5度，或放置在关节面边缘下方1.5毫米处。在中部，放置角度为20度或距离为10毫米；在后部，放置角度为32度或距离为15毫米。
本研究表明，采用外侧入路，可以在不破坏内侧距下关节关节面的情况下定位内固定螺钉。
