Study on sustentaculum tali screw placement for constant fragment of calcaneal fracture

目的: 探讨跟骨载距突（sustentaculum tali，ST）解剖特点及跟骨后距下关节面 ST 螺钉固定恒定骨折块（constant fragment，CF）的安全入口位置和植入方向。. 方法: 从 2016 年 1 月—4 月收治并行足踝 CT 扫描的 100 例跟骨骨折患者中，纳入 33 例符合选择标准的患者资料。男 18 例，女 15 例；年龄 18～60 岁，中位年龄 41.0 岁。骨折侧别：左侧 16 例，右侧 17 例。将 CT 扫描原始数据导入 Mimics 17.0 软件，建立跟骨三维模型；测量 ST 上缘长度、下缘长度、中线长度及高度、ST 中线与足底水平面成角，ST 螺钉入口（P’点）位置、植入角度相关参数以及 ST 螺钉长度。比较不同性别及侧别间各测量参数的差异。. Results: The length of upper edge of the ST was (16.60±2.23) mm, lower edge (20.65±2.90) mm, midline (20.56±2.62) mm, and the height of midline was (9.61±1.36) mm. The horizontal angle between the midline and foot plantar surface was (23.43±3.36)°. The vertical distance from P' point to the lowest point of the tarsal sinus was (3.09±1.65) mm, while the horizontal distance was (14.29±2.75) mm. The distance from P' point to the apex of the lateral talus, subchondral bone of subtalar joint, calcaneocuboid joint was (11.41±3.22), (6.59±2.22), (34.58±3.75) mm, respectively. The horizontal angle between the ST screw and foot plantar surface was (-1.17±2.07)°. The anteversion angle of ST screw was (16.18±2.05)° and the length was (41.64 ± 3.09) mm. There were significant differences in the length of upper and lower edge, the length and height of the midline, the distance from P' point to the apex of the lateral talus, subchondral bone of subtalar joint, and calcaneocuboid joint, and the anteversion angle and length of the ST screw between males and females ( P 0.05). 结论: 跟骨骨折复位后采用经跗骨窦最低点平行足底后方约 14 mm、上方约 3 mm 确定入口，男性前倾约 17°、女性前倾约 15° 植入 ST 螺钉。.