Required screw length measurement in distal tibia based on three-dimensional simulated screw insertion

Kun Zhang, Yanxi Chen, Minfei Qiang

COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(4) 138-144

Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, 150 Jimo Rd, Shanghai 200120, China

The objective of the study was to provide morphological data of the distal tibia to offer guidance on the required screw length. Computed tomography scans of the ankle in 225 patients were reviewed. Then parameters in the three-dimensional reconstruction images were measured by three independent, qualified observers on 2 separate occasions. The anteroposterior length increases from medial to lateral margin at the level of the base of the tibiofibular syndesmosis. On both proximal and distal planes of tibiofibular syndesmosis, the medial-lateral width increases from posterior to anterior margin. Significant differences were observed in all parameters between male and female and in the minimum width at the level of the roof of the syndesmosis between left and right limbs (P<0.05). All of the parameters exhibited moderate to excellent intra-class correlation coefficient. The anteroposterior screws would probably penetrate the far cortex and injure the structures surrounding the distal tibia if longer than 35.35 mm and 32.53 mm in male and female. The screws should not longer than the maximum diagonals which are 51.29 mm and 46.58 mm on distal plane and 43.64 mm and 38.24 mm on proximal plane in male and female respectively, or inadvertent distal tibiofibular syndesmosis penetration may occur.