Appropriate Choice of Plate for the Posterior Malleolus: Computed Tomography Study of 122 Chinese Adult Patients

Abstract

Background Plating of the posterior malleolus (PM) is a common procedure for treatment of PM fracture but its osteology was seldom mentioned. In this study, we evaluated the anatomy of the PM in relation to the choice of plate. Method A total of 122 adult patients with normal distal tibia computed tomography films were recruited. The width available for PM plating, total width of the PM, the inclination angle of the groove for the posterior tibial tendon, and the proportions of the width available for plating with reference to the total width were obtained. Results Presence of the groove was found in 98.4% of the patients ( n = 120). The mean width available for plating was 20.4 mm for male patients and 18.4 mm for female patients ( p<0.05). The mean inclination angle was 36.9° for male and 28.9° for female patients ( p<0.05). The ratio comparing the width available for plating with the width of the PM at the level of syndesmosis was 0.49 for both sexes. Conclusion Our study demonstrated the importance of understanding the anatomy of the PM for safe and effective plating of PM fractures. It provided estimations for appropriate width of plate and the method to evaluate the correctness by comparing with the width of the tibia.