The morphology of medial malleolus and its clinical relevance.
OBJECTIVE
To provide morphological data of medial malleolus to decrease the possibility of posterior tibial tendon injury and inadvertent ankle penetration.


METHODS
Computed tomography scans of the ankle in 215 patients were reviewed. Then parameters in the 3-D reconstruction images were measured by three independent, qualified observers on two separate occasions.


RESULTS
The average angle between tibia plafond and the articular facet of the medial malleolus was 55.88±4.11°. The distance from the most anterior point of the anterior colliculus to the center of the intercollicular groove was 11.68±1.13 mm. And the average angle between the bimalleolar axis and the articular facet of the medial malleolus was 76.61±2.04°. Significant differences were observed in the distance from the most anterior point of the anterior colliculus to the center of the intercollicular groove between males and females. (P<0.05) All of the parameters exhibited moderate to excellent intra-class correlation coefficient (ICC).


CONCLUSIONS
According to this study, the insertion angle is much smaller than previously believed, and adequate space only exists for two 4.0-mm screws in some large cases. The second screw will probably be near the posterior tibial tendon, especially in some small cases.
Kun Zhang, MS, Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, 150 Jimo Rd, 200120 Shanghai, China.
Kun
K
Zhang
Yanxi Chen, MD, PhD, Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, 150 Jimo Rd, 200120 Shanghai, China.
Yanxi
Y
Chen
Minfei Qiang, MS, Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, 150 Jimo Rd, 200120 Shanghai, China.
Minfei
M
Qiang
Yini Hao, MS, Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, 150 Jimo Rd, 200120 Shanghai, China.
Yini
Y
Hao
Haobo Li, MS, Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, 150 Jimo Rd, 200120 Shanghai, China.
Haobo
H
Li
Hao Dai, MS, Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, 150 Jimo Rd, 200120 Shanghai, China.
Hao
H
Dai
Imaging; Medial malleolus; Tibia; Tomography; X-ray computed; three-dimensional