Malleolar tips as reference points for positioning of syndesmotic screw: A preliminary CT based analysis.

PURPOSE

The risk of malpositioning of the syndesmotic screws is very high. A lack of standard radiological or physical references for accurate syndesmotic screw placement is a potential contributing factor in syndesmotic screw malpositioning. Malleolar tips are clinically as well as radiologically appreciable bony references. The purpose of this preliminary CT based study was to investigate the axial relations of the central syndesmotic axis with the malleolar tips.

METHODS

CT based studies of uninjured adult ankle joints with intact syndesmosis, conducted over a six months period were analysed. The axial differences between the coronal plane along the malleolar tips and that along the central syndesmotic axis in the axial plane were measured. Gender-based variations were also analyzed.

RESULTS

A total of 70 CT studies were analyzed, and the axial difference between the malleolar tips based coronal plane and that along the central syndesmotic axis was observed to be 3.70 ± 5.61°. The male and female measurements were comparable.

CONCLUSION

Being in a static relation to the syndesmosis independent of the foot position and the limb rotation, the malleolar tips can be reliably used as references for directing syndesmotic screw in the axial plane. A knowledge of this axial difference between malleolar tips and central syndesmotic axis can help surgeons in an accurate syndesmotic screw placement.