Ligaments of the tarsal sinus: improved detection, characterisation and significance in the paediatric ankle with 3-D proton density MR imaging.

Background: No study in the paediatric literature--and only a single study in all of the literature--has evaluated the visualization frequency of the sinus tarsi ligaments on MRI. That 20-year-old study demonstrated only limited visualisation.

Objective: The objective of this study is to re-evaluate the visualisation frequency of the sinus tarsi ligaments and to characterise their morphology on isotropic three-dimensional proton density imaging (3-D-PD). The authors hypothesise that by using 3-D-PD, these ligaments will be able to be demonstrated in nearly all paediatric patients.

Materials And Methods: Patients were scanned on either 1.5- or 3-Tesla scanners using 3-D-PD. Of 174 patients reviewed, 50 were identified who met inclusion and exclusion criteria.

Results: The interosseous talocalcaneal ligament (ITC), the cervical ligament (CL) and the roots of the inferior extensor retinaculum (IER) were successfully visualised and characterised in three planes in 50 out of 50 children. The mean ligament thickness was 4.22 mm for the ITC, 2.74 mm for the CL and 1.04 mm for the IER roots.

Conclusion: With modern parameters, the tarsal sinus ligaments can be visualised in 100% of patients, a percentage substantially higher than previously reported.