Lateral ankle ligaments: MR arthrography with anatomic correlation in cadavers

Objective

The purpose of our study was to use magnetic resonance (MR) imaging and MR arthrography to demonstrate the anatomy of the lateral ankle ligaments using standard and oblique imaging planes in cadavers.

Material and methods

MR imaging of ten cadaveric ankles was performed before and after intra-articular administration of contrast solution. Proton-density MR images were acquired in standard and oblique imaging planes. MR imaging was correlated with anatomic sections. Measurements using oblique imaging planes were obtained to characterize the morphology of the lateral ligaments.

Results

The anterior talofibular ligament (ATFL) had a variable number of bands in all specimens, separated by fat signal oriented obliquely parallel to the long axis of the ligament. The fibular attachment of ATFL was located in close proximity to the fibular attachment of the distal band of the anterior tibiofibular ligament (AITFL). The angle formed by the calcaneofibular ligament (CFL) and the fibular shaft varied with different ankle positions. Special axial oblique plane best demonstrated the CFL. The posterior talofibular ligament (PTFL) was multi-fasciculated in appearance. Dorsiflexion of the ankle joint helped elongate the PTFL and best depicted this ligament in its entirety in the axial plane.

Conclusion

Oblique imaging planes parallel to the long axis of the individual ligaments may improve visualization of the anatomy of the lateral ankle ligaments. The orientation of the lateral ankle ligaments is affected by the position of the talocrural and subtalar joints. Understanding the morphology of the lateral ankle ligaments can help radiologists diagnose abnormalities of these ligaments.