Justin Charles Lee MBBS, Presenter: Nothing to Disclose

Kelly Wimpey, Abstract Co-Author: Nothing to Disclose

Jeremiah Healy MBBCH, Abstract Co-Author: Nothing to Disclose

The posterolateral corner of the knee consists of a complex of several static and dynamic stabilisers, of which the popliteus and biceps femoris tendons, and the lateral collateral (LCL) and popliteofibular ligament (PFL) are felt to be the most important. Injuries to the posterolateral corner are usually associated with ACL injury, and can result in instability and ACL graft failure. We aim to evaluate these structures using isotropic 3D WE DESS MRI compared with 2D coronal oblique STIR MRI.

A prospective analysis of patients referred for MRI of the knee following trauma is being performed. MRI findings are correlated with clinical evaluation, MUA, arthroscopy, and open surgery when performed. Subjects are imaged on 1.5T MRI using isotropic WE DESS volume acquisition through the whole knee and coronal oblique STIR sequence through the posterolateral corner. All images are assessed on the MRI viewer independently by two musculoskeletal radiologists. The presence of the popliteus and biceps femoris tendons, LCL and PFL are documented. 10 volunteers with no history of knee trauma have been imaged to evaluate these structures in normal individuals. The clinical group has been sub-divided into those with, and those without ACL injury. We have imaged 40 patients so far and aim to have imaged 100 within two months. Of these 40 patients, 11 have an ACL injury.

The popliteus and biceps femoris tendons, and the LCL are seen in 100% of cases on both sequences. In the normal group, the PFL is seen in 5/10 and 9/10 of the STIR and WE DESS sequences respectively. In those patients without an ACL injury, the PFL is seen in 10/29 and 23/29 of the STIR and WE DESS sequences respectively. Of the 11 patients who have an ACL injury, the PFL is seen in 4/11 and 8/11 of the STIR and WE DESS sequences respectively. One of the ACL injury group was later shown to have an injury of the PFL at surgery.

The WE DESS sequence appears to significantly enhance the ability to identify the PFL over conventional STIR coronal oblique images through the posterolateral corner.

Lee, J, Wimpey, K, Healy, J, MR Imaging of the Popliteofibular Ligament: Comparison of 3D Isotropic WE DESS versus Coronal Oblique STIR Sequences.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4411282.html