ARTHROSCOPIC APPEARANCES OF THE MENISCOFEMORAL LIGAMENTS CORRELATED WITH MAGNETIC RESONANCE IMAGING

Abstract

Purpose: To correlate arthroscopic appearances of the anterior and posterior meniscofemoral ligaments (aMFL and pMFL respectively) with their appearances on magnetic resonance imaging.

Methods: 50 patients underwent MRI scanning of their knees for a variety of suspected pathologies. The radiological presence or absence of the MFLs was assessed by examination of sequential coronal and sagittal T2 weighted MRI scans. Arthroscopic examination of the knees was subsequently performed, during which the MFLs were identified using several anatomical cues. These included their femoral and meniscal attachments, their obliquity relative to the PCL, and the meniscal “tug test”. Identification was classed as “easy” or “hard” by the operating surgeon.

Results: From 50 knees 44 (88%) aMFLs and 30 (60%) pMFLs were identified on MRI scanning, whilst 47 (94%) aMFLs and 5 (10%) pMFLs were identified arthroscopically. Identification of the presence or absence of the aMFL was classed as easy in 47 (94%), whilst the pMFL was easy to identify in only 5 (10%) of knees, of which 3 (6%) had a ruptured PCL. Using arthroscopy of the aMFL as the gold standard, the sensitivity and specificity of MRI in detecting the aMFL were 94% and 75% respectively. Equivalent values for the pMFL were not calculated due to the difficulty of identifying the pMFL arthroscopically. Thus, with the exception of PCL-deficient knees, it was felt that many pMFLs were missed due to difficulties in identification through anterior portals.

Conclusions: This is the first study correlating the MRI appearances of the MFLs with arthroscopic findings. MRI is relatively sensitive in identifying the aMFL, but its accuracy in identifying the pMFL remains undetermined. Accurate identification of the MFLs at MRI is of value when assessing the status of the PCL, as these ligaments may contribute to stabilising the PCL-deficient knee.