3-Tesla MRI: Beneficial visualization of the meniscofemoral ligaments?

Recent investigations have confirmed an important stabilizing and protective function of the meniscofemoral ligaments (MFLs) to the knee joint and suggest a clinical relevance. Concerning their incidences, however, there have been discrepancies between data acquired from cadaveric studies and MRI data using 0.3- to 1.5-Tesla field strengths probably due to lower resolution. This study aims to investigate whether imaging with 3-Tesla magnetic resonance imaging (3-T MRI) is beneficial in gaining information regarding the ligaments' incidence, length, width and anatomic variation.

3-T MRI images of 448 patients (224 males, 224 females, with, respectively, 32 patients of each sex in the age groups: 0-20, 21-30, 31-40, 41-50, 51-60, 61-70, >70years) were retrospectively reviewed. The influence of the parameters 'sex' and 'age' was determined.

Whereas 71% of the patients had at least one MFL, 22% had an anterior MFL (aMFL), 53% had a posterior MFL (pMFL) and five percent had coexisting ligaments. The pMFLs were more likely to be present in female patients (P<0.05) but if so, they were longer in the males (P<0.05). The pMFL was categorized according to its insertion on the medial femoral condyle.

3-T MRI enables an excellent illustration of the anatomic variations of pMFLs. By modifying an anatomic classification for radiological use we measured lengths and widths of the MFLs without any difficulties. Despite its increased resolution, 3-T MRI lends no diagnostic benefit in visualizing the course of the aMFL or filigree coexisting ligaments as compared to MRI at lower field strengths.