(Research Hub Theater) A Comparative Study of Weight-bearing CT Arthrography with Conventional MRI to Determine Meniscal Morphology

Background and/or Objectives: To evaluate the rate of detection of meniscal lesions on weight-bearing CT arthrography (WBCTa) in comparison with non-weight bearing magnetic resonance imaging (MRI), the current standard of care.

Design: WBCTa images were acquired within a mean of 6 days following MRI collection for 29 participants (age ≥18), who on history and physical exam had suspected meniscal pathology. Musculoskeletal radiologists, each with greater than 20 years of experience reading knee MRI and CT, used the MRI Osteoarthritis Knee Score (MOAKS) scoring system on both MRI and WBCTa to semi-quantitatively assess meniscal morphology. In accordance with MOAKS, meniscal damage was classified by the absence or presence of meniscal tears, extrusion (≥2 mm), hypertrophy, and cysts.

Setting : Cross-sectional, observational study of adults in Kansas City, Kansas

Participants : 29 participants with suspected meniscal pathology who underwent clinical knee MRI. Subjects had mean±SD age (45±13 years), BMI (28.97±6.49 kg/m2), and 20/29 were women.

Interventions: Not applicable

Main Outcome Measures: Presence or absence of meniscal lesions

Results: WBCTa identified meniscal tears in the body and posterior horn of the medial meniscus for 39% and 32% of the knees respectively that appeared normal or had only non-specific signal abnormality visualized on MRI (p=0.009 and p=0.011). In 52% of knees that were scored as normal on MRI (p=0.018), WBCTa detected medial meniscal extrusion. In only one knee did MRI identify a meniscal tear not seen on WBCTa. Differences in scoring for meniscal root tears, lateral meniscal tears and extrusion, hypertrophy, and cysts were non-significant between WBCTa and MRI.

Conclusions: WBCTa detects a higher rate of meniscal tears in the body and posterior horn of the medial meniscus, as well as medial meniscal extrusion, compared with non-weight bearing MRI. Detection of meniscal root tears, lateral meniscal tears and extrusion, hypertrophy, and cysts was similar between WBCTa and MRI.