Meniscal ramp lesions: diagnostic performance of MRI with arthroscopy as reference standard.

Background: The posteromedial meniscal region is gaining interest among orthopedic surgeons, as lesions of this area has been reported to be significantly associated with anterior cruciate ligament tears. The current imaging literature is unclear.

Purpose: To evaluate the diagnostic performance of MR in the detection of meniscal ramp lesions having arthroscopy as reference standard.

Materials And Methods: We retrospectively included 56 patients (mean age of 25 ± 7 years; 14 females) from January to November 2017 with a arthroscopically proved ACL tear and posterior meniscocapsular separation. On preoperative MRI, two radiologists with 13 and 2 years' experience in musculoskeletal imaging assessed the presence/absence of ramp lesion, meniscotibial ligament lesion, peripheral meniscal lesion, or their combination, bone bruise. Having arthroscopy as reference standard, diagnostic performance of MRI in the evaluation of ramp area lesions was calculated. Cohen's kappa (k) and Fisher's Exact Test statistics were used.

Results: Agreement between radiologists ranged from κ = 0.784 (meniscotibial ligament lesions) to κ = 0.918 red-red meniscal lesion. Sensitivities were 97.4% for ramp lesions, 95.8% for meniscotibial ligament lesion, 94.4% for peripheral meniscal lesions; specificities were 88.9%, 81.3%, and 97.4%, respectively; accuracies were 94.6%, 87.5%, and 96.4%, respectively. Agreement between MR and arthroscopy was almost perfect in identification of ramp lesions (κ = 0.871) and red-red zone meniscal lesions (κ = 0.908). The agreement between the two methods was substantial (κ = 0.751) for meniscotibial lesion. No significant association between tibial plateau bone bruise and the different type of lesions was found (κ ≥ 0.004 and p ≥ 0.08).

Conclusion: MR has high diagnostic performance in meniscal ramp area lesion assessment, with substantial to almost perfect inter-reader agreement.