Comparison of CT and MRI in patients with tibial plateau fracture: can CT findings predict ligament tear or meniscal injury?

OBJECTIVE: (1) To determine the accuracy of computed tomography (CT) in the evaluation of ligament tear and avulsion in patients with tibial plateau fracture. (2) To evaluate whether the presence or severity of fracture gap and articular depression can predict meniscal injury. DESIGN AND PATIENTS: A fellowship-trained musculoskeletal radiologist retrospectively reviewed knee CT and MRI examinations of 41 consecutive patients presenting to a level 1 trauma center with tibial plateau fractures. Fracture gap, articular depression, ligament tear and footprint avulsions were assessed on CT examinations. The MRI studies were examined for osseous and soft tissue injuries, including meniscal tear, meniscal displacement, ligament tear, and ligament avulsion. RESULTS: CT demonstrated torn ligaments with 80% sensitivity and 98% specificity. Only 2% of ligaments deemed intact on careful CT evaluation had partial or complete tears on MRI. Although the degree of fracture gap and articular depression was significantly greater in patients with meniscal injury compared with those without meniscal injury, ROC analysis demonstrated no clear threshold for gap or depression that yielded a combination of high sensitivity and specificity. CONCLUSIONS: In the acute setting, CT offers high sensitivity and specificity for depicting osseous avulsions, as well as high negative predictive value for excluding ligament injury. However, MRI remains necessary for the preoperative detection of meniscal injury.

Marginal fractures of the medial tibial plateau: possible association with medial meniscal root tear.

We report two cases of marginal fractures of the medial tibial plateau associated with medial meniscal root tears. Both patients sustained knee dislocations, with complete tears of the posterior horn medial meniscal root. One sustained a "reverse Segond fracture"; the other sustained an "anteromedial impingement fracture" of the tibial plateau. The meniscal root tears were arthroscopically confirmed and repaired. In the first patient, the integrity of the meniscal root repair was confirmed at a 6-month follow-up arthroscopy for lysis of adhesions. In the second patient, follow-up MRI at 10 months demonstrated a healed meniscal root. The association of medial meniscal root tear with marginal fractures of the medial tibial plateau has not been previously reported.