Purpose: To compare magnetic resonance imaging (MRI) and X-ray tomography in assessing the type of fracture, degree of comminution and amount of articular surface depression in acute tibial condylar fractures and to describe the associated soft tissue injuries diagnosed with MRI.
Method: 27 patients with acute tibial plateau fractures were investigated using linear X-ray tomography and MRI employing T1-weighted and proton density turbo spin echo, STIR, and T2-weighted gradient echo images. Fractures were classified according to the AO classification system. The degrees of depression and comminution were measured and soft tissue injuries were recorded.
Results: Fractures were classified as type B1 in 7, as B2 in 6, and as B3 in 6 cases by MRI. More complex C-type fractures were diagnosed in 8 cases. MR and X-ray grading were consistent with the exception of two B3 fractures, which were graded as B1 by X-ray tomography. X-ray tomography under-estimated the degree of comminution 63% of the patients had either meniscal tears or complete ruptures of their cruciate or collateral ligaments. Ten meniscal tears were diagnosed in 9 of 27 patients. Complete tears of the anterior cruciate ligament were seen in 4, and avulsions of the posterior cruciate ligament in 2 patients.
Conclusion: MRI allows a detailed assessment of acute tibial plateau fractures and can replace conventional X-ray tomography. The high rate of fracture-associated soft tissue lesions makes MRI an especially valuable tool.