Magnetic resonance imaging of the multiple-ligament injured knee

To evaluate magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) in detecting soft tissue, neurovascular, and bony injury after multiple ligament knee injury, including knee dislocation.

A retrospective search was performed for patients presenting with reported knee dislocation from May 1993 through May 2000 who underwent both MRI and surgical reconstruction. Twenty-one patients met these criteria (15 men and six women; age range 14 to 75 years; mean 32.6 years). Magnetic resonance diagnoses of soft tissue and bony injury were compared with the patients' operative findings. MRA of the popliteal vessels was performed in seventeen of our twenty-one patients, and the results of these studies are described.

Multiple ligamentous, tendinous, meniscal, chondral, osseous, and neural injuries were seen. There was excellent correlation (kappa > 0.8) between the magnetic resonance and operative findings with regard to the size and location of tears. Regarding meniscal tears, the type (e.g., bucket, radial split, meniscocapsular separation) and location correlated well with surgery. All ten nerve injuries noted on magnetic resonance were confirmed at surgery. Six of our patients had both conventional angiograms and MRAs with 100 percent agreement between the studies. In one patient an intimal flap in the popliteal artery was seen on MRA and confirmed on conventional angiographic images.

MRI is an accurate method of assessing soft tissue, osseous, and neural damage after knee dislocation. Our early experience with popliteal fossa MRA is encouraging with complete agreement between the MRA and conventional angiography in patients who had both studies.