Passive Posterior Tibial Subluxation on Routine Knee MRI as a Secondary Sign of PCL Tear

Figure 1

Measurement technique for tibial translation on knee MRI. Magnetic resonance images of the knee in a patient with isolated PCL tear were obtained using sagittal proton density weighted pulse sequence (TR = 3000; TE = 12.168; 1 NEX; 256 × 192 matrix; ETL = 8; 3.00 mm slice thickness). (a) Midmedial compartment measurement of tibial translation demonstrates posterior (+) tibial translation of 7.8 mm in the presence of a PCL tear. (b) Magnified view of measurement of midmedial compartment. (c) Midlateral compartment measurement of tibial translation demonstrates posterior (+) translation of 5.3 mm.

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