The axial view in evaluating tibial translation in cases of insufficiency of the posterior cruciate ligament.

The purpose of this report is to present a new radiological method of diagnosis and evaluation of posterior instability using the patellofemoral axial view. During a period of 22 months, we performed clinical and radiological assessments on 20 patients (6 acute and 14 chronic) with isolated posterior instability caused by posterior cruciate ligament (PCL) rupture and on 20 patients with normal knees. The radiological examination included stress radiographs using the Telos device (Telos, Griesheim, Germany) as well as a modification of the routine axial patellofemoral view. Both diagnosis and quantification of the posterior tibial translation was possible in all cases by measuring, on the axial view, the distance between the anterior edge of the tibial plateau and the center of the femoral groove (trochlea). Clinical examination, conventional radiography, KT-1000 arthrometry, stress radiography at 90 degrees and at 20 degrees of flexion, and magnetic resonance imaging all assist in diagnosing a PCL tear. This new radiographic technique is simple, fast, and consistently effective both in patients with acute and those with chronic PCL tears, as well as in those who have undergone PCL reconstruction.