Abstract: Objective To screen the parameter of CT scan for distinguishing patellofemoral malalignment. Methods 22 patients (42 knees) with patellofemoral pain and 12 asymptomatic volunteers (24 knees) were studied. The patellofemoral joints were examined with CT scan at 0°, 15°, 30° and 60° flexion. The parameters including femoral trochlear angle, lateral patellofemoral angle, patellar tilt angle, congruent angle and patellofemoral index were compared. Results Congruent angle and patellofemoral index in symptomatic group were bigger than those in asymptomatic group (P<0.01), but others were not different significantly between two groups (P>0.05). Conclusion CT scans is useful in diagnosis of patellofemoral malalignment. Congruent angle and patellofemoral index are more susceptible parameters for it.

Key words: patellofemoral joint, alignment, anterior knee pain, computed tomography (CT), diagnosis