CT scanning and arthroscopic evaluation of patellofemoral malalignment

Objective To determine the pattern of malalignment and the extent of chondral damage, the patellofemoral joint was evaluated by CT scanning and the findings were proved by arthroscopic examination. Methods In 20 cases, 40 knees were examined by CT scanning with and without quadriceps contraction in order to differentiate between static and dynamic abnormalities. The CT images were analyzed. The arthroscopic examination was carried out for 27 knees in 20 cases. Results Ten knees had static patellar lateral subluxation and 16 knees dynamic lateral subluxation. Eleven knees had static patellar lateral tilt, and 7 knees dynamic tilt. All of the 27 knees showed arthroscopic patellar maltracking and chondral damage. Conclusions The patellofemoral alignment, affection of quadriceps, and the extent of tight retinaculum may be precisely evaluated by CT measurement and proved by arthroscopic examination.