Correlation between trochlear dysplasia and anterior cruciate ligament injury.

PURPOSE. To evaluate the correlation between trochlear dysplasia and anterior cruciate ligament (ACL) injury METHODS. Magnetic resonance images (MRIs) of 95 knees in 54 males and 36 females aged 4 to 74 (mean, 28) years who had anterior knee pain and suspected ligamentous injury were reviewed. The MRIs were independently reviewed by 2 musculoskeletal radiologists on 2 occasions. According to the Dejour classification, trochlear dysplasia was classified into types A, B, C, and D. Intra-articular injuries/ disorders of the patients included patellofemoral osteoarthritis, chondromalacia patella, meniscal tears, and ligamentous injuries. Intra- and inter-observer variability was calculated. RESULTS. 58 of the knees had trochlear dysplasia, 38 of which were Dejour type A. The intra- and inter-observer variability was good to excellent (Kappa=0.76-1). ACL tear was the most common injury (n=13). No ACL injury occurred in patients without trochlear dysplasia. The odds of having sustained an ACL injury were 8.8 fold greater in Dejour type-A knees than in non-type-A knees (p=0.023). CONCLUSION. Dejour type-A trochlear dysplasia was associated with ACL injuries.