Relationship between the Articular Cartilage Thickness of the Patella and Trochlea in Trochlear Dysplasia Compared to Normal Knees

Abstract Introduction: Anterior knee pain is not an uncommon problem. A plethora of pathologies can cause anterior knee pain. Patellofemoral maltracking (trochlear dysplasia) is not an uncommon cause of anterior knee pain in adolescents and young adults. Aim: We hypothesize that there is an alteration of articular cartilage of the patella and trochlear in trochlear dysplasia. Materials and Methods: Magnetic resonance images of 86 knee joints were reviewed independently by two musculoskeletal radiologists. Standard magnetic resonance imaging (MRI) sequences were used in this study. Based on the Dejour classification for trochlear dysplasia, the patients were divided into normal, Type A, B, C, and D. The articular cartilage thickness of the patella and trochlea was measured and compared between the groups. Results: Out of the 86 MRI scans of the knees which were reviewed, 32 patients were male and 54 were female. The mean patient age was 21.9 years (range = 10–40). Sixty-six knee joints had trochlear dysplasia, with 15 patients classified into Dejour Type A, 13 in Type B, 31 in Type C, and 7 in Type D. There was no significant difference in the articular cartilage thickness of the lateral facet of the patella between all groups (ANOVA F = 1.43, P = 0.23). Conclusion: There was no significant difference in the articular cartilage thickness in the lateral facet of the patella and trochlea in patients with normal knee joints compared to those with trochlear dysplasia of Type A–D.