The evaluation of the association between patella types and chondromalacia patella by magnetic resonance imaging

Abstract

302 non-traumatic patients, who had an MRI scan of the knee with the suspicion of any diagnosis were evaluated in terms of patella types and their relationship to chondromalacia patella. Outerbridge MRI grading system was used in the evaluation of patellar chondromalacia. Type II patella is the most common type. The distribution of patella type was not statistically significantly different between the two genders ( p > 0.05). Patella types have no specific distribution. Chondromalacia in varying degrees was seen in 14 patients among 41 with Type I patella (34%), while this rate was 81 out of 207 (39%) in patients with Type II patella, and 34 out of 53 (64%) in patients with Type III patella. One patient with Type IV patella did not have chondromalacia patella. When all patellar types were included, the rate of chondromalacia in females and males was 50% and 34%, respectively. Chondromalacia was 42.7% in our study. Grade I chondromalacia was observed in 22 knees (12%), Grade II chondromalacia was seen in 32 knees (23%), Grade III chondromalacia was seen in 28 knees (21%), and Grade IV chondromalacia was seen in 49 knees (37%). The frequency of high grade (Grade III and Grade IV) chondromalacia was seen in 59% of cases, while this rate was reported up to 41% in other studies. In our study, the association between Type III patella and chondromalacia was found to be statistically significant.