Comparison of the predictive value of Catterall- and Herring-classification in patients with Perthes-disease

Question: Investigation of the predictive value of the Catterall- as compar ed to the Herring-classification in patients with Perthes disease. Method: A radiological follow-up study including 53 patients with a total o f 59 affected hips was carried out. In the initial diagnosis the Catterall- , Waldenstrom- and Herring-stages were assessed. The epiphyseal ratio, the head-neck ratio and the lateral subluxation were measured and compared at t he time of diagnosis, fragmentation stage and in a follow-up examination, w hich was carried out 4, 9 years after diagnosis on the average. The results of the follow-up examination were assessed using the Mose-classification a nd compared as well. In addition the two classifications were compared as t o the necessity of an upgrading Results: Both classifications yielded similar descriptions of the radiomorp hometric course. There was a good correlation between the results of Herrin g A and Catterall I, Herring B and Catterall II and III and Herring C and C atterall IV. Upgradings were necessary in the Herring- and the Catterall-cl assification in 21 cases, and 18 cases, respectively. Conclusion: The predictive values of both classifications are comparable.