[Comparison of the prognostic value of the Catterall and Herring classification in patients with Perthes disease].

QUESTION: Investigation of the predictive value of the Catterall- as compared to the Herring-classification in patients with Perthes disease.

METHOD: A radiological follow-up study including 53 patients with a total of 59 affected hips was carried out. In the initial diagnosis the Catterall-, Waldenström- and Herring-stages were assessed. The epiphyseal ratio, the head-neck ratio and the lateral subluxation were measured and compared at the time of diagnosis, fragmentation stage and in a follow-up examination, which was carried out 4, 9 years after diagnosis on the average. The results of the follow-up examination were assessed using the Mose-classification and compared as well. In addition the two classifications were compared as to the necessity of an upgrading.

RESULTS

Both classifications yielded similar descriptions of the radiomorphometric course. There was a good correlation between the results of Herring A and Catterall I, Herring B and Catterall II and III and Herring C and Catterall IV. Upgradings were necessary in the Herring- and the Catterall-classification in 21 cases, and 18 cases, respectively.

CONCLUSION

The predictive values of both classifications are comparable.