Congenital pseudarthrosis of the tibia: History, etiology, classification,and epidemiologic data

Congenital pseudarthrosis of the tibia is a rare disease with a variable hi story. The pseudarthrosis is usually not present at birth (and therefore is not truly congenital) but occurs during the first decade of life. Paget in 1891 was the first to describe a case. The etiology is unknown. Neurofibro matosis plays a role;in approximately 50% of patients. In the others, hered itary and mechanical factors are debated. Various (morphologic) classificat ion systems have been proposed (Andersen, Boyd; Crawford). Because the appe arance changes during the course of the disease, all classification systems have limited value: the determining factor is the stage of the disease at which it was classified. Because of the rarity of the disease and the varia bility of its history, the European Pediatric Orthopaedic Society decided t o carry out a multicenter study on this disease. This paper presents the ep idemiologic data on the patients involved. Data have been gathered on 340 p atients from 13 countries. Two hundred patients were male (58.8%), 140 were female: (41.2%). The right side was affected in 165 patients (48.5%) and t he left side in 172 (50.6%); 3 patients had bilateral disease. Symptoms of neurofibromatosis were present in 54.7%. Histologic examinations in 192 pat ients showed a nonspecific appearance in 45.3%; in 15.6% the ultrastructure resembled fibrous dysplasia, and in 39% there was histologic evidence of n eurofibromatosis. Most of the lesions were initially localized in the middl e or distal third of the tibia. In 29% the localization changed during the course of the disease.