[Staging of hemophilic osteoarthropathy using the Pettersson score. A study of 40 children and adolescents].

The degree of haemophilic osteoarthropathy was assessed by the Pettersson-score in 219 knees, elbows and ankles of 40 children and adolescents suffering from haemophilia. 55.3% of the joints were unaffected and only 8 joints showed score values greater than 8. Enlargement of epiphyses (36.1%) and irregular subchondral surface (32.9%) were the most frequent observations, while osteoporosis (5.4%) was only rarely observed. Haemophilic osteoarthropathy was most severe in the ankles, while the knees were only moderately affected. Among 11 patients 493 bleedings into 61 joints were observed during a four-year period. If the bleedings recurred, more than 3 bleedings per year always resulted in haemophilic osteoarthropathy.