[Ankylosing spondylitis with juvenile onset. Study of 62 cases]

The study of 338 files of patients hospitalized for ankylosing spondylarthritis between 1977 and 1985, has enabled to select 52 cases (15 p. cent) of juvenile forms (onset before the age of 16). An additional 10 cases followed in pediatric clinic are included. The male predominance is definite (88.7 p. cent); the onset is late (mean age: 11.6 +/- 3.2 years) and, most of the time, at the level of a peripheral joint (79 p. cent). The evolution, studied with a mean follow-up of 11.2 +/- 4.8 years, is usually manifested by bouts of peripheral and/or axial arthritis (82.2 p. cent). Joint involvement predominates in the lower extremities: knees (23 cases) and feet (21 cases). The late appearance of spinal and/or sacro-iliac joint involvement explains the late diagnosis (5.6 +/- 4.8 years). Visceral involvement is less frequent (12 cases of eye involvement). The functional prognosis is dominated by a severe involvement of the coxo-femoral joints (46.6 p. cent). Heel pain with posterior and/or inferior talus erosions (15 cases) are, because of their frequency, interesting for making the diagnosis. The total functional prognosis is relatively good: Steinbrocker stage 0-1 for 26 patients (44 p. cent). A bilateral arthroplasty was performed in 9 patients with an excellent result in 7 cases.