Fibrodysplasia ossificans progressiva. The clinical features and natural history of 34 patients

TLDR

Fibrodysplasia ossificans progressiva is a rare disorder characterized by skeletal malformations and progressive ectopic bone formation. In 34 patients, diagnosis was frequently delayed, yet all exhibited classic malformations and ectopic ossification, and disability progressed erratically, with severe shoulder and spine restriction by age 10, hip involvement by 20, and most wheelchair‑bound by 30, while trauma, biopsies, surgeries, injections, venepuncture, and dental work exacerbated progression and no medical therapy altered the course, highlighting the importance of avoiding these triggers.

Abstract

Thirty-four patients wtih fibrodysplasia (syn., myositis) ossificans progressiva are described. Marked delay in diagnosis was usual, but all had characteristic skeletal malformations and ectopic ossification. The clinical features included: four types of malformation of the big toe, reduction defects of all digits, deafness, baldness of the scalp, and mental retardation. Progression of disability was erratic in all, but severe restriction of movement of the shoulder and spine was usual by the age of 10 years; the hips were usually involved by the age of 20 years; and most patients were confined to a chair by the age of 30 years. Exacerbating factors included trauma to the muscles, biopsy of the lumps, operations to excise ectopic bone, intramuscular injections, careless venepuncture and dental therapy. Progression of disability did not appear to be influenced by any form of medical treatment and therefore management of the patients must concentrate on the avoidance of exacerbating factors.