Fibrogenesis imperfecta ossium

Fibrogenesis imperfecta ossium is a rare disorder of bone that was first described by Baker and Turnbull (1950). It is characterised by the formation of abnormal collagen fibres in osteoid which are not birefringent when examined under polarising light. The osteoid does not calcify normally, resulting in soft brittle bones. Clinically the patients suffer pathological fractures and increasing bone pain.

Nine cases of fibrogenesis imperfecta ossium have been reported previously, and we report a tenth case in this paper. The radiological appearances of these ten cases are reviewed, and the diagnostic skeletal changes are discussed. The clinical histories, and the characteristic features that suggest a diagnosis of fibrogenesis imperfecta ossium, are also reviewed.

A 71-year-old woman presented in 1980 with aching of the shoulders and thighs which had been slowly worsening over the previous ten years. She described the pain as severe, particularly on movement and weight bearing. It was associated with stiffness which did not improve during the day, and which prevented her from rolling over in bed.

On examination she moved stiffly and was diffusely tender, particularly over the limb girdles. Passive movement of her joints was pain-free. The following investigations were abnormal; erythrocyte sedimentation rate 55 mm in the first hour; serum alkaline phosphatase (bone isoenzyme) 256 IU/1 (normal 20–110 IU/1); IgG kappa light chain monoclonal gammopathy of 12.2 g/1 in the serum, with a trace in the urine.