• One of a group of sclerosing bone disorders• Rare• Cause is unknown• Produces thickening of the endosteum and periosteum• Peak age of presentation is 5-20 years• May be monostotic, monomelic or polyostotic• Twice as common in lower extremities than elsewhereAssociations• sclerodermic skin changes : thickening & fibrosis ofoverlying skin• vascular tumours and malformations• muscle atrophy
Clinical Findings• About 50% affected develop symptoms by age 20• Adults present with• Pain• Joint stiffness• Deformity that may progress over time• Children may present with• Leg length discrepancies• Joint contractures
Radiologic features• Patterns described include:1. Resembling osteoma(s)2. Candle-wax appearance (classic)3. Resembling myositis ossificans4. Resembling osteopathia striata5. MixedThe classic appearance is one of thick undulating ridges ofbone, reminiscent of molten wax. The abnormality appearsconfined to sclertomes, and can be seen apparently flowingacross joints to the next bone.• Usually low signal on MRI Enhance with Gadolinium• Bone scan is markedly positive
• Differential Diagnosis• Osteopathia striata• Longitudinal dense striations• Osteopoikilosis• Punctate, rounded bone islands surrounding joints• Osteosarcoma• Bone destructionNot infrequently features of melorheostosis, osteopathiastriata and osteopoikilosis may co-exist in so-called overlapsyndromes.