Osteitis Deformans
- D: Second most common metabolic bone disease (first is osteoporosis) characterised by excessive / disorganised bone formation and resorption
- I/A: Increasing incidence with age - 3-4% over 40 years, 10% 85+
- S: More common in men than women
- G: More common in the west, less common in east asian countries
- A: Unknown but though to be persistent infection in bone from a virus (Measles, mumps, RSV)
- P: Alternating phases of rapid bone resorption/formation
- M: Long bones have thicked shafts/deformities, cysts and stress fractures seen. May be areas of localised softening - "osteoporosis circumscripta".
- M: (1) Osteolytic phase - clasts produce excavations which are filled with vascular fibrous tissue (2) Mixed lytic-sclerotic phase - blasts lay down woven bone which is subsequently resorbed by osteoclasts (3) Quiescent osteosclerotic stage - clasts less active, eroded areas filled with brittle woven bone
- P
Clinical features
- Usually asymptomatic
- Bone: 15% monostotic, 85% polyostotic
- Long bones - become bowed/deformed
- Cranium - compression of cranial nerves as pass through foramina (8th - leading to deafness), compression of nerve roots (causing pain)
- Pathological fractures
- Osteosarcoma (1%)
- Cardiac
- High output cardiac failure - most common in polyostotic disease (increased bone blood flow)
Investigations
- Radiology
- Increased ALP (reflects osteoblastic activity)
- Plasma calcium normal/raised
Treatment
- Control pain
- Suppress bone turnover - bisphosphonates, serum ALP for measuring disease progression
- Surgery - pathological fractures, joint replacement, nerve/cord decompression
