radiotherapy

Mirels Prediction system for Pathological Fracture

Clin Orthop 1989 

- 38 patients treated with DXRT without surgery 

- most breast cancer

- developed scoring system

- predicts post DXRT fracture risk in preDXRT long bones

- risk of fracture within 6 months 

- irradiated without fixation

Four risk factors

Definition

Extraskeletal bone formation in periarticular tissues 

- HA crystals within osteoid matrix

Different to calcification 

- osteoid matrix laid down

Types

1.  Myositis Ossificans

- post traumatic

Epidemiology

80% cancer patients have spinal metastasis at autopsy 

Spine is number one site for bony metastasis (50%)

Cause

Hexagon: PBBLTK

                 Prostate    Breast