Myositis ossificans

• Myositis ossificans:

  • Calcification occurring in the soft tissues, usually after a haematoma/contusion injury
• Myositis ossificans - Proposed mechanism:

  • Poorly understood
  • Injury causes inflammatory cascade
  • Inflammatory cascade differentiates fibroblasts to extra-skeletal osteoblasts = extra-skeletal bone
• Myositis ossificans - Population:

  • Normally occurs in athletes aged 20 - 30
  • Frequent occurrence in lower extremities: adductors and quadriceps
  • 25% of cases is of unknown aetiology with no relevant history
• Myositis ossificans - Symptoms

  • Pain, swelling and joint stiffness of affected limb
  • Pain normally resides longer than anticipated for sporting injury
  • Bone calcifies over 2 - 3 months. Difficult to specify on imaging (XRAY, MRI, US)