Pathological fracture risk (Mirel classification)

Dr Henry Knipe et al.

Mirel classification is a system used to predict the highest risk of pathological fracture among long bones affected by metastases, and is based on site, location, matrix and/or presence of pain. 


  • 1 point
    • upper limb
    • involving <1/3 of bone diameter
    • blastic/sclerotic lesion
    • mild pain
  • 2 points
    • lower limb
    • involving 1/3-2/3 of bone diameter
    • mixed sclerotic/lytic lesion
    • moderate pain
  • 3 points
    • trochanteric region
    • involves >2/3 of bone diameter
    • lytic lesion
    • functional pain

This will give a minimum score of four and a maximum score of 12. A score of ≥9 suggests that prophylactic fixation should be performed 1,2. For score 8 lesions, treatment is based on clinical judgment and for lower scores clinical management and radiotherapy is suggested. The overall sensitivity of the Mirel classification predicting fracture is ~90% but specificity is only 35% (meaning there will be unnecessary fixations) leading to debate about its usefulness 1,4.

Bone tumours

The differential diagnosis for bone tumors is dependent on the age of the patient, with a very different set of differentials for the pediatric patient.

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Article information

rID: 40745
Synonyms or Alternate Spellings:
  • Mirel's classification
  • Mirel score
  • Mirel's score
  • Pathological fracture risk: Mirel's classification

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