Calculators · Orthopaedics · Score

Mirels score (impending pathological fracture)

Also called Mirels criteria, Mirels' classification

Risk of pathological fracture through a metastatic lesion of a long bone, to decide on prophylactic fixation before radiotherapy.

Site
Pain
Lesion type
Size (fraction of cortical width/diameter)

Fill 4 more fields to see the result.

Formula and scoring

Four items scored 1–3: site (upper limb / lower limb / peritrochanteric), pain (mild / moderate / functional), lesion (blastic / mixed / lytic), size (<1/3, 1/3–2/3, >2/3). Total 4–12.

Exam and ward pearls

  • Functional pain was the strongest single predictor in Mirels’ series; all such lesions fractured.
  • Mean score was 7 in lesions that did not fracture and 10 in those that did.

When not to rely on it

  • Retrospective, 78 lesions; high sensitivity but low specificity, so it over-calls fixation. Not validated for spinal lesions (use SINS) or primary bone tumours.

Source

  1. Mirels H. Metastatic disease in long bones. A proposed scoring system for diagnosing impending pathologic fractures. Clin Orthop Relat Res. 1989;(249):256-64. PMID 2684463
  2. Jawad MU, Scully SP. In brief: classifications in brief: Mirels’ classification: metastatic disease in long bones and impending pathologic fracture. Clin Orthop Relat Res. 2010;468(10):2825-7. doi:10.1007/s11999-010-1326-4 · PMID 20352387

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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