Mirels Score (impending pathologic fracture)
Mirels Score (4–12) for the risk that a long-bone metastasis will progress to a pathologic fracture; ≥ 9 (> 33% risk) recommends prophylactic fixation.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Site
- Lower limb (2)
- Pain
- Functional / mechanical (3)
- Radiographic nature
- Lytic (3)
- Size relative to cortical diameter
- Under ⅓ of cortex (1)
Result: Mirels 9/12 — High risk. >33% fracture risk — prophylactic fixation recommended before radiotherapy.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Bands
- ≤7 low (~0–4% fracture risk; irradiate/observe), 8 borderline (~15%; clinical judgment), ≥9 high (>33%; prophylactic fixation). The ≥9 cutoff is sensitive (~91%), not specific.
What you enter
- Site
- Pain
- Radiographic nature
- Size relative to cortical diameter
How this is calculated
- Factors
- four factors each 1–3: site (upper 1 / lower 2 / peritrochanteric 3), pain (mild/moderate/functional), nature (blastic/mixed/lytic), size (<⅓ / ⅓–⅔ / >⅔ of cortex). Total 4–12.
Mirels H. Metastatic disease in long bones: a proposed scoring system for diagnosing impending pathologic fractures. Clin Orthop Relat Res. 1989;(249):256-264. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.