Metastatic disease in long bones. A proposed scoring system for diagnosing impending pathologic fractures.
Mirels H. Clinical orthopaedics and related research 1989 · PMID 2684463 · doi:10.1097/01.blo.0000093045.56370.dd
- Question
- Can a simple score predict the risk of pathological fracture through a long bone metastasis to guide prophylactic fixation?
- Design
- Retrospective review of irradiated long bone metastases scored before radiotherapy and followed for 6 months for fracture.
- Patients
- Patients with long bone metastases treated with radiotherapy without prophylactic fixation.
- Intervention
- Weighted score combining site, pain, lesion type (lytic/blastic/mixed) and size
- Comparison
- Fracture versus no fracture during follow-up
- Primary outcome
- Subsequent pathological fracture
- Key result
- Lesions that fractured had a higher mean score than those that did not (10 versus 7), and fracture risk climbed as the score rose above 7; Mirels proposed that lesions scoring 7 or less can be irradiated safely, whereas higher scores merit prophylactic fixation before radiotherapy.
- Limitations
- Small retrospective series with modest specificity, so many high-scoring lesions would not fracture; inter-observer reliability of the size and pain components is imperfect.
- Impact on practice
- Remains the most widely used and examined tool for deciding prophylactic fixation of long bone metastases in UK practice and the FRCS exam.