Synopsis
Detect a metastatic long bone approaching mechanical failure, integrate symptoms and cross-sectional cortical assessment with decision tools and stabilise electively before fracture when benefit outweighs operative burden.
- Functional pain during weight bearing or transfer is the most important bedside warning of impending long-bone failure and should trigger immediate load protection.
- First-line imaging is full-length radiography in two planes; CT is the preferred structural adjunct for circumferential cortical loss and operative geometry.
- Mirels scores site, pain, lytic character and lesion size from one to three each; a total of nine or more historically supports fixation consideration.
- Use Mirels as decision support, not an automatic rule: intermediate scores, lesion geometry, CT cortex, tumour response, survival and patient goals require specialist judgement.
- MRI answers occult fracture and marrow or soft-tissue extent; it does not measure everyday torsional strength by itself.
- Protect weight bearing while the plan is made, because radiotherapy and antiresorptive treatment cannot immediately rebuild critically absent cortex.
- Prophylactic fixation generally permits easier surgery and earlier function than reconstruction after a complete fracture when risk and prognosis justify intervention.
- Choose nail, plate, cement augmentation or endoprosthetic replacement to bypass the entire mechanically relevant lesion and remain durable without depending on union.
Key red flags
Pain produced by standing, rising from a chair or rotating the limb is a mechanical warning even when resting pain is controlled.
A peritrochanteric lytic lesion with extensive circumferential cortical loss can fracture during an ordinary transfer and needs urgent protection.
Increasing pain after radiotherapy may mean progression or microfracture; tumour treatment does not certify immediate structural recovery.
A solitary lesion, unusual matrix or absent confirmed primary requires staging and tumour-aware biopsy before a prophylactic implant is passed through it.
A renal-cell or thyroid metastasis can bleed substantially during fixation and should prompt embolisation and blood-loss planning.
New skin compromise, distal sensory or vascular change or rapidly enlarging swelling requires same-day surgical reassessment rather than score calculation.
Investigation priorities
Establish lesion phenotype, longitudinal extent, cortical destruction, fracture and relation to joints or existing implants.
Management branches
Functional pain or imaging indicates a high-load cortex may fail during ordinary activity.
- Prescribe explicit protected or non-weight bearing and provide a safe aid before further transfers.
- Obtain full-length radiographs and urgent CT, adding MRI for occult fracture or uncertain extent.
- Document skin and distal neurovascular findings and repeat them after any sudden symptom change.
- Escalate loss of alignment or a crack as completed fracture rather than continuing score-based observation.