Synopsis
Recognise mechanically unstable metastatic bone disease, establish diagnosis before contaminating surgery and construct a coordinated stabilisation, radiotherapy and systemic-treatment plan that restores useful function.
- Deep progressive pain is common, but functional pain with standing, transfers or limb rotation is the high-yield sign of mechanical instability.
- First-line imaging of a symptomatic peripheral bone is radiography in two planes including the whole lesion and adjacent joint; a normal film does not exclude marrow disease.
- CT defines cortical destruction and fixation anatomy, while MRI is the reference study for marrow, occult fracture, soft tissue and neural involvement.
- Protect weight bearing immediately across a painful proximal femoral or other high-load lesion until specialist assessment determines fracture risk.
- Before biopsy or fixation, establish whether histology is already secure; stage and sample a solitary or atypical lesion because primary sarcoma remains possible.
- Surgery aims for immediate durable stability, usually using load-sharing fixation, cement augmentation or endoprosthetic replacement chosen to survive the patient's expected lifespan.
- Postoperative radiotherapy improves local control for many stabilised metastatic lesions, but radiotherapy alone cannot immediately restore a critically weakened cortex.
- Tumour-specific systemic therapy and zoledronic acid or denosumab can reduce later skeletal events but do not replace analgesia, fracture protection, decompression or fixation.
Key red flags
Functional pain on standing or transfers through a proximal femoral lesion indicates mechanical failure risk even before a visible fracture line.
A painful deformed limb after minimal force is a completed pathological fracture requiring splintage and urgent orthopaedic oncology review.
Night spinal pain, radicular symptoms, weakness, gait deterioration or sphincter change may be metastatic cord or cauda-equina compression.
A solitary destructive lesion with no secure primary diagnosis could be sarcoma, myeloma or infection and must not undergo empirical intramedullary fixation.
Renal-cell and thyroid metastases may be markedly vascular, creating major biopsy and operative bleeding risk that sometimes warrants preoperative embolisation.
Confusion, dehydration, vomiting, constipation or arrhythmia with extensive lytic disease suggests hypercalcaemia requiring urgent biochemical treatment.
Investigation priorities
Define fracture, lesion phenotype, cortical loss, joint involvement and other deposits along the proposed construct.
Management branches
Functional pain, cortical destruction or a complete fracture threatens safe limb use.
- Stop unprotected loading, splint a completed fracture and document skin, pulses and neurological function.
- Provide multimodal analgesia and assess bleeding, calcium, renal function, VTE and pressure-area risk.
- Obtain whole-bone radiographs and urgent CT or MRI according to cortical, occult-fracture or neural questions.
- Contact orthopaedic oncology early rather than waiting for routine radiotherapy review.
The lesion is painful but structurally stable or surgery offers no proportionate benefit.
- Provide explicit loading guidance, aids and multimodal analgesia rather than generic activity as tolerated.
- Use palliative external-beam radiotherapy for local pain and tumour control according to oncology planning.
- Start or optimise tumour-specific systemic treatment and eligible bone-modifying therapy.
- Reassess urgently for increasing functional pain or radiographic cortical loss because stability can change during treatment.