KnotesFree Orthopaedic & FRCS notes, viva stations and higher order SBAs

Metastatic Bone Disease

Must KnowApplied Basic SciencesthinKbox SBA

Presentation

Bone metastases may present with:

  • pain
  • pathological fracture
  • impending fracture
  • hypercalcaemia
  • spinal cord compression
  • an incidental destructive lesion

In an adult with an unexplained destructive bone lesion, metastasis and myeloma are common considerations.

Evaluation

Local lesion

  • full-length radiographs of the involved bone
  • CT for cortical destruction and surgical planning
  • MRI for marrow/soft-tissue extent and neural compression

Search for primary disease

Guided by history, examination and epidemiology. Investigations may include:

  • FBC, renal/liver profile, calcium and bone profile
  • serum protein electrophoresis/free light chains when myeloma is possible
  • selected tumour markers only when clinically appropriate
  • CT chest/abdomen/pelvis or targeted imaging

If the diagnosis remains uncertain, biopsy is performed before definitive fixation unless the clinical context makes the diagnosis unequivocal.

Impending fracture

Assess:

  • pain with function
  • site
  • lesion size and cortical destruction
  • lytic versus blastic character
  • expected survival

Scoring systems such as Mirels can support but should not replace clinical judgement.

Risk assessment considers:

  • pain
  • lesion size
  • site
  • cortical destruction
  • lytic character
  • mechanical demand

Scoring systems such as Mirels can support decision-making but should not substitute for clinical judgement or modern imaging assessment.

Fixation principles

Reconstruction should be durable enough for the patient's expected lifespan and allow rapid mobilisation.

Options include:

  • intramedullary fixation
  • plate/cement reconstruction
  • endoprosthetic replacement
  • arthroplasty around joints

Treatment is integrated with oncology, radiotherapy and palliative-care goals.

Clinical problem

Metastatic bone disease is more common than primary malignant bone tumour in adults. Management aims to:

  • relieve pain
  • prevent or treat pathological fracture
  • preserve mobility
  • maintain independence
  • support systemic cancer treatment

Treatment should match expected survival and functional goals.

Common patterns

Metastases may be:

  • lytic
  • sclerotic
  • mixed

Common primary sources include breast, prostate, lung, kidney and thyroid cancers, but any suspicious lesion still requires appropriate diagnostic reasoning.

Unknown primary

For a destructive bone lesion without a known cancer diagnosis:

  • history and examination
  • blood tests
  • staging imaging
  • tumour-specific investigations where indicated
  • biopsy when diagnosis remains uncertain

Do not assume every lesion in an older patient is a metastasis.

Prophylactic fixation

Fixation before fracture can:

  • simplify surgery
  • reduce morbidity
  • permit earlier mobilisation
  • preserve function

The construct should be durable for the patient’s expected lifespan and often needs to protect the entire involved bone.

Pathological fracture

Surgery must address:

  • poor biological healing potential
  • extensive bone loss
  • need for immediate stability

In some locations, endoprosthetic replacement is preferable to fixation because it provides immediate durable load bearing.

Adjuvant oncology treatment

Radiotherapy is important for pain control and local disease management. Systemic therapy depends on tumour biology.

Coordination with oncology is essential.

Spine

Metastatic spinal disease requires assessment of:

  • neurological deficit
  • mechanical instability
  • tumour radiosensitivity
  • systemic disease
  • overall prognosis

Spinal cord compression is an oncological emergency.

FRCS synthesis

The operation for metastatic disease should be designed to outlast the patient, permit immediate function and avoid dependence on biological union when that is unlikely.

Written/reviewed by Kishore Puthezhath

Professor of Orthopaedics and Consultant Paediatric Orthopaedic Surgeon

FRCS (Tr & Orth) revision resource

Reviewed: September 2026