Pathological Fractures

Question 1

Define a pathological fracture.

Answer 1

A fracture that occurs in an abnormally
weakened bone
–Occurs without an adequate force that would
break normal bone.
–The disease process leads to a mismatch in bone
resorption and formation
–This weakens bone structure and fracture
following minimal stress

Question 2

Outline the disease processes which lead to pathological fractures.

Answer 2

Generalised:

–Metabolic
• Osteoporosis (most common)
• Paget’s disease, hyperparathyroidism, vit D/calcium 
deficiency
–Genetic
• Osteogenesis Imperfecta

Focal
–Tumours
• Primary 
– Benign
– Malignant
• Secondary (metastatic)

Question 3

What should be considered in the history of a patient with a suspected pathological fracture?

Answer 3

– Trauma involved minimal (low energy)
– Preceding pain
– Red flag symptoms (weight loss, haemoptysis, 
haematemesis, PR bleeding)
– History of malignancy
– Consider age of patient

Question 4

Outline the metabolic causes of generalised bone disease/pathological fractures.

Answer 4

• Osteoporosis (most common): sparse and thin trabeculae (vertebral body, hip, wrist fractures, pelvic ring insufficiency fractures)
• Paget’s disease: abnormal bone remodelling and osteoclast activity (risk of developing osteosarcoma)
• Osteomalacia: defect in mineralisation leading to to large amount of unmineralised osteoid
• Hyperparthyroidms, vitamin D/calcium deficiency

Question 5

Outline the investigations involved in metabolic causes of pathological fractures.

Answer 5

Blood tests:

– Bone profile, parathyroid, thyroid function tests to rule out other causes of bone resportion, Alk. Phos (raised in Pagets)
– Vitamin D levels (25 hydroxyvitamin D)

Imaging:
– Plain films – diagnosis of pathognomonic fractures or other involved sites
– DEXA (Dual energy xray absorptiometry) to confirm diagnosis of osteoporosis
– +/- CT or MRI for diagnosis/operative planning

Question 6

What is osteogenesis imperfecta?

Answer 6

Genetic cause of pathological fractures. Hereditary decrease of collage type 1

Question 7

What are focal bone lesions indicative of?

Answer 7

• Primary tumour
• Metastases
• Benign tumour
• Cyst

Question 8

Outline bone tumour X-ray appearance.

Answer 8

• DENSITY –LYTIC, SCLEROTIC, MIXED
• LOCATION- EPIPHYSIS, METAPHYSIS, DIAPHYSIS
• LESION DEMARCATION – WELL DEMARCATED USUALLY BENIGN, POORLY DEMARCATED USUALLY MALIGNANT
• PERIOSTEAL REACTION
• MATURE/IMMATURE SKELETON
• SOLITARY OR MULTIPLE

Question 9

What investigations must be done when a lytic bone lesion is identified?

Answer 9

EXAMINATION:
• LOOK FOR PRIMARY (BREAST, THYROID EXAM, PR)

INVESTIGATIONS

• BLOODS (FBP, ESR, U&E, LFT, CA, PHOS, ALP, PSA,
TUMOUR MARKERS, MYELOMA SCREEN)

– STAGING
• PLAIN X-RAY WHOLE AFFECTED BONE (XR NEED 30% BONE LOSS TO DETECT LESION)
• CT CHEST ABDOMEN PELVIS (? PRIMARY OR OTHER
SITES)
• ISOTOPE BONE SCAN (? OTHER SITES)
– BIOPSY OFTEN REQUIRED UNLESS KNOWN
METASTASIS
• (DISCUSS WITH ORTHO TEAM RE: BIOPSY ROUTE TO AVOID SPREAD OF TUMOUR CELLS)

Question 10

Outline primary malignant bone tumours.

Answer 10

• Relatively rare (often unsuspected)
• Suspect primary tumour in younger patients with
aggressive appearing lesions
– poorly defined margins (wide zone of transition, lack
of sclerotic rim)
– matrix production
– periosteal reaction
• Patients usually have antecedent pain before
fracture, especially night pain
• Most common primary malignancy is myeloma
• Malignant proliferation of plasma cells
• Plasmacytoma = solitary lesion
• Multiple Myeloma = many lesions

Question 11

How is bone disease in myeloma treated?

Answer 11

• Non operative
– Multiagent Chemotherapy
– Bisphosphonate
– Radiotherapy

• Operative - Stabilise
– Spinal fractures - Vertebroplasty if painful kyphosis
– Long bones –intramedullary nail or joint replacement if intraarticular
– Stabilise impending fractures

• NB! Plasmacytoma –wide local excision and reconstruction (curative)

Question 12

Outline osteosarcoma.

Answer 12

• Usually occur in kids and young adults
• 2nd decade
• 2nd peak in elderly with history of Pagets.
• Usually around knee
• Xray – Blastic, destructive, Sunburst matrix and Codman’s triangle

Question 13

How is osteosarcoma treated?

Answer 13

• Chemotherapy
–Pre-op 8 to 12 weeks
–Maintenance 6 to 12 months post op.
• Surgery
–Limb salvage if possible 
(95%)
–Wide local excision and reconstruction

Question 14

What is Ewing’s sarcoma?

Answer 14

• Bone or soft tissue sarcoma.
• Age 5 -25 years
  – 50% diaphysis - commonly in femur > tibia > humerus
  –Treatment:
  • Chemotherapy and surgical resection

Question 15

In what patient cohort should you suspect bone metastases?

Answer 15

> 50 years.

Question 16

What cancers commonly metastasise to bone?

Answer 16

• thyroid
• prostate
• breast
• kidney
• lung

Question 17

How is metastatic bone disease treated?

Answer 17

• Palliative if prognosis poor <3 months
• Pre-operative embolisation may be required in vascular metastasis e.g. renal and thyroid
• If impending fracture, protect entire bone
• Stabilise fractures using IM nail or joint replacement (e.g. endoprosthesis)
• Solitary renal metastasis –wide local excision and reconstruction (curative)
• Post-operative radiotherapy