Pathological Fractures

What makes a fracture "pathological"

Healthy bone can withstand everyday loads. When disease reduces its strength or replaces bone with weaker tissue, a fracture can happen with forces that would not break normal bone. Doctors use several related terms:

Causes

Osteoporosis

Osteoporosis is by far the most common cause. Bone density and quality fall with age, menopause, steroid use and other factors. Typical fractures are spinal compression fractures, hip fractures, wrist fractures and upper arm fractures.

Cancer that has spread to bone

Bone metastases are common in breast, prostate, lung, kidney and thyroid cancers. The spine, pelvis, ribs, femur and upper arm are the usual sites. Sometimes a fracture is the first sign of cancer.

Multiple myeloma

Multiple myeloma, a blood cancer of plasma cells, causes punched-out holes in bones, especially the spine, skull, ribs and pelvis, along with anemia, kidney problems and high calcium.

Primary bone tumors and cysts

• Benign: bone cysts, giant cell tumors, enchondromas, fibrous dysplasia, more common in children and young adults
• Malignant: osteosarcoma, chondrosarcoma, Ewing sarcoma

Other bone diseases

• Paget's disease of bone: enlarged, structurally weak bone
• Osteomalacia: soft bones from vitamin D deficiency
• Osteogenesis imperfecta: inherited brittle bones
• Hyperparathyroidism and chronic kidney disease
• Bone infection (osteomyelitis)
• Radiation damage to bone
• Long-term use of certain medicines, rarely including atypical femur fractures with bisphosphonates

Symptoms

• Sudden pain at the fracture site after minimal force
• Swelling, bruising and deformity
• Inability to bear weight or use the limb
• For spinal fractures: sudden back pain, height loss and stooping; sometimes only vague back pain
• Before the fracture: aching bone pain, often worse at night or at rest, which can signal a tumor or metastasis
• Symptoms of the underlying disease: weight loss, fatigue, thirst and confusion from high calcium

Diagnosis

1. X-rays show the fracture and features of weakened bone, such as a lytic (bone-destroying) lesion.
2. CT or MRI define the lesion and its extent, and check spinal cord compression.
3. Bone scan or PET-CT looks for other affected bones.
4. Blood tests: calcium, kidney function, alkaline phosphatase, vitamin D, parathyroid hormone, blood count, and serum and urine protein electrophoresis with free light chains for myeloma. PSA in men if prostate cancer is suspected.
5. Biopsy of a bone lesion if cancer is suspected but not yet diagnosed. This should be done before fixation when a primary bone tumor is possible.
6. Bone density scan (DXA) after a fragility fracture.

Treatment

Treating the fracture

• Surgery: rods, plates, screws or joint replacement to stabilize the bone and allow early movement. Fixation often spans the whole bone if metastases are present
• Vertebral augmentation (kyphoplasty or vertebroplasty) for some painful spinal fractures
• Bracing or casting for some fractures
• Preventive (prophylactic) fixation for impending fractures at high risk
• Pain control and early mobilization

Treating the cause

• Osteoporosis: bisphosphonates, denosumab, or bone-building medicines such as teriparatide, abaloparatide or romosozumab, plus calcium, vitamin D and fall prevention
• Bone metastases and myeloma: radiation therapy to the affected bone, systemic cancer treatment, and bone-modifying agents (zoledronic acid or denosumab) to reduce further fractures
• Benign lesions: curettage and bone grafting
• Osteomalacia: vitamin D and calcium replacement

Prevention

• Get a bone density test if you are a woman 65 or older, or younger with risk factors
• Treat osteoporosis after any fragility fracture
• People with bone metastases or myeloma should receive bone-protective medicines as recommended
• Prevent falls with strength and balance exercise and home safety measures
• Report new or persistent bone pain promptly, especially with a history of cancer

Frequently asked questions

What is a pathological fracture?

It is a broken bone caused by an underlying disease that has weakened it, such as osteoporosis, cancer that has spread to bone, multiple myeloma or a bone cyst. It often happens with minimal force, such as everyday activity or a minor fall.

What are the most common causes of pathological fractures?

Osteoporosis is the most common cause. Others include cancer spread from the breast, prostate, lung, kidney or thyroid, multiple myeloma, benign bone tumors and cysts, Paget's disease and osteomalacia.

What are the warning signs before a pathological fracture?

Bone pain that is persistent, worse at night or at rest, or gradually increasing can be a warning sign, especially in someone with cancer. Unexplained weight loss, fatigue and height loss can also signal underlying bone disease.

How are pathological fractures treated?

Treatment combines stabilizing the fracture, often with surgery, and treating the underlying cause. This may include osteoporosis medicines, radiation and systemic cancer therapy for metastases or myeloma, and bone-strengthening drugs to prevent further fractures.

Do pathological fractures heal?

Fractures from osteoporosis usually heal normally. Fractures through tumors may heal more slowly or not at all without treating the tumor, which is why surgery, radiation and cancer treatment are often combined.