Paget's disease of bone

Chronic localised bone remodelling disorder characterised by increased bone resorption, bone formation, and remodelling, which may lead to major long-bone and skull deformities.

Majority of patients are asymptomatic. Symptomatic patients typically experience pain localised to the bone or joint, either from the pagetic lesion, secondary osteoarthritis, deformity, or pathological fracture.

Neurological symptoms due to bone overgrowth with consequent nerve impingement may include hearing loss, chronic facial pain, hydrocephalus, peripheral nerve entrapment, and spinal stenosis. Very rarely, high-output cardiac failure caused by high blood flow to metabolically active bone sites may occur.

Diagnosis is incidental in the majority of patients, with an elevated serum alkaline phosphatase raising suspicion for disease. Radiographs have classical appearance. Bone biopsy is the only confirmatory diagnostic test, but it is rarely indicated.

If treatment is indicated, bisphosphonates are the first-line therapy to retard excessive osteoclastic activity. Adjunctive therapy includes physiotherapy, orthoses, and walking and hearing aids. Analgesics are indicated for pain and inflammatory symptoms.

A chronic bone disorder that is characterised by focal areas of increased bone remodelling, resulting in overgrowth of poorly organised bone. This unbalanced process may lead to osseous deformities, altered joint biomechanics, nerve compressions, and pathological fractures.