Paget's Disease

Populations and Risk Factors

Adults over age 50, most frequently of Northern European descent
Genetic predisposition (15-40% have a first-degree relative with the condition)
Suspected viral trigger (possibly paramyxovirus or measles virus)
Male predominance (slight)
Small risk (< 1%) of malignant transformation to osteogenic sarcoma — sudden worsening pain in a known Paget lesion is an urgent red flag

Osteoclast overactivity: Giant, multinucleated osteoclasts (10-100 nuclei vs. normal 3-5) resorb bone much faster than normal
Compensatory osteoblast response: Osteoblasts produce new bone rapidly but in a chaotic, disorganized (woven) pattern rather than organized lamellar bone
Structural result: Enlarged bone with a high spongy-to-compact ratio, hypervascular and mechanically weak despite increased density on X-ray
Elevated ALP: The intense osteoblastic activity produces elevated serum alkaline phosphatase — the hallmark laboratory marker
Cardiovascular complication: The hypervascular bone creates arteriovenous shunting. In polyostotic (multi-bone) disease, the heart must pump harder to supply the vascular bone networks, which can lead to high-output congestive heart failure
Neurological complications: Thickened skull bones can compress cranial nerves (hearing loss, tinnitus, headaches). Vertebral involvement can cause spinal stenosis and nerve root compression

Deep, persistent bone pain, often worse at night and with weight-bearing
Bowing of the femur or tibia. Enlarged, thickened skull
Palpable heat over affected bone (hypervascularity)
Hearing loss, tinnitus, or chronic headaches (thickened cranial bones pressing nerves)
Waddling gait and increased thoracic kyphosis
Many patients are initially asymptomatic (diagnosed incidentally by elevated ALP or X-ray)
Pathological fractures in affected bones
Red flags: Sudden worsening pain in a known Paget lesion raises suspicion for osteogenic sarcoma — urgent referral; signs of heart failure (dyspnea, edema) in polyostotic disease

CMTO Appendix category A1 (MSK conditions)
Key differential: Paget disease (elevated ALP) vs. osteoporosis (normal ALP)
Know the malignancy risk (osteogenic sarcoma < 1%) — sudden change in pain pattern requires investigation
Cardiovascular complication: CHF from hypervascular bone tissue in polyostotic disease
Bone is enlarged but structurally weak — fracture risk requires pressure modification

Fracture risk: Affected bones are structurally compromised despite appearing enlarged and dense. Rigorous or deep tissue massage over affected bones is locally contraindicated
Pressure and positioning: Careful pressure modification to avoid pathological fractures. Avoid positions placing the affected spine in excessive extension
Palpable heat: Warmth over affected bones is from hypervascularity, not infection — but note the finding
Appropriate: Massage in concert with medical management to maintain flexibility and address secondary muscle tension from altered biomechanics
Spinal involvement: Avoid positions placing spine in excessive extension. Monitor for neurological symptoms (radiculopathy from spinal stenosis)
Cardiovascular awareness: In polyostotic disease, monitor for signs of heart failure and adjust treatment intensity accordingly

Paget disease involves overactive osteoclasts producing enlarged, hypervascular, brittle bone with chaotic structure. Elevated ALP is the hallmark
Affected bones are structurally compromised and fragile. Rigorous or deep tissue massage over affected bones is locally contraindicated
Key differential from osteoporosis: Paget has elevated ALP while osteoporosis has normal ALP
Advanced polyostotic cases can cause congestive heart failure because the heart works harder to pump blood through vascular bone networks
There is a small (< 1%) risk of malignant transformation to osteogenic sarcoma — sudden worsening pain is an urgent red flag