Paget disease of bone

Clarify how the disease was found and whether current pain is bony, articular or neurological. Active bone pain is often deep, persistent and present at rest, with local warmth. Osteoarthritic pain relates more to movement and joint-line loading, while focal pain in a bowed femur or tibia may mark a fissure fracture. Ask about increasing hat size, hearing, dental fit, limb bowing, previous fracture, gait change and family history. Rapid progression or mass is a tumour warning.

Inspect skull contour, limb alignment and gait and compare local temperature. Palpate the full painful bone and adjacent joints, measure range and assess leg length and mechanical axis. Complete a neurological examination for spinal or skull-base disease and document pulses and nerve function before managing a deformed limb. Do not attribute every symptom to Paget disease: examine hip, knee, lumbar spine and vascular status for common competing causes.

Radiographs show cortical thickening, coarsened trabeculae, bone expansion and region-specific patterns such as pelvic brim thickening or blade-of-grass advancing osteolysis. Image the entire symptomatic long bone, including both joints, because deformity and fissures can extend beyond a narrow field. A new aggressive lytic area, interrupted cortex, periosteal reaction or soft-tissue mass is not routine activity and enters the sarcoma pathway.

Check total ALP with liver tests to establish whether elevation is likely skeletal. Calcium and phosphate are usually normal outside immobilisation or other disease. When total ALP is normal but radiographic monostotic disease appears active, bone-specific ALP, PINP or resorption markers can support assessment. Radionuclide scintigraphy then maps metabolically active distribution; it is sensitive but not specific, so unexpected uptake requires targeted anatomical imaging.

Treat the explanation for disability. A painful incomplete fissure needs load protection and orthopaedic assessment, not analgesia alone. Secondary hip or knee arthritis is managed with activity adaptation, aids, analgesia and selected arthroplasty. Neural compression needs MRI and spinal or skull-base review. Bisphosphonate may relieve active pagetic bone pain, but it does not straighten established deformity, repair advanced cartilage loss or decompress a stenotic canal.

For active disease causing bone pain, intravenous zoledronic acid 5 mg once is preferred when renal function, calcium and vitamin-D status permit. Verify adequate mineral intake and hydration and explain transient fever, myalgia and arthralgia after the first infusion. Oral risedronate can be used where infusion is unsuitable under specialist guidance. Calcitonin is rarely used when bisphosphonates cannot be given. Re-treatment follows clinical relapse rather than automatic annual dosing.

Pagetic fracture fixation must account for curvature and dense but weak bone. A standard straight intramedullary implant may not pass through a bowed canal, while plates face long lever arms and poor biology. Preoperative CT can define anatomy, and corrective osteotomy may be combined with fixation in selected cases. Arthroplasty planning addresses acetabular or femoral deformity, sclerotic reaming, blood loss and component position. Control of active turnover before elective surgery may be considered, but evidence for reducing blood loss is limited.

Follow pain and function alongside ALP or a chosen marker. A large biochemical fall after zoledronate confirms suppression, but persistent joint pain can remain entirely mechanical. Re-image a focal site when pain changes rather than assuming biochemical relapse. Hearing loss needs audiology, and neurological symptoms require urgent imaging. Relatives do not undergo indiscriminate scanning; specialist advice can guide ALP screening in families with strong or genetically confirmed disease.