Paget disease of bone

Last updated: September 11, 2023

Summarytoggle arrow icon

Paget disease of bone (PDB, or osteitis deformans) is a slowly progressive skeletal disease; it can be monostotic or polyostotic. In PDB, increased bone turnover causes normal lamellar bone to be replaced by weak woven bone. PDB is common but underdiagnosed, and its etiology is not known. PDB predominantly affects individuals over 55 years of age. The condition is often identified incidentally based on a finding of isolated elevated serum alkaline phosphatase (ALP) on blood tests. Symptomatic patients present with localized pain and bony deformities (such as bowing of long bones). Skeletal x-rays, bone scans, and serum ALP are important tests for diagnosing and monitoring the progression of PDB. Treatment is mainly supportive and involves bisphosphonate use to inhibit osteoclastic function. Surgical therapy may be indicated in patients with bone deformities or pathological fractures.

PDB should not be confused with Paget disease of the breast or Paget disease of the vulva, which are named after the same physician.

Epidemiologytoggle arrow icon

  • Prevalence: second most prevalent skeletal disease after osteoporosis in individuals > 50 years of age [1]
  • Sex: > (1.2:1)
  • Age of onset: : > 55 years [1]

Epidemiological data refers to the US, unless otherwise specified.

Pathophysiologytoggle arrow icon


Stages of Paget disease

Bone remodeling in Paget disease occurs in three phases, followed by a quiescent stage: [2]

Disease localization

The pelvis, skull, vertebral column, and long bones of the lower extremities are the most commonly affected sites.

  • Monostotic PDB: affects only one bone (∼ ⅓ of cases)
  • Polyostotic PDB: affects two or more bones (∼ ⅔ of cases)

Clinical featurestoggle arrow icon

Diagnosticstoggle arrow icon


  • Suspect PDB in adults with any of the following:
    • Idiopathic serum ALP elevation
    • Incidental radiographic findings of bone disease
    • Characteristic clinical features, e.g., bone pain
  • Obtain x-rays to confirm the diagnosis. [3][4]
    • Symptomatic: targeted imaging of affected areas
    • Asymptomatic: imaging of abdomen, skull, facial bones, and tibias
  • If PDB is confirmed:

PDB should be considered in asymptomatic patients with isolated total ALP elevation that cannot be explained by any other condition (e.g., cholestasis or bone metastases).

Imaging studies [3][4]


In isolation, the following findings are nonspecific; in combination, they can confirm the diagnosis. [3][5]

Bone scintigraphy

  • Indications: all patients with confirmed PDB
  • Use: to assess the extent of metabolically active disease [3]
  • Findings: Increased uptake of Tc-99m resulting from increased vascularity in active pagetic foci

CT and/or MRI

  • Not routinely required for diagnosis
  • May be used to assess for complications of PDB, e.g., osteosarcoma

Laboratory studies [3][4][7]

Laboratory studies support the diagnosis and rule out alternative diagnoses, and they should be obtained after imaging studies.

Initial studies

Immobilization of affected bones can cause non-PTH-mediated hypercalcemia (and hypercalciuria). Secondary hyperparathyroidism affects 12–18% of patients with PDB. [8]

Additional studies [3][7]

For patients with normal serum total ALP, consider the following in consultation with a specialist, e.g., endocrinology:

Bone biopsy

  • Not routinely recommended or performed
  • Typically shows a chaotic, mosaic-like pattern of irregularly juxtaposed lamellar and woven bone

Differential diagnosestoggle arrow icon

The differential diagnoses listed here are not exhaustive.

Treatmenttoggle arrow icon

Pharmacotherapy [3][4]


  • First-line therapy for patients with bone pain and those at risk of bone complications [9]
  • Mechanism: induce apoptosis of osteoclasts
  • Agents

Other agents [3][7]

Surgical therapy [3][4]

Complicationstoggle arrow icon

We list the most important complications. The selection is not exhaustive.

Referencestoggle arrow icon

  1. Lalam RK, Cassar-pullicino VN, Winn N. Paget Disease of Bone. Semin Musculoskelet Radiol. 2016; 20 (3): p.287-299.doi: 10.1055/s-0036-1592368 . | Open in Read by QxMD
  2. Le T, Bhushan V,‎ Sochat M, Chavda Y, Abrams J, Kalani M, Kallianos K, Vaidyanathan V. First Aid for the USMLE Step 1 2019. McGraw-Hill Medical
  3. Ralston SH, Corral-Gudino L, Cooper C, et al. Diagnosis and Management of Paget's Disease of Bone in Adults: A Clinical Guideline. J Bone Miner Res. 2019; 34 (4): p.e3657.doi: 10.1002/jbmr.3657 . | Open in Read by QxMD
  4. Frederick R. Singer, Henry G. Bone, David J. Hosking, Kenneth W. Lyles, Mohammad Hassan Murad, Ian R. Reid, Ethel S. Siris. Paget's Disease of Bone: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2014; 99 (12): p.4408-4422.doi: 10.1210/jc.2014-2910 . | Open in Read by QxMD
  5. Daphne J. Theodorou, Stavroula J. Theodorou, Yousuke Kakitsubata. Imaging of Paget Disease of Bone and Its Musculoskeletal Complications: Review. American Journal of Roentgenology. 2011; 196 (6_supplement): p.S64-S75.doi: 10.2214/ajr.10.7222 . | Open in Read by QxMD
  6. Jameson JL, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J. Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2). McGraw-Hill Education / Medical ; 2018
  7. Stuart H. Ralston. Paget's Disease of Bone. N Engl J Med. 2013; 368 (7): p.644-650.doi: 10.1056/nejmcp1204713 . | Open in Read by QxMD
  8. Brandi ML, Falchetti A. What Is the Relationship Between Paget's Disease of Bone and Hyperparathyroidism?. J Bone Miner Res. 2006; 21 (S2): p.P69-P74.doi: 10.1359/jbmr.06s213 . | Open in Read by QxMD
  9. Tuck SP. Adult Paget disease of bone: a tale of two guidelines. Rheumatology. 2020; 59 (9): p.2197-2198.doi: 10.1093/rheumatology/keaa345 . | Open in Read by QxMD

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