Paget's disease is a condition where there is excessive and disorganized bone remodeling, leading to thickened and deformed bones. It was first described in 1877 and typically involves the pelvis, femur, skull and spine. The cause is unknown but genetic and viral factors may play a role. It progresses through lytic, mixed, and sclerotic phases with abnormal osteoclast and osteoblast activity. Complications include fractures, arthritis, and neurological or vascular issues. Diagnosis involves elevated alkaline phosphatase and imaging showing thickened bones. Treatment focuses on suppressing active disease with bisphosphonates or calcitonin to reduce pain, deformity, and complications.

1. PAGET’S DISEASE OF THE BONE
DR.HARI PRASATH P
1ST YEAR POST GRADUATE

2. INTRODUCTION
The condition was initially described by Dr. James Paget in 1877
 Also called as Osteitis Deformans
 Partial or complete involvement of a single or multiple bones by
exaggerated rates of resorptive and osteogenic activity leading to bony
thickening and deformity.
 Schmorl believed that approximately 3% of everyone above 40 years had
osteitis deformans

3. INTRODUCTION (Cont)
 It has a predilection for the axial skeleton
 Pelvis>tibia > Femur > Skull>spine >clavicle
 But any bone may be affected
 Paget disease is common in Europe, North America
 It is rare in Asia and Africa

4. ETIOLOGY
 UNKNOWN
 Occasionally hereditary influence is noted on chromosome 18q
 On electron microscopy of bone biopsies has demonstrated nuclear
inclusions,
 similar to those found in viral diseases (Paramyxoviridae family) are found
in the highly nucleated osteoclasts
 Endocrine and metabolic disturbances are unlikely because despite
extensive involvement , many bones are free of disease

5. PATHOPHYSIOLOGY
 3 Phases:
i) Lytic
ii) mixed Lytic and Blastic
iii) Sclerotic
 Different skeletal lesions may progress at different rates.
 At a given time, multiple stages of disease may be demonstrated in
different skeletal regions of same patient

6. LYTIC PHASE
 Disease begins with lytic phase
 The bone is resorbed by osteoclasts that are more numerous, larger, and
have more nuclei (upto 100)
 Bone turnover rate increased as much as 20times normal

7. Mixed Lytic and Blastic phase
 Rapid increase in bone formation from numerous osteoblasts
 Morphologically osteoblasts are normal
 The newly formed bone is abnormal with collagen fibers deposited in
haphazard fashion rather than linear
 As osteoclastic and osteoblastic activity repeats, high degree of bone turn
over occurs

8. Sclerotic Phase
 The bone formation dominates and has a disorganized woven pattern and
is weaker than normal bone
 Woven pattern allows the bone marrow to be infiltrated by excessive
fibrous connective tissue and blood vessels leading to hyper vascular bone
state
 Eventually osteoblastic activity also declines and enters a sclerotic or
burned-out phase
 Continued bone resorption is minimal or absent

9. Histology

10. Osteoclast & osteoblasts Jigsaw puzzle / Mosaic pattern
1
2

11. Complications
 Fractures and bony deformity
 Secondary osteoarthritis ( when pagets disease around a joint)
 Neurological complications – nerve root compression and cauda equina
syndrome
 Skull involvement- deafness
vertigo
tinnitus
dental malocclusion
basilar invagination
cranial nerve disorders
Sarcomatous degeneration - Osteosarcoma
 Increased bone vascularity – high output cardiac failure

12. SURGICAL COMPLICATIONS:
 Highly vascular marrow – Profuse bleeding
 Structurally weak bone
 Spinal / Epidural Anesthesia may be difficult

13. Investigations
 Serum Alkaline phosphatase , BSAP
 Serum Acid phosphatase
 Urinary Markers – hydroxyproline, deoxypyridinoline, C-telopeptide, N-
telopeptide
 Serum calcium and phosphate levels will be normal

14. X-RAYS
 Long bones:
bowing
thickening of cortex, narrowing of medulla
honey combed or spongy, large dense bone
looser’s zone of transformation

15. Brim Sign:
thickening of the right pelvic brim
(ileopectineal line) as compared to
the left

16. Skull
osteitis circumscripta or cotton wool exudates

17. tam o' shanter sign
widening of the diploic space and an
overall enlargement of the cranium

18. Pagets Spine
Ivory Vertebra
Picture frame sign

19. Blade of Grass or Candle flame sign:
begins as a subchondral area of lucency with advancing
tip of V-shaped osteolysis, extending towards the
diaphysis

20. Looser’s Zone:

21. Scintigraphy
Technetium 99 scan shows increased
uptake in right hemipelvis and spine

22. DIFFERENTIAL DIAGNOSIS:
 Osteomalacia
 Fibrous Dysplasia
 Multiple Myeloma
 osteopetrosis

23. TREATMENT
 Inactive lesions doesn’t require any intervention
 Goals of treatment:
Suppression of Active disease
Relief of Pain
Prevention of Deformity and fractures
High output cardiac dysfunction
Reducing the Sarcomatous transformation

24. Suppressive Agents
 BISPHOSPHONATES
 2nd generation bisphosphonates like Tiludronate, Alendronate, risendronate
produces longer remission at lower doses.
 Pamidronate – 30mg IV/day over 3hours for 3days
 Zolidronic Acid- 5mg IV over 5 mins
First choice where rapid mineralization is required
in neurological symptoms, severe bone pain, risk of fracture
prior to elective surgery
Vitamin D and calcium supplements
 It normalizes the ALP in 6 months
 Bisphosphonates should not be used in patients with renal impairment

25. Calcitonin
 Dosage – 100 IU / day SC/IM for 6-18 months
reduced to 50 IU / day x 3/week
 Calcitonin therapy can temporarily arrest active disease
 ALP, urine Hydroxyproline is reduced
 Positive Calcium balance
 High output heart failure is improved
 Bone pain relieved
Surgical treatment is reserved for fractures, correction of bone deformity,
THR, Spinal surgery
Preoperatively and postoperatively calcitonin therapy gives good results and
reduces bleeding

26. CASE
Alkaline phosphatase – 1510 IU/L
Sr. calcium – 8.7mg/dl
Sr. Phosphorus – 3.1 mg/dl

28. THANK YOU