PAGET¶S DISEASE Osteitis Deformans
Paget¶s
disease
Is a state of increase metabolic metabolic activity in the bone characterized by excessive bone remodeling, both resorption and formation.
Named First
after Sir James
Paget
(1814-1899)
described osteitis deformans in 1877
Bone
Bone Phase
Remodeling Cycle
Remodeling Cycle
1 (activation)
a stimulus activates the bone cells precursors in the localized area of the bone to form osteoclasts. Phase
2. (resorption) 2.
osteoclast forms a ³cutting cone´ which gradually resorb bone, leaving behind and elongated cavity. Phase
3 (formation)
laying down of new bone by osteoblast lining the walls of the resorptive cavity.
Etiology The possible causes are many, but no exact etiology has been defined. ± Genetic factor (Sequestrosome (Sequestrosome 1 gene on chromosome 5) ± Virus infection may be necessary to trigger ± Chronic infection (Osteitis Deformans) ± Hormonal dysfunction ± Autoimmune ± Autoimmune states
Histological features
Osteoclasts are enlarged
Increased bone turnover produces a mosaic pattern of lamellar bone
Three phases recognised osteolytic, mixed and sclerotic
Osteolytic Osteolytic or Destructive Phase ± Initial phase marked by extensive resorption of existing bone
Mixed
or Active
Phase
± Osteoclasts destroy the ordered lamellar lam ellar bone and osteoblast respond to the destruction by rapid disposition of vascular connective tissue and remodeled lamellar lam ellar bone
Sclerotic or Osteoblastic
Phase
± last phase wherein bone formation outstrips resorption
Pagets disease Pathophysiology
Etiology
Dysfunction
Hyperactivity of osteoclasts
Autoimmune States
Osteoc Ost eoclas lastt des destro troys ys
Hormonal
y
y
Viral Causation
y
Chronic Infection y
Genetic Factor (Sequestrosome 1 gene on chromosome 5)
Ca ECF
lamellar bone Increase extensive resorption
y
oste osteob oblas lastt res respon ponse se
Compensatory Mechanism
Rapid disposition of vascular connective tissue Incr cre ease one for ation
Increase one size and thickness
Poorly
Compressionof nerves
mineralized bones Bowing
of legs
Curve backbone
Bone
pain
Spinal stenosis
Numbness Weakness
(Skull) headaches, dizziness, facial droop with vision or hearing impairment
Overgrown bone
Skull
enlargement bitemporally and frontally Enlargemen
t of pelvis
Signs
& Symptoms
There are usually no symptoms for a prolonged period. ± If symptoms occur, they develop insidiously insidiously,, with pain, stiffness, fatigue, and bone deformity. ± Bone pain is aching, deep, and occasionally severe, sometimes worse at night. ± Pain also may arise from compression com pression neuropathy or osteoarthritis.
Signs may include:
± Spin Spine: e: curve curve backbone backbone nerve nerves s can become damaged and cause leg pain, numbness, weakness, or cauda equina syndrome (an emergency condition with symptoms that include loss of feeling in the pelvic area and legs)
Skull: skull enlargement bitemporally and frontally (frontal ³bossing´); dilated scalp veins; headaches, dizziness, loss of muscle strength in the face (facial droop), or problems with vision or hearing.
Bowed
pelvis
legs,
Enlarged
Radiological
features
Osteolytic phase can produce osteoporosis Osteolytic circumscripta (localized cranial osteoporosis)
Bone
softening can produce bowing, platybasia, platyb asia, protrusion acetabuli or greenstick fractures
Mixed
phase shows generalized bone enlargement
Sclerotic phase shows increased density density,, trabeculae and cortical thickening
Complications Patho athologic logical al
fractures fract ures - comple complete te or
incomplete Neurological
effects
± Cra Crani nial al nerv nerve e lesio lesions ns ± Spi Spina nall cord cord lesi lesion ons s
Osteoarthritis
Sarcomas
Biochemistry
Serum calcium and phosphate are usually normal
Serum alkaline phosphatase is increased
Uric
acid increased in about 30% of patients
Diagnosis Plain
x-rays and radioisotopes bone scan
± Incre Increased ased bon bone e sclerosis sclerosis ± Abno Abnormal rmal archite architecture cture with with coarse cortica corticall trabeculation trabeculat ion or cortical thickening ± Bowing ± Bony enlargement
Serum alkaline phosphatase, Ca, and
Bone
scan after diagnosis established
PO4
Nursing
Diagnosis
1. Acute pain related to impingement of abnormal bone on spinal cord 2. Bathing/hyg athing/hygiene, iene, dressing/groo dressing/grooming, ming, toileting selfcare deficit related to musculoskeletal impairment 3. Disturbed body image related to bowing of legs. 4. Impaired physical mobility related to asymmetrical bowing of tibia and femur
