Adult Medical-Surgical Nursing Musculo-skeletal Module: Pagets Disease

Bone Formation  Bone is a dynamic tissue constantly reforming and resorbing  Bone cells (osteocytes) are:  Osteoblasts (bone formation)  Osteoclasts (bone destruction, resorption, remolding)

Bone Formation  Osteoblasts secrete collagen and glycoproteins to form a bone matrix  Deposit minerals in the matrix (calcium, magnesium, phosphorus, chloride)  Osteoclasts resorb calcium and minerals from bone causing depletion

Hormones Affecting Bone Turnover  Hormones which promote bone formation: (inhibit resorption)  Oestrogen and calcitonin  Testosterone in males ( ↓ with age)  Hormone which increases bone turnover and resorption:  Parathormone ( ↑ with age)  (Also insufficient oestrogen/ calcitonin/ testosterone)

Factors Influencing Bone Formation  Local stress: usage/ weight-bearing and walking aid bone formation  (Immobility leads to increased calcium resorption from bone and osteoporosis)  Adequate calcium and vitamin D (intestinal absorption of calcium)  Parathormone/ Calcitonin activity  Blood supply (inadequate → necrosis)

 Bone Pathology

Bone Pathology: Classification  Osteoporosis  Osteomalacia  Pagets Disease  Bone tumour:  Benign  Malignant primary  Metastases

 Pagets Disease

Pagets Disease: Description  Pagets disease (osteitis deformans) is a condition of localised rapid bone turnover  Affects the skull, femur, tibia, pelvic bones, vertebrae  Affects 2-3% of population > 50 years  Affects males more than females  Causes deformity and risk of pathological fracture

Pagets Disease: Aetiology  Cause unknown  Family history  Increased risk with age

Pagets Disease: Pathophysiology  Localised rapid bone turnover:  Primary proliferation of osteoclasts (bone resorption)  Compensatory ↑ osteoblastic activity  Leads to a disorganised pattern of bone in the areas affected (mosaic):  Highly vascular, structurally weak areas

Pagets Disease: Outcome  Bones are prone to:  Deformity  Pathological fracture

Pagets Disease: Clinical Manifestations  Insidious onset  May only show on a routine Xray

Pagets Disease: Clinical Manifestations  Skeletal deformity:  Bowing of tibia and fibula, deformed pelvic bones, cortical thickening long bones  Ape-like posture  Skull enlargement: face appears small, triangular, hearing affected (cranial nerve)  Pain in back, joints, arthritis, warmth tenderness over bones ( ↑ vascularity)

Pagets Disease: Diagnosis  Xrays confirm  Bone scans  Bone biopsy  Serum alkaline phosphatase ( ↑ )  ↑ urinary hydroxyproline ( ↑ osteoblastic activity)  Serum calcium is normal

Pagets Disease: Medical Management  Control weight  Adequate dietary calcium and vitamin D and supplements  Non-steroidal anti-inflammatory drugs (NSAIDs)  Drugs to reduce bone resorption/ turnover:  Calcitonin, Fosamax  Cytotoxic antibiotic (Mithracin) if severe

Pagets Disease: Management of Complications  May require hearing aid  Hip replacement surgery  Fracture care: closed or open reduction and internal fixation  Regular follow-up examination for early detection treatment

Pagets Disease: Nursing Considerations  Ensure patient education about condition and means of preventing deterioration  Adequate dietary and calcium/ vitamin D supplements (note levels)  Weight control  Psychological/ emotional support  Careful gentle handling and ensure adequate pain relief. Monitor hearing