2. Metabolic Bone Disorders Dr. Mohammed M. Zamzam
Associate Professor & Consultant
Pediatric Orthopedic Surgeon
3. Calcium Homeostasis - Bone is not only for support
- Bone formation & bone resorption
- Hydroxyapatite crystals
- Calcium & phosphate control
* Intestinal absorption
* Renal excretion
* Bone
4. Vitamin D * Sources - Diet
- Ultraviolet rays on skin
* Cholecalciferol activation
- PTH
- Phosphate concentration
* Action - Intestinal absorption of Ca
- Bone resorption
5. Parathyroid Hormone - Fine regulator of Ca exchange
- Serum Ca regulate its secretion
- Action
* Increase phosphate excretion
* Increase Ca reabsorption
* Vitamin D activation
6. Calcitonin - C cells of thyroid gland
- Serum Ca regulates its secretion
- Action
* Rapid hypocalcaemic effect by inhibiting
bone resorption
7. Secondary rule Other Hormones Non-hormonal Factors - Estrogen
- Corticosteroids
- Thyroxin - Mechanical stress
- Prostaglandin E
- Acid-base balance
10. Rickets & Osteomalacia - Different expressions of the same disease
- Inadequate mineralization
- Rickets
* Areas of endochondral growth
- Osteomalacia
* All skeleton is incompletely calcified
11. Rickets & Osteomalacia * Causes
- Calcium deficiency
- Hypophosphataemia
- Defect in Vitamin D metabolism
nutritional
underexposure to sunlight
intestinal malabsorption
liver & kidney diseases
12. Rickets & Osteomalacia Symptoms & Signs
*Rickets
- Tetany or convulsions ?
- Failure to thrive , muscle flaccidity
- Craniotabes , joint thickening
- Pigeon chest , rickety rosary , Harrison’s sulcus
- Deformities
15. Rickets & Osteomalacia Symptoms & Signs
*Osteomalacia
- Bone pain , backache
- Muscle weakness
- Vertebral collapse kyphosis
loss of height
- Deformities & stress fractures
16. Rickets & Osteomalacia Biochemistry
Hypocalcaemia,… Hypocalcuria
High alkaline phosphatase
21. Rickets & Osteomalacia X-rays
*Rickets
- Growth plate widening & thickening
- Metaphyseal cupping
- Diaphyseal deformities
*Osteomalacia
- Looser zone , biconcave vertebra , protrusio acetabuli
- Spontaneous fractures
*Signs of secondary hyperparathyroidism
30. Rickets & Osteomalacia Treatment
*Vitamin D deficiency
- Rickets controlled Vitamin D
sun exposure
correct residual deformities
- Osteomalacia Vit. D + Ca
fracture management
correct deformity if needed
32. Hyperparathyroidism *Primary
hyperplasia - adenoma - carcinoma
*Secondary
persistent hypocalcaemia
*Tertiary
secondary leads to hyperplasia
33. Hyperparathyroidism Pathology
- PTH overproduction
- Increased renal tubular absorption , intestinal
absorption and bone resorption of Ca
- Hypercalcaemia and hypercalciuria
- Suppressed phosphate tubular reabsorption
- Hypophosphataemia and hyperphosphaturia
34. Hyperparathyroidism Pathology
*Hypercalcaemia
calcinosis , stone formation , recurrent infection and soft tissue calcification
*Bone resorption
loss of bone substance , subperiosteal erosion
osteitis fibrosa cystica and brown tumors
35. Hyperparathyroidism Symptoms & Signs
*Hypercalcaemia
anorexia , nausea , depression and polyuria
*Bone rarefaction
pain , pathological fractures and deformities
*Biochemistry
hypercalcaemia , hypophosphataemia , high
alk. Phosphatase and serum PTH
39. Hyperparathyroidism X-rays
- Subperiosteal bone resorption
- Generalized decrease in bone density
- Brown tumors
- Chondrocalcinosis
knee , wrist and shoulder
46. Hyperparathyroidism Treatment
Surgical excision of adenoma or hyperplastic
parathyroid tissue
*Hungry bone syndrome
treated by vitamin D
48. Osteoporosis * Normal mineralization
* Decrease bone mass
(amount of bone per unit volume)
* Age related
* Associated or manifestation of other conditions
49. Osteoporosis Causes
* Idiopathic
* Nutritional
* Endocrine disorders
* Drug induced
* Malignant diseases
* Miscellaneous
51. Osteoporosis - Idiopathic osteoporosis - normal investigations
- In old patients we have to role out malignancy
and multiple myeloma
- Younger patients must be fully investigated
- Several causes may be involved
- Osteoporosis can be associated with osteomalacia
52. Osteoporosis Symptoms & Signs
- Bony aches
- Easy fractures
spine - lower radius - femoral neck
- Rib fracture , chest pain
- Normal biochemistry
55. Osteoporosis X-rays
- Decrease bone density
- Wedging or biconcave vertebrae
- Thin cortex and deformities
- Dexa Scan
- Biopsy
61. Osteoporosis Treatment
- Treat underlying cause
- Idiopathic , extremely difficult
- Calcium and vitamin D
- Fluoride and triple therapy
- Calcitonin , Diphosphonate
- Treat fractures
63. Osteoporosis Prevention
* Good diet
* Exercise
* Exposure to sun light
* Ca supplement
* Hormone therapy
