1. Metabolic Bone Disorders
Prof. Mamoun Kremli
AlMaarefa College

2. Objectives Bone as an active tissue Calcium is an important mineral
Calcium metaboism – normal control
Diseases
Osteoporosis
Rickets and Osteomalacia
Hyperparathyroidism
Scurvy

3. Functions of bone tissue
Mechanical:
Support & protect soft tissue
Load transmission
Mediate movement
Mineral reservoir
Largest reservoir of Ca
Regulation of Ca

4. Basic Anatomy of Bone

5. Bone components A: Matrix: Organic: (40% of dry weight)
Collagen fibers
Cells
Inorganic (Minerals): (60%)
Ca hydroxyapetite, Ca phosphate
Others
B: Cells:
Osteoblasts, osteoclasts, osteocytes, others

6. Bone cells Osteoblasts Osteoclasts Osteocytes Osteone:
a unit, not a cell

7. Bone is active Continuous activity and flow
Structure and composition changing all the time
Regulations by regulating cellular activity:
Osteoclasts & Osteoblasts
Cellular Activity
Modulation of Bone Structure & Composition
Changes in mineral ion concentrations
Hormones & Local Factors

8. Bone growth & remodelling
Epiphyseal: Endochondral ossification
On surface: Oppositional ossification
In Adults:
Remodelling of existing bone (no growth)
Annually: 4% of cortical and 25% of cancellous
“old bone” continuously replaced by “new bone”
Initially: formation slightly exceeds resorption
Later: resorption exceeds formation
Bone mass steadily declines

9. Age related bone changes
Childhood – adolescence: Growth ( size & change shape)
Adolescence – 35 (40) years:
Bones get heavier and stronger
Annual bone mass gain: 3%
35 (40) – 50 years:
Slow loss of bone mass annually:
Men: 0.3%
Women:
0.5% to menopause,
then 3% for 10 years - (Why?) (↑ osteoclastic activity by ↓ hormones)
65 years – onwards:
Loss of mass slows gradually to 0.5% (↓osteoblastic activity)

10. Body Calcium Most of Ca in body is present in bone
Release of Ca from bone is a slow process
Serum calcium is essential for cell function, nerve conduction, and muscle contraction
Normal level: mg/dl ( mmol/L)
S. levels have to be controlled quickly
Intestinal absorption
Renal reabsorption

11. Causes of Calcium absorption
 intake of phosphates (as in soft drinks)
 intake of oxalates (as in tea and coffee)
Drugs: corticosteroids
Intestinal malabsorption syndromes

12. Players in Ca regulation
Vit. D is the general crude regulator
Target organs:
Small intestines
Bones
PTH is the sensitive fine regulator
Kidneys (v quick)
Bones (slow)
(indirectly): small intestine

13. Players in Ca regulation
Cacitonin: C cells of Thyroid
Opposite PTH on bone and kidneys
Oestrogen:
Protects bone from PTH
Corticosteroids:
Bad to bone
Local – BMP (Bone Morphogenic Proteins)
Mechanical stress:
Strengthens bone

14. Calcium metabolism

15. Hormonal regulation of Ca met.

16. Hormonal regulation of Ca met.
Mesutti, 2011

18. Laboratory investigations
X-rays
Bone mineral density (BMD)
DEXA scans: Dual Energy X0ray Absorptiometry
Biochemical tests:
Serum Ca, Phosphate
Serum Alkalin Phosphatase
Osteoclastic activity, measures bone turnover rate
Vit. D levels
Urine Ca and Phosphate excretion
Renal profile
Liver function test

19. Common Diseases Osteoporosis Rickets Osteomalacia
Hyperparathyroidism (osteitis fibrosa)

20. Osteoporosis Reduction of bone mass Types:
Bone minerals and matrix both reduced
Matrix present is normally mineralized
Types:
Generalized:
systemic disease
Localized:
disuse (e.g. in cast)

21. Osteoporosis More in women In men:
Post menopausal
Oestrogen withdrawal
Increased with:
cigarette smoking
when start menopause with weak bones
In men:
15 years later
In elderly, may be associated with osteomalacia

22. Osteoporosis – clinical features
Weak bones: easily fractures:
Vertebral compression fractures
Backache, kyphosis
Colle’s fracture
Neck of femur
Proximal humerus
Orthopedic Radiology, A Greenspan. lippincott

23. Osteoporosis – clinical features
Weak bones: easily fractures:
Vertebral compression fractures
Backache, kyphosis
Colle’s fracture
Neck of femur
Proximal humerus
Orthopedic Radiology, A Greenspan. lippincott

24. Osteoporosis – clinical features
Weak bones: easily fractures:
Vertebral compression fractures
Backache, kyphosis
Colle’s fracture
Neck of femur
Proximal humerus
Apley’s System of Prthop & Fractures
Orthopedic Radiology, A Greenspan. lippincott

25. Osteoporosis – clinical features
Weak bones: easily fractures:
Vertebral compression fractures
Backache, kyphosis
Colle’s fracture
Neck of femur
Proximal humerus
Loss of cortical thickness
seen on X-rays
Apley’s System of Prthop & Fractures
Orthopedic Radiology, A Greenspan. lippincott

26. Risk Factors for postmenopausal osteoporosis
Caucasian (white) or Asiatic ethnicity
F.H. of osteoporosis
H.O. anorexia nervosa or amenorrhea
Low peak bone mass in third decade
Early onset menopause
Very slim built
Oophorectomy and early hysterectomy
Nutritional deficiency
Chronic lack of exercise

27. Osteoporosis - Prevention
Good Ca and Vit. D intake
Good physical activity
Exposure to sun
No smoking
No alcohol

28. Osteoporosis - Prevention
If BMD low:
Hormone replacement therapy (oestrogen):
Effective early
For initial five years
Problems:
Dysfunctional uterine bleeding
Risk of uterine and breast cancer – on long use

29. Osteoporosis - treatment
Treat the fractures
Maintain good Ca and Vit D intake
May be associated with osteomalacia
Maintain good physical activity
Trying to reduce rate of further bone loss
Hormone replacement therapy
Bisphosphonates

30. Rickets & Osteomalacia

31. Rickets & Osteomalacia
Same disease: (children / adults)
Inadequate absorption and/or utilization of Ca
Common causes:
Lack of Vit. D
Sever Ca deficiency
Hypophosphatemia
Results in loss of mineralization of bone

32. Rickets - pathology Matrix forms, not calcified In growing physis
Widened physis (epiphyseal growth plate)
Cupping of metaphyseal end (weak new bone)
In all bone
Osteopenia, Thin cortex, Deformity
Harrisons sulcus, frontal bossing
In sever cases: hypocalcaemia:
Tetany, convulsions, failure to thrive

33. Rickets – clinical picture
Enlarged ends of long bones
Wrists, knees
Rickety rosary:
costo-chondral junctions
Harrisons sulcus
Frontal bossing
Bowing of legs:
Localized – distal tibiae
In sever cases: tetany, convulsions
Orthopedic Radiology, A Greenspan. lippincott

34. Rickets – clinical picture
Enlarged ends of long bones
Wrists, knees
Rickety rosary:
costo-chondral junctions
Harrisons sulcus
Frontal bossing
Bowing of legs:
Localized – distal tibiae
In sever cases: tetany, convulsions

35. Rickets – clinical picture
Enlarged ends of long bones
Wrists, knees
Rickety rosary:
costo-chondral junctions
Harrisons sulcus
Frontal bossing
Bowing of legs:
Localized – distal tibiae
In sever cases: tetany, convulsions

36. Rickets – clinical picture
Enlarged ends of long bones
Wrists, knees
Rickety rosary:
costo-chondral junctions
Harrisons sulcus
Frontal bossing
Bowing of legs:
Localized – distal tibiae
In sever cases: tetany, convulsions

37. Rickets – clinical picture
Enlarged ends of long bones
Wrists, knees
Rickety rosary:
costo-chondral junctions
Harrisons sulcus
Frontal bossing
Bowing of legs:
Localized – distal tibiae
In sever cases: tetany, convulsions

38. Rickets – clinical picture
Enlarged ends of long bones
Wrists, knees
Rickety rosary:
costo-chondral junctions
Harrisons sulcus
Frontal bossing
Bowing of legs:
Localized – distal tibiae
In sever cases: tetany, convulsions
N Engl J Med 2009

39. Orthopedic Radiology, A Greenspan. lippincott
Rickets – X-rays
Widened physis (epiphyseal growth plate)
metaphyseal end of physis
Cupping of (weak new bone)
Irregular
Deformed bones
Orthopedic Radiology, A Greenspan. lippincott

40. Orthopedic Radiology, A Greenspan. lippincott
Rickets – X-rays
Orthopedic Radiology, A Greenspan. lippincott

41. Orthopedic Radiology, A Greenspan. lippincott
Rickets – X-rays
Orthopedic Radiology, A Greenspan. lippincott

42. Rickets – lab results Serum Ca: Serum Phsphate: Alk Phosphatase:
slightly low /or normal
Serum Phsphate:
Alk Phosphatase:
High – a lot of bone turnover
Vit. D level:
low
PTH level:
Increased – scondary effect – to keep s. Ca level
Urinary Ca: V. low

43. Rickets - treatment Vit. D and Calcium
Most deformities correct gradually
Sever deformities might need surgical correction

44. Hopophsphataemic rickets
Vit. D resistant rickets
Familial, X-linked
Impaired renal tubular reabsorption of phosphate
Lab. Results:
Serum Phosphate: low
Urinary phosphate: high
Treatment:
High dose Vit. D
Phosphate

45. Orthopedic Radiology, A Greenspan. lippincott
Osteomalacia
Caused by defective Vit. D:
Deficiency – lack of sun exposure
Intestinal malabsorption
Defective formation of active Vit. D:
Liver or Renal disease
Clinical features
Bone aches – backache, hip pain
Compressed vertebral fracture
Insufficiency fractures of femur / tibia
Orthopedic Radiology, A Greenspan. lippincott

46. Apley’s System of Prthop & Fractures
Osteomalacia – X-rays
Weak osteopaenic bone
Biconcave vertebrae & compression fractures
Trefoil pelvis – acetabular protrusion
Typically: Looser’s zones:
Poorly healing stress fractures
Neck of scapula
Neck of femur
Pubic bones
Apley’s System of Prthop & Fractures

47. Apley’s System of Prthop & Fractures
Osteomalacia – X-rays
Weak osteopaenic bone
Biconcave vertebrae & compression fractures
Trefoil pelvis – acetabular protrusion
Typically: Looser’s zones:
Poorly healing stress fractures
Neck of scapula
Neck of femur
Pubic bones
Apley’s System of Prthop & Fractures

48. Orthopedic Radiology, A Greenspan. lippincott
Osteomalacia – X-rays
Weak osteopaenic bone
Biconcave vertebrae & compression fractures
Trefoil pelvis – acetabular protrusion
Typically: Looser’s zones:
Poorly healing stress fractures
Neck of scapula
Neck of femur
Pubic bones
Orthopedic Radiology, A Greenspan. lippincott

49. Apley’s System of Prthop & Fractures
Osteomalacia – X-rays
Weak osteopaenic bone
Biconcave vertebrae & compression fractures
Trefoil pelvis – acetabular protrusion
Typically: Looser’s zones:
Poorly healing stress fractures
Neck of scapula
Neck of femur
Pubic bones
Apley’s System of Prthop & Fractures

50. Orthopedic Radiology, A Greenspan. lippincott
Osteomalacia – X-rays
Looser’s zone
Orthopedic Radiology, A Greenspan. lippincott

52. Hyperparathyroidism Primary: Secondary: Tertiary:
Parathyroid adenoma / hyperplasis
Secondary:
Hyperplasia due to hypocalcaemia
Tertiary:
Autonomous activity after secondary hyperplasis

53. Orthopedic Radiology, A Greenspan. lippincott
Hyperparathyroidism
Effect of PTH
Target organs:
Kidneys
Bones
Intestines (indirect)
Bone weakens, resorption
Increased serum Ca
Orthopedic Radiology, A Greenspan. lippincott

54. Hyperparathyroidism Bones Stones Moans Groans Rarefaction
Subperiosteal resorption (middle phalanges)
Reorption of lateral end clavicle
Brown tumors
Stones
Kidney stones and nephroclacinosis
Moans
Abdominal pain, renal pain
Groans
Pschological depression, stress

55. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification

56. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification
Orthopedic Radiology, A Greenspan. lippincott

57. Hyperparathyroidism – x-rays
Subperiosteal bone resorption
Orthopedic Radiology, A Greenspan. lippincott

58. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification
Orthopedic Radiology, A Greenspan. lippincott

59. Hyperparathyroidism – x-rays
Subperiosteal bone resorption
Orthopedic Radiology, A Greenspan. lippincott

60. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification
Orthopedic Radiology, A Greenspan. lippincott

61. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification
Orthopedic Radiology, A Greenspan. lippincott

62. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification

63. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification
Orthopedic Radiology, A Greenspan. lippincott

64. Hyperparathyroidism – x-rays
Bones
Rarefaction
Bone resorption
Subperiosteal resotption
middle phalanges
Tibial shaft
lateral end clavicle
Brown tumors
Skull: salt & pepper
Soft tissue calcification
Orthopedic Radiology, A Greenspan. lippincott

65. Hyperparathyroidism - treatment
Hydration
Reduced calcium intake
If adenoma:
Surgical removal
Beware of the “hungry bone” syndrome post operatively – severe hypocalcaemia (why?)

66. Scurvy – Vit. C deficiency
First discovered in sailors
Failure of collagen fibers formation
Weak osteoid matrix
Clinical picture:
Child irritable, anemia
Bleeding gums
Pain and swellings at ends of long bones

67. Scurvy – Vit. C deficiency
X-rays:
Osteopaenia – more at mataphysis
Sub-periosteal bleeding
Periosseous calcification
Ring epiphysis
Sclerosis at juxtaepiphyseal metphysis
Treatment:
Vit C (large doses)

68. Scurvy – Vit. C deficiency
Orthopedic Radiology, A Greenspan. lippincott

69. Scurvy – Vit. C deficiency
Orthopedic Radiology, A Greenspan. lippincott

70. Scurvy – Vit. C deficiency
X-rays:
Osteopaenia – more at mataphysis
Sub-periosteal bleeding
Periosseous calcification
Ring epiphysis
Sclerosis at juxtaepiphyseal metphysis
Treatment:
Vit C (large doses)

71. Summary Bone is an active tissue Calcium is an important mineral
Continuous absorption and rebuilding
Calcium is an important mineral
Calcium control
Diseases
Osteoporosis
Rickets and Osteomalacia
Hyperparathyroidism
Scurvy