Metabolic bone disease in Orthopaedics presentation including osteoporosis, pages disease, rickets ,

1. Osteoporosis and Metabolic disease of
Bone
Moderator –
Dr. Yoseph Z.( orthopedic surgeon)
Presenter – Dr. Ayalew.(ORII)

2. Outline
 Introduction
 Osteoporosis
 Osteomalacia and rickets
 Paget's disease

3. Introduction
 Bone is a dynamic organ constantly being formed
(modeling) and re-formed (remodeling).
 it is a mineral reservoir which helps to regulate the
composition and in particular the calcium ion
concentration of the extracellular fluid
 Bone Metabolism ; A multi-organ process that
involves the coordination of various hormones and
complex feedback mechanism.
 Parathyroid gland, kidney, liver, intestine, and bone

5. METABOLIC BONE DISORDER
INTRODUCTION
• DEFINITION: DISORDERS THAT AFFECT THIS ORGAN
AND THE PROCESS OF MINERALIZATION ARE
DESIGNATED METABOLIC BONE DISEASES
. Osteoporosis, Osteomalacia, Paget’s Disease etc

6. Osteoporosis
 Defined as low bone mass with micro architectural
disruption, resulting in increased skeletal fragility and
fracture.
 Decrease in bone strength.

7. Classification
Osteoporosis
Generalized
Primary
Type 1 ( post
menopausal)
Type 2 (
Senile)
Secondary
Localized
..

8. Primary osteoporosis
Type 1 ( postmenopausal osteoporosis)
 Due to loss of estrogens protective bone effect
 mainly increased bone resorption
 Affects females 51 to 75
 Distal radius and vertebral fractures are more
common

9.  Type2 (senile osteoporosis)
 Occurs ages of 70 an
 Trabecular and cortical bone loss
 Fractures of femur neck and pelvis are common

10. Secondary causes of osteoporosis

11. Localized Secondary Osteoporosis
1.Disuse osteoporosis (prolonged immobilization of a
limb)
a. Plaster cast
b. Paraplegia
c. Quadriplegia.
2. Monoarticular rheumatoid arthritis.
3. Sudeck’s osteodystrophy

13. clinical Presentation
 is asymptomatic
 Vertebral fracture is most common manifestation
 Hip fracture.
 Back pain
 Increased thoracic kyphosis
 Decrease in height

14. Approach
 History – smoking, alcohol, physical activity,
nutrition
 Physical Examination – height and weight
 Investigation
 CBC
 LFT, SE, RFT
 Vitamin D
 X-ray

15. X rays
 Osteopenia :bone witch appears less dense than
normal
 More characteristic signs of osteoporosis
 loss of trabecular definition
 Thinning of cortices
 Insufficiency fractures
 Compression fracture of vertebral bodies
 Ballooning of the disc spaces

16. BMD
 Bone mineral density is gold standard to diagnosis
osteoporosis
 Measured using DEXA( dual energy x-ray
absorptiometry)
 Measurement sites are the hip and spine ( L2 – L4).
 Take the lowest of the two measurement.

18. Prevention and treatment
 Non Pharmacologic treatment
 Diet
 Exercise
 Cessation of smoking
 Pharmacologic treatment
 Hormone replacement therapy
 Bisphosphonates

19. PHARMACOLOGIC THERAPY
 Candidates
 History of hip or vertebral fracture.
 T-score ≤-2.5 (DXA) at the femoral neck or spine, after
appropriate evaluation to exclude secondary causes.


20. PHARMACOLOGIC THERAPY

21. Bisphosphonates
 Inhibit bone resorption
 They are used in the treatment of hypercalcaemia,
osteoporosis, metastatic bone disease, Paget
disease
 The nitrogen-containing bisphosphonates are more potent
inhibitors of bone resorption than the simple
bisphosphonates.

22. Bisphosphonates
Oral regimen — alendronate , risedronate
 poorly absorbed orally (less than 1 percent of the dose)
 must be taken on an empty stomach
 ALENDRONATE
 10 mg PO daily or 70 mg PO weekly
 The regimens were similar for increasing BMD and had similar
low rates of side effects
 Risedronate
 5 mg po daily
 35 mg po weekly
 150 mg po monthly

23.  IV regimen
 Alternative option for patients who cannot tolerate oral
bisphosphonates,
 Zoledronic acid (ZA) is administered yearly and infused
over a period of at least 15 minutes,
 Ibandronate is administered every three months as a 15
to 30 second intravenous injection

24.  Hormone Replacement Therapy;
 SERM; Raloxifene , Estrogen/progestin therapy
 PTH;
 Men or postmenopausal women with severe osteoporosis
 who are unable to tolerate bisphosphonates
 Patients who fail other osteoporosis therapies

25. Rickets and Osteomalacia
 Rickets refers to deficient mineralization at the
growth plate, as well as architectural disruption of
this structure.
 Calcipenic rickets is caused by calcium deficiency
 Phosphopenic rickets usually is caused by renal
phosphate wasting

26. Etiology
 Depending on the predominantly deficient mineral
 Rickets can be
 Calcipenic Rickets
 Phosphopenic rickets

27. Calcipenic rickets
 Nutritional rickets – Calcipenic rickets is usually
caused by dietary deficiency of vitamin D ( classsic
form of rickets) or rarely ca deficiency
 Vitamin D-dependent rickets type I – Vitamin D-
dependent rickets type I (VDDR-I),
 Hereditary vitamin D-resistant rickets – Hereditary
vitamin D-resistant rickets (HVDRR), also known as
vitamin D-dependent rickets type II,

28. Calcipenic Rickets
 Calcium level is too low to demand of bone growth
because of supply or absorption
Vitamin D deficiency Rickets
 Presents between three months and three years of age
because of rapid growth and less sun exposure.
 Risk factors
 Maternal vitamin D deficiency during pregnancy
 Breast feeding without sun exposure or supplementation
 Low sun exposure
 Black skin
 Malabsorption
 Drugs – anti - convulsions, ART

29. Phosphopenic rickets
 Phosphopenic rickets is characterized by low serum
phosphorus with normal PTH concentrations.
Phosphopenic rickets in children and adolescents is
almost always caused by renal phosphate
wasting

30. PATHOGENESIS
 Vascular invasion requires mineralization of the growth
plate cartilage and is delayed or prevented by deficiency
of calcium or phosphorus .
 In these circumstances, growth plate cartilage
accumulates and the growth plate thickens
 chondrocytes of the growth plate become disorganized
with characteristic expansion of the hypertrophic zone
 metaphysis, the mineralization defect leads to the
accumulation of osteoid
 Those changes lead to
 increases in the diameters of the growth plate and metaphysis.
 bone stability is compromised leading to bowing

31. CLINICAL MANIFESTATIONS
 Initially manifest at the distal forearm, knee, and
costochondral junctions
 Skeletal findings.
 Delayed closure of the fontanels
 Parietal and frontal bossing
 Craniotabes (soft skull bones)
 Enlargement of the costochondral junction visible as beading along
the anterolateral aspects of the chest (the "rachitic rosary")
 Formation of Harrison sulcus (or groove) at the lower margin of the
thorax caused by the muscular pull of the diaphragmatic attachments
to the lower ribs
 Widening of the wrist and bowing of the distal radius and ulna
 Progressive lateral bowing of the femur and tibia.

33. Approach
 History and Physical examination
 Diet ( calcium, vitamin D)
 Sun exposure
 medication
 Investigation
 lab – serum calcium, phosphorus, PTH, LFT and RFT
 X – ray
 laboratory values .nutrional rickets
 low to normal serum calcium
 low serum phosphate
 elevated alkaline phosphatase
 elevated parathyroid hormone
 low vitamin D

34. X-ray
 Best seen in areas of rapid bone growth.
 Wrist
 knee
 Early signs
 Widening of the plate
 Loss of zone of provisional calcification.
 Advanced signs
 Disorganization of the growth plate with cupping, splaying,
formation of cortical spurs, and stippling.
 Epiphyseal bone centers may be delayed, or they may be small,
osteopenic, and ill-defined.
 shafts of the long bones are osteopenic, and the cortices may become
thin.
 Deformity.
 Pathologic fracture.

37. prevention
 Supplement pregnant women with vitamin D
 Supplement newborn with vitamin D
 Sun exposure

38. Treatment
 Treatment of Vitamin D deficiency Rickets
 Use vitamin D2 or D3
 If no absorption abnormality, dose is
o < 1 month – (1000 IU/day)
o 1 – months – (1000 – 2000 IU/day)
o > 12 months – 2000 IU
o Maintenance dose is 600 IU/day
 If absorption abnormality – 2 – 3 x higher
 If elevated PTH
 Calcium 30 – 75 mg/kg in three divided doses.

39. Calcium Deficiency Rickets
 In very low calcium deficiency.
 Treatment
 Calcium 1000 mg/day
 Maintenance dose of vitamin D.

40. Surgery
 Orthopedic intervention may be necessary if deformities do
not improve once the radiologic appearance of the growth
plates has normalized.
 If patients are experiencing increasing pain or difficulty
walking, surgical correction of angular deformities should
be performed

41. Osteomalacia
 Osteomalacia is a disorder of decreased
mineralization of newly formed osteoid at sites of
bone turnover
 Mechanism
 Hypocalcaemia
 Hypophosmatemia
 Direct inhibition of the mineralization process.

42. Etiology of Osteomalacia

43.  May be asymptomatic with incidental finding of
osteopenia on x-ray.
 Symptoms and signs
 Bone pain
 Muscle weakness
 Bone tenderness
 Difficulty of walking
 Muscle spasm

45. Lab

46. x-ray findings
 Reduced bone density with thinning of the cortex is
the most common finding but it is very nonspecific
 More specific are changes in vertebral bodies and
Looser zones.
 Vertebral Bodies –
 a loss of radiologic distinctness of vertebral body trabeculae
 concavity of the vertebral bodies called codfish vertebrae.
 The vertebral disks appear large and biconvex

48. Treatment
 Treat the underlying disorder.
 correct hypophosphatemia, hypocalcaemia, and
vitamin D deficiency.
 Vitamin D deficiency
 Vitamin D supplementation at dose of 50000 IU/ day.
 Calcium 1000 mg/day.
 Hereditary hypophosphatemic rickets
 phosphate supplementation and calcitriol.

49. Paget disease.
 a focal disorder of bone metabolism that occurs in
the aging skeleton; it is characterized by an
accelerated rate of bone remodeling, resulting
in overgrowth of bone at a single or multiple
sites and impaired integrity of affected bone
 Commonly affected areas include
 skull, spine, pelvis, and long bones of the lower
extremity.

50. Etiology
 remains unknown
 Proposed theories
 Genetic
 Virus –

51. PATHOGENESIS —
 Paget disease of bone (PDB), which is characterized
by
 an accelerated rate of bone remodeling,
 resulting in overgrowth of bone at selected sites and
 impaired integrity of affected bone, is believed to be a disease
of the osteoclast

52.  HISTOPATHOLOGY — The osteoclasts in patients
with Paget disease are bizarre in appearance,
multinucleated, and excessive in number
Epidemiology
 Occur after the age of 55.
 Shows familial and geographic clustering.
 Common in Britain and Australia.

53. CLINICAL MANIFESTATIONS
 majority of patients are asymptomatic,
 Pain
 Deformities
 fractures, bone tumors, neurologic disease, and
abnormalities in calcium and phosphate balance

54.  Skull; deformity, hearing loss (due to cochlear
involvement), headache
 Spine; bone pain, and nerve compression,
Fracture
 pelvis; pain, arthritis, and protrusio acetabuli
 Long bones — Bowing deformities

55. laboratory findings
 serum alkaline phosphatase usually elevated
 other markers of bone turnover ; PINP, NTx..
often elevated
 Serum calcium and phosphorus are normal in
most patients

56.  plain radiography
 Classic triad; thickening of the cortex, trabecular
accentuation and increase bone size
 Skull
 Spine
 Pelvis
 Long bones
 bone scan
 CT and MRI
Imaging

57. plain radiography
 Earlier; lytic lesion
 Osteoporosis circumscripta
 flame shaped”
 Mixed lytic/sclerotic lesions resulting in
 thickening of cortical bone,
 heightened trabecular markings, and
 distortion and overgrowth of involved bone

59. DIAGNOSIS
 The diagnosis of Paget disease is primarily
radiologic
 serum alkaline phosphatase is elevated

60. Complications
 Fractures
 OA
 Nerve compression and spinal stenosis
 Bone sarcoma (osteosarcoma)
 Occurs in around 1% of the cases
 Suspect ;if bone becomes more painful ,tender or swollen
 Prognosis :extremely grave
 High out put cardiac failure

61. Treatment
 Goals
 Reduce pain
 Decrease rate of remodeling
Pharmacologic
Surgery

62. Treatment
INDICATIONS FOR THERAPY
 The presence or absence of symptoms from active
disease
 distribution of pagetic lesions
 metabolic activity of pagetic lesions
 The potential consequences of bony overgrowth at
affected sites

63.  Symptomatic Paget disease;
 bone pain at a pagetic site
 Asymptomatic Paget disease
 location of the disease and the presence of comorbidities
are important factors
 ALP is more than 2-4X the upper limit of normal

64. Pharmacologic
 Bisphosphonates
 The nitrogen containing are the primary agents used for the initial
treatment of Paget disease
 zoledronic acid , pamidronate , risedronate ,
alendronate , ibandronate , and neridronate
 Calcitonin is now used infrequently;

65.  Preoperative antipagetic therapy
 nitrogen-containing bisphosphonate, beginning three
months prior to surgery

66. ROLE OF SURGERY
 corrective osteotomy for long bone deformity,
 fracture fixation,
 joint Arthroplasty,
 spinal decompression, and
 resection of bone tumors
 Patients are at increased risk for blood loss,
which may be decreased by preoperative
antipagetic treatment.