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![INVESTIGATIONS:
BLOOD TESTS
Calcium Reduced,
Phosphate reduced
Alkalline Phosphatase increased
Urinary excretion of calcium diminished
Calcium phosphate products (= serum [Ca] x serum [PO4])
normally 30. In rickets and osteomalacia is less than 24](https://image.slidesharecdn.com/bonespathologyi-250403043545-40db7189/75/Pathology-of-diseases-of-Bones-Pathology-I-pptx-46-2048.jpg)
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Pathology of diseases of Bones Pathology I.pptx
- 1. Musculoskeletal Pathology Bones PathologyI Dr. Emad Ibrahim Osman
- 2. Bone pathology outline •Congenitaland inherited diseases •Acquired diseases of bone development • Fractures • Osteonecrosis • Osteomyelitis • Tumors
- 3. Congenital diseases ofbone • Osteogenesis imperfecta • Achondroplasia • Osteopetrosis
- 4. Osteogenesis imperfecta • Inheriteddefect in collagen synthesis • Osteopenia and brittle bones • Often- defective tooth formation, blue sclera, faulty hearing • Inheritance can be dominant, recessive or by new mutation • Several degrees of severity
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- 6. Achondroplasia • Involves adefect in normal cartilage development • Epiphyseal plates close early in long bones; individual has short arms and legs, but normal spine and skull • Dominant inheritance, but frequent new mutations • Other organs develop normally • Individuals live a normal lifespan
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- 8. Osteopetrosis Osteopetrosis, also knownas marble bone disease, refers to a group of rare genetic diseases that are characterized by reduced bone resorption and diffuse symmetric skeletal sclerosis resulting from impaired formation or function of osteoclasts. The term osteopetrosis refects the stonelike quality of the bones. However, the bones are abnormally brittle and fracture easily, like a piece of chalk. Osteopetrosis is classifed into variants based on both the mode of inheritance and the severity of clinical fndings.
- 9. Acquired diseases ofbone development • Osteoporosis • Paget disease • Rickets and osteomalacia • Hyperparathyroidism • Renal Osteodystrophy
- 10. Osteoporosis “porous bone” •Most common metabolic bone disease in North America • Can be attributed to genetics, diet or hormones • Most osteoporosis is idiopathic osteoporosis • Bone loss due to an identifiable cause is secondary osteoporosis • Bone tissue is mineralized normally, but over time the structural integrity of bone is lost and it becomes thinner and weaker, and more prone to fractures.
- 11. • Key features:bone fracture and the associated pain. • WHO defines osteoporosis by bone density: • Normal bone > 833 mg/cm2 • Osteopenia 833 to 648 mg/cm2 • Osteoporosis < 648 mg/cm2 • Can be generalized, involving major portions of the axial skeleton • Can be regional, involving one segment of the appendicular skeleton 11
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- 13. • Remodeling isconstant • Teen years more bone is laid down than reabsorbed • Peak bone mass or maximum density reached at around 30 years of age • After age 30, bone is reabsorbed faster than it is laid down • In women, bone loss is most rapid in the first years after menopause, but continues throughout postmenopausal years • Est. 55% of people over 50 have osteoporosis or low bone mass. 13
- 14. • Men alsolose bone density, but start out with more bone mass so takes longer. • By age 90 about 17% of males have had a hip fracture, vs. 32 % of females • Vertebral fractures also occur → kyphosis • Most common in whites, but affects all races. • African Americans have about half the fracture rates of whites (higher peak bone mass) 14
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- 18. Osteoporosis disease characterizedby low bone mass and structural deterioration of bone tissue normal bone osteoporotic bone
- 19. Compression fractures due to osteoporosis thatresults in kyphosis MRI of Spine
- 20. What’s left ofvertebral body
- 21. Medical Terminology: ALiving Language, Fourth Edition Bonnie F. Fremgen and Suzanne S. Frucht Copyright ©2009 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Abnormal spinal curvatures: kyphosis, lordosis, and scoliosis.
- 22. Risk factors • Familyhistory • White race • Increased age • Female sex • Small stature • Fair or pale skin • Thin build • Early menopause (natural or surgical) • Late menarche 22
- 23. Risk factors cont. •Nulliparity • Obesity • Weight below a healthy range • Acidosis • Low dietary calcium and vitamin D • High caffeine intake • Sedentary life style • Smoker • Excessive alcohol consumption • Liver, kidney disease, rheumatoid arthritis, etc. 23
- 24. • Often progressessilently for decades until fracture occurs • Bones can fracture spontaneously • Most severe in spine, wrist and hips • Estrogens and androgens may be factors in both sexes • Testosterone is converted into estrogen in peripheral tissues and decreases bone loss • Rapid bone loss is osteoclast mediated • Slow bone loss is osteoblast mediated 24
- 25. Clinical manifestations • Painand bone deformity • Kyphosis caused by vertebral collapse • Fractures of long bones • Fatal complications include fat or pulmonary embolism, pneumonia, hemorrhage and shock • 20 % die as a result of surgical complications
- 26. Prevention • Intake ofcalcium, vitamin D, magnesium and possibly boron • Regular, weight-bearing exercise • Avoid tobacco and glucocorticoids • No alcoholism • Hormone replacement? • Parathyroid hormone? • Testosterone for men and possibly women
- 27. Pagets disease(OsteitisDeformans): • Characterizedby repetitive episodes of frenzied, regional osteoclastic activity and bone resorption (osteolytic stage), followed by exuberant bone formation (mixed osteoclastic-osteoblastic stage), and finally by an apparent exhaustion of cellular activity (osteosclerotic stage). The net effect of this process is a gain in bone mass; however, the newly formed bone is disordered and lacks strength.
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- 29. • Bone enlargementand thickening • Increased osteo-clast/blast activity > increased turnover • Aet - unknown but racial difference ?viral • CF - M=F, >50, ache but not severe unless fracture or tumour • Investigation - X-ray appearance is characteristic, alkaline phophatase is increased and hydroxyproline in urine is increasded • Rx - bisphos, calcitonin
- 30. Rickets and Osteomalacia •Inadequate mineral deposition in essentially normal organic matrix • Softened bone: • Subject to malformation and distortion – pain 30
- 31. Rickets • Dietary vitaminD deficiency causes inadequate mineralization of the developing skeleton in infants and children • Rarely seen in Western nations • Poverty • Ignorance • Bones are soft and easily deformed • Tendency to fractures • Therapy: suppliment vitamin D and calcium 31
- 32. Osteomalacia • Rarely dueto vitamin D deficiency • Usually GI malabsorption, renal defect or chronic kidney or liver diseases. • Elderly often affected due to inadequate diet or lack of outdoor activity • May accompany and complicate osteoporosis. 32
- 33. RICKETS & OSTEOMALACIA Def.:reduction in bone mineralization !
- 34. Normal bone metabolism •CALCIUM 99% in bone. Main functions - muscle/nerve function, clotting. Plasma calcium - 50% free, 50% bound to albumin. • Dietary needs- Kids- 600mg/day, Adolesc.-1300mg/day, Adult-750mg/day, Pregnancy- 1500mg/day, Breastfeeding-2g/day, Fractures- 1500mg/day • Absorbed in duodenum (active transport) and jejunum (diffusion), 98% reabsorbed in kidney prox. tubule, may be excreted in stool.
- 35. Normal bone metabolism •PHOSPHATE 85% in bone. Functions - metabolite and buffer in enzyme systems. • Plasma phosphate mainly unbound. Daily requirement 1-1.5g/day
- 36. Regulation of Calciumand Phosphate Metabolism: Peak bone mass at 16-25 years. Bone loss 0.3- 0.5% per year (2-3% per year after 6th decade). 1. Parathyroid Hormone (PTH) 2. Vitamin D3 3. Calcitonin 4. Other Hormones: Estrogen: Prevents bone loss Corticosteroids: Increases bone loss Thyroid hormones: Leads to osteoporosis Growth hormones: Cause positive calcium balance Growth factors
- 39. Endocrine,paracrine and intracrine functionsof Vitamin D
- 40. RICKETS, OSTEOMALACIA PATHOLOGY: Sufficient osteoid,poor mineralization RICKETS is found only in children prior to the closure of the growth plates, while OSTEOMALACIA occurs in persons of any age. Any child with rickets also has osteomalacia, while the reverse is not necessarily true.
- 41. CAUSES: 1. Nutritional deficiency 1.Vit D 2. chelators of calcium- phytates, oxalates, phosphorous 3. Antacid abuse, causing reduced dietary phosphate binding 2. GI absorption defects 1. Post gastrectomy 2. Biliary disease (reduced absorption of Vitamins ) 3. Small bowel disease 4. liver disease 3. Renal tubular defects 4. Renal osteodystrophy 5. Miscellaneous causes
- 42. CLINICAL FEATURES: • Rickets- Tetany , convulsions, failure to thrive, Restlessness, muscular flaccidity. Flattening & softening of skull (craniotabes), Thickening of wrists from epiphyseal overgrowth, Stunted growth, Rickety rosary, spinal curvature, Coxa vara, bowing, # of long bones • Osteomalacia – Aches and pains, muscle weakness, loss of height, stress #s.
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- 44. XRAY FINDINGS: RICKETS Thickening andwidening of epiphyses, Cupping of metaphysis, Wide metaphysis, Bowing of diaphysis, Blurred trabeculae.
- 45. XRAY FINDINGS: OSTEOMALACIA Loosers zones- incomplete stress # with healing lacking calcium, on compression side of long bones. Codfish vertebrae due to pressure of discs Trefoil pelvis(Triangular), due to indentation of acetabulae stress #s
- 46. INVESTIGATIONS: BLOOD TESTS Calcium Reduced, Phosphatereduced Alkalline Phosphatase increased Urinary excretion of calcium diminished Calcium phosphate products (= serum [Ca] x serum [PO4]) normally 30. In rickets and osteomalacia is less than 24
- 47. MANAGEMENT: Depends on thecause Nutritional Vitamin D deficiency Dietary chelators of calcium Phytates Oxalates Phosphorus deficiency (unusual) Antacid abuse Treatment- vitamin D (5000u) and Calcium (3g/day)
- 48. MANAGEMENT: Depends on thecause Renal Osteodystrophy – in chronic renal failure Miscellaneous Hypophosphatasia Anticonvulsant therapy SURGERY For deformities Vitamin D resistant (familial hypophosphatemic rickets) Treatment; Phosphate 1-3 gm daily, Vit D3 high dose
- 49. Factors affecting boneturnover • PTH and calcitonin • Oestrogen • gut - increased absorption • bone - decreased re-absorption • Glucocorticoids • gut - decrease absorption • bone - increased re-absorption/decreased formation • Thyroxine • stimulates formation/resorption • net resorption
- 50. Bone metabolic disorders Presentation? •Skeletal abnormality • osteopenia - osteomalacia/osteoporosis • osteitis fibrosa cystica - replacement of bone with fibrous tissue usually due to PTH excess • Hypercalcaemia • Underlying hormonal disorder When to investigate? • Under 50 • repeated fractures or deformity • systemic features or signs of hormonal disorder
- 51. Hyperparathyroidism • Excessive PTH •Due to prim (adenoma), sec (hypocalc), tert (second hyperact -> autonomous overact) • Osteitis due to fibr repl of bone • Clin feat - hypercalc • Invest - Calcium incr, PO4 decr, incr PTH • Rx surgery
- 52. Renal osteodystrophy Combination of •osteomalacia • secondary PTH increase (osteitis fibrosa) • osteoporosis/sclerosis • CF - renal disorder, depends on predominant pathology • Rx - vit D or 1,25-DHCC • renal disorder correction
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Editor's Notes
- #19 This MRI of the spine demonstrates marked kyphosis with compressed fractures. Such a finding can be seen as a consequence of osteoporosis.
- #20 Here is a "compressed" fracture of the vertebral column. The middle vertebral body shown here is greatly reduced in size. Such fractures are common in persons with osteoporosis in which there is accelerated bone loss, particularly older women, and can occur with even minor trauma.