Bones

1,945 views

Published on

Bones

Published in: Health & Medicine, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,945
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
15
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Bones

  1. 1. BONES
  2. 2. Normal skeletal system  Bone is a type of connective tissue  Inorganic component – calcuim hydroxyapatite  Organic component – cells & protein of matrix
  3. 3.    Bone forming cells – osteoprogenitor cells, osteoblasts & osteocytes Osteoblasts – uninucleate, along new bone forming surfaces, synthesise bone matrix Osteoblasts surrounded by matrix - osteocytes
  4. 4.    Osteocytes – numerous, osteoblasts which get incorporated into bone matrix during synthesis, found within lacunae Osteoclasts – large multinucleate cells, bone resorption Osteiod matrix – 90-95% of type I collagen
  5. 5.  Osteoblasts depositing collagen in random weave – woven bone / orderly layered – lamellar bone
  6. 6.       Cartilage lacks blood vessels, lymphatics & nerves 2 components – cartilage matrix & chondrocytes Cartilage matrix – inorganic – hydroxyapatite Organic – 80% water, 20% type II collagen & proteoglycans Chondrocytes – primitive mesenchymal cells – chondroblasts -> chondrocytes Hyaline cartilage, fibrocartilage, elastic cartilage
  7. 7. INFECTIONS – OSTEOMYELITIS  Inflammation of bone & marrow  Manifests as primary solitary focus of disease  Systemic diseases spreading to bone – typhoid, actinomycosis, syphilis, brucellosis, myc etoma  * Pyogenic bacteria & mycobacteria
  8. 8. PYOGENIC OSTEOMYELITIS  Bacterial infection – hematogenous route , contiguous site , direct implantation  Infants & young children – 5-15 yrs  Long bones / vertebral bodies  Common – staph aureus- express receptor to bone matrix components & facilitates adherence to bone tissue
  9. 9.     E.coli, Pseudomonas, Klebsiella Location – neonate-> metaphysis Children – metaphysis Adult – epiphysis
  10. 10. Morphology –  Depends on stage – acute , subacute or chronic & location of infection  Suppuration, ischaemic necrosis, healing by fibrosis & bony repair  Acute inflammatory reaction -> cell death  Entrapped bone – necrosis  Bacteria & inflammation spreads
  11. 11.    Infection begins in metaphyseal end of marrow cavity occupied by pus, microscopy shows congestion, oedema, & exudate of neutrophils Infection spreads along marrow cavity to endosteum, haversial canal – Periosteitis May reach subperiosteal space – subperiosteal abscess
  12. 12.    May penetrate through cortex creating draining sinus tracts Combination of suppuration & impaired blood supply to cortex results in erosion, thinning & infarction necrosis of cortex – Sequestrum Later there is formation of new bone beneath periosteum present over infected bone. This forms encasing sheath around necrosed bone Involucrum
  13. 13.   Continued neo-osteogenesis gives rise to dense sclerotic pattern of osteomyelitis Occasionally acute osteomyelitis may be contained to a localised area & walled off by fibrous tissue & granulation tissue – Brodie’s abscess
  14. 14. Clinical course –  Acute systemic illness with malaise , fever, chills , leucocytosis & pain  X – ray – lytic focus of bone destruction surrounded by zone of sclerosis  Blood culture , biopsy
  15. 15. Complications  Septicaemia  Acute bacterial arthritis  Pathologic #  SCC  Secondary amyloidosis
  16. 16. TUBERCULOUS OSTEOMYELITIS  Adolescents or young adults Morphology –  Blood borne , originate from focus of active infection  Sites – spine , knees & hips
  17. 17.    Central caseous necrosis, granuloma Involvement of joint space & interverebral disc are frequent Pott’s disease – TB of spine commences in vertebral body, may be associated with compression #, destruction of intervertebral discs -> permanent damage & paraplegia
  18. 18.  Psoas abscess – extension of caseous material alongwith pus from lumbar vertebrae to sheaths of psoas muscle
  19. 19.    Pain on motion , localized tenderness , fever,chills & weight loss Kyphosis & scoliotic deformities Neurologic deficits

×