ap 50 11-12 1 orthopedic pathology

Department of Pathology, Faculty of Medicine, Ramathibodi Hospital…..


Orthopaedic Pathology Bone,

cartilageSoft tissue nearbySynoviu

mTendonBursaFibrous tissueMuscle


Fig. 28 A synovial joint, on section.


Rigid endoskeleton

- Supports the body

- Protects viceral organ

- Provides attachments for muscles

Metabolism of calcium and other minerals

Contains hematopoietic marrow

Function of Bone


Fig. 2.1 Embryonic development of a long bone during the first six months


Normal

Rickets


Bone marrow

hematopoietic lineage

Bone marrow stromal cell

lineage

BONEBONE


Bone marrow hematopoietic lineage

CFM-GM ( colony forming unit granulocyte-macrophage )

monoblast

promonocyte

monocyte

Tissue macrophage

osteoclast


Bone marrow stromal cell

lineage ( mesenchymal stem cell )CFU-F(Colony forming

unit fibroblast)

Stromal osteoblast precursor cell

Transitory osteoblast

Secretory osteoblast

Osteoblast( bone lining cell )


( Receptor activator for nuclear factor Kappa B)

( Rank ligands )

Osteoblast-

osteoclast

interaction


Osteoblasts

• Secrete interleukin-6 & 11• Tissue growth factor β• Activated by parathyroid hormone;

1,25 vitamin D, interleukin 1, TNF


Parathyroid hormone

-collagen type 1

-Fibronectin

-Alkaline phosphatase

-Osteocalcin

-sialoproteinOsteoblast

Estrogen

interleukin 6


Osteoclast

• Calcitonin-receptor

• Vitronectin receptor

• Tartrate-resistant acid phosphatase

• Cytoplasmic carbonic anhydrase

• Osteopontin


Osteoclast

calcitonin

Integrins

cadherins

N-cam

Vitronectin

Cytoplasmic carbonic anhydrase

calcitonin

Integrins

calcitonin

Integrins

calcitonin

Integrins

cadherins

N-cam

Vitronectin

calcitonin

Integrins

cadherins

N-cam

Vitronectin

calcitonin

IntegrinsIntegrins

calcitonin

Tartrate resistant acid phosphatase

selectin

osteopontin


Histology of Synovium

•Intimal layer: A thin layer of synovial cells or synoviocytes

•Subintimal layer: arterioles, fat and other connective tissue cells such as fibroblasts, histiocytes, and occasional mast cells


Congenital anomalies

Developmental abnormalities:

complex, variable,

genetic based and manifest

during the earliest stages

of bone formation


Developmental

anomalies1) Defect in nuclear proteins and transcription factor ( dysostosis) 2) Mutations in the hormone

and signal transduction ( dysplasia )3) Defect in extracellular

structural proteins


OSTEOGENESIS IMPERFECTA

A group of distinct clinical syndromes with

various modes of inheritance and having in

common an increased propensity to fracture.


Osteogenesis ImperfectaAbnormal secretion type I

collagen

Decreased synthesis type I collagen Decreased

Deletion 1(I) geneMatrix

Deletion 2 gene

Unstable type I collagen


Ehlers-Danlos

syndrome


Direct inoculations following

compound fracture

Osteomyelitis : caused by

Hematogenous spreading

(staphylococcus aureus, Salmonella)


OsteomyelitisOsteomyelitis

Involucrum:

New bone formation in perioste umSequestrum

:

Dead bone


Figure 231. Tuberculous osteomyelitis.Figure 231. Tuberculous osteomyelitis.

A sagittal section of a portion of the vertebr

al column. Two vertebrae are involved and have

collapsed, causing kyphotic angulation with co

mpression of the spinal cord.


Spinal tuberculosis (Pott’s disease)

Psoas abscess

Disc destruction

Vertebral collapse

Paraplegia


Commonly affects the spine

Spreads usually from pulmonary

disease via blood stream

Tuberculosis


A

BFigure 244. Congenital syphilis. A, There areradiolucent defects adjacent to the zones of provisional calcification and periosteal newbone around the diaphysis. The defect in the proximal tibia is symmetrical (Wimberger’s sign). B, Reexamination of the forearm threeweeks later reveals evidence of healing of the metaphyseal lesions.


Simple fracture

Impacted fracture

Comminuted fracture

Stress fracture

Greenstick fracture

Trauma to normal bone


Osteoporosis

Osteomalacia

Hyperparathyroidism

Paget’s disease

Osteogennesis imperfecta

Tumors

Pathological fracture


Hematoma


Granulation tissue


Callus-formation

Osseous callus

Osteo-cartilaginous

callus


Sequence of bone healing in fracture

•Hematoma•Granulation tissue

•Callus formation

•Remodeling


Complication of fracture

Delayed union

Non-unio

n

pseudarthrosis

Malunion


Avascular necrosis

•Synonym: Aseptic necrosis

osteonec

rosis


Cause of osteonecrosis

• Idiopathic

• Post fracture

• Fat embolism

• Legg-Calves Perthes disease

• Steroid induce

• Alcohol


Legg-Calves Perthes


Rheumatoid arthritis

• Self-perpetuating , inflammatory joint disease

• Initially characterized by swelling in several joints and stiffness

• Roentgenographically show a chronic inflammatory destruction of the joint

• Laboratory findings: Rheumatoid factor, ESR


Terminology in Rheumatoid arthritis

•Pannus: inflammed synovium attaching on articular cartilage

•Rheumatoid nodules


Rheumatoid nodule


PATHOLOGY OF SYNOVIUM in rheumatoid arthritis


Proposed mechanism for rheumatoid

diseases

Robbins and Cotran ( 7th. Ed) p. 137


Inflammatory joint diseases

Seropositive: 1) Rheumatoid arthritis 2) Juvenile rheumatoid

arthritis Seronegative: 1) Ankylosing

spondylitis 2) Psoriasis 3) Reactive arthritis

( Reiter’s syndrome )


Bone tumors• Primary bone tumors

• Metastatic bone tumors


Histologic typing of bone tumor- Bone forming tu

mors Cartilage formin g tumors Giant cell tu

mors Bone marro w tumors


Bone forming tumors

• Benign : OSTEOMA

• Malignant: OSTEOSARCOMA


Cartilage-forming tumors

• Benign : OSTEOCHONDROMA, ENCHONDROMA, CHONDROBLASTOMA, CHONDROMYXOID FIBROMA

• Malignant : CHONDROSARCOMA


Bone marrow-forming tumors

• Ewing’s sarcoma


Chicken-wire calcification


Periosteal reaction


Eosinophilic granuloma

( Langerhans cell granulomatosis, Langerhans cell

histiocytosis )


Bone-remodeling

unit


Metabolic bone diseases

- Matrix

- Mineralization

- Deposition of waste product

formation

resorption


Matrix formation defect

- Osteogenesis imperfecta

- Paget’s disease

- Mucopolysaccharidosis


Matrix resorption defect

Hyperparathyroidism

Osteopetrosis


Osteitis fibrosa cystica


Osteomalacia

Looser’s zone

(pseudofracture )

Milk-man’s fracture


Rachitic rosaries


Rickets

Irregularity of

growth plate

Genu varusIrregularit

y of growth plate


Table 1. Comparison of two types of involutional osteoporosis. From Riggs and Melton(1986)with permission.

Type IType I Type IIType II

Age (years) 51-75 > 70Sex ratio (female : male) 6:1 2:1Type of bone loss Mainly cancellous Cancellous and compactRate of bone loss Accelerated Not acceleratedFracture site Vertebrae (crush) and Vertebrae (wedge) distal radius and hipParathyroid function Decreased IncreasedCalcium absorption Decreased Decreased Metabolism of 25-OH-D to Secondary decrease Primary decrease 1.25(OH)2D

Main causes Factors related to Factors related to menopause ageing

25-OH-D = 25-hydroxyvitamin D ; 1.25(OH)2D = dihydroxyvitamin D.


PATHOGENESIS OF OSTEOPOROSISPATHOGENESIS OF OSTEOPOROSISModelModel

Figure 4. Conceptual model of the pathogenesis of fractures relate to osteoporosis. Modified from Riggs (1988).


Deposition of waste product

- Pseudo - gout

- Gout

- Oxalosis

- Ochronosis


Gouty tophi


PseudPseud-o gou-o goutt

Calcium pyrophosphate

crystal


OchroOchronosisnosis


ochronosis

ap 50 11-12 1 orthopedic pathology

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