2.  Type of hyaline cartilage covers the bone
ends and makes smooth movements possible.
 It distributes the load across
joints,minimizing the peak stress on
subchondral bone.

3.  Relatively acellular.
 No vascular,neural or lymphatic supply
 Has little capacity to heal after injury.
 Wear resistant
 Low frictional
 Lubricated surface
 Slightly compressible and elastic

4.  Differs from hyaline cartilage in that it is
not covered by perichondrium.
 Collagen fibres of articular cartilage matrix
are of type-II which exhibit characteristic
cross banding of collagen fibres exsist.

5.  Young cartilage – typically white,smooth,
glistening and compressible
 Aged – thinner,less cellular,firmer and more
brittle with less regular surface and
yellowish opacity.
 Thickness –
 Bony end plate

6.  ZONES OF ARTICULAR CARTILAGE
1) SUPERFICIAL ZONE
Not smooth,layer of hyaluronic acid
LAMINAR SPLENDENS –most superficial
Elongated chondrocytes,relatively inactive
2) TRANSITIONAL ZONE
Thicker ,cells rounded & larger, arranged pairs
Actively engaged in matrix component
synthesis

7. DEEP ZONE
- Largest zone
- Largest collagen fibrils,highest
proteoglycan content, lowest water
ZONE OF CALCIFIED CARTILAGE
- Irregular cells pyknotic nuclei /stability
- TIDE MARK
- Continuous with subchondral plate

8.  PERICELLULAR MATRIX
- CHONDRON
- Modulate the pressure transmission
- regulation of chondrocyte response to
pressure,prevent squashing
 TERRITORIAL MATRIX
- Fibrillar basket
- surrounds the pericellular matrix

9.  INTERTERRITORIAL MATRIX
- Largest matrix compartment
- parellel arrangement of collagen fibrils
- responsible for mechanical properties.

10.  Less than 1% of tissue volume
 Rarely divide normally / cell density
decreases with age
 Synthesize matrix components-
proteoglycans constantly renewed,collagen
slow turnover
 CILIUM – Regulation of matrix turnover

11.  COLLAGEN
- Type II ,major (90%)
- Characteristic cross banded fibrils
- Type IX,X,XI minor
 NON-COLLAGENOUS PROTEINS
- Link protein /binding GAG to hyaluronic acid
- Chondronectin and anchorinCII

12.  PROTEOGLYCANS
- Family of glycoproteins large protein core
attached to GAG side chains.
- Form of large aggregates
- Provide the resilience to A.C under load

13.  Mature A.C – diffusion from synovial fluid
 Immature A.C – vascular channels in sub
chondral bone,base of cartilage,S.F
 Energy – anerobic pathway
 Microenviroment:high CO2 & low O2
 Survive for more than 2 days after death

14.  CHONDROMALACIA:
A.C damage or degeneration
 OUTER BRIDGE Classification:
Based on arthroscopic exam

15.  GRADE O- Normal
 GRADE I- Swelling & softening of intact A.C
 GRADE II-Fissuring & fibrillation over small
area < .5 inch
 GRADE III- Same over larger area > .5 inch
 GRADE IV- Erosion of subchondral bone

16.  Mitosis induced by laceration,compression,
 Superficial lacerations – doesn’t cross tidemark donot
heal.
 Penetrates the subchondral bone- reach
S.C vessels initiate healing process
 Fibrinous arcade – scaffold that directs the
mesenchymal cells to form F.C matrix
 Repaired tissue – intermediate between H.C
& F.C / poor biomehanical properties.

17.  Biphasic material – solid & liquid phase
 Fibre reinforced gel- mutually repellant
macromolecules binds water-osmotic P.
 Water resides in microscopic pores and flow
of the water induced by pressure gradient
or matrix contraction.Flow pressure
provides load support & minimize stress
on matrix.

18.  JT loading & motion required to maintain
normal adult A.C
 Immobilisation of JT cause rapid loss of
proteoglycans so deformation in response
to load will increase.
 Excessive use or increased loading affect

19.  Debridement of chondral flaps and removal
of loose chondral fragments.
 Abrasion chondroplasty
 Microfracture

20.  Periosteal & Perichondrial grafting
 Autologous cartilage implantation
 Osteochondral autograft
 Osteochndral allograft