Structure and Composition:

Composed of chondrocytes embedded in an extracellular matrix (ECM) of collagen (mainly type II), proteoglycans, and water (up to 80%).
Organised into four histological zones:
Superficial (Tangential) Zone – flat chondrocytes, high collagen, resist shear
Middle (Transitional) Zone – rounder chondrocytes, high proteoglycans
Deep Zone – vertical collagen fibres, resist compressive forces
Calcified Zone – anchors cartilage to subchondral bone

Functions:

Biomechanical Properties:

Injury and Degeneration:

Assessment Modalities:

Repair Techniques:

Orthopaedic Relevance:

Central to sports injuries, osteoarthritis, and joint preservation surgery
Success of cartilage procedures depends on patient age, defect size, and mechanical alignment

Bioabsorbable Materials