Articular Cartilage and its Restoration

Structure and Function of Articular Cartilage

Articular cartilage, a specialized connective tissue, covers the ends of bones in synovial joints, providing a smooth, low-friction surface for movement. Its avascular nature (lack of blood vessels) makes repair challenging. It is composed primarily of chondrocytes (cartilage cells) embedded within an extracellular matrix of collagen, proteoglycans, and water. This matrix provides the cartilage's resilience and shock-absorbing properties.

Causes of Cartilage Damage

Damage to articular cartilage can result from various factors including osteoarthritis (a degenerative joint disease), trauma (e.g., injury from a fall or accident), overuse, and genetic predisposition. The progressive loss of cartilage can lead to pain, stiffness, and reduced joint function.

Current Treatment Approaches

Conservative Management

Non-surgical approaches focus on pain management and slowing disease progression. These may include physical therapy, weight management, assistive devices, and medication (e.g., analgesics, anti-inflammatory drugs).

Surgical Interventions

• Arthroscopy: A minimally invasive procedure used to assess and address cartilage damage, potentially involving debridement (removal of damaged tissue) or microfracture (stimulating bone marrow to form new cartilage).
• Osteotomy: A surgical procedure to realign the bones to reduce stress on the damaged cartilage.
• Chondrocyte implantation (autologous chondrocyte implantation - ACI): Involves harvesting healthy cartilage cells from the patient, culturing them, and then re-implanting them into the damaged area. This technique requires a two-stage surgical process.
• Matrix-induced autologous chondrocyte implantation (MACI): A variation of ACI that involves seeding chondrocytes onto a biodegradable scaffold that provides a structural support for cartilage regeneration.
• Osteochondral transplantation: Involves replacing severely damaged cartilage and underlying bone with tissue grafts from a donor or from a non-weight-bearing area of the patient's own knee.
• Total Knee Arthroplasty (Knee Replacement): A surgical procedure where the damaged joint surfaces are replaced with artificial implants. This is generally considered when other treatments have failed.

Emerging Regenerative Therapies

Research is ongoing in the field of cartilage regeneration, exploring innovative approaches such as gene therapy, growth factor stimulation, and the use of biomaterials to enhance cartilage repair and prevent further degeneration.

Prognosis and Rehabilitation

The success of any treatment approach depends on various factors, including the extent of the cartilage damage, the patient's age and overall health, and adherence to post-treatment rehabilitation programs. Rehabilitation generally involves physical therapy to restore joint function and range of motion.