Articular cartilage injury ,Common sites injury,Treatment of articular cartilage injury

 Articular cartilage  lines the ends of long bones. It absorbs shock and compressive forces and permits almost frictionless movement of joints. These injuries are far more common than was previously realized. With the advent of new imaging techniques such as magnetic resonance imaging (MRI) and the increas ing availability of arthroscopy, it is now possible to distinguish three classes of articular cartilage injuries :

1. disruption of the articular cartilage at its deeper layers with or without subchondral bone damage,           while the articular surface itself remains intact

2. disruption of the articular surface only  

3. disruption of both articular cartilage and subchondral bone .

 Articular cartilage may be injured by acute shearing injuries such as dislocation and subluxation.

 ➽Common sites of chondral and osteochondral injuries 

➥Superior articular surface of the talus, 

➥Femoral condyles, 

➥Patella 

➥Capitellum of the humerus.

 Osteochondral injuries may be associated with soft tissue conditions such as ligament sprains and complete rupture (e.g. anterior cruciate ligament injury). As an initial X-ray examination is often normal, the clinician must maintain a high index of suspicion of osteochondral damage if an apparently 'simple joint sprain remains painful and swollen for longer than expected. 

These injuries should be investigated with MRI. Arthroscopy may be required to assess the degree of damage and to remove loose fragments or to perform chondroplasty (smooth loose edges of damaged articular cartilage)

 Acute damage to articular cartilage is present in association with complete ligament ruptures! and may predispose to premature osteoarthritis. Therefore, every try should be made to restore the smooth surface of the articular cartilage.

 Immobilization has a detrimental effect on articular cartillage but continuous passive movement may help counter this effect.

 Articular cartilage injuries generally do not heal fully. A variety of treatments have the potential to improve healing of articular surfaces

➤Perforation of subchondral bone

➤Altered joint loading, periosteal 

➤Perichondrial grafts

➤Cell transplanttion

➤Growth factors

➤Artificial matrices 

➤Mesenchymal stem cells. 

The latter treatments are still at an experimental stage and as yet no treatment can be said to restore a durable articular surface reliably.