Articular cartilage is a complex avascular (no blood supply) tissue which consists of cells called chondrocytes suspended in a collagenous matrix. It appears as a smooth, shiny, white tissue at the ends of the bones which come in contact with each other to form a joint.
This cartilage is subjected to the normal wear and tear and may sometimes get damaged because of injury causing pain and impaired function.
Articular cartilage reduces the friction when the bones glide over each other and makes the movements smooth and enables the joint withstand weight. Alternately, it acts as a shock-absorber.
Articular cartilage injuries occur as a result of sports injury (direct blow) or progressive degeneration (wear and tear). Degeneration of the cartilage occurs as a progressive loss of structure and function of the cartilage. The process begins with softening of the cartilage which then progresses to fragmentation. As the articular cartilage lining is lost, the underlying bone has no protection against the normal wear and tear and it starts breaking down leading to osteoarthritis. The risk factors that can contribute to osteoarthritis include twisting injuries, abnormal joint structure, instability of joints and inadequate muscle strength.
The symptoms of cartilage injuries include:
- Pain and swelling of the knee joint
- Locking of the knee
- Catching or giving way
Your doctor will perform a physical examination to look for altered range of motion, swelling, and alignment of the bones. As cartilage is uncalcified it does not show up in X-rays. A high quality MRI often required and arthroscopy is used as the final determination to what technique may be best used.
Initial treatment includes physical therapy, anti-inflammatory medications, and steroid injections. Surgery to restore articular cartilage may be considered for patients with large articular lesion or if conservative treatment fails. Articular cartilage repair is performed to provide relief from pain, improve range of motion, slow the progression of the damage, and delay the option of joint replacement surgery.