Knee Cartilage Damage
What is it?
The ends of bones inside any joint are lined with a very smooth tissue called articular cartilage, which provides a very low friction environment, allowing the ends of the bones to move over each other smoothly during movement of the joint.
Why does it occur?
Damage to this smooth articular surface can occur for a number of reasons, such as a result of trauma, a degenerative process such as osteoarthritis, an inflammatory process such as rheumatoid arthritis, or other rarer conditions. The severity of the damage to the cartilage varies, from minor softening to full thickness loss, leading to patches of bare bone within any given joint. Unfortunately, once damaged, specialised articular cartilage is unable to heal or repair itself.
What are the symptoms?
The symptoms of articular cartilage damage are generally related to the severity of the cartilage loss. These can include pain in the affected joint with associated swelling, the catching or giving way of the joint, a restricted range of movement, or locking.
How is it diagnosed?
Severe cartilage damage is evident on x-rays of the affected joint, and for this reason your consultant may well recommend an x-ray. More subtle damage to the cartilage or evidence of loose bodies (small fragments of cartilage that have detached from the joint surface and are floating freely within the joint) may not be detectable on an x-ray alone, and in those situations an MRI scan is often recommended.
How is it treated?
The treatment options available for articular cartilage damage are again very dependent upon the severity and location of the damage. In the early phases, non-operative management and injections are often very helpful at offloading the damaged area and providing symptomatic relief. As the damage becomes more severe, other options may have to be discussed. Localised full thickness articular cartilage damage can be treated with joint-preserving surgery such as those described below.
Microfracture – small drill holes are placed into the bone beneath the articular cartilage lesion, in an attempt to encourage new fibrocartilage growth within the defect.
Osteochondral grafting – this involves the implantation of a donor cartilage graft, with some underlying subchondral bone, either from an alternative location within the affected joint or from a cadaveric donor.
Osteotomy – this involves re-aligning the joint in question, in an attempt to distribute load through the unaffected part of the joint and away from the area of damaged cartilage.
In more severe or widespread cases of cartilage damage or loss, we may recommend a partial or total joint replacement. Your consultant will discuss with you fully the risks and benefits of each course of action, and the most appropriate management plan for your specific situation.
