Cartilage Damage
(Chondral Lesions)
Chondral lesions of the knee result from damage to the articular cartilage of the knee. Articular cartilage is a specific connective tissue that covers the joint surfaces. Visually, it appears white and shiny. Microscopically, it consists of water, collagen, and a wide variety of matrix proteins and lipids.
Articular cartilage is not innervated, so it does not cause pain or tenderness when it experiences mild or moderate injury. In turn, it does not have the ability to self-repair this damage. While the symptoms of articular cartilage injuries may not become evident until later stages of life, they are very common.
Many factors influence chondral lesions of the knee, including the patient’s age when degeneration begins, their activity level, weight, and the presence of ligament damage. Even if the cartilage damage has been present for years, sometimes a sudden injury is needed for the symptoms to become evident. If this sudden injury does not occur, after many years of bone-on-bone contact and wear, the patient will develop arthritis or osteoarthritis, causing a variety of symptoms.
Cartilage damage is classified into grades from mild to severe, with all grades presenting characteristics of osteoarthritis.
Grade 0:
Normal cartilage.
Grade I:
At this stage, the cartilage begins to soften due to inflammation.
Grade II:
At this stage, there is a partial thickness defect with fibrillation (shredded appearance) or fissures on the surface that do not reach the bone or do not exceed a diameter of 1.5 cm.
Grade III:
This stage presents an increase in the amount of fibrillation and fissures reaching the subchondral bone in an area with a diameter greater than 1.5 cm. Patients often complain of sounds when bending the knee and pain or difficulty getting up from a squatting position.
Grade IV:
At this stage, the subchondral bone is exposed, implying that the cartilage has completely worn away. When the areas involved are extensive, the pain usually becomes very severe, limiting activity.
Symptoms often begin mildly and progress over time, as with arthritic pathology. Once they appear, they include:
- Intermittent swelling (only present when symptomatic).
- Pain associated with prolonged walking or climbing stairs.
- The knee gives way or bends abruptly when subjected to weight.
- The knee may “lock”.
- The knee may produce noises during movement.
Diagnosing a chondral lesion can be difficult. Often an inflamed knee can present a normal examination. Imaging techniques such as X-rays, MRIs, or an arthroscopic exam can determine if cartilage loss has occurred, reducing the space between bone surfaces.
Articular cartilage degeneration is generally treated without surgery. Dr. Mauricio González will recommend weight-bearing exercises to strengthen the muscles around the joint, supplements, and possibly hyaluronic acid injections to improve joint lubrication and reduce friction. Medications can be prescribed to treat symptoms associated with chondral lesions. However, since new cartilage growth is not possible, these medications do not cure the condition but allow the patient to lead a more active and pain-free life. The next step in treatment is surgical intervention.
In the past decade, there have been promising advances in the surgical treatment of articular cartilage defects. The most frequently used treatments for chondral defects are shaving, microfractures, and autologous cartilage transplantation (OATS).
Get Expert Care
Book Your Consultation with Dr. Mauricio González Campos