Knee articular hyaline cartilage injuries – Chondromalicia
The knee has two different types of cartilage, the articular hyaline cartilage and fibrocartilage meniscus. The articular hyaline cartilage covers the ends of the bones in the knee joint. In a young normal knee the articular hyaline cartilage is a smooth, glistening, slippery joint surface which allows the joint to move with ease through a full range of motion. The cartilage is bathed in a synovial joint fluid that lubricates the joint. The articular hyaline cartilage has no direct blood supply and has limited capacity to repair itself; therefore injuries to the articular cartilage usually do not heal.
Over the years as we age the articular hyaline cartilage undergoes wear and tear that accumulates and develops into degenerative chondromalacia and ultimately degenerative osteoarthritis. The initial cartilage degeneration begins with cartilage softening (Grade 1 – Chondromalacia) then progresses to fragmentation and loss of the articular cartilage down to the bone (Grade 4 Chondromalacia). As the loss of the articular cartilage continues the underlying bone begins to break down leading to degenerative osteoarthritis. Patients report progressive worsening of joint pain, stiffness, loss of motion and swelling as the condition worsens.
Articular cartilage injury can also occur as a result of a sudden traumatic injury to the knee. Occasionally an articular fragment completely breaks loose from the underlying bone, forming a loose body in the joint which may cause mechanical locking and catching.
The orthopedic surgeon utilizes history, physical examination, X-rays, MRI scans and arthroscopy to evaluate articular cartilage injury. Plain X-rays don’t visualize cartilage but are used to rule out other abnormalities in the bones.
MRI scans are very helpful, but an experienced orthopedic surgeon understands the limitations of the MRI scan and the radiologist report which may under report articular cartilage conditions. The ultimate diagnostic tool for articular cartilage is arthroscopic evaluation of the joint when the orthopedic surgeon scopes the knee joint.
Treatment of articular hyaline cartilage injuries and conditions will depend on many variables. For many patients, non-surgical treatment with lifestyle modification, rehab exercise, oral medication or knee injections may be all that is needed. For more complicated problems there are now additional surgical options available. The age of the patient, type and size of the injury, shape of the knee, alignment of the knee, physical demands of the patient and other health problems all factor in to the ultimate decision for the choice of surgery.