Three bones meet to form the knee joint, the femur (thighbone), the tibia (shinbone) and the patella (kneecap). The menisci are two crescent-shaped pieces of tough rubbery cartilage that sit between the shinbone and the thighbone and act as shock absorbers. The menisci are vital knee structures key to knee stability, even load distribution, and joint nourishment. They also play an important role in maintaining healthy articular cartilage that covers the ends of the bones in the joint.
The outer one third of the meniscus is called the ‘red zone’ meaning it has a rich blood supply which provides the ability to heal on its own or with surgical repair. However, the inner two thirds of the meniscus is called the ‘white zone’ because there is insufficient blood supply which means a tear cannot heal. The menisci are easily injured and difficult to repair.
About meniscus tears
Meniscus injuries are one of the most common knee injuries at any age. Athletes who play contact sports like football or hockey are at significant risk of meniscus tears. Meniscus tears are one of the most common athletic injuries and result in functional impairment. Repair or replacement is crucial to relieve pain and prevent degenerative joint diseases like osteoarthritis.
When you hear the term “torn knee cartilage” that is a reference to a meniscus tear.
Meniscus tears are characterized based on the location of the tear and the type. Common meniscus tears are bucket handle, flap and radial tears. Sports related meniscus tears frequently occur with other knee injuries including injuries to the ACL ligament.
What are the symptoms of a meniscus tear?
- Moderate to severe pain
- Stiffness and swelling
- Knee locking or catching
- Knee buckling
- restricted range of motion
The type of tear determines whether the meniscus can be repaired or must be replaced. Meniscus repair is only used to treat lesions in healthy tissue in the red-zone and the red-white zone.
How is a meniscus tear diagnosed?
Dr. Hackett will conduct a complete examination of the knee including testing range of motion and evaluating symptoms like swelling and tenderness. He may perform the McMurray maneuver to identify positions that cause pain or catching, which is an indication of a meniscus tear. He will order imaging studies including an MRI which is an accurate method of diagnosing a meniscus tear, and to identify any other knee damages.
What are the treatment options for a meniscus tear?
Meniscus injuries are considered essential predictors of the potential development of osteoarthritis (OA). Precisely because of the increased risk of OA, numerous surgical repair techniques have been explored but continue to fail. A partial meniscectomy (removal of the damaged part of the meniscus) and complete meniscectomy (removal of the entire meniscus) have been shown to significantly increase the risk of OA and joint degeneration. For this reason, they are no longer performed. Today the preferred method for knee joint restoration is a meniscal transplant.
What is meniscus allograft transplantation (MAT)?
MAT is an established surgical treatment for people with irreparable tears where the meniscus cannot be saved and must be removed with a procedure called a meniscectomy.
MAT offers patients pain relief and improved knee function. Importantly, MAT can halt the progression of OA. There is a low risk of complications. MAT Is an outpatient procedure performed arthroscopically. Dr. Hackett’s arthroscopic surgical accuracy will ensure the best possible outcome.
After surgery you must wear a brace to immobilize the knee. Your knee will be painful and swollen. No weight bearing is allowed for the first six weeks. Range of motion exercises will begin almost immediately after surgery. Physical therapy will begin with gentle stretching and as you heal exercises to regain strength will be added. It can take six to twelve months to return to sports. Dr. Hackett will provide you with complete post-operative instructions.
Who is a good candidate for MAT?
Good candidates are symptomatic patients under the age of fifty, with a breakdown of the knee joint due to the absence of all or part of the meniscus and are at risk for OA and/or misalignment of the bones in the knee joint. They must also have stable knee ligaments. Patients who have severe OA, uncorrected misalignment or instability, irreparable cartilage damage, active infection or rheumatoid arthritis are not good candidates. Misalignment, instability or cartilage defects may be corrected during the MAT procedure.
MAT is an option to replace the meniscus before joint degeneration and to avoid or delay a knee replacement which especially important in young and active patients. This procedure can restore normal joint biomechanics, alleviate pain and disability and minimize degenerative changes in the knee joint. 90% 0f MAT patients are satisfied with their MAT surgery.
Dr. Tom Hackett is a board certified, and fellowship trained orthopedic surgeon and sports medicine expert whose focus is on the treatment of complex injuries of the knee, elbow and shoulder. When you or a loved one has a painful condition that interferes with the ability to play sports and participate in activities that give meaning to living, contact him to schedule a consultation. Located in Vail Colorado, Dr. Hackett has patients world over.