Netcare Sunninghill Hospital
Tel: 011 257 2179
Mediclinic Sandton Hospital
Tel: 011 463 8830 | 011 463 8833
Normal Anatomy of the knee
The knee joint is a complex weight bearing joint that relies on ligaments and muscles to provide stability. The knee is made up of three bones: The thigh bone (femur), the shin bone (tibia), and the kneecap (patella). There are 4 major ligaments in the knee: the Anterior cruciate (ACL) and posterior cruciate ligaments (PCL), Medial collateral (MCL) and lateral collateral ligaments (LCL). There are a number of other smaller ligaments as well as tendons around the knee which contribute to stability and function.
Inside the joint there are 2 “C-shaped” discs of cartilage attached to the tibia known as the medial and lateral meniscus. These important structures give extra cushioning to the cartilage inside the joint to prevent wear and tear. If a meniscus is damaged, extra load will be placed on the cartilage, resulting in accelerated wear and tear. This will lead to arthritis. The severity and timing of this arthritis depends on many factors including your age, activity levels, weight and degree of meniscal damage.
A meniscus tear is often caused by a single acute injury—such as a sudden twist or quick turn during sports activity. Because the menisci weaken and wear thin over time, older people are more likely to experience a degenerative meniscus tear. The meniscus has a very poor blood supply and rarely heals without intervention.
Some people feel a pop in the knee. The injury is not usually severe and most people can continue with sports or at least can walk around without too much pain.
This can usually be made based on the history and examination alone. An MRI test may be ordered to confirm the diagnosis and to exclude other pathology but this is usually not needed and may delay treatment.
The meniscus rarely heals itself (due to its poor blood supply) and treatment for a meniscal tear usually involves surgery. The torn meniscus can be trimmed, removed or repaired using keyhole surgery (arthroscopy). The decision to repair is based on age, activity levels, occupation and sporting demands. Only tears in the outer half of the meniscus have the potential to heal. The final decision can not be made until the time of surgery as it depends on the size, site and the quality of the remaining meniscus tissue. Most patients with a repairable meniscus are under 45 years of age and up to 80 percent of these are associated with a tear of the anterior cruciate ligament. There is no point in repairing a meniscus which is unlikely to heal. Repair can usually be performed arthroscopically using special stitching devices but one or two additional incisions in the skin may be required. There are advantages and disadvantages of meniscal repair.
Advantages
Disadvantages
Overall if a meniscus can be repaired (in the right patient with the right type of tear) it is best to do so as it protects the knee from premature arthritis.
Meniscal root tears are devastating tears of the meniscal cartilage in the knee at the point where it connects to bone. In essence, the root is the anchor point of the meniscus. Such tears can lead to significant knee pain, dysfunction, instability and rapid development of osteoarthritis.
Depending on how they occur, meniscal root tears can be defined as traumatic or degenerative. Traumatic meniscal root tears generally occur in the younger, athletic population and are typically more commonly located in the lateral meniscus in conjunction with an ACL tear. They may be caused by a sudden twisting motion when planting the foot.
Degenerative meniscal root tears generally occur in patients above the age of 40 years and are more common in the medial meniscus. Patients with medial meniscus root tears will typically complain of a mild ache in the back of the knee for a few weeks and then report a sharp increase in pain and inability to bear weight (walk) after a trivial injury (stepping of a curb or stair). In these scenarios, the meniscus root is under going some wear and tear and then finally fully tears – sometimes patients will hear or feel a “pop”. After a few days of pain and swelling, the symptoms generally improve to the point of being able to walk on the knee, but not without some level of pain or dysfunction.
Symptoms include pain, swelling, and feeling as if the knee is going to “give out.” Without surgery, healing potential for these meniscus root injuries is poor, with a nonoperative natural history of 95% failure and advanced arthritis within 12 – 18 months.
Should you decide on surgical management you will be admitted into the hospital on the morning of the surgery.
For more information please read the booklet below