A normal knee has three joint areas (compartments) covered by articular cartilage (pearly white stuff seen on the ends of all bones), a ligament on the inside of the knee (medial collateral ligament), a ligament on the outside of the knee (lateral collateral ligament), and 2 ligaments in the middle of the knee (anterior and posterior cruciate ligaments). The ligaments stop the knee from moving in certain directions and give stability to the knee. The knee also has a different type of cartilage, called menisci, one on the inside of the knee (medial meniscus) and one on the outside of the knee (lateral meniscus). The menisci serve several functions in regards to normal knee mechanics. Most importantly they act as shock absorbers to cushion the articular cartilage. They also provide stability to the knee and help with nutrition of the articular cartilage. In the past, they were thought to be extra tissue found in the human body and they were removed at the first sign of problems. We now know that they are extremely important to the knee and meniscal preservation should be the goal of all orthopaedists.

What is the incidence of meniscal tears in children and adolescents?
The incidence is rising because of increased participation and physicians being better at diagnosing the problem. Football, basketball, and soccer seem to have the highest incidence of tears. In the past, meniscal tears in children less than 12 years of age were thought to be due to a congenitally abnormal meniscus. In fact, meniscal tears do occur in children with normal knees. After age 12, the incidence dramatically increases because of more damaging physical activity and a change in the mechanical properties of the menisci.

How is a meniscal tear diagnosed?
Taking a history from a child or adolescent is very difficult because of their inability to communicate about the problem. They are usually very vague about how they injured their knee, the symptoms they are feeling, the location of the pain, and whether or not they have any mechanical symptoms like locking, catching, or giving way. The physical examination can be difficult because of the fear that the child has about going to the doctor. Determining where the pain is located is very important to determining the cause.

Will x-rays be ordered?
Plain x-rays may be ordered depending on the onset of pain and injury. Sometimes a MRI will also be ordered to look at the structures on the inside of the knee which do not show up on regular x-rays.

What is the treatment of a meniscal tear?
Fortunately for children and adolescents, most meniscus injuries occur in a way than can be fixed. Younger individuals usually tear the back of the meniscus where there is good blood supply. Adults usually tear their menisci after a lot of wear and tear. The goal is always to preserve the meniscus in order to maximize long-term function of the knee. If a meniscal tear is identified, an arthroscopy will usually be performed. This is a surgical procedure where 2 small holes are made in the skin and a camera is placed into the knee. The meniscus can be repaired by using very small instruments and watching through the camera. If the meniscus cannot be repaired, then the torn part is trimmed back to an area that is not loose.

How soon can my child return to sports?
The answer to this question depends on whether the meniscus was partially resected (trimmed) or repaired. If a partial resection was performed, the patient can usually return to activities in a few weeks after they have progressed through the physical therapy criteria. If a repair was performed, the patient will be on crutches, then start physical therapy, and be out of all activities for 3-4 months. Though a meniscal resection seems easier at the beginning, it is not the best answer for the long-term function of the patient and their knee.