Meniscus of the Knee - Essay Example

The menisci also cup the joint surfaces of the femur and therefore provide some degree of stabilization to the knee. The meniscus itself is for the most part avascular that is it doesn't bleed if cut and doesn't have blood vessels inside. The exception to this is at the periphery where it joins to the vascular knee lining providing the outermost 20% of the meniscus with a blood supply. As a result of this avascularity a torn meniscus doesn't have the ability to heal itself unless there is just a small tear confined to the peripheral vascular zone.

Similarly the nerve supply providing pain and sensation to the meniscus is for the most part limited to the zone where the blood vessels are located. In terms of descriptive terminology orthopaedic surgeons divide the meniscus into thirds with three geographical zones;the front third is referred to as the anterior horn, the back third the posterior horn, and the middle third the body. Some people think that only athletes can tear a meniscus. This is not true. Even people who do not consider themselves "athletes" can tear a meniscus.

Some menisci (plural) tear during activities of daily living such as getting in and out of a car or squatting. Menisci also tear during participation in recreational activities such as skiing, dancing, or racquetball.There are two different mechanisms for tearing a meniscus. Traumatic tears result from a sudden load being applied to the meniscal tissue which is severe enough to cause the meniscal cartilage to fail and let go. These usually occur from a twisting injury or a blow to the side of the knee that causes the meniscus to be levered against and compressed.

Degenerative meniscal tears are best thought of as a failure of the meniscus over time. There is a natural drying-out of the inner centre of the meniscus that can begin in the late 20's and progresses with age. The meniscus becomes less elastic and compliant and as a result may fail with only minimal trauma (such as just getting down into a squat). Sometimes there are no memorable injuries or violent events which can be blamed as the cause of the tear. The association of these tears with aging makes degenerative tears in a teenager almost unheard of.

There are many techniques for meniscal repair and these will depend on the location of the tear. The techniques include an open procedure (following arthroscopic examination of the joint) or the arthroscopic 'inside-out', 'outside-in' and 'all-inside' procedures. The open technique has been advocated for vertical tears of the posterior horn of the lateral and medial menisci within 1-2 mm of the meniscosynovial junction, where visualisation with the arthroscopy is difficult. In all cases the torn surfaces of the meniscus are derided of scar tissue and fibrin clot can be placed in situ before the sutures are tied to enhance healing.

Repaired meniscal tears heal if there is adequate blood supply and tissue stability. A stable knee is therefore important and increased