The knee is made up of three bones: the femur (thigh bone), the tibia, (shin bone) and the patella (knee cap). The menisci — the medial meniscus and lateral meniscus - are crescent-shaped bands of thick, rubbery cartilage attached to the tibia. They act as shock absorbers and stabilize the knee. The meniscus allows weight to be equally distributed across the bones. Made of cartilage, this not only stabilizes the knee, but also allow the joint to smoothly slide and move in many directions. The medial meniscus is on the inner side of the knee joint. The lateral meniscus is on the outside of the knee.
When the meniscus is torn or damaged, weight is no longer applied evenly across the bones, so grinding and wearing occurs as bone meets bone. After time, arthritis of the knee joint develops as the stressed bones take on more of the burden the body’s weight.
Meniscus tears are most commonly caused by trauma (athletic injuries) and the aging process (as we age cartilage becomes dehydrated and brittle.) A meniscus tear can occur when the knee is suddenly twisted while the foot is planted on the ground. A tear can also develop slowly as the meniscus loses resiliency. In this case, a portion may break off, leaving frayed edges. Walking can become difficult. Additional pain may be felt when flexing or twisting the knee. A loose piece of cartilage can get stuck in the joint, causing the knee to temporarily lock, preventing full extension of the leg. Meniscus tears can vary widely in size and severity. The meniscus does not regenerate or heal after it is damaged. Meniscus tears hurt because they upset the lining or the synovium of the knee. The synovium has many nerves and this synovium will cause significant pain, and swelling when it is irritated. Surprisingly, most people are still able to walk after tearing their meniscus.
Symptoms of a Torn Meniscus
- knee pain;
- Stiffness and swelling
- A popping noise when the injury first occurs
- Unable to move knee the full range of motion
- Locking of the knee
In many cases the pain from a meniscus tear will either improve significantly or go away without surgery. Immediate first aid is to apply the PRICE principles of protection, rest, ice, compression and elevation. Rest to allow the injured tissues to heal. Conservative treatment involves continuing to applying the PRICE principles to reduce pain and swelling and wear a knee support to protect the knee. Medications such as NSAID's or anti inflammatory drugs like Ibuprofen in the early stages will help with pain and swelling. Electrotherapy including ultrasound, laser therapy and TENS may also be beneficial in reducing swelling. A glucosamine or joint healing type supplement may be of benefit in the healing of cartilage injuries
If the knee recovers fully after PRICE treatment, then no other treatment may be necessary. However, If symptoms persist with nonsurgical treatment, surgery may be required to restore proper function. Surgery is sought when the knee becomes problematic and interferes with day to day activities. Most patients with acute, traumatic meniscus tears should consider surgery to repair the tear. In patients who have a degenerative tear, or a meniscus that simply worn out, many patients will only have pain for a few weeks.
Meniscus tear surgery is performed arthroscopically using small incisions. This less invasive technique involves removing a torn portion of the meniscus, where as a meniscus repair surgery involves stitching the tear back together. The type of tear will dictate whether a repair or partial meniscectomy is done. Both meniscus repair and partial menisectomy are arthroscopic surgeries