One of the most common knee injuries requiring arthroscopic surgery is a torn meniscus. Now, you may be wondering exactly what is a meniscus and more importantly what purpose does it serve.
There are two C-shaped rubbery discs called menisci located within the knee joint between the tibia (shin bone) and the femur (thigh bone). The meniscus residing on the inner aspect of the knee is referred to as the medial meniscus while the one on the outer aspect is called the lateral meniscus. The meniscus acts as shock absorbers providing a cushion to help stabilize the joint and distribute the body’s weight evenly across the knee. This cushion prevents wear and tear to the bones however, if torn and shredded, broken fragments can catch in the joints and cause locking of the knee. It does not take much to tear a meniscus; kneeling, squatting, turning the wrong way or stopping suddenly can all result in an injury. The aging process also makes us more prone to sustain a tear since there is considerable weakness of the meniscus through the progression of time. Athletes who participate in contact sports where there is a risk of a traumatic impact to the knee or a sport involving a great deal of jumping, pivoting, or cutting are also susceptible. Additionally a simple twisting or buckling of the knee can cause the meniscus to become caught and torn resulting in swelling, pain, popping, and even locking of the knee joint. This locking or catching sensation is oftentimes felt in the back of the knee while walking.
If you are experiencing any of the above mentioned symptoms you should visit an orthopedic specialist who will diagnosis your condition, beginning with an x-ray. While x-rays do not pick up cartilage, it will exclude other conditions which may be at the root of your symptoms such as arthritis, bone spurs, or calcifications. Depending upon the results of your x-ray, an MRI may be required to assess the soft tissue and cartilage around the knee.
Treatment of a meniscus tear depends on the severity and location of the tear and can be as simple as applying ice, elevation, and rest along with a prescription for pain medication. In some instances, your orthopedist may suggest a physical therapy program to aide in strengthening the muscles around the knee. In the case where conservative measures have failed to improve the symptoms, arthroscopic surgery may be recommended to either repair or remove the damaged cartilage. The decision between a repair or removal is based upon the type, size, and location of the tear, along with the age of the patient.
The outer 1/3 of the meniscus has an abundant supply of rich blood and is referred to as the “red zone.” A tear in this area is optimal for a meniscus repair as the rich blood flow will aide with the healing process of the meniscus post-surgery. The inner 2/3 of the meniscus lacks a blood supply and is referred to as the “white zone.” Tears in this portion of the meniscus are unable to heal due to the lack of a blood supply. Since the pieces in the white zone cannot grow back together, tears in this particular area are surgically trimmed away. This removal of a portion of the meniscus is called a partial meniscectomy.
Meniscus repairs and a partial meniscectomies are both performed in an outpatient setting. The surgery consists of the surgeon creating a small incision and inserting a thin tube called an arthroscope into the knee. The tube contains a camera and a light source. Additional small incisions are made around the knee for surgical instruments that are utilized to address the tear. The surgery can usually be performed in less than one hour. Your total time at the outpatient surgical center is approximately 4 hours and you go home that same day with a set of crutches provided by the center.
Recovery time is based on several factors such as age, weight, and activity level. The older and heavier a patient is usually results in a longer recovery period than that of a younger, more physically fit individual. The extent of the tear and the type of surgery also can determine the recovery time. Preexisting conditions also play a part in recovery time; for instance, the presence of arthritis where some or all of the cartilage on the end of the bones is missing can result in the continuation of knee pain after surgery. Your orthopedist will discuss anticipated recovery times based on your individual diagnosis during your office visit.