What is Meniscus Surgery?
Meniscus surgery is used to treat tears of the medial and/or lateral meniscus. The meniscus is a rubbery, halfmoon shaped shock absorber cartilage in the knee that lies on top of the tibia (shin bone). It acts to cushion the cartilage that coats the bottom of the femur (thigh bone) and the coating cartilage on the top of the tibia.
The blood supply to our meniscus is limited and this affects its ability to heal. The outer one-third of the meniscus has some blood supply. This area is known as the “red” zone. Tears in the red zone may heal on their own. In contrast, the inner two-thirds of the meniscus, known as the “white” zone, lacks blood supply. Without nutrients from blood, meniscus tears or injuries to any tissue cannot heal. These inner rim tears occur where the meniscus is thinner and often worn.
During meniscus surgery, tears in the white zone are carefully trimmed away arthroscopically, as they will not heal even when securely sewn together. However, whenever possible, Dr. Cunningham carefully repairs a torn meniscus, thus preserving this important cushion cartilage in the knee.
Dr. Cunningham is a meniscus surgeon at Vail Summit Orthopedics and Neurosurgery. He is an expert at diagnosing and treating meniscus tears for patients in Vail, Summit County, Aspen, and Denver, CO.
When is Meniscus Tear Surgery Needed?
Patients with a meniscus tear commonly report catching, popping and pain in the knee. These symptoms are more noticeable when rotating on the knee or bending down. The knee pain is usually located on the inside (medial meniscus tear) or outside (lateral meniscus tear). The knee pain from a meniscus tear may decrease by simply changing the position of the knee. Because the pain and catching comes and goes without warning, most patients do not trust the knee. These symptoms are more frequent when worse when doing a cutting and pivoting sport such as skiing or soccer.
Common functional or mechanical symptoms, which affect normal movement of the knee, may include:
- Clicking and popping sound in the knee joint with associated pain
- Sudden inability to straighten the knee (locking sensation)
- Decreased range of motion when bending the knee
Meniscus tears are diagnosed by first taking a history and then doing a good physical exam. Usually there is point tenderness over the meniscus. Specific physical exam tests can reproduce the catching of a meniscus flap tear. An MRI is usually obtained to confirm the diagnosis of a meniscus tear as well at determine the location of the tear and the tear pattern.
If the MRI shows a meniscus tear and if a patient’s symptoms warrant it, then arthroscopic meniscus surgery is indicated. Dr. Cunningham repairs meniscus tears whenever possible, but some tears are degenerative with there being no blood supply to the torn area. In these cases, unstable flaps of the meniscus, which are causing pain and catching, are removed arthroscopically while preserving all the normal sections of the meniscus.
Repairing a torn meniscus and thus preserving the meniscus will help prevent early arthritis in the knee. The load transmission, shock absorption, and functional mechanics of the meniscus are vital to a normal, healthy knee and to resuming your active lifestyle. Meniscus repair is a well established, successful treatment with a very low risk of complications. Preserving the knee joint structures, and preventing degenerative changes, like the onset of knee arthritis, are good reasons to choose arthroscopic meniscus repair. If a meniscus tear is not repaired soon after it tears, the tear worsens over time and the tissue becomes more complexly torn which may make it unrepairable. Given this, it is better to have the meniscus repaired soon after tearing it.
How is Meniscus Surgery Performed?
The goal of torn meniscus surgery is to preserve the meniscus if possible. Meniscus repair is the treatment of choice when the tear is located within the red zone, where blood supply is adequate for healing. When the injury is in the white zone or along the inner rim of the meniscus where blood supply is absent, repair is not recommended, as the tissue will not heal even if repaired. Healing requires blood supply. For inner rim tears, torn flaps are removed arthroscopically while preserving all of the remaining meniscus.
What are the Different Types of Torn Meniscus Surgery?
- Arthroscopic All-inside Meniscus Repair: A tiny medical camera, known as the arthroscope, is inserted into the knee. The tissue around the tear is abraded in order to incite some bleeding and increase the healing environment. The tear is then sutured together by deploying several suture devices across the tear. These all inside suture devices are designed such that when the suture is tensioned, the suture shortens thus reapproximating the tissue back together. These devices come preloaded with self securing knots so that the surgeon only has to tension the device properly. Because meniscus tears are slow to heal, non-absorbable sutures are used, but your body often grows tissue over the suture material with time.
- Arthroscopic Inside-Out Meniscus Repair: A small incision is made on the side of the knee over the tear. The arthroscope is inserted into the knee for visualization. Zone specific cannulas, which look like tiny, thin metal straws, are inserted into the knee. Through these cannulas, long needles with attached sutures are passed first across the top and then across the bottom of the meniscus. The sutures are then tensioned and tied outside the knee through the incision that was made, thus cinching the tear together securely with this suture material. This technique is considered “the gold standard” of meniscus repair, but as technological advancements are made with all-inside meniscus repair devices, this inside-out technique is being used less than it was in the past. This technique is commonly used to repair a bucket handle meniscus tear, where a large flap of meniscus has torn and flipped into the center of the knee.
- Partial meniscectomy: When either the medial or lateral meniscus is torn along the inner rim in the white zone where there is no potential for healing, then torn flaps of meniscus that are catching in the knee and causing pain are carefully removed. Dr. Cunningham is very careful to only remove the portions of the meniscus that are unstable and not serving their normal shock absorbing function, as you do not want to preserve all normal portions of the meniscus. This procedure is commonly done in older patients who have degenerative type tears or for tears that have occurred as a result of years of wear and tear to the meniscus.
How Long is Meniscus Surgery Recovery?
Recovery from torn meniscus surgery is dependent upon whether the meniscus was able to be repaired or not. If the meniscus tear has no blood supply and torn flaps are removed arthroscopically, then the recovery is quite fast. After this procedure, called a partial menisectomy, patients go home the same day. They can walk on the knee right away and have no need for a knee brace or crutches. Patients are encouraged not to walk much on the knee for the first 3-5 days in order to decrease pain and swelling. Range of motion exercises are started immediately. Patients can spin on an exercise bike as soon as they wish but with minimal resistance to start. A few visits of physical therapy are recommended, but some patients choose to exercises on their own. Most patients are back to all their activities in 4-6 weeks following arthroscopic partial menisectomy surgery.
If a meniscus tear is able to be repaired, then the repair must be protected in a brace in order to allow it to heal. The need to wear a knee brace makes the recovery time longer, but it is worth it as in the end, the meniscus tissue is preserved. A knee brace is worn holding the knee straight when walking for 6-8 weeks, depending on the size of the tear. However, when not walking, patients can take the brace off and move the knee fully. Physical therapy is started soon after surgery in order to work on swelling reduction, easy range of motion exercises, and later strengthening. After the first 6-8 weeks, the brace is discontinued and more aggressive strengthening is begun. However, patients are not allowed to perform a deep squat (which places high stresses across the meniscus repair) until 12 weeks from surgery. Returning to all cutting and pivoting sports can take 3-4 months.
Dr. Cunningham is a meniscus surgeon at Vail Summit Orthopedics and Neurosurgery. He is an expert at diagnosing and treating meniscus for patients in Vail, Summit County, Aspen, and Denver, CO.