Meniscal Cartilage and Meniscus Tears
Kevin G. Shea, M.D.The meniscus acts as a shock absorber between the ends of the thigh bone and shin bone. It 'cushions' the bone ends, and decreases the contact pressure between the bones. By decreasing the contact pressure, it decreases the risk of joint degeneration or arthritis. The meniscus also provides some stability to the knee joint. Throughout much of the 20th century, surgeons would remove the entire meniscus after a knee injury. Long-term follow-up studies have shown that complete meniscus removal can result in early knee arthritis. In recent years, orthopaedic surgeons have recognized the importance of the meniscus, and many techniques are being developed to repair the meniscus and minimize the risk of future degenerative arthritis.
INJURIES TO THE MENISCAL CARTILAGE
Tears of the meniscus are common knee injuries. These can occur in young athletes after serious knee injuries, and may be associated with other injuries such as ligament tears or damage to the articular cartilage. As a general rule, meniscus tears are not as common in young athletes, especially those under 16 to 18 years. As young athletes are competing more aggressively in sports, the incidence of meniscal injury is increasing in this population. In older athletes, meniscus tears are more common, and they may occur after relatively minor twisting injuries to the knee. In many people, the meniscus starts to degenerate with time, making it more prone to injury after minor traumatic events.
SURGERY TO REPAIR OR REMOVE A TORM MENISCUS
Meniscus tears frequently produces symptoms in the knee, such as locking, catching, or painful popping. Pain while sitting or driving for long periods of time is also seen with some meniscus tears. Like articular cartilage, the healing potential for the torn meniscus is limited. In many cases, surgical treatment is necessary for these injuries, to promote healing. The meniscal tissue has a limited blood supply, and because of this, its potential for healing is limited, especially in older athletes. In cases where the meniscus has signs of degeneration, the chance of healing after surgical repair is lower. Because of this, your surgeon may not recommend meniscal repair. Current surgical methods attempt to repair the meniscus, or save as much meniscal tissue as possible, to decrease the probability of future knee arthritis. In cases where the meniscus cannot be repaired successfully, your surgeon will remove as small a portion of the meniscus as possible.
In younger patients, the meniscus has better potential to heal after surgical repair, and your surgeon may attempt to surgically repair the meniscus. Even in young patients, the meniscus may not be repairable, especially if it is an older tear. With older tears, the meniscus may sustain more damage, making successful repair impossible. In cases where the meniscus tissue has a reasonable chance of healing, the meniscus is repaired by sutures or other devices to hold the torn edges of the meniscus together. You may require additional incisions over your knee to repair the meniscus. In most cases, the meniscus is repaired with arthroscopic assistance, but the knee joint may also require a separate incision to complete the repair.
The meniscus is an important structure for the long-term function of the knee. If a significant meniscal injury has occurred, it requires early evaluation. In many cases, a meniscus is easier to repair if the injury is identified soon after the injury. With time, the torn meniscus may sustain further damage, making the surgical repair more difficult or even impossible.
FREQUENTLY ASKED QUESTIONS ABOUT MENISCAL SURGERY
How is the meniscus repaired?
The meniscus is repaired using sutures, or anchor devices to hold the edges of the torn meniscus together. Procedures will also be done to increase the blood supply to the meniscus.
What is the success rate after meniscus repair surgery?
This depends on several factors. Younger patients probably heal better than older patients. Larger tears do not heal as well as smaller tears. Older tears, or tears with degeneration do not heal as well. People with an ACL tear have a higher rate of meniscus repair failure. If the meniscus repair is performed at the same time the ACL is repaired, the healing rate is much higher.
If your meniscus does not adequately heal after surgery, you may require another surgery in the future to either remove the torn meniscus, or to attempt another repair. What restrictions will be necessary after surgery?
The post-operative rehabilitation for meniscal repair is quite different than the post-operative rehabilitation for removal of the torn meniscus. If your torn meniscus is removed, you will be allowed to return to full weight bearing soon after surgery, and will probably not require a knee brace. If your meniscus is repaired, you will not be able to bear weight for 4-8 weeks, and you may be treated in a brace that limits your motion. Some patients do not want to be limited in the post-operative period, and cannot be on crutches for 4-8 weeks because of work or personal reasons. Although we recommend meniscus repair in many cases, some patients cannot adhere to the strict post-operative restrictions. If this applies to you, discuss this with your surgeon. In some cases, we will remove your meniscus to make the post-operative rehabilitation easier.
When will I start my therapy after meniscus surgery?
In both meniscal repair or meniscal removal surgery, you will require extensive therapy after surgery. Therapy is usually started within 1 week of your surgery. In many cases, a physical therapist will help you with your rehabilitation, and design a program for rapid recovery. You will need to be an active participant in exercises to regain motion, decrease swelling, recover strength, and fully recover from your surgery. In many cases, the use of an exercise bike will be very helpful for your rehab. We recommend that you borrow or purchase an exercise bike, or join a gym that allows access to exercise equipment.
What type of anesthesia is required?
You may require a general anesthetic, and your anesthesiologist will discuss this with you before surgery. Prior to surgery, the anesthesiologist may perform additional procedures to minimize the pain during and after surgery. This may include injections of local anesthetic into the knee region, as well as around nerves in your thigh. This is known as a femoral nerve block, and greatly reduces your pain during and after surgery.
What can I do to reduce my pain after surgery?
After surgery, we recommend that you use an 'Iceman' device, or ice packs, to apply cool fluid to your knee. This will help with pain control, and minimize the swelling and need for narcotic pain medication.