A meniscectomy is a surgical procedure to remove all or part of a damaged meniscal cartilage.
The knee is a complex, hinged joint, formed by the articulation of three bones, the femur (thighbone), tibia (shinbone), and the patella (kneecap). At the inner and outer edges of the knee joint, between the femur and tibia and attached to the synovium (a membrane within the fibrous joint capsule), are two crescent-shaped pads of tough cartilage, the menisci. These serve as shock absorbers for the knee, cushioning the articulating ends of the bones, and providing stability for the knee by balancing body weight across the joint. Because they are, effectively, spacers between the femur and tibia, they also allow the nourishing and lubricating synovial fluid in the joint to diffuse into the articular cartilage at the ends of the bones, thereby helping to prevent arthritis.
Injuries to the meniscus are common. As we age, cartilage begins to deteriorate and becomes increasingly vulnerable to injury. A relatively minor twisting of the knee might cause a meniscal tear. Another common cause are sporting injuries that can happen when an athlete squats then twists the knee.
Factors in deciding on surgery:
- The outer third of a meniscus has a rich supply of blood, which means that tears in this area usually heal well. If surgery is necessary for a meniscal tear in the ‘red zone’, a successful outcome is likely.
- The inner two-thirds of a meniscus, the ‘white zone’, has no blood supply and therefore tears may not heal. Surgery may be necessary to remove a fragment of meniscal cartilage if it has been torn away and become wedged in the small space between the femur and tibia, as it will cause painful swelling and loss of mobility in the knee if untreated.
- Surgery may be required to smooth rough areas of cartilage.
- Sometimes a tear will travel through the red zone into the white zone, in which case the decision whether or not to have surgery is more difficult.
- The shape of a tear: Some tears, such as a flap or a horizontal tear, need to be surgically trimmed.
- Your age, general health and activity level
- The condition of the entire knee
After proper diagnosis of the injury, including medical history, physical examination, x-rays and possibly an MRI scan, a decision will be made, in consultation with you, as to whether surgery is indicated and whether you require a partial or complete meniscectomy. It is considered preferable to try to retain as much of the meniscus as possible, in order to best protect the joint from degeneration, which is likely to lead to arthritis.
A meniscectomy is usually performed using arthroscopy, and is done on an outpatient basis, which means that you will not have to spend the night in hospital, although you will need to have arranged transport to take you home after the procedure. Very occasionally open knee surgery is necessary, in which case your hospital stay will be longer.
You will meet with an anesthetist who will explain the type of anesthetic that you will receive. It might be local, in which case just your knee will be numbed, regional, meaning that you will be completely numb below the waist, or general, in which case you will be asleep throughout.
After appropriate anesthesia, surgery will begin. Arthroscopy involves making three or four very small incisions around the knee, through which various instruments are passed into the joint in order to make the necessary surgical repairs. The arthroscope is a flexible, narrow tube with a light and a tiny camera. The camera is connected by cable to a video monitor screen in the theatre, enabling the orthopedic surgeon to clearly view the knee joint. To prepare the knee for surgery, a saline solution is flushed through the joint to both clear out any cloudy fluid and to enlarge the space, thereby giving the surgeon the clearest possible view and room in which to work.
Depending on your particular needs, the surgeon will remove some, or all, of the damaged meniscus. Every attempt will be made to preserve as much cartilage as possible. Loose or detached fragments are removed, and any rough areas smoothed.
The length of time it takes to recover after an arthroscopic meniscectomy depends on several factors. Your age, general health and activity levels will all influence the length of time it takes to get back to your pre-injury state.
Immediately after the surgery you will be required to wear a knee brace for about 6 weeks, to keep the knee straight. You will also need crutches when walking. Pain medication will be provided, as you will experience some discomfort from the surgery. Ice packs applied to the knee will help reduce swelling. These should be used for 15-20 minutes at a time, several times a day. You should also keep the knee elevated above heart level whenever possible.
Physical therapy usually begins soon after surgery and will include exercises that focus on restoring range of motion, followed by weight-bearing and strengthening exercises, as your knee heals. Follow instructions as to when and how much you are allowed to exercise, and seek permission from your doctor before returning to full sporting activities.
Sitting or lying down, press the knee down against the table or floor. Hold the position for 5-10 seconds then relax. Repeat 10-15 times for 1 set. Do 3 sets.
Straight leg raise:
Lie on your back on the floor. Bend the unaffected leg to a 90-degree angle, keeping the foot flat on the floor. Keep the affected leg straight and, using the thigh muscles, slowly lift the leg about 1 foot off the floor. Hold for 5 seconds then slowly lower to the floor. Repeat 10 times for 1 set. Do 3 sets. Low weights may be added gradually, starting with a 2 lb weight.
Knee bend and flex:
Sit on a table with the knee at the edge, letting the lower leg hang down. Simply straighten and bend the knee as far as it will comfortably go. Repeat 10-15 times.
Lying on your back with your unaffected leg bent and the foot flat on the floor, and with a rolled towel under the injured knee, gradually straighten the injured knee as far as you can. Hold the position for 5-10 seconds then slowly lower. Repeat 10 times for 1 set. Build up to 3 sets.
Lying face down with a rolled towel under the ankle of the injured leg (to prevent the toes hitting the floor), slowly raise and lower the foot by bending the knee. Repeat 10-15 times for 1 set. Weights may be added as strength is gained.