Acute Knee Problems

So you’ve finally found time to go out and shoot some baskets first exercise in a week and what happens but your knee gives way just when you plant and pivot, about to drive in with your killer slam dunk. What’s wrong? If it’s acute, you should find an answer in this chapter.

ACUTE MENISCAL TEARS (see also “Sprains,” this chapter)

We’ve already talked a little about the knee’s shock absorbers, the menisci. When you talk of a tornncartilage it’s the meniscus that has been folded, spindled, and . . . well, you know.

Acute tears most commonly occur from a twisting action while putting weight on the knee; you may feel a tearing sensation at the time of injury. Repetitive squatting or kneeling as well as natural aging processes can weaken the menisci and set the stage for an acute meniscal injury. In fact, it’s amazing how little force is necessary to damage even a healthy meniscus: simply squatting to pick up something from the floor or getting out of a car can be the last straw that completes the tear. Of course not all cartilage is created equal. God gave some people top-of-the-line cushioning while others got brand X.

Symptoms

When a meniscus is first tom, bleeding within the joint irritates the lining, or synovium, of the knee. ln an attempt to wash away the irritant, the knee increases its production of synovial fluid and
the knee swells.

One of the most common tears of the meniscus is the “buckethandle” tear. The meniscus develops a split and part of it becomes trapped within the joint. When this portion of meniscus is separated, yet still attached at either end, it appears to be the shape of a bucket, with the entrapped portion representing the handle. The knee is locked and prevents complete leg straightening. There’s also pain along the edge of the “bucket” and swelling, usually two to six hours post-injury.

Often you try to ignore a damaged meniscus and, for a time, your knee cooperates. Some movement retums and you begin to think that you’re going to recover. Of course your leg won’t straighten completely or bend as far as it used to, but between these extremes there is acceptable movement. However, some swelling simply refuses to go away, so you break down and make an appointment with your doctor.

Diagnosis is often one of exclusion, and unless your knee is locked by a bucket-handle tear, it may be weeks after your initial injury before you know exactly what’s wrong with your knee. The most revealing symptoms are tendemess, inability to squat, duck, walk, or bounce up and down while standing. There is also pain when you attempt to rotate with the feet planted.

Treatment

A tom meniscus means surgery most of the time. But today most physicians agree that unless the meniscus is definitely unstable -or symptomatic, it should be left in—or only part of it removed-to protect the knee from osteoarthritis. That’s why 90 percent of the nearly 100,000 meniscectomies done in the United States today are only partial meniscectomies.

Certain tears in the meniscus can be sutured. However, this is not always possible, and it does involve an extended period of disability and recovery. There are particular modifying factors that affect a decision to do a meniscal repair. First, what is the complexity of the tear? It is much harder to get multiple tears to heal than it is if there is one discreet tear. Second, where has the tear(s) occurred? The outer one third of the meniscus has an excellent blood supply, which means it has the greatest capacity for healing. There are individual variations, but in general the farther into the meniscus a tear occurs, the less chance there is of healing and recovery.

Other considerations include the age of the injured, and his or her individual healing potential and life-style. Usually the younger person is the most amenable technically and socially to the repair process. For a meniscectomy, you’re on crutches for a few days; for a meniscal repair, six to eight weeks. If a simple, partial meniscectomy is performed, recovery takes about six weeks. For a meniscal repair, recovery will take six to twelve months. That’s a big difference. I don’t think it makes sense to try a repair on a sixty-year-old construction worker who is moving, twisting, and squatting all day as a part of his job. Will he be willing, let alone able, to take a year off or a reassignment in order to recover from the more complicated surgery? On the other hand, a total meniscectomy on a patient under the age of sixteen can be a real catastrophe. Ten to fifteen years later that individual may face real arthritic problems. So if I tore my meniscus, I’d say just take it out arthroscopically. If my daughter tore hers, I would want it repaired if possible. If there were multiple tears, I’d need to see some statistics to indicate that the repair will heal and she will be better off after a year of recovery.

Exercise

A large meniscal tear that causes the knee to lock, block, or give way probably will not be affected by a strengthening program. Even so, a rehabilitation program is valuable; if surgery is performed, the strengthening program will help prevent further injury and facilitate postoperative recovery. Whenever a knee injury occurs, muscle strength, power, and endurance quickly weaken in the affected leg. A loss of just 15 to 20 percent of muscle strength significantly Increases the risk of reinjury. During the first two weeks most people will have at least 15 percent deficiency, and by the time I we most of my patients, one month after the onset of symptoms the vast majority have lost 30 to 40 percent of their muscle strength.