Sometimes individuals have a congenital defect and the kneecap tends to run off the track or “subluxate” in the face of a severe sudden twist or constant stress. Picture a sliding door with a tendency to run off the track momentarily because it wasn’t built right. For other people there may not be anything inherently wrong with the knee; a traumatic event, such as a fall, dislocates the kneecap and the next time it takes less trauma to cause a recurrence.
This is probably the second most common disorder of the kneecap. It is also one that has captured the imagination of many orthopedic specialists. For example, by 1959 there were at least 137 surgical methods designed to solve this problem. This is a sure sign that no one really knows what will consistently work.
Yet we have to keep trying because this problem comprises a significant segment of knee injuries and represents a major cause of intemal derangement. Each time a kneecap dislocates there will likely be cartilage or joint damage, a fracture of the undersurface of the kneecap, or even a fracture of the lateral femoral condyle, which is the bone end that the kneecap slides over as it dislocates. If that’s not bad enough, over time this condition can lead to the onset of arthritis and further degenerative damage.
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| The sites of major knee problems |
Symptoms
Because the subluxation happens quickly, the patient rarely reports a completely dislocated kneecap. Instead, the complaint is generally of poorly localized knee pain and a history of vague complaints that the knee “gives way,” “pops,” “locks,” or “goes out of place.” In fact, what generally convinces someone to seek medical advice is not the pain of subluxation but rather the pain caused by the degenerative changes taking place inside the knee.
The pain is aggravated by both activity, especially stair climbing, and inactivity with the knee bent (such as in an automobile or theater). During sports participation, subluxation occurs when your knee gives way when you tum, cut back, or push oft during activity.
Typically, the first dislocation is recalled with great clarity: “I slid into second base, I hit the baseman, and ‘Pow!’—I thought my knee was coming off!” The next dislocation was almost as painful, but the third time not nearly so. After that the kneecap goes off its track and there’s a moment of instability and that’s about it. There’s little pain and hardly any swelling.
That first episode causes everything anchoring the kneecap to become stretched or torn. The muscles and tendons heal, but in a lengthened position, and after a while they become very stretched out. The longer the problem is ignored, the greater degenerative problem there will be to manage.
The complaints—locking, giving way, pain, and swelling-are the same symptoms associated with meniscal injuries, which means diagnosis can be difficult. I’ve seen people who have had their meniscus removed when in fact their problem was really a subluxating patella. This obviously didn’t solve the problem and often resulted in severe arthritic degeneration as the subluxation continued.
One of the key diagnostic features of this problem is something called the “apprehension sign.” People with subluxation often display marked apprehension when the doctor moves to push the patella laterally while testing for stability or increased mobility. This isn’t as sadistic as it sounds. A good examiner will note this apprehension and back off, hoping to avoid the “throat sign,” which is where the patient grabs the examiner if he goes one step further.
Treatment
The most notable feature of patella subluxation is a wasting of the vastus medialus muscles, which are part of the quadriceps. The quads hold the patella tightly against the femur, so retuming these muscles to peak condition is a primary goal of treatment. Nonpainful leg lifts and leg lifts with weights are important in getting the kneecap back on track. Support by bracing is also often recommended.
Studies suggest that with conservative treatment—that is, nonsurgical remedies-—dislocations become less frequent over time and there is little evidence of osteoarthritis. For people who have undergone surgery there is a higher recurrence rate, a risk that further surgery may be necessary, and a disturbingly high incidence of osteoarthritis. Therefore, surgery should be considered only after conservative rehabilitative techniques have failed.
BURSITIS (“I-Iousemaid’s Knee")
The letters -itis mean inflammation, so bursitis is inflammation of the bursa. The what? The bursa are little empty sacs around any joint that for the most part go unnoticed-—until they fill with fluid and swell. They’ re a little like air bags in cars, tucked away, out of sight and out of mind until—WHAMl-and they’re suddenly real hard to ignore.
There are fourteen bursas around the knee and any one of them can become inflamed. What generally happens is that something initates the knee, maybe the knee strikes a sharp object, or maybe the knee’s owner has been kneeling a bit too much, and the bursa decides the knee could do with some extra protection. So it fills with fluid or blood and tries to protect the knee from further injury. That’s great for the knee but, if it’s your knee, you will find there’s a cost for this added protection: intense pain.
The bursa in front of the knee is what gets irritated by too much kneeling and the result is a bursitis known as “housemaid’s knee.” Of course you don’t have to be anywhere near a kitchen floor to have angry bursa; carpenters, bricklayers, plumbers, and even ministers are often victims.
If you have gout, gouty crystals may form in the knee causing irritation and bursitis.
Symptoms
Localized pain, swelling, and tenderness are the hallmarks of bursitis.
Treatment
The first order of business is to eliminate the irritant. For example, either get a long-handled mop or pray standing up. Then oral anti-inflammatory drugs will help calm the bursa. In severe cases the bursa may have to be drained, the area injected with cortisone, and the fluid checked for special conditions like gout or infection. One to three injections of cortisone generally brings quick relief.
Bursitis is usually a very self-limiting phenomenon, unless it is also associated with gout, or arthritis, or some other condition that will cause continued irritation and continually angry bursa.
PATELLAR TENDINITIS (“Jumper’s Knee”)
The kneecap is connected to the front thigh muscle and shinbone by patellar and quadriceps tendons. A small tear here causes tendinitis, or “jumper’s knee.” This condition is usually sport-related, represents overuse of the involved tendon, and is common among basketball and volleyball players, hurdlers, and dancers. It may also be a complicating factor of Osgood-Schlatter disease in children.
Symptoms
A sharp pain in and around the patella is usually exacerbated by jumping. The knee may show swelling, redness, even warmth around the kneecap. Straight leg raising also causes pain. Various stages have been classically described: Stage 1——aching after participation; Stage 2-—aching during participation; Stage 3-aching and pain during participation, which is now affecting ability to participate; Stage 4—the catastrophic event that is caused by deterioration of the tendon to the point that it ruptures. Ouch!
Treatment
Jumping must be avoided for one to three weeks until the pain stops. Anti-inflammatory agents and massage can be helpful. In ice/friction massage, ice is rubbed on the skin for several minutes until numbness occurs. (lce is also used with cross-fiber friction massage, followed by the use of a dry washcloth to rewarm the skin. This. is repeated twice, ending with ice to stimulate the circulation. )
For some people, shoe orthotics, knee wraps, or a “jumper’s knee brace” may be beneficial.
As with chondromalacia patellae, quadriceps-strengthening and -stretching exercises can prevent recurrence.
My own experience suggests that about 70 percent of patients seem to be able to arrest their condition at the Stage 1 level with braces, an exercise program, use of minimal anti-inflammatory medication, and ice/friction massage. Of the remaining 30 percent, two out of three end up with more aggressive medical management, including perhaps a steroid injection, a more prolonged period of rest and recovery, and, in truly severe cases, perhaps surgery. And 10 percent will have to significantly modify their activities and go to a different sport. For example, basketball or volleyball will have to be replaced with a less knee-demanding activity. Strangely enough, this problem was much more common several years ago than it is now. Although there’s no concrete proof, I would like to ascribe this to better training habits, improved training
surfaces, better shoes, and better exercise regimens.
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