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The knee, which bends, twists, floats, glides and sometimes wears out, is a marvelous mechanism—but not designed for the rigors of sport

The knee. It was for a long time misunderstood as being simply a joint made for bending. It was thought that it worked like a garden gate. Gray's Anatomy, that classic medical student's tome first published in 1858, pointed out this mistake, saying, "The knee joint was formerly described as a ginglymus or hinge joint, but is really of a much more complicated character."

Complicated character, indeed. Gray—Dr. Henry Gray, Fellow of the Royal College of Surgeons—was speaking only of the anatomical complications of the knee; he scarcely could have dreamed of the real complications—legal, economic, emotional, even sociological—that would befall that strange and perilous joint in the late 20th century.

The horror stories are endless, the statistics staggering. A roster of big-name athletes—superstars, stars, would-be stars—who have been crippled, slowed, weakened or forced to retire because of knee injuries in the past five years alone reads much like the list of names on a plaque at the base of a statue commemorating the dead of this war or that—young people cut down before their time. If you multiply the roster of famous crippled athletes by 10,000 or so, you will approximate the number of all the others—high school quarterbacks and YMCA forwards and commercial-league Softball shortstops—who were also cut down by bad knees before they were anywhere near ready to quit.

The knee is the single most abused joint in sports, particularly football. Two Saturdays ago, for sad example, senior Quarterback Gifford Nielsen of Brigham Young University, the nation's most effective college passer this season and a leading Heisman Trophy candidate (he had completed 62.8% of his passes, 16 of them for touchdowns), was cut down while releasing a pass against Oregon State. He suffered torn ligaments in his left knee and, as abruptly as that, his Heisman hopes and his college career came to an end. So far this year, more than 50 NFL players have had their seasons cut short by knee injuries. The average NFL career is 5.03 years. One of every five players who compete that long suffers knee damage. Last year the Miami Dolphins had a nightmarish knee-injury record: eight Dolphins had a total of 11 knee operations, and 21 hurt their knees one way or another. Coach Don Shula spliced together a movie reel of his players being injured so team doctors could study the causes. What the film showed merely added to the mystery and fear surrounding the knee—there was no common denominator to the injuries. Some players were hurt hitting opponents, others while being hit. One Dolphin hurt his knee when a teammate rolled over him in a pileup, another was accidentally blindsided by a teammate in an open field, and two defensive backs hurt themselves while running pass-coverage routes in which there was no contact at all.

The knee has generated its own lore. The scarred knees of Joe Namath, Bobby Orr, Gale Sayers, Willis Reed and E. J. Holub are enshrined in the annals of athletic injury. So, too, is the knee of Mack Lee Hill of the Kansas City Chiefs. Hill hurt the knee in 1965, his second pro season, when he was on the verge of stardom. But he was terrified of surgery and resisted it until he was convinced that it was his only chance to play again. Hill died during the operation. The cause has never been specified, but one theory is that he died of fright. Each year the Chiefs honor his memory with an award to their best rookie.

The knees of Holub, a middle linebacker and center for the Chiefs for nine years before he retired in 1970, will never be forgotten: while a player, he underwent 11 knee operations, six on the left, five on the right—and has since had two more. "I guess my biggest handicap," says Holub, "is that I don't lay off it long enough after I have the surgery. The minute I start feeling good, I start getting back on the knee. The doctors aren't exactly excited about the way I am." Did all those operations do any good? "They've all been good," he says, "but I am still in pain all the time. I've just learned to live with it. I've got scars all over both knees. A friend of mine saw my knees once, and he said it looked like I'd been in a knife fight with a midget."

If Holub's knees make the Hall of Fame for frequency of repair, then Dick Butkus' right knee ought to be honored for first producing top dollar in court. Butkus was awarded a record $600,000 in 1976 as the result of a suit against the Bears and a Chicago doctor. Dozens of similar cases are pending against pro teams and their doctors.

The knee is one of the few parts of the body to have a worldwide association devoted to it. Last May orthopedic surgeons from half a dozen countries gathered in Rome for the first meeting of the International Society of the Knee. So urgent is the need to develop a common nomenclature for the myriad forms of knee instability, as well as to communicate new techniques in diagnosis, surgery and rehabilitation, that it seems only a global organization of its own can do justice to the knee.

Says Dr. Robert Kerlan, the Los Angeles orthopedist, "The old trick knee has turned out to be a lot trickier than anyone ever suspected, hasn't it?"

All the tricks the knee is capable of remained unknown for so long because men didn't put it through the stresses and strains it undergoes routinely in present-day athletics. Dr. Kerlan says, "The joint itself hasn't changed in millions of years. It is as old as man. In the earliest skeletons found, the knee joints are pretty much the same as they are today. The fact is, the human anatomy is simply not constructed for the games men play today."

Dr. James A. Nicholas, who as team physician for the New York Jets performed four operations on Namath's knees, says flatly, "The knee is the most poorly constructed joint in the body, given the torques and loads it takes in sports. And not just in football. Everything from plain running and jumping to bike riding, almost everything people do for recreation, is tough on the knee."

At its most fundamental, the knee acts as a hinge between the femur (thigh bone) and the tibia (leg bone). It is so flexible that when you sit, the two bones separate so that they are barely touching. But when you stand, the bones lock firmly together, forming a strong, unified structure. The end of the thigh bone resembles a rounded knob, the end of the tibia is relatively flat. Yet these two fit together perfectly, working against each other without friction, smooth as ball bearings rolling in a cup of oil.

Along with acting as a hinge, the knee glides, slides, twists, rocks and rolls. These movements occur over five different planes and points of contact between bones while the knee is supporting the bulk of the body through a variety of velocities, torques and pressures. The knee's delicate apparatus is expected to function flawlessly through all manner of self-inflicted trauma—jumpers' jolts and linebackers' impacts, joggers' heels thud-thud-thudding against pavements and backpackers' feet jarring down hillsides, explosive sprints and sharp veers, wrenching zig-outs and screeching halts, cleats caught in plastic grass, spikes snagged on second base, skates twisted in rutted ice.

It is a lot to ask of a joint that was designed two and a half million years ago.

Briefly, the anatomy of the joint that gives the leg both explosive power and tree-trunk strength is this: the thigh bone is connected to the leg bone by a series of ligaments. They form the basic structural support to the joint through their tension and stability. There are four major ligaments. The medial collateral ligament running up the inside of the leg and the lateral collateral running up the outside keep the joint stable from side to side. In the joint, between the bones, are the anterior and posterior cruciate ligaments, which cross. They prevent the two bones from slipping backward or forward out of the joint. No matter how powerful the muscles around the knee, without strong resilient ligaments the joint would be useless. A sound working ligament is a wonder to behold. Gray's Anatomy describes it as being "pliant and flexible, so as to allow perfect freedom of movement, but strong, tough, and inextensible, so as not to yield readily under the most severely applied force...."

The kneecap or patella rides in a groove in the lower end of the thigh bone. It lies in a large tendon connecting the quadriceps muscle on the front of the thigh to the leg bone. Behind the patella, filling the spaces within the joint, is a material known as synovial tissue. It is a delicate membrane of connective tissue that secretes a thick, viscid substance—"glairy, similar to the white of an egg," says Gray's. This synovial fluid lubricates the structures of the joint. Secreted excessively when the joint is hurt or irritated, the fluid used to be called "water on the knee."

Then there is the famed and troublesome knee cartilage known as interarticular fibrocartilage. Such cartilage is found in only a few joints of the body, and Gray's speaks of it as rather heroic stuff. "These cartilages are found in those joints which are most exposed to violent concussion and subject to frequent movement. Their uses are to obliterate the intervals between opposed surfaces in their various motions; to increase the depths of the articular surfaces and give ease to the gliding movements; to moderate the effects of great pressure and deaden the intensity of the shocks to which the parts may be subjected." (Two other joints with similar cartilage are the wrist and the jaw.)

There is also cartilage behind the patella and a lining of cartilage on the top of the tibia, where it comes into contact with the femur. This works basically as a shock absorber, a super-slippery cushion that affords a satiny surface for the thigh bone to ride on with a minimum of friction. It is this cartilage that is most frequently torn, cut, pinched or loosened in knee injuries. The sections of it are called menisci because they resemble a lens or meniscus. The medial meniscus is on the inside of the tibia and the lateral meniscus is on the outside. They are half-moon shaped, and anatomists refer to them as the semi-lunar cartilage.

There is a thick and powerful structure of muscles and tendons in the thigh and leg that works to flex, drive and support the knee. Three major muscle groups are involved: the gastrocnemius (calf), the quadriceps femoris (front of thigh) and the hamstrings (back of thigh). The conditioning of muscles is essential for a sound athletic knee, but muscle injuries are rarely as crippling as those that involve the intricacies of the joint itself.

The number of possible combinations of knee injuries and resulting forms of instability is staggering. Dr. Kerlan says exasperatedly, "People ask me, 'What really is wrong with Bobby Orr's knee?' I tell them I've never seen it, that there could be any one of 11 things wrong." Dr. Nicholas says, "I can tell you off the top of my head 30 different things that could cause pain in the knee—and I wouldn't even mention the most common, which is wear and tear on the tendons of the patella."

The art of treating the knee has advanced so rapidly in the past 15 years that orthopedists are hard pressed to keep up with the variety of injuries and instabilities they are learning to diagnose and define. Dr. Kerlan recently sent a memo to a nurse listing new classifications developed by Dr. Jack Hughston and Dr. James Andrews regarding eight basic forms of knee instability. The eight were: straight medial, straight lateral, straight posterior, straight anterior, anteromedial rotary, anterolateral rotary, posterolateral rotary and combined rotary instability.

Dr. Donald Slocum of Eugene, Ore., one of the top knee specialists in the U.S., says, "I don't think there are actually so many more knee injuries per player than there were before. I think what we have now is better diagnosis. We are recognizing new types of conditions all of the time as a result of that. And, of course, the types vary greatly with each sport. There is a different type of injury when the foot is planted on the ground as it receives a blow than there is when the knee is injured in the air—as with a skier, for example. There are many more types of knee injury now than before simply because more people are participating in so many different sports. Many types of injuries are becoming more common, but 15 years ago we didn't recognize them at all."

Knee injuries, as Dr. Slocum indicated, can come from multiple sources. Blows to the kneecap after constant pressure (such as one endures while kneeling to clean floors, the celebrated "housemaid's knee") can cause inflammation, tendinitis and dislocation. Countless mini-traumas are produced in the knee joints of long-distance runners, hurdlers, cyclists, cross-country skiers, even hikers—and each can eventually result in debilitating harm, such as a frayed patella tendon or damaged cartilage. Obviously, the thunderous jolt of a 250-pound body hurtling against the side of a locked knee can rip the tendons from the bone. Or a misstep on a tennis court—or while shagging a fungo, as happened to the Tigers' Mark Fidrych—can tear cartilage, strain a ligament, pinch the synovial tissue.

Dr. Hughston, who practices in Columbus, Ga. and is another of the nation's leading knee surgeons, says, "Most knee injuries are caused by pure accident. A boy runs off the field and steps on a teammate's foot and tears all the ligaments on the outside of his knee. Basketball players come down wrong on their feet. Pole-vaulters, tennis players and water skiers have a lot of knee problems. Most knee problems are caused by non-contact sports."

Yet to generalize at all on the basic causes of knee injuries may be folly. Here, briefly, are some theories from Dr. Nicholas, Namath's doctor, who founded the Institute of Sports Medicine and Athletic Trauma and is chairman of the Research and Education Committee of the American Orthopedic Society for Sports Medicine. Dr. Nicholas feels there may be too much stress put on the knee as a single isolated joint. He says, "You can't separate the joints one from another. They're all in a linkage system. To work on the knee you have to have a total conception of the body. There are 400 muscles, 600 ligaments. We may be getting too fragmented in our views. I'm strongly for the Knee Society, but we must keep in mind all the linkages."

Besides the myriad effects that an out-of-line hip or an inturned ankle can have on a knee, Dr. Nicholas points out that no two people are constructed exactly alike, no two knees react identically. "There is no average man," he says. "We are all slightly dissimilar to each other. Everyone has different kinds of stress on every joint. What works for one man—a preventive brace or special taping to protect a knee—won't work for another. Age makes a difference, too; as you get older you get tighter. No, there is no average man, and this makes preventive medicine tough."

Dr. Nicholas has come to believe that there is a relationship between serious knee injuries and a person's being loose-jointed or tight-jointed. In general he has discovered that people who are loose have injuries that differ markedly from those who are tight. The tight-jointed suffer more ruptured tendons, spinal-disc troubles and articular lesions inside the knee. They pull muscles more often, and tend to have more serious knee injuries. Loose-jointed people are more prone to dislocation of joints. Women, generally, are more loose-jointed than men, and have many more dislocated patellas than men.

One of the earliest practitioners of sports medicine as a specialized pursuit was Dr. Daniel H. Levinthal, now 82, a perky old fellow who recently retired after 58 years as an orthopedist. For 21 of those years he was an official team surgeon for the Chicago Bears. Dr. Dan, as he was called, estimates that he has operated on some 6,000 knees, many of them belonging to such athletic heroes of the past as Bill Osmanski ("That was a real lesson in anatomy, that knee") and Kenny Washington ("His knee was full of little marbles of cartilage"). "The injuries were a bit different in the old days," says Dr. Levinthal. "There was no artificial turf, which has come to be a serious problem. And the helmet was just a little leather thing, not a lethal weapon for spearing like it is now when it can crack a kneecap. Players are taught to hit harder now. In football there is a killer spirit that causes severe injuries of all kinds, especially to the knee. Of course, techniques for diagnosis were limited in the old days. We had the X ray, but you can't see anything but bone—cartilage and muscle do not show. And we had external examinations—the push-pull test for cruciate ligaments, rotation for the medial meniscus, the spring reflex to see if the knee straightens or stays bent. There were many routines for these tests. But the best, of course, was an incision. I could usually make a two-to-three-inch incision and see everything I could want to know about a knee."

An arthrotomy (opening the joint surgically) is still considered an excellent way to diagnose an injury, but it is painful and disabling, and diagnostic techniques have progressed beyond it, especially in the last 10 years or so. One well-tested method is the arthrogram, a form of X-ray procedure in which a special liquid dye is injected with air into the knee. Viewed through the X ray, the dye forms a pattern on the soft-tissue structures so that a ligament or cartilage tear can be seen clearly where the dye penetrates. The procedure is relatively painless and takes no more than 45 minutes.

Newer yet is the use of arthroscopy. This technique involves a tiny one-suture incision, through which a sort of tubular telescope is inserted directly into the inner knee for immediate viewing. With certain new optical equipment that produces a light source, the specific abnormalities of the knee can be directly observed by the doctor, and photographed or projected on a television screen. The use of arthroscopy usually involves a bit of complication and inconvenience, but more and more outpatient clinics are now set up to handle it. Even though general anesthesia is required, new techniques have shortened the procedure to a matter of hours.

In recent years arthroscopy has also been used as a corrective measure in minor afflictions in which bits of cartilage are loose in the tissues of the knee. Arthroscopy is used to flush liquid through the knee, which washes out the debris causing the pain or disability.

Says Dr. Nicholas, "We are right 75% to 80% of the time with just an X ray, and a thorough history and examination. Adding an arthrogram we gain another 8% or so accuracy. Combining them all with the arthroscope, we can get up to 98% precise diagnosis of what is wrong."

Surgical techniques have been advancing rapidly, too. For many years the major problem was to find a way to stabilize torn ligaments. Relatively primitive surgery to accomplish this was begun during World War I, but the first breakthrough did not occur until the late 1930s, with Dr. Don O'Donoghue of Oklahoma City, widely known in the U.S. as the "father of knee surgery," in the forefront of this work.

Dr. O'Donoghue is still in active practice—and in great demand by top athletes. (He has performed two operations on the right knee of Willis Reed, the new coach of the New York Knicks.) Dr. O'Donoghue has seen revolutionary changes in knee treatment since he began practicing nearly 50 years ago. "The only known treatment for many years was to put a knee in a cast and hope the injury would go away in a few weeks," he says. "Knee surgery was seldom done in the early '30s. There was a general feeling that when you got to the surgeon with your knee, your day of athletic competition was over. Then I began to notice that people who demanded surgery, because of the seriousness of their injury, got better results than people who were less seriously hurt and didn't have surgery. Then we got involved in some experimental work—ligament repair on dogs, for example. We felt we could then prove it was clinically possible for it to work on humans. It wasn't easy. Some people called us knife-happy."

In 1949 Dr. O'Donoghue published a paper, now considered a classic, on the case histories of 25 University of Oklahoma athletes who had major surgical repair on their knees and were able to play again. "That is when the concept finally arrived," he says, "that a doctor should do everything he could to make the player well enough to decide himself whether he wanted to go back to playing."

Dr. O'Donoghue's pioneering work was followed by other breakthroughs. Dr. Slocum recalls, "The concept of having ligaments repaired, not just in the forward-and-backward plane, but also in the side-to-side plane, was not arrived at until the early 1960s, when the theory of rotational instability was introduced. That led to a whole new line of thinking and the development of new techniques in the last 15 years."

As Dr. Nicholas puts it, "Surgery now has been developed to the point where any competent orthopedist can do it. You don't have to go flying off to some far-off wizard to have knee surgery."

However, the fact that surgery is so much more a matter of routine does not mean that it is a cure-all. Excruciatingly painful arthritic knees may occur in middle age after major surgery. Irritation and inflammation of the joint is difficult to avoid in many cases after the removal of cartilage. Thus, there are tough decisions for doctors—and athletes—to make every time surgery is contemplated. "The doctor represents the player," says Dr. Kerlan, "not the management, and he should play a kind of medical father to an athlete. We aren't just interested in patching a man up so he can play more. We have to consider what goes on after the stresses of athletics. We have to think of the rest of a man's life. These people are young. They have 40 or 50 years left to live. They could spend it all in constant pain. But when a player is a professional, his future depends on earning money while he can play. It's a critical period—10 or 15 years of earning power that can make him secure for life. So the players say, I know my knee is hurt, and I know there's a serious risk if you operate again, but I have to go ahead with it. I have to play, this is my life.'

"A doctor may argue with him and tell him, 'You may end up with lots of arthritic pain if we operate.' But these fellows say, 'I don't care.' "

The pressures on superstars to continue playing, no matter what the cost in pain and trauma and future mobility, are great indeed. Recalls Dr. Levinthal, who was a consultant for the Bears when Halas sent Butkus to him in 1968, "I examined him and said, 'This knee won't stand pro football. Nor will it stand the routine trauma of life.' His knees were worn out. They were bone-to-bone. He'd worn out the inner cartilage. The semilunar cartilage was torn. There was irritation on the surface of the femur. Every move would be painful. He said to me, 'When do you want to operate?' I said, 'I won't do it.' "

Butkus went on to play another six years—often brilliantly—before he was forced to quit in 1974 at the age of 31. He went to court to win the fortune he wasn't able to make on the gridiron.

If athletes insisting on surgery have come to be a critical problem for orthopedists, even more so is the proliferation of lawsuits against the doctors who treat them. Dr. Kerlan says, "We are up to our necks in lawsuits from guys who forced us to do things for their careers. Sports medicine is new. Knee injuries are relatively new. We are learning so fast, maybe too fast. But we have to be allowed to continue our work in an orderly manner. This can't be done if there are aggressive attorneys waiting at every turn to sue us. We can't live in constant fear of being financially wiped out for life because we want to try something new, something better."

New techniques are exciting indeed. Doctors can replace ligaments. They can replace cartilage with steel and plastic connections. They can replace the whole knee joint. The artificial knee will not stand up to violent exercise, but as Dr. Kerlan says, "When some old guy from the Canton Bulldogs comes in with his trick knee, we can give him a new one so he can at least walk without pain. Just that chance to walk well is an amazing new lease on life for people who have limped in pain for 30 or 40 years."

Whatever magic the surgeon's knife and orthopedist's inventions may produce in a damaged knee, none of it is worth a plugged patella unless it is accompanied by a monumental post-operative program to rebuild the joint for further hard use. And it is here, in rehabilitation, that there seems to be a relative weakness in modern therapy—the Achilles heel of the knee, as it were. Dr. Slocum says, "Rehabilitation is a lot more advanced than it used to be, no question about that. But it is not carried out every place. At the university and professional levels, they do an excellent job. At the high school level, it is frequently inadequate just because they don't have the money for enough good trainers. I wouldn't say that rehabilitation techniques are lagging, they are just not widespread enough."

Hank Kashiwa of Steamboat Springs, Colo., the 1975 professional ski-racing champion, experienced the confusion and doubt that follow many knee operations. He had torn a ligament during a race in January of 1976, and reinjured it two weeks later while preparing for the Superstars. This time he tore the cartilage on both sides of the knee, as well as the anterior cruciate ligament. Nonetheless, he competed in the rowing, biking and boating events before dropping out.

Kashiwa was operated on by Dr. O'Donoghue, but there were complications—for one thing, it was found that one of his cruciate ligaments had deteriorated to the point of non-existence. And his tibia had a tendency to slip forward out of joint, then drop back into alignment with a disconcerting clunk.

"I had always prided myself on having good knees," says Kashiwa, "but now the doctors told me I'd never have a normal knee again. This was beyond my realm of comprehension. I went into a real depression. Finally I asked what I should do to get back in shape. They said, lift weights. That's all—lift weights. Dr. O'Donoghue said I should lift as much as I could. That was all I had to go on. I was in the dark when I started my rehabilitation. I lifted so much weight I could have moved a mountain."

Kashiwa's knee remained weak. There was a constant build-up of fluid. In the summer of 1976, the knee was put in a splint for six weeks. Kashiwa was disconsolate and confused. He contacted Tage Pedersen, long the trainer of the American ski team. "Tage reminded me that every knee is different," says Kashiwa. "He said the weaknesses in my legs from my knee injury were probably different from anyone else's, that the muscle groups involved could be different. And he reminded me that when you lift a weight, you can only lift as much and as long as your weakest muscles allow. So you end up exercising only those muscles to an ultimate extent. There had to be something that could adjust itself to the individuality of my own condition."

It was then that Kashiwa discovered isokinetic exercise equipment. Some of the apparatus looks a little like an electric chair. Its practical value is that it can simulate actual athletic movements through a series of exercises in which loads are moved under calibrated progressive resistance. Rather than the killing sensation of moving dead weight, workouts on these machines—the Cybex Leg Press, the Orthotron, the Fitron—allow a person to exercise every muscle group in the body separately and to keep an ongoing record of the amount of power generated in each group. A rigorous series of sets and programs can be created—each to suit the specific needs of the individual. The equipment is expensive. The three machines cost Kashiwa and his partner in the club about $5,000. But it was worth it. By the end of the 1977 pro season Kashiwa was skiing with all of his former abandon, and in the last series of the season he finished second to Henri Duvillard—which is what everyone else had done all year, too. Kashiwa was so enthused that he equipped an entire room in the Storm Meadows Athletic Club at Steamboat Springs with the apparatus and has opened a clinic for athletes and anyone else who needs this special treatment.

"Pro teams have some of this stuff," says Kashiwa, "and universities do, too. But a lot of them don't know how to use it, to adjust it to the individual's needs. That's the trouble—you can't generalize about knee rehabilitation. Every knee is as different as a fingerprint."

Different as a fingerprint but, as Gray's Anatomy might have put it, "of a much more complicated character."





Los Angeles orthopedist Dr. Robert Kerlan is in attendance on bench during Rams game.



When Ron Jessie hurt his knee, Kerlan was there to study and explain the damage.



Arthroscope lets doctors see knee damage, possibly correct it without major surgery.



Joe Namath's right knee is wrapped in ice after play to reduce inevitable swelling.