Muscle Medicine: The Revolutionary Approach to Maintaining, Strengthening, and Repairing Your Muscles and Joints (38 page)

The two cruciate ligaments (the anterior cruciate ligament, or ACL, and the posterior cruciate ligament, or PCL) cross each other inside the knee joint, hence the name
cruciate,
which means “cross.” They keep the tibia and femur stable by preventing forward or backward movement of the tibia under the femur. The two collateral ligaments (the lateral collateral ligament, or LCL, and the medial collateral ligament, or MCL) keep the two leg bones from sliding side to side. A single collision or violent motion can injure one or any combination of them.

Depending on which way the knee moves after it’s hit, the ligaments will tear in a predictable sequence, and these multiple ligament injuries are usually the most challenging to treat. But the ACL is the most frequently injured and is the star ligament that receives the most attention in the sports medicine and media worlds. Injure it and you may hear a pop, then feel the pain and endure the swelling.

The decision to surgically reconstruct the ACL is not automatic. For older people whose idea of the sporting life is a nice, brisk walk, a knee with a torn ACL and compromised stability may be good enough, especially if they commit to therapy to
relax and strengthen the joint muscles. Unlike with meniscus tears, age isn’t always an overriding factor in the decision to operate. If your torn ACL means you can’t walk across the street without your knee buckling, you’re a surgical candidate even if you do carry an AARP card. However, if joint replacement surgery is in your near future, having two major knee surgeries within a few years of each other is probably not a good idea. Wearing a brace can be a workable stopgap solution for an unstable knee.

PROTECT YOUR ACL

Wear well-fitted athletic shoes. If you have a bowlegged or knock-kneed gait that results from your foot structure, consider orthotic inserts for your shoes.

Be in top physical condition for your sport; make sure the leg muscles are strong and balanced.

Work with a competent coach on proper sports form and technique.

ACL RECONSTRUCTION

Most ACL reconstructions are done as “minimally invasive” surgery, with an arthroscope. A small fiber-optic camera is inserted into the joint so the procedure, performed with delicate instruments, can be monitored on a video screen. The surgeon harvests a new piece of replacement connective tissue from the patella or hamstring tendon and screws it into place using holes drilled into the femur and tibia. Sometimes, donor tissue from a cadaver is used instead.

For a younger person, especially someone active in sports, ACL surgery is pretty much a slam-dunk decision. Pivoting and jumping without the ligament is just an invitation to further injury and the fast track to osteoarthritis. (Ligaments outside the joint capsule do have the capacity to heal themselves, but there will likely be some permanent loss of strength and support.) Fortunately, ACL reconstruction is one of the great success stories of modern orthopedics— positive outcomes are in the mid-90 percent range. This success story owes much to improvements in surgical technique (see the “ACL Reconsruction” box above), and also to orthopedists paying closer attention to the muscles that ultimately have to
be able to drive the joint and the leg. As the story of the skier shows, treating and strengthening the muscles before and after surgery can greatly reduce the recovery and rehabilitation time. And your knee will probably function better, sooner.

In the last few years, the sports medicine world has begun to appreciate the connection between the bone structure of the knee and the ACL tear. The latest research shows that women injure their ACLs at over twice the rate of men. In sports such as soccer, volleyball, and basketball, where both sexes play according to similar rules, the female rate of ACL injury may be as much as five times as high. As we said earlier, women generally have a larger Q angle—wider hips create a steeper line from the hip to the knee—which is likely one factor that explains the difference between injury rates. Women’s weight also falls more on the inside of the knee, which can overstress the ACL. A running gait where the knees pull toward the midline is a sign of a large Q angle and a potential problem (see the Self-Defense box on page 205).

Osteoarthritis

Several years ago, we treated a top amateur marathoner and triathlete in his late thirties. Let’s call him Sam. We discovered that a hip-muscle imbalance was causing his knee muscles to overcontract. As a consequence, the femur and the tibia were twisting against each other, progressively shearing away the protective articular cartilage. In addition, some osteoarthritis had developed. We told Sam he had only a few good options: a sustained course of manual therapy to resolve the hip problem, physical therapy for the knee injury, and a cut back on the running. A hard-charging Manhattan business executive, Sam sought a second opinion that suited him better: several rounds of cortisone injections to quiet the inflammation, no lifestyle change required. Eventually, Sam underwent joint replacement surgery to replace his osteoarthritis-ridden right knee. But being hardheaded isn’t all bad. He’s since switched to cycling and is now one of the top amateur cyclists in his area.

Doctors sometimes like to use the analogy of a tire when they’re trying to get the attention of patients whose knees have begun to show signs of osteoarthritis: “You have this much tread left. Do you want to keep jogging and use it up in six months to a year, or do you want to try to keep your knees for longer?” What patients sometimes fail to appreciate is that while it may have taken twenty or thirty

OSTEOARTHRITIS

There is no known cure for arthritis; we manage it. Weight control is essential. In climbing stairs, an extra 50 pounds translates to 150 to 200 pounds of extra pressure on your knees. High-impact exercise such as running is out; low-impact exercise such as swimming or cycling or the elliptical-trainer machine is in. Rhythmic movement that doesn’t jar the joints and stimulates the production of lubricating synovial fluid can only help. Recent research shows that building muscle strength with weight training can help— start slowly and gradually increase the intensity of the exercise. Pain can be managed with anti-inflammatory drugs and, if necessary, occasional corticosteroid injections. Advances in manual medicine suggest that by releasing tightness in the surrounding muscles, manual therapy may lessen the pressure on the joint capsule, reducing the friction of bone moving against bone and slowing the progression of the disease. The goal may be to hold off severe, disabling arthritis indefinitely or to buy time so that if a patient anticipates knee replacement down the line, only one surgery is necessary.

THE “MINI-KNEE” AND TIBIAL OSTEOTOMY

If arthritis is present in only part of your knee joint, you could be a candidate for a partial or “unicompartmental” knee replacement, nicknamed the mini-knee, which leaves the healthy portion of the joint untouched. Younger patients whose arthritis is contained are good candidates for a procedure called a tibial osteotomy where a wedge of the shinbone is removed from the healthy side of the knee so that pressure is directed away from the diseased, arthritic portion. The goal of both procedures is to buy time, as much as a decade, before replacing the whole knee, reducing the chance of needing more than one total replacement in a lifetime.

years of pounding the pavement to trigger the disease, once osteoarthritis has set in, the knee can go from sore but functional to almost useless in months.

Our osteoarthritis patients tend to fall into two camps. They’re like Sam, who
aggravates the problem in the pursuit of competition, fitness, and feel-good endorphins. Or they’re older, often in their sixties or seventies, and unaware that they’re subjecting the knee to unusual stress. Influenced by genetics or by knee injuries sustained earlier in life, their articular cartilage silently wears away until one day knee pain announces itself, or their altered biomechanics may cause a meniscal tear.

Focal Chondral Injury

Not all damage to the knee’s articular cartilage is from wear and tear. Blows to the knee, typically in sports, can damage a segment of cartilage right down to the bone. If you’re under forty, and the health of the rest of your cartilage is good, you should be able to take advantage of one of a growing number of surgical procedures that either replaces the injured area with a cartilage graft or encourages new cartilage to grow. If the “focal defect” isn’t fixed, it may set in motion the downward slide to “global” osteoarthritis.

KNEE

The knee has two movements that concern us here: flexion and extension (bend and straighten). While the joint also allows for some medial and lateral rotation, there is certainly not enough movement to protect it from the torquing forces put on it in life and sports, which can cause discomfort and injury. The knee muscles’ main functions are to propel the body and to cushion impact, and the best way for you to assist the joint is to maintain the balance and strength of those supporting muscles.