You’ve got a bum knee. Now what?
New research sheds light on treatment choices for torn knee ligaments.
A30-year-old soccer player takes a sharp turn on the field and hears a dreaded “pop” in his right knee. He has ruptured the anterior cruciate ligament (ACL) – a band of tissue that’s important for stabilizing the joint. After icing, compressing, and elevating his swollen knee, he visits the doctor. Now it’s time to decide on treatment. If he’s an elite sportsman or has additional knee damage, the choice is fairly clear: Reconstructive surgery to replace the ACL, plus intense physical therapy. But if he’s a weekend exerciser who doesn’t do many knee-stressing sports, forgoing surgery in favour of rehabilitation through physical therapy may be a sensible approach. A recent study by researchers in Sweden and Denmark confirms this. The investigators followed 121 young, active adults with ACL tears, half of whom were randomly assigned to have physical therapy and surgery, while the others had physical therapy with surgery as an option later. Two years after their injuries, people in both groups had “substantial improvement:” in their knee condition, and there were no major differences in five knee-related categories such as pain, other symptoms like swelling, and function in daily living and sports activities. The results suggest a wait-and-see approach may be right for some with torn ACLs and that more than half of expensive ACL reconstructions could be avoided “without adversely affecting outcomes,” the investigators wrote in the The New England Journal of Medicine. In other words you can take the time to weigh your choices instead of rushing into surgery.
TWIST OF FATE
The ACL has been described as the seat belt for the knee ( see illustration). It runs through the middle of the knee joint and keeps the shinbone (tibia) from sliding forward past the thighbone (femur). The ACL is one of four main ligaments in the knee – and one of the most commonly injured ones. The ACL can be stretched, torn, or both during a sudden or awkward twist, turn, or stop, typically while people
are playing sports that require sudden changes in direction (pivoting and cutting) or jumping. The sports on that list include basketball, football, skiing, soccer, tennis, martial arts, volleyball, and some kinds of aerobic dance. Collisions aren’t necessary: about 70% of ACL tears occur without direct contact with another player or object. Although ACL tears are usually a sports injury, they do occur outside the gym and playing field like among dancers, active adults whose jobs involve pivoting or hard cutting, and individuals who do heavy manual work. People get their ACLs torn in car crashes. A simple trip or fall that twists the knee can also result in a tear. Women appear to be more vulnerable to ACL injuries, due to differences in
muscle strength, alignment, and estrogen levels that can loosen ligaments. There’s also some evidence that women are more likely than men to turn their knees inward when changing direction suddenly, placing added strain on their knees and ACLs.
PROMISE OF THE SCALPEL
Diagnosis of an ACL tear usually involves several hands-on tests and an MRI scan. Then it’s time to choose a treatment. Surgical reconstruction involves replacing the injured ligament with a piece of tendon taken from the person’s own leg or from a cadaver. When the patient’s own tissue is used, it often comes from either the patellar tendon below the knee or from tendons in the thigh. Using tissue from cadavers has become increasingly common, in part because it avoids the pain caused by removing the patient’s tendon tissue. Doctors have tried repairing the ACL by sewing the torn pieces together, but that has generally proved to be ineffective. These days, ACL surgery is usually done arthroscopically, through small incisions. That approach has shortened the recovery period, but you can still feel a fair amount of pain in the days and weeks after the operation. Months of physical therapy are needed to restore strength, coordination, and range of motion. As with all surgery, there are risks,
like infection; in some cases, the operation fails to stabilize the knee.
WHO NEEDS SURGERY?
Replacing the torn ligament with tendon does tend to make the joint more stable than physical therapy rehab alone, which is an advantage for people who place a lot of stress on their knees. Your knee has suffered substantial damage. Surgery may also be the preferred route if there are additional injuries – for example, if a meniscus has been torn.
With a long-term success rate of 82% to 95% many people – esp sportspersons – who get reconstructive surgery resume their preinjury activities; But doctors say the joint never quite works exactly the way it did before the tear, and more research is needed to understand why. Another big disadvantage of having surgery is a slow recovery. And therein lies the irony: People who don’t get surgery normally recover enough to be active again within two or three months. Whereas it takes about six months for surgery patients to get back on their feet researchers find. It takes longer to recover from surgery because tendon graft used to replace the ACL needs to fully heal and be ready to withstand the stress that playing sports can put on it. Early-onset osteoarthritis is another common complication of ACL tears, probably caused by increased wear on the leg bones and shock-absorbing cartilage in the knee over time. It’s not clear whether surgery reduces the risk of osteoarthritis.
NO -KNIFE APPROACH
The ACL doesn’t heal on its own but there are no-knife ways to cope with a bum knee. Physical therapy can strengthen the muscles around the knee enough so they compensate for the non-working ACL. Treating an ACL tear with physical therapy alone is worth considering if it’s a partial tear or if you’re not very active. Custom-made knee braces may be useful for tennis, soccer, or other activities that involve twisting if you’re a weekend warrior and not a pro player. Find a new sport Adults who are active but do “in line” activities such as cycling or running might also do well with just physical therapy because those sports don’t usually involve turning and twisting the knee. The best way to treat an ACL injury can be a judgment call that factors in extent of the injury, the your age, and your activities. Each situation is a little bit different. It’s important to get a second opinion and carefully weigh your options.