Hear a Patient Power interview with Dr. Christina Allen, who talks about ACL injuries in women. The anterior cruciate ligament (ACL) is one of the most commonly injured ligaments of the knee and interestingly, women are more prone to have ACL tears than men.
Hello, this is Andrew Schorr. Thank you for joining us once again for another edition of Patient Power sponsored by UCSF Medical Center. When it comes to sports injuries, one injury that people worry about a lot is damage to their knees. We're going to learn about ACL injuries, not just in anyone, but in women and understand the difference.
Our guest today is Dr. Christina Allen. Dr. Allen is an orthopedic surgeon at UCSF Medical Center, and she specializes in treatment of knee and shoulder injuries, and she has a lot of experience. She is an orthopedic doctor for the U.S. National Women's Soccer Team, the University of California at Berkeley athletics teams, and the U.S. National Taekwondo team. She previously served as a team doctor at the U.S. Olympic training center in Colorado Springs, Colo. Thank you so much for joining us.
Good afternoon to you. People are listening because maybe somebody in the family has had an ACL knee injury, but let's zero right in. Whether you're a weekend athlete or you're a premier soccer player, what's unique about it in women?
Unfortunately, women have a little bit more of a predisposition for tearing their anterior cruciate ligament and then, too, we find this in particular sports especially that there is a much higher prevalence of injury, specifically soccer and basketball and gymnastics. There are several reasons why that is. Some of the issues are controversial, such as hormonal issues, but also there are alignment issues and muscle balance issues that particularly affect women or cause women to have a higher incidence of injury.
So there they are. They're playing basketball or soccer. They're cutting back and forth. How do they know that they have an ACL injury? I imagine there can be terrible pain, but what typically happens to say, "Uh oh."
The "Uh oh" sign usually is someone feels a sharp pop in their knee, almost like the sound of a pencil cracking. Unfortunately, many of the players on soccer teams and basketball teams have been around someone who has had a similar injury, and a lot of them know, "oh that's what happened," but the other thing is that the knee very rapidly swells up within two to three hours due to the injury in the knee.
That's kind of a cardinal sign those two things combined, the pop in the knee and then the rapid swelling, is almost 90 percent of the time an ACL tear.
What about stability?
That often isn't very obvious until later. Sometimes people feel like they're a little shaky on their knee because the knee is swollen, but the instability isn't obvious until the swelling goes down. Someone tries to get back on the soccer field and make a sharp cut, and then they find that their knee gives way on them, and this kind of gives them a "spinning out" type of sensation that the knee's wobbly when they try to make a sharp change in direction.
Now, what is the ACL exactly? What's its function?
The ACL's main function is to provide rotation stability to the knee. If you were to ask someone who does anatomy what it does, they would tell you it's to prevent the tibia, the lower leg, from coming forward underneath the femur, the thigh bone, but the main function is to prevent the knee from spinning out just like patients will tell you when they have a tear. It feels like its rotating on itself, and the knee feels like it's going to give way, and I think that's because it doesn't just go from the front of the tibia to the back of the thighbone, it actually crosses at a little bit of an angle, so it helps control rotation.
Of the injuries that an athlete can have to their knee, how serious would you say this is?
It's a very serious injury unfortunately because when the ligament is torn, sometimes other injuries can happen to other structures in the knee, and it's not just that one ligament is torn. There is cartilage damage that can happen, things called bone bruises, which is the knee bones kind of smack into each other. The cartilage can take an injury or an impact that it has trouble recovering from, and then the menisci, the two cartilage pads in the knee, sometimes can also be torn. Some of the supporting cast of other ligaments in the knee sometimes can get stretched out a little bit also.
It sounds bad. When you go to the doctor, and this has happened to you, how is the diagnosis of what the injury was confirmed? What evaluation typically would happen?
Usually, we'd do a full physical exam. We check that ligament with some tests. One is called the anterior drawer, which isn't as accurate as the Lachman test. Sometimes people might notice if they show a football player on close-up on the field, you might see the team physician pulling on the leg to see if it is a little bit loose, and there are some other examination techniques such as a pivot shift where you try to see if the knee feels like it gives way or gives that "spin out" type of feeling to the patient. We also test the other ligaments in the knee to make sure that they're not additionally stretched out or partially torn or fully torn.
What about X-rays, or do you need an MRI?
Yes. X-rays sometimes can give you little bits of signs that might suggest an ACL tear, but the more definitive test, in addition to examining the knee, is to get an MRI because that can show what's happened to the ligaments and if there is damage to the meniscus pads and the cartilage and the other ligaments in the knee.
So, how do you counsel people? Do they always need surgery? What happens if they don't have surgery?
I try to tailor the conversation to the patient and try to read what the patient's needs are. There are a lot of factors in determining who should really have surgery.
There's an age issue. It's a very big surgery to recover from, and some people might have trouble with the rigors and the discipline that are necessary. It's at least a six-month recovery, requiring going to physical therapy and to the gym to do workouts very regularly, three or four times a week. So, some people might not be able to do that type of recovery or have the discipline, and surgery sometimes can make people worse if they don't do things the way that they really need to, to get better.
Generally, though, for a young healthy patient who really wants to get back to sports that involve a lot of what we call "cutting and pivoting," change of direction sports where you're heading one way and rapidly have to switch to the opposite direction, we recommend the ACL reconstruction.
There are some types of sports that you don't necessarily need to have that anterior cruciate ligament to be able to participate in them. Running, biking, and swimming are what we call "straight ahead" or triathlon-type sports that you don't need your anterior cruciate ligament to participate in.
The only problem is if someone decides after a couple of years that they want to change over to doing martial arts or playing basketball, then they're going to have an unstable knee for those types of activities. So generally for an active patient, I recommend that they think about having the surgery if they can keep with the program and be disciplined about the recovery process.
If somebody says, 'Well I've injured my ACL earlier in life, and I'm just going to live with it.' If one of the complications could be, depending upon what they do in life, arthritis, would that mean that maybe someday later they're going to need another kind of surgery for their knee?
Yes, that's true. I just have to clarify one thing for the sake of being fully honest.
When people tear their ACL, as I said before, there are injuries to other surfaces in the knee, such as the articular cartilage, and the cartilage never fully recovers, we think, from the original injury. The bones kind of smack into each other, and the articular cartilage, I always say, gets caught in the crossfire, and it gets a little softened and perhaps a little less resilient to the stress of just walking around and running and thinks like that.
Tthere have been studies that have shown that ACL reconstructions don't totally avoid someone getting arthritis later on in their life but there's some initial injury that happens to the cartilage with the very first injury. But for sure if someone plays soccer or football without an ACL, they are definitely going to cause more damage to their knee and set themselves up for arthritis. So, it's kind of a modification of the effect, I guess, of tearing that ACL and what happens long term.
Now, short term though, if somebody does have the surgery, in most cases can they return back to that sport they love?
Yes, which would be very difficult for someone who doesn't have an ACL, and there are some people, there are some rare people, who don't have an ACL who are able to participate in those heavy, demanding types of cutting and pivoting sports, but most people really need to have their ACL reconstructed in order to get back to full activities.
Doctor, just briefly in laymen's terms, can you tell us what do you do when you do an ACL repair surgery?
Basically, what we need to do is replace that ligament. We can't take a ligament from somewhere else in your knee or your other knee because then you'll make that knee ACL deficient. So, we use a tendon to replace that anterior cruciate ligament. It has about the same strength, so we can just have that take the same path as the old anterior cruciate ligament. We can take a tendon from the patient, which is what we call an autograft, or we can take that tendon from a cadaver, which is called an allograft, and the tendon is passed through some tunnels, which basically start and end where the old anterior cruciate ligament was. It's held in place with some pins or screws depending on what tendon is used to replace the graft.
We can do this through pretty small incisions — two little poke holes to look in the knee and place some instruments in the knee, and then generally one more incision to either get the new tendon, what we call the graft, or to drill the tunnels. It's a pretty small incision compared to the old days where people would have 10-inch incisions across their knee.
Dr. Christina Allen, orthopedic surgeon, and helping a lot of people with this ACL surgery at UCSF Medical Center, thanks for being with us and explaining this to us.
For more information about the physicians and services at UCSF, just call the physician referral line. Here's the number: (888) 689-UCSF. Dr. Allen, thanks so much. I hope I or my daughter never need your services, but it's great to know you're there should we need it.
Give me a call. Hopefully you won't need my services, but I'm there to help if need be.
Recorded February 2008
Reviewed by health care specialists at UCSF Medical Center.
This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.
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