Dr. Eric Chehab (NorthShore)
Hi Stacy - ACL injuries do not repair themselves, so yes, surgery is the only way to fix them, and any surgery will produce scars, but since the surgery is done arthroscopically, the incisions are typically quite small. The cosmetics is usually acceptable.

There are other ways to manage ACL injuries besides surgery, but those management strategies require lifestyle changes, and for young active patients, lifestyle changes can be quite difficult.

Dr. Eric Chehab (NorthShore)

Hi Lisa. Thanks for your question.

This is definitely a sign something is wrong. The knee should not pop out of place. That may be a sign of the kneecap being unstable and not tracking properly. It could be a sign of a ligament injury, such as to the ACL, or it might be your meniscus, which is a piece of soft cartilage that pads the knee. If it gets torn, it can get caught in the knee, making if feel like it pops out of place. These would be the most likely problems.

Dr. Eric Chehab (NorthShore)
Hi Jaime - yes, there are sports with higher rates of ACL injuries. The sports where there is a lot of jumping, cutting and decelerating tend to be related to a higher incidence of injury. I commonly see football, soccer, lacrosse and basketball players. Skiing is also quite common. It's not as common in baseball and softball, though Kyle Schwarber is an example of a baseball players injuring the ACL. Hockey also has a lower rate, but an ACL injury can happen in ANY sport, and so there's always a small risk. For instance, it would be rare for a marathon runner or cyclist to tear the ACL, as they would not be cutting and decelerating to cause the injury.

Dr. Eric Chehab (NorthShore)
Thomas - the most common cause of soreness on the outer sides of your knee is due to tightness of the muscles, particularly the IT band, so stretching the IT band can lead to pain relief. A physical therapist can show you how to properly stretch the IT band. I would focus my efforts on the stretching of those muscles to prevent soreness and future injury.

Dr. Eric Chehab (NorthShore)
Hi Anna - This is an excellent question. You've already experienced a tear, and the research shows your OTHER knee is at risk. There are neuromuscular training programs that are quite helpful in reducing the risk of an ACL injury to your other knee, and re-injury to the involved knee. The focus is on training the muscles about your core, hip and knee to absorb shock and minimize energy through the knee. These programs are particularly effective. Bracing can be helpful as well, though the research results regarding bracing have been mixed. Some studies show bracing helps prevent re-injury, but others don't. My guess is, bracing PROBABLY helps, given the above. Those would be the two things I suggest you consider to prevent another ACL tear.

Dr. Eric Chehab (NorthShore)
Gordon - The answer is yes, they can, but its not common. I would not worry so much about that. I think the important thing to focus on with elementary school children is the quality of the equipment, and the quality of the fields. Coaching is also important, with proper techniques. We can't prevent all injuries, and if I had the choice, I would not let the small risk of an ACL injury stop your child from participating. The benefits are much greater than the risks. As a side note, I injured my ACL as a 7th grader, which might explain why I became an orthopaedist, so there's always a silver lining!

Dr. Eric Chehab (NorthShore)
Hi Caroline - Depends on how many months.... Normally, the ACL reconstructions, which use other tissues around your knee (hamstring, patella tendon or quad tendon), take a full year to mature. Once mature, the re-injury rates are at their lowest, so early on <6months, the ACL is vulnerable to re-tear if you do too much.

The rates vary depending on the type of reconstruction. For patella tendons, the rate is about 3-5%. For hamstrings, it's about 5-8%. Though one seems better than the other, the side effects are also quite different, so there's a lot to consider. It's important to complete the physical therapy after surgery, and to have the muscles protect the knee as the reconstructed ACL matures.

Dr. Eric Chehab (NorthShore)
Hi Elizabeth - That's not unusual, but like all things, it depends. There is scar tissue that forms within the knee that can cause popping. If it's painful popping, or popping that makes your knee feel unstable, that should be evaluated by your surgeon. If it's popping associated with swelling of your knee, then that should also be evaluated by your surgeon. If it's popping you can hear, but doesn't hurt or cause the knee to feel unstable, that's QUITE common and usually benign.

Dr. Eric Chehab (NorthShore)
Hi Kay - There is no known association between gastrocnemius injuries and ACL problems. The gastrocnemius tears do take time to recover, and can sometimes recur. I nearly always recommend formal physical therapy for gastrocnemius injuries because it returns patients more quickly to their activity, and lowers their risk for re-injury.

Dr. Eric Chehab (NorthShore)
Hi Christy - I'm sorry to hear about your son. It can be hard sometimes to tell. I've had patients feel like they only "tweaked" the knee, and are surprised to find the injury was more involved. Hindsight is always 20/20, and it can be hard to tell if the ACL is injured. The usual signs of an ACL injury are knee swelling, the knee feeling unstable to the patient and the patient having felt a pop. Other than that, it would be difficult for non-health care professional to know. What I hope helps is that most patients with an ACL are not operated on right away, and do not do damage while walking on it. We always recommend evaluation as soon as you can, but it is VERY unlikely your son damaged his knee while awaiting evaluation. Again, most of the time, we delay the operation for a few weeks (or even months) to help the knee recover from the injury and feel more normal again before any operation is undertaken. Hope this helps alleviate concerns or parental guilt.

Dr. Eric Chehab (NorthShore)
It is not absolutely necessary; however, I am one of those surgeons who recommends it for the first season back. There was a question earlier related to this, and the studies are mixed regarding bracing and its effectiveness for preventing re-injury. I do think athletes benefit from the brace to build confidence as they return. What I suggest to my patients is to use the brace for the first season back, and then I leave it up to the athlete for long term use. It's usually about a third to half of the athletes who like to use it over the long haul. Hope this helps.

Dr. Eric Chehab (NorthShore)
Hi Ted - it depends on the workout. Most weightlifting activity or straight ahead activity is safe from an ACL injury standpoint. If you are doing a workout with running, cutting and decelerating, then yes, there are pre-workout activities that help. You may notice that teams are not doing so much static stretching, but are instead doing dynamic stretching. The dynamic stretching incorporates some of the neuromuscular training that helps protect the knee. Bottom line is to be sure to be warmed up, stretched particularly in the quads, doing a dynamic warm-up and not exercising until exhaustion.