Your knee twists and you have swelling and pain. You are struck by another player and have bruising, but no swelling. Are these serious knee injuries? As an active athlete or competitor you know that knee injuries are common. Both contact and non-contact knee injuries can be serious. This post will cover 5 signs to look for to help determine if you might have a severe knee injury. In general, the most common and worrisome finding is immediate, significant swelling.
Even though most of the injuries I see in the office turn out to be mild, it is important for you to know what the warning signs are to look for a potentially severe knee injury.
5 signs of a possible serious knee injury:
Your Knee Is Swollen
Swelling in the knee immediately or shortly after an injury is a common sign that indicates you may have sustained a serious knee injury. In many instances the swelling is due to blood. The bleeding will stop, but the swelling will remain. Common causes of swelling after a serious knee injury include a tear of the ACL, a patella or kneecap dislocation, a meniscus tear, an MCL tear or an injury to the articular cartilage. Over 70% of athletes with a swollen knee who felt a pop while running and pivoting will have either an ACL tear or a patella dislocation. Most will find it very difficult to walk without severe pain. Crutches, icing and elevation are very useful in these cases. Very few knee injuries will require a brace or a cast. The most important part about seeing a sports medicine physician after and injury that causes swelling is to rule out injuries that require urgent surgery.
Your Knee Is Locked And You Can’t Straighten It
If you had a knee injury and you are not able to fully straighten the leg, you may have a locked knee. The most common cause of a locked knee is a unique meniscus tear called a bucket handle tear. A bucket handle tear is considered a serious knee injury and will usually require surgery to fix the tear. The reason these tears are serious is that a large piece of the meniscus tears, flips over and becomes stuck in the middle of the knee joint. We discuss bucket handle tears here. Not all locked knees will be found to have a bucket handle tear. Especially in older athletes, a flap tear, or other different types of meniscus tears typically occur.These types of tears are very important to identify early on. Most all bucket handle tears are repairable. The torn bucket handle should not be removed from the knee if at all possible. These tears which cause a locked knee are very large. If the piece is removed and not repaired then you have a significant change of developing osteoarthritis. These bucket handle tears do not require emergency surgery, but they are urgent and you should see a sports medicine doctor if you feel like something is preventing you from straightening your knee all the way.
Your Knee Feels Unstable or You Felt a Pop
If you felt or heard a loud pop as you twisted or turned to avoid another player then you may have torn your ACL. Other causes of popping include a patella or kneecap dislocation. If you felt or heard a loud pop in your knee then you probably have a serious knee injury. Most ACL injuries and patella dislocations are non-contact injuries. A running back turning to head upfield. A striker moving laterally to avoid the defense. These are common stories when we see high school and college athletes who have torn their ACL. This post dives further into the immediate management of suspected ACL injuries.
Another very common diagnosis after a loud pop is heard is a patella dislocation. They are more common than most people think. Everyone has heard of an ACL tear, but most are not aware that the patella or kneecap can dislocate. Many patella dislocations will spontaneously reduce or go back into place. That means that the patella was only dislocated for a second or two. Patients with a patella dislocation often require an MRI to see if you injured the cartilage on the patella when it dislocated. Surgery to repair the patella ligaments is usually not necessary for a first dislocation. This post provides more information about patella dislocations.
You Have Significant Weakness Trying To Straighten Your Knee
Weakness when trying to straighten the knee, even a few days after the injury could mean that you suffered a serious injury. Common causes of weakness include patella dislocations, patella tendons tears and quadriceps tendon tears. Patella tendon and quadriceps tendon injuries are not common in youth or collegiate sports, but active sports docs see a few each year. In older weekend warriors who are wondering why their knee is weak after a serious injury, patella tendon and quadriceps tendon injuries are far more common. If you are over 35 and felt a loud pop in your knee while pushing off during tennis, or basketball then you need to consider that your injured your patella or quadriceps tendon(s). After the injury you will find that the knee is very unstable and unable to support your weight without giving way. You should be promptly evaluated by a Sports Medicine physician to determine the type of injury you had. Both quadriceps and patella tendon injuries require surgery to repair these large important tendons.
Patella dislocations occur mostly in younger athletes. Most patella dislocations occur when the knee is bent, the athlete is twisting and then they are struck in their leg. The patella will usually snap back into place but the damage is done. Any suspected patella dislocation should be evaluated by a sports medicine physician since patella dislocations can cause injuries to the cartilage or the ligaments which hold the patella in place.
You Have Significant Difficulty Walking
Of course, many knee injuries make it painful and hard to walk. For people with serious knee injuries it is usually very hard if not impossible to walk. You will usually need to be helped off the field and require crutches. Anyone who is placed on crutches should be considered to have a serious knee injury until you are evaluated by an Orthopedic Surgeon. In many of these cases an urgent X-ray is useful to rule out a fracture if the athlete can not put any weight on the knee.
Knee injuries are common across all sports. Most knee injuries are mild and the athlete can expect to return to play relatively soon. Identifying the serious or severe knee injuries and acting quickly can make the all the difference when it comes to getting you back in the game and minimizing your risk of further damage.
Disclaimer: this information is for your education and should not be considered medical advice regarding diagnosis or treatment recommendations. Some links on this page may be affiliate links. Read the full disclaimer.