Knee injuries while playing soccer are very common. This is especially true for women, where tears of the ACL may most commonly occur due to soccer activities.
Why are ACL Tears Common in Soccer?
Most ACL tears are noncontact and this is the most common mechanism of an ACL tear in a soccer player. Often, the player may step in a hole, plant their leg, and twist suddenly without having appropriate muscle strength to counteract that twisting, or they may plant and pivot suddenly and their knee slips out and their ACL tears. Commonly one will feel a pop, which is the bone bruise that happens with the tibia slips forward and contacts the front part of the femur on the outside of the knee. Most athletes who tear their ACL feel that their knee “slips” when they first walk on it or it feels “wobbly.” In this circumstance, the pain for the injury really has not set in yet, so one can test their knee function and see if it feels unstable or not. Over the course of the next few hours, if the knee swells up with blood, this is a very ominous sign because it indicates that the ACL has a high likelihood of being torn. In sporting injuries in adolescents and young adults, the most common cause for bleeding inside the knee joint, about 75% of the time, is an ACL tear.
Ligament Knee Injuries in Soccer
Other injuries that can occur to the knee while playing soccer include injuries to the collateral ligaments. The most common collateral ligament injury is a tear of the MCL. In this circumstance, the athlete may collapse down towards the inside of their knee or sustain a contact injury to the outside of their knee and the MCL gives out. If one feels that their knee is wobbly side to side, or they feel a tearing sensation, they have to be worried that their MCL is torn. MCL tears by themselves do not often cause a lot of swelling inside the knee and most of the swelling will be on the inside part of the knee.
Tears of the lateral collateral ligament, commonly called the fibular collateral ligament, can also occur. In these circumstances, a blow to the inside of the knee which puts extra stress on the outside of the knee, or similarly shifting towards the outside of their knee and having it give out can cause a tear of the LCL. These injuries can be particularly bothersome. Although they are much less common, these injuries do not heal and when one does completely tear their LCL, surgery is indicated.
MCL Tears in Soccer
Most isolated tears of the MCL can heal with a rehabilitation program. In particular, MCL tears that tear off the femur have a high likelihood of healing unless the knee gaps open wide when the knee is out straight. Also, tears of the MCL off the tibia often recoil up and the MCL does not heal down because the MCL gets stuck over the hamstring tendons on the inside part of the knee. MCL tears are graded according to the amount of injury to the structure. A grade 1 tear means that there is some injury to the structure, but the knee really is not unstable and most athletes can get back to full function within 1 to 2 weeks after a grade 1 MCL tear with a proper rehabilitation program. A grade 2 MCL tear is one where there is some gapping in the knee, but there are still some fibers intact in the MCL and it does not gap open significantly. Most grade 2 MCL tears will heal within 3 to 4weeks of injury. A complete MCL tear, whereby one has the knee wobble side to side when one tests it, or when an examiner has it gap open a lot on the inside of the knee, often will heal with a 6-week rehabilitation program. We recommend a period of bracing, the use of a stationary bike (which helps MCLs to heal better than any other exercise), and a program of icing to keep the swelling down is beneficial. In those circumstances where the knee wobbles to the outside when the knee is out straight or where it is torn off the tibia, a program of rehabilitation may be indicated, but the athlete has to recognize that there is a higher risk that this MCL tear will not heal, and in my own patient population through the years about 80-90% of these tears do not heal even with a 6-week rehabilitation program and a period of bracing of their knee.
Meniscus Tears in Soccer
Other injuries in soccer can include a meniscus tear or a kneecap dislocation. A meniscus tear is a tear of the cushion of the knee, and the meniscus is felt to be the most essential structure to protecting long-term joint health. If one has a meniscus tear which can be repaired, it should be repaired, and sooner rather than later because this gives you the best chance of preventing any progression of arthritis. If one has their meniscus taken out, especially if it is repairable but the surgeon chooses to take it out, then one does have a very high risk with the development of osteoarthritis, and usually their knee will not function well over the long term. Thus, if one injures their knee in soccer and has difficulty with pain in the back of their knee with squatting, or has pain directly over the inside or outside joint lines, they should be examined and possibly obtain an MRI scan to determine if they have a meniscus tear present.
Kneecap Dislocations in Soccer Players
Kneecap dislocations are more common in women soccer players than male soccer players. In this circumstance, usually the knee is close to being out straight and the kneecap pops to the outside and dislocates when one twists, turns, or pivots. Early placement of the kneecap back into position is important to ensure that one does not have any cartilage damage. A proper rehabilitation program is also important to try to maximize the chance that the kneecap will not dislocate again. In athletes where they have a deep groove on the end of their femur called a trochlear groove, which is more common in men than women, this deep groove will provide stability to the kneecap and often allow it to heal with a rehabilitation program to the point where the torn medial patellofemoral ligament on the inside of the knee will heal sufficiently that the kneecap will not dislocate again. Those athletes who are at a higher risk for having the kneecap dislocate again are those with a high riding kneecap or ones whose trochlea is flat, which means they do not have a lot of bony stability to hold the kneecap in place, and often the medial patellofemoral ligament tear will heal loose or not heal at all. In these circumstances, the kneecap is at risk for dislocating again and again, and every time it does it can knock off a piece of cartilage and cause osteoarthritis.
The usual treatment for a kneecap dislocation is physical therapy if it is the first time. Those patients who do require surgery include those who have knocked off a piece of bone and cartilage, have a fracture, or may have such poor bony anatomy to stabilize the kneecap that one would have a very high risk for having the kneecap dislocate again if it was not treated surgically. We do know in most of these circumstances that a reconstruction of the torn ligament, usually the medial patellofemoral ligament, is preferred over repair because reconstructions have a high success rate while repairs have about a 50% to 60% success rate.
When to Seek Treatment After Soccer Knee Injury
Knee injuries are unfortunately very common in soccer. This is particularly true for women athletes. If one has a knee injury where they feel a pop, where the knee feels unstable after the injury, or where one’s knee swells up right away, which most commonly means it fills with blood, one should be seen relatively quickly by a specialist to ensure that there is not a problem that should be fixed sooner rather than later. In most of these circumstances, surgery would be indicated to address the particular injury, and most often early surgical treatment is better for one’s joint health than delayed surgery whereby tissues can scar in a nonanatomic position, cartilage problems may be nonrepairable, and meniscus tears may occur due to an ACL tear or become not repairable because the knee is unstable and they get chewed up over time.