How footballers are brought to their knees

How footballers are brought to their knees

As football becomes faster and more intense, and as players face more matches and more training sessions in the course of a year, the risk of injury increases also. And among the most common of all are knee injuries.

FIFA studies have shown that foul play is a major factor in modern football injuries. While some 40 ~ 70% of the injuries players sustain to ligaments, especially to the anterior cruciate ligament (ACL), and to the meniscus and articular cartilage are suffered either with or without body contacts, foul play accounts for the other 30%.

Knee injuries can be produced by extrinsic and intrinsic forces;
- Extrinsic forces are outside forces acting on the player, such as tackles or collisions with opponents
- Intrinsic forces are produced by the player himself as he accelerates or decelerates while running, stopping, jumping and landing.

Knee ligaments act to stabilize the knee. The medial and lateral collateral ligaments stabilize the inner and outer side of the knee, while the anterior cruciate ligament (ACL) stabilizes the tibia (shinbone) from sliding forward on the femur (thighbone). The posterior cruciate ligament (PCL) stabilizes the tibia from sliding backwards on the femur.

The ACL is the most important stabilizer of the knee. ACL injuries have become well known as the most common serious ligament injuries, and can occur whether the player has body contact or not, produced by extrinsic and intrinsic forces.

When two players collide, a tackle from the outer side can result in combination injuries with a medial collateral ligament (MCL) and the ACL. If the impact in such a situation is particularly violent, the PCL can even rupture.

But as mentioned, ACL injuries can also occur through intrinsic forces without any body contact, as the player runs, turns, stops, lands or makes other such movements with his foot fixed to the ground. Such ACL injuries result in instability with the knee giving way when having to bear weight.

Most ACL injuries need surgical treatment, usually performed by arthroscopy using the central part of the patella tendon. Rehabilitation after surgery is an important and legthy process, often taking several months, with the player unable to return to match action for at least 6 ~ 12 months.

Injuries to the lateral collateral ligament (LCL) are also serious, and are usually caused by a tackle that hits the inside of the knee. Such injuries should be operated on in the acute stage in order to restore the stability of the knee, and chronic LCL instability is very difficult to treat in an optimal way.

Injuries to the medial collateral ligament (MCL) and posterior cruciate ligament (PCL) usually respond well to conservative treatment. However, combination injuries with ACL-PCL, ACL and MCL, and ACL-LCL with combined instability may be treated with surgery in the acute stage to restore the stability. The more ligaments injured, the more unstable the knee-and the greater the risk of chronic instability unless treated adequately.

FIFA’s campaign against the tackle from behind is of particular relevance here, for this kind of foul, as well as tackles from the front, can also cause ACL and PCL injuries.

MENISCUS INJURIES
Meniscus injuries are the most common knee injuries in football. The menisci are C-shaped wedges of fibrocartilage located between the articular surface of the condyles of the tibia and femur, one on the medial side and one on the lateral side.

The medial and lateral menisci function as load distributors, shock absorbers and stabilizers of the knee.

There are different types of meniscus injuries, but most are caused by a twisting impact on the knee, causing it to rotate either externally or internally. These injuries, however, may also be a result of hyperextension (overstretching) and hyperflexion (overbending) of the knee.

Injuries to the medial meniscus are 5 times more common than injuries to the lateral meniscus. This is due to the fact that tackles and twisting cause more external rotation of the lower leg than internal rotation, and also to the fact that the medial meniscus is more restricted in its motion because of its fixation to the medial collateral ligament (MCL).

The most common symptoms of meniscus injuries are pain, locking and swelling. Meniscus injuries are diagnosed and treated by arthroscopic evaluation and surgery, removing the injured part of the meniscus. Sometimes, when the meniscus is torn off close to the capsular attachment, it is preferable to re-fix the meniscus by suturing than to remove the whole meniscus. Today’s tendency is to try to save as much of the meniscus of good quality as possible, not least because total removal of the meniscus may cause the articular cartilage to wear down over time and to end up in osteoarthritis.

Meniscus surgery can also throw a player out of the game for a long time, rehabilitation taking some weeks or even months, depending on the type of treatment.

ARTICULAR CARTILAGE INJURIES
The bony ends of the tibia and the femur are covered with articular cartilage, which has lower friction than ice. This cartilage enables motion and weight bearing, and also acts as a shock absorber and load distributor. But once the articular cartilage is damaged, it has minimal capacity to repair itself.

Articular cartilage injuries can occur together with ACL injuries and with meniscus injuries, and are evident in as many as 20 ~ 70% of cases of chrnic instability of the knee. The most common cause is a rotational imapst or a contusion by external forces acting on the articular surfaces.

Injuries to the articular cartilage of the knee joint are serious when they penetrate the cartilage down to the underlying bone, and especially when they affect weight-bearing areas of the knee. Cartilage injuries penetrating to the bone have a great tendency to progress with continued activity,, and over time can develop into osteoarthritis.

The symptoms of articular cartilage injuries are almost the same as for the meniscus, with pain on weight bearing, locking or catching and swelling of the joint. Smaller defects of one to two cm2 may be treated by debridement of the cartilage injuries to stable edges.

Healing of the fibro-cartilage is sometimes helped by drilled or micro-fracturing of the underlying bone, while larger defects may be treated with osteochondral grafts or cartilage cell transplantation. These procedures have a relatively long rehabilitation period of up to a year before the patient can start playing football again.

PREVENTING KNEE INJURIES
With almost one in three of all knee injuries caused by foul play, the importance of playing to the rules needs no be repeated here. But good physical conditioning and muscular strength and endurance, together with good playing technique and motor coordination, also help prevent knee injuries, and to this end a specific training program should be included in all players’ physical preparations.

It is, of course, essential that any minor injury or knee injury be completely rehabilitated and the function restored before the patient returns to training and playing matches. Indeed, incomplete rehabilitation is one of the most common causes of serious injury and recurring injury.

Stabilizing braces to prevent knee injuries are not effective in preventing such injuries, and neither are they comfortable to wear. Moreover, these devices may even cause injuries to opponents in collisions.

Contact between the sole of the player’s football boot and the ground is very important, too, with the fixation of the foot on the ground playing a major role in causing serious knee injuries. Here, the design and number of studs may play an important role in the injury mechanism. But further biomechanic studies are still needed to find a better solution for the reduction and severity of football knee injuries as a result of player’s contact with the ground.

A better balance between training and matches and the number of matches played through the year is without doubt a crucial factor to reduce knee injuries. There must be a proper balance in the amount of time allocated for training and recovery in the players’ overall training and playing schedules – for the short and long-time sake of the players’ overall health, of course, but especially as far as knee injuries are concerned.