One of the most difficult concepts to impart to an athlete is Einstein's definition of crazy: doing the same thing over and over and expecting different results. Athletes want to keep doing their sport with the same intensity in the same way. Their method of performance is to do the same thing over and over, and injury is the result. When an athlete visits a doctor, his expectation is that the doctor will create a magical healing so that the athlete can continue to repeat exactly what caused the injury. A great sage once said, "When you are sick and tired of being sick and tired, you'll change."

Knee injuries generally fall into one of two categories:

1. Traumatic: a sudden injury caused by either exterior impact (such as a football tackle) or an unintended twisting or hyperextension of the knee (such as a skiing fall)
2. Repetitive: problems such as "runner's knee" (patello- femoral syndrome) or iliotibial band syndrome that are created over time by doing a damaging motion again and again.

In addition, knees may suffer from pathological conditions (those that seem to be genetically predetermined or related to a disease). Some conditions, such as osteoarthritis, may result from a combination of genetics and traumatic or repetitive injury.

In this chapter we'll address the symptoms of traumatic and repetitive knee injuries and immediate steps to take so that you don't worsen your condition before it can be fully diagnosed medically and treated properly.

TRAUMATIC INJURIES

Anyone who has suffered a traumatic knee injury knows how painful, and how frightening, it can be. The most common traumatic knee injuries are described in the sections that follow.

Anterior Cruciate Ligament (ACL) Injury

Anterior cruciate ligament injury (injury to the ligament on the front of the inside of the knee) is primarily a result of a sudden twisting or hyperextension of the knee. Approximately 70 percent of all traumatic knee injuries are of the anterior cruciate ligament. They occur most frequently during sports that require the foot to be planted while the body changes direction rapidly. For instance, if a skier falls, while her body cuts sharply to the right or left, the skis may keep her feet planted either forward or in the opposite direction from her body, forcing the knee joint into extreme torsion (twisting) and stretching or tearing the ACL. In basketball, the problem of extreme torsion is often exacerbated by hyperextension of the knee while landing from a jump. Injuries range from straining or bruising to a partial, or at worst complete, tearing of the ligament.

Another, less common, cause of ACL injuries is a direct blow, for example, if the knee is slammed into the dashboard during a car accident or is hit in a high-contact sport such as football.

One of the most brutal knee injuries is O'Donoghue's triad. Occurring most often on the football field, this injury results when a player is hit from the side, leading to a series of tears: an ACL rupture plus tears of the medial meniscus and the medial collateral ligament.

The severity of ligament injuries is graded on a scale of one to four:

1. First-degree sprain is an acute mild trauma. A few ligamentous fibers have been torn, resulting in mild pain but no joint instability.
2. Second-degree sprain is an acute moderate trauma. A moderate number of ligamentous fibers are torn, resulting in moderate pain, swelling, and disability but little or no joint instability.
3. Third-degree sprain is an acute and complete tear of the ligament. Swelling and pain may range from minimal to severe. Disability is always severe, and the joint is rendered unstable.
4. Fourth-degree sprain is a complete rupture between the ligament and the bone. Pain, swelling, and disability are severe, and the joint is rendered unstable.

The immediate symptoms indicating that you have suffered an ACL injury vary according to the degree of injury involved. The most common immediate symptom is a loud pop that you both feel and hear. Next your knee may give way.

Frequently you are rendered immobile by an ACL injury. Even if you can move a little, you certainly cannot continue the activity that caused the injury. Your knee may begin to swell immediately and continue to do so until reaching its worst state 2 to 3 hours after the damage was first done. Even if the injury is mild enough to allow you to stand, your knee may feel unstable as if it wants to bend too far back.

The first thing to do if you believe you have suffered an ACL injury is to stop all activity. For some immediate relief employ the treatment commonly referred to as RICE: rest, ice, compression (Ace bandage), and elevation. The next step is a trip to the emergency room, where your knee may be X-rayed and immobilized in a brace.