Knee Trauma

The knee is the largest joint in the human body and is susceptible to sports related injury due in part to its limited range of motion forward and backward or side-to-side. Knee injuries range from minor sprains or strains to serious hyperextensions and ligament or cartilage tears.

The Most Common Cause Of A Lost Season

By Mike Haskew

Ligaments and Cartilage

The stability of the knee joint is maintained by four ligaments. The medial collateral ligament (MCL) and lateral collateral ligament (LCL) are on the sides of the knee and prevent the joint from bending inward or outward. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) form an “X” on the inside of the knee and prevent the tibia (shin bone) from sliding out in front of the femur (thigh bone) or the tibia from sliding backwards under the femur.

Inside the knee, there are two shock-absorbing pieces of cartilage called menisci that sit on the top surface of the tibia. The menisci allow the femoral condyles (lower end of the femur) to move on the tibial surface without friction, preventing the bones from rubbing on each other. Without the menisci, the friction of bone on bone would cause inflammation, or arthritis.

Knee tissue called articular cartilage provides the smooth gliding surface in joints. Unfortunately, cartilage does not repair itself, so injuries of this nature are more concerning for the athlete.

Tears – The Most Serious Injury

Torn ligaments and cartilage are among the most serious of knee injuries – typically caused by a sudden blow to the front, back or side of the knee or twisting of the knee. Tears of ligaments or cartilage are characterized by sharp pain and swelling. The injured athlete may require assistance to move, and the joint itself is sometimes unable to bear weight. Sprains, strains and tears to structures of the knee can occur simultaneously. In other words, a ligament may be strained while cartilage is torn, or vice versa. For example, a soccer player may tear the ACL and meniscus in the same injury.

ACL Damage: More than 200,000 ACL injuries occur annually in the United States. While knee injuries are common in many sports, the ACL tear is one of the most problematic and is more common in women than men. As many as 75,000 reconstructive operations are performed on the ACL in the U.S. each year. Physical therapy over the course of several months is required for athletes to return to their sport.

MCL and LCL Tears: These ligaments can be stretched or torn when the foot is planted and a sideways force is directed to the knee. A knee immobilizer, a removable Velcro splint that keeps the knee straight and stable, and RICE (rest, ice, compression, and elevation) are the mainstays of treatment.

Meniscus Tears: The cartilage of the knee can be acutely injured from a twisting motion of the knee, or it can gradually tear. Pain and swelling occur gradually over many hours. Treatment depends on the athlete’s activity level and the severity of the injury. Some individuals benefit greatly from the surgical repair or removal of the torn part of the meniscus, others may do well with little or no treatment.

Articular Cartilage Damage: Sharp pains, swelling and giving way occur. Usually activity modification and rehab are treatments for articular cartilage damage. If unsuccessful, specialized surgery is required to relieve pain.

The prevention of knee injuries includes regular exercises, wearing proper gear, good warm-ups, and supporting previously injured knees with sleeves or heavier braces.