Overview of Common Knee Sports Injuries

In 2014, there were 10.4 million visits to a doctor’s office because of knee injuries. The knee is a complex joint with multiple components. This complexity makes it vulnerable to a variety of injuries. Knee injuries can be successfully treated using simple measures, such as physical therapy rehabilitation exercises and bracing.

Knee Components

The structures and components of the knee joint include:

  • Bones – Three bones meet to form the knee joint: femur (thighbone), tibia (shinbone), and patella (kneecap).Knee anatomy picture
  • Articular cartilage – The ends of the tibia and fibula, and back portion of the patella, are covered with a slippery articular cartilage. This allows the bones to glide smoothly across each other as you bend or extend the leg.
  • Meniscus – Two wedge-shaped pieces of cartilage that act as shock absorbers are the menisci (singular – meniscus). This tough, rubbery material stabilizes the joint.
  • Ligaments – Bones are connected to other bones via ligaments, and the knee contains four main ligament structures.
  • Tendons – These fibrous structures connect bones to muscles.

Knee Sprains and Strains

A sprain is a tear or stretch of a ligament, which holds bone to bone. A strain is injury of a tendon and/or muscle. You are at increased risk for knee injury if you have a history of strains and sprains, are overweight, or are in poor physical condition. Sprains and strains are categorized according to severity:

  • Mild – Tendon or ligament is stretched slightly, but there is no joint loosening.
  • Moderate – There are partial tears of the tendon or ligament, producing joint instability and some swelling.
  • Severe – Produces excruciating pain during movement, and the tear is complete.


The most common knee bone that is broken is the patella. Many patellar fractures are caused by high energy trauma, such as in a motor vehicle collision or a fall from a high structure. The patella is injured during sports by falling directly on it, or when there is a high impact collision with another player.


During sports play, a dislocation can occur when the bones of the knee go out of place. Dislocations are either partial or complete. The tibia and femur can be forced out of alignment, or the patella can slip out of position. A dislocation occurs as a result of sports-related contact.

Anterior Cruciate Ligament (ACL) Tears

The anterior cruciate ligament is often injured with sports play, such as football, basketball, and soccer. This ligament is torn when the athlete changes direction rapidly, or when he/she lands from a jump incorrectly. About 50% of ACL tears occur along with damage to another knee structure, such as meniscus, other ligaments, or articular cartilage.

Posterior Cruciate Ligament (PCL) Injuries

Tearing of the posterior cruciate ligament occurs from a direct blow to the front of the knee when the knee is in a bent position. PCL tears are usually partial tears and can heal without surgery.

Collateral Ligament Injuries

The collateral ligaments are torn or injured by a force that pushes the knee sideways, as with contact sports. Injury to the medial collateral ligament (MCL) often occurs from a direct blow outside of the knee, whereas the lateral collateral ligament (LCL) is injured from a blow to the inside of the knee.

Meniscal Tears

Tears to the meniscus occur when cutting, twisting, pivoting, or being tackled. These injuries also occur from arthritis or aging. A meniscal tear to a weakened meniscus can occur from an awkward twist when rising from a chair.

Tendon Tears

The patellar and quadriceps tendons can be torn or stretched easily during sports activities. These occur from falls, landing awkwardly from a jump, or from a direct force to the front aspect of the knee.

OSPI offers the top sports medicine specialists in Arizona serving Gilbert, Chandler, Mesa, Queen Creek and Maricopa AZ. All types of tendon and ligament injuries are treated with regenerative medicine procedures, bracing, physical therapy and operative procedures when necessary.

Most insurance is accepted, and the Board Certified orthopedic surgeons in Gilbert are experts at getting athletes back to activity quickly, call today!