Magnetic Resonance Imaging of the Knee

Knee injuries are very common in our orthopedic practices. These may include tears of the meniscus (cartilage tears), ligament tears, fractures, and dislocations. While routine x-rays are very helpful in diagnosing certain knee problems, magnetic resonance imaging may be recommended to evaluate the extent of your knee injury.

Cartilage Tears

Tearing of the cartilage within the knee is extremely common. The cartilage, or meniscus, acts as a shock absorber between the two large bones of the knee (the femur and the tibia). Symptoms often include pain, clicking, catching, popping, or locking within the knee joint. Swelling is also fairly common.. MRI scanning is often the best imaging study to evaluate tears of the meniscus.

The normal meniscus is seen as a triangular structure that is dark black. A white line through the meniscus indicates a tear of the meniscus as seen in the image below:

Surgery may be recommended for meniscal tears that interfere with work or athletic activities.

Ligament Injuries

Ligament Injuries are commonly seen in our office. These commonly occur in high-performance athletes and recreational athletes. Ligament injuries often result in a sense of instability, "buckling", or the knee "giving-out". While the diagnosis of a ligament injury is often made at the time of the office visit, the extent of the injury is best assessed using magnetic resonance imaging.

While any of the four major ligaments of the knee may be injured, the most commonly injured ligament is the ACL, or Anterior Cruciate Ligament. This ligament is especially important in activities that require lateral, or cutting-type, motions. A torn ACL will result in buckling of the knee during these activities.

The ACL starts in the middle of the Tibia (the large long bone in the lower leg), attaches to the back of the femur (the large long bone of the thigh). It normally is seen as a dark black structure on magnetic resonance imaging as seen below:

Tears of the ACL will result in disruption of the fibers of the ligament, usually at the attachment to the femur. This is seen in the magnetic resonance image below:

While many patients with an ACL tear may be able to return to normal daily functions with the use of an ACL brace and supervised orthopedic therapy, most athletes will require Anterior Cruciate Ligament (ACL) Reconstruction. Some patients with labor-intensive job requirements will also require surgery to correct the instability of the knee.