Orthopedic Knee Problems

The knee is comprised of the femur, the tibia, the meniscus and the patella. The femur connects to and rotates on the tibia, and the knee cap slips into the grooves on the end of the femur. The meniscus helps cushion the knee, and absorbs motion and shock to prevent injury. The knee also contains ligaments that help the body move.

Common Injuries

• There are four common injuries that occur in the knee, which often happen to athletes engaged in various types of motion. These injuries include an ACL injury, an MCL injury, a PCL injury and torn ligaments.

ACL

• The ACL, or articular cartilage, is one of the knee's structures that helps protect the knee from shock during motion. The ACL absorbs contact, distributing the impact across the entire knee. It also helps provide support for the knee joint.

  Injuries to ACL are common in athletes and occasionally in older patients as part of general degeneration of the body. ACL injuries are often accompanied by injuries to the menisci. ACL and meniscus injuries can be treated surgically or nonsurgically.

MCL

• The MCL, or medial collateral ligament, is a ligament within the knee. The MCL extends from the femur to the tibia along the inside of the knee and helps keep the inner knee stable. The MCL, along with other ligaments and tendons, including the hamstring, keep the knee from opening when the tibia extends laterally.

  Injuries to the MCL cause inner knee pain and result in swelling and bruising. Some patients report hearing an actual "pop" when the injury occurs. MCL injuries can often be diagnosed without X-rays or physical exams, based on the appearance of the knee and a description of the injuring event and symptoms.

PCL

• PCL, or the posterior cruciate ligament, works with the ACL to stabilize the knee and keep the shinbone in place in front of the thighbone. PCL injuries occur when the knee is unnaturally bent, usually due to contact sports. The bending or unusual position of the knee causes the PCL to tear. Generally, this is accompanied by pain in the knee and swelling. Doctors may suspect PCL injuries if the knee feels loose to the touch, however an accurate diagnosis typically must be made by taking a radiographic image of the knee after the swelling has gone down (which usually occurs seven to 10 days after the injury). An MRI may also be used to diagnose PCL injuries.

  Typically, PCL injuries are treated with rehabilitation and physical therapy, although they may accompany other knee problems which require surgical treatment.

Torn Cartilage

• Torn cartilage can refer to a tear in any cartilage throughout the knee. Generally, torn cartilage refers to a tear in the meniscus. This is often accompanied by an ACL injury, and typically is treated with surgery, as described above. However, depending on the type or extent of the cartilage tear, physical therapy, rest and reduced activity may be sufficient.