M23.91: Internal derangement of knee, unspecified: Anterior cruciate ligament or anterior horn of medial meniscus

Your knee joint is damaged.

In the knee joint, the thighbone (femur) is connected to the shinbone (tibia). Between the two bones are two pieces of crescent-shaped cartilage. These pieces of cartilage and fiber are the menisci. There is a medial meniscus and a lateral meniscus. The medial meniscus is on the inside of the leg, while the lateral meniscus is on the outside of the leg. The menisci perform various functions. They balance out any unevenness in the joint surfaces of the bones. The menisci also act as shock absorbers. They absorb violent shocks.

The knee joint is stabilized by various ligaments. The cruciate ligaments are on the inside of the knee joint. There is an anterior and a posterior cruciate ligament. The cruciate ligaments restrict the forward and backward movement of the lower leg. The collateral ligaments sit to the right and left of the knee. There is a medial and a lateral collateral ligament. The collateral ligaments stabilize the knee, when standing in particular.

Your anterior cruciate ligament or the front of your medial meniscus is damaged. The anterior cruciate ligament usually prevents your lower leg from moving too far forwards compared to your thigh. If the anterior cruciate ligament is not tight enough, the lower leg may move further forward than normal. When a meniscus is damaged, you may no longer be able to move and turn your knee properly. The knee may then be painful.