Knee, Ankle & Foot
Knee Instability, Dislocation and Subluxation
The knee is made up of four main bones: the femur (thigh bone), the tibia (shin bones), the fibula (outer shin bone) and the patella (knee bone).
Knee cap/patella instability means that the knee cap/patella joint is too loose and is able to slide around too much in the socket. In some cases, the unstable patella actually slips out of the socket. If the patella slips completely out of the socket, it is a dislocation. If not treated, instability can lead to arthritis of the knee joint. Patella instability may be treated by bracing, physical therapy or by surgically stabilizing.
Patellar dislocation happens when a direct blow or sudden twist occurs and the patella (kneecap) slips out of its normal position and can cause intense pain with swelling of the knee. Medial patella-femoral ligament (MPFL) is sometimes torn during patella dislocation, sometimes leading to patella instability and may require ligament reconstruction to stabilize the patella.
The anterior cruciate ligament (ACL) is one of the most commonly injured ligaments of the knee. The goal of the ACL reconstruction surgery is to prevent instability and restore the function of the torn ligament, creating a stable knee.
The kneecap is designed to fit in the center of the trochlear groove and slide evenly within the groove. Patellar subluxation is when the kneecap is pulled towards the outside of the knee and does not slide centrally within its groove creating discomfort with activity and pain around the side of the kneecap. Depending on the severity of the subluxation, the improper tracking could lead to dislocation of the patella. For patients who have significant pain or recurrent dislocations, Dr. Kostman may recommend surgery once he has assessed the underlying issue that needs to be corrected.
Three bones meet to form your knee joint: your thighbone (femur), shinbone (tibia), and kneecap (patella) and two meniscus (wedge-shaped pieces of cartilage) that act as shock absorbers between your thighbone and shinbone.
A meniscus tear is a common injury to the cartilage that stabilizes and cushions the knee joint and may be caused by turning the knee quickly or twisting it with the foot planted and the knee bent or by the aging process. You may experience pain, swelling, stiffness, cracking or popping and an inability to straighten the knee.
Menisci tear in different ways. Tears are noted by how they look, as well as where the tear occurs in the meniscus. Common tears include bucket handle, flap, and radial. Sports-related meniscus tears often occur along with other knee injuries, such as anterior cruciate ligament (ACL) tears. Sudden meniscus tears often happen during sports. Players may twist the knee, causing a tear. Direct contact, like a tackle, is sometimes involved. Older people are more likely to have degenerative meniscus tears