Knee Joint

quadriceps tendon

also known as the patellar tendon, allows the quad muscles (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius) to converge on the superior aspects of the patella on the anterior of the thigh, which continues as the patellar ligament. A tendon connects muscle to bone, while a ligament connects bone to bone. The quadriceps tendon works with the quadriceps to extend the leg.

patellar ligament

an extension of the quadriceps tendon. It extends from the patella (kneecap); a ligament is a type of fibrous tissue that usually connects two bones. It helps keep the kneecap in its proper position but also helps the leg bend at the knee. When this is torn the leg won't extend properly and people cannot walk on it.

patella

the kneecap; small bone in front of the knee

femur

the longest, heaviest, and strongest bone in the entire body. All of a humans body weight is supported by this bone. Extreme forces can act on this bone due to the strength of the muscles of hip and thigh that act on this bone to move the leg.

articular cartilage

the smooth, white tissue that covers the ends of bones where they come together to form joints. Healthy cartilage in our joints makes it easier to move. It allows the bones to glide over each other with very little friction. This can be damaged by injury or normal wear and tear.

tibial (medial) collateral ligament

a broad, flat band of tissue that connects the medial condyle of the femur (thigh bone) to the medial condyle of the tibia at the knee joint. It helps with resisting force from the knees outer surface preventing side to side displacement of the knee in the inner direction

medial meniscus

a fibrocartilage semicircular band that spans the knee joint medially, located between the medial condyle of the femur and the medial condyle of the tibia.

lateral meniscus

a fibrocartilaginous band that spans the lateral side of the interior of the knee joint. It is nearly circular and covers a large portion of the articular surface. It can occasionally be injured or torn by twisting the knee or applying direct force, as seen in contact sports.

tibia

a large bone located on the lower front portion of the leg, it is also known as the shinbone and is second largest bone in the body. It bears the bodys weight from the knees and ankles. There are two bones in the shin area and connect at the ankle to work together

fibula

long, thin and lateral bone of the lower leg. It runs parallel to the shin bone and helps stabilize ankle and muscles of the lower leg. It is thinner than the shin bone and supports the shin bone.

anterior cruciate ligament

one of a pair of cruciate ligaments in the human knee. Also called cruciform ligament as it is arranged in a crossed formation. In the quadruped stifle joint (analogous to the knee), based on its anatomical position, it is also referred to as the cranial cruciate ligament. The anterior cruciate ligament is one of the four main ligaments of the knee, and the ACL provides 85% of the restraining force to anterior tibial displacement at 30 degrees and 90 degrees of knee flexion.

posterior cruciate ligament

one of the four major ligaments of the knee. It connects the posterior intercondylar area of the tibia to the medial condyle of the femur. This configuration allows the PCL to resist forces pushing the tibia posteriorly relative to the femur. It is an intracapsular ligament along with the anterior cruciate ligament (ACL) because it lies deep within the knee joint. They are both isolated from the fluid-filled synovial cavity, with the synovial membrane wrapped around them. The PCL gets its name by attaching to the posterior portion of the tibia.

fibular (lateral) collateral ligament

prevents side to side displacement of the knee in the outer direction. It consists of a strong round cord located between the lateral condyle of the femur (thigh bone) and the head of the fibula at the knee joint