The knee

patellofemoral joint

One of the knee joints. The knee has three parts. The thigh bone (femur) meets the large shin bone (tibia) forming the main knee joint. This joint has an inner (medial) and an outer (lateral) compartment. The kneecap (patella) and the femur form a third joint, called the patellofemoral joint.

retropatellar surface

Patellofemoral pain syndrome (PFPS) is a syndrome characterized by knee pain ranging from severe to mild discomfort seemingly originating from the contact of the posterior surface of the patella (back of the kneecap) with the femur (thigh bone).

synovial membrane

The synovial membrane (also known as synovium or stratum synoviale) is a specialized connective tissue that lines the inner surface of capsules of synovial joints and tendon sheath.

tibial plateau

The tibial plateau is a critical weight-bearing area located on the upper extremity of the tibia and is composed of two slightly concave condyles (medial condyle and lateral condyle) separated by an intercondylar eminence and the sloping areas in front and behind it.

effusion

an instance of giving off something such as a liquid, light, or smell.

pes ansurine

refers to the conjoined tendons of three muscles that insert onto the anteromedial (front and inside) surface of the proximal extremity of the tibia. The muscles are the sartorius, gracilis and semitendinosus sometimes referred to as the guy ropes.

tibiofemoral joint

relating to or being the articulation occurring between the tibia and the femur

epiphyseal plates

the epiphyseal plate (or epiphysial plate, physis, or growth plate) is a hyaline cartilage plate in the metaphysis at each end of a long bone. The plate is found in children and adolescents; in adults, who have stopped growing, the plate is replaced by an epiphyseal line

Articular cartilage

the highly specialized connective tissue of diarthrodial joints. Its principal function is to provide a smooth, lubricated surface for articulation and to facilitate the transmission of loads with a low frictional coefficient

patella

the kneecap.

Quadricep

the large muscle at the front of the thigh, which is divided into four distinct portions and acts to extend the leg.

lateral meniscus

the lateral meniscus (external semilunar fibrocartilage) is a fibrocartilaginous band that spans the lateral side of the interior of the knee joint. It is one of two menisci of the knee, the other being the medial meniscus. It is nearly circular and covers a larger portion of the articular surface than the medial.

Medial meniscus

The medial meniscus of the knee is a thickened crescent-shaped cartilage pad between the two joints formed by the femur (the thigh bone) and the tibia (the shin bone). The meniscus acts as a smooth surface for the joint to move on.

patellar tendon

The patellar ligament is the distal portion of the common tendon of the quadriceps femoris, which is continued from the patella to the tibial tuberosity. It is also sometimes called the patellar tendonas it is a continuation of the quadriceps tendon.

Anterior cruciate ligament

a cruciate ligament of each knee that attaches the front of the tibia with the back of the femur and functions especially to prevent hyperextension of the knee and is subject to injury especially by tearing —called also ACL.

valgus

a deformity involving oblique displacement of part of a limb away from the midline.

varus

a deformity involving oblique displacement of part of a limb toward the midline.

crepitus

a grating sound or sensation produced by friction between bone and cartilage or the fractured parts of a bone.

medial collateral ligament (MCL)

a ligament of the inner knee that connects medial parts of the femur and tibia and helps to stabilize the knee joint —called also MCL.

lateral collateral ligament (LCL)

a ligament of the outer knee that connects the lateral epicondyle of the femur with the lateral side of the head of the fibula and that helps to stabilize the knee by preventing lateral dislocation—called also fibular collateral ligament, LCL; compare medial collateral ligament

condyle

a rounded protuberance at the end of some bones, forming an articulation with another bone.

sesamoid

a small independent bone or bony nodule developed in a tendon where it passes over an angular structure, typically in the hands and feet. The kneecap is a particularly large sesamoid bone.

synovial fluid

a transparent viscid lubricating fluid secreted by a membrane of an articulation, bursa, or tendon sheath—called also joint fluid, synovia.

posterior cruciate ligament (PCL)

to attach to the medial aspect of the femur, that functions to prevent hyperflexion of the knee