The knee is a joint which is subjected to tremendous lateral stress
during normal activity and is guarded by a number of transverse and cruciate
ligaments to help lend it support. Even so, however, the increased
stresses placed upon this joint during extreme athletic activity (for example,
in football, basketball, or tennis) which require the competitor to alter
direction rapidly, the knee often bears the brunt of intolerable shearing
force. Such incidences often result in torn ligaments within the
knee which
require corrective surgery.
The anterior and posterior cruciate ligaments connect the inner surfaces
of the head of the femur with the head of the tibia. They are
so named because they cross each other, with the anterior ligament extending
from the inside of the lateral condyle of the femur to the medial side
of the tibial head, and the posterior ligament extending from the inside
of the medial condyle of the
femur to the lateral side of the tibial head.
The anterior meniscofemoral ligament extends from the inside of the lateral condyle of the femur, near the anterior cruciate ligament, across to the medial meniscus. This connection provides some of the lateral support for the knee in flexion and extension.
The posterior meniscofemoral ligament extends from the inside of the medial condyle of the femur, near the posterior cruciate ligament, across to the lateral meniscus. This connection provides some of the lateral support for the knee in flexion and extension.
The biceps femoris tendon connects the patella to the femur. It is responsible for extension of the knee joint and is given its name because it features two muscular heads, one at the femur and one at the patella.
Two ligaments flank the knee joint, running along the sides of the joint to secure the bones laterally. These collateral ligaments are named for the bones which they secure to the femur. The tibial collateral ligament runs along the medial side of the femur and down to the head of the tibia. The fibular collateral ligament runs along the lateral side of the femur to the head of the fibula.
The popliteal tendon is the tendon in the popliteal space (the depression behind the knee joint) which connects to the popliteus muscle and aids in the rotation and flexion of the leg.
The lower end of the femur features two prominences called the lateral and medial condyles. These condyles articulate with the patella and the articular surface of the tibia to form the hinge-like knee joint. The medial condyle is the inside prominence, resting on the medial meniscus, while the outside, or lateral, condyle rests on the lateral meniscus.
The lateral condyle of the tibia is the bony prominence on the lateral, or outer, side of the head of the tibia. It articulates with the lateral condyle of the femur and is cushioned from it by the lateral meniscus. The lateral condyle of the tibia is connected to the fibula at the superior tibiofibular joint.
The medial condyle of the tibia is the bony prominence on the medial, or inner, side of the head of the tibia. It articulates with the medial condyle of the femur and is cushioned from it by the medial meniscus. The medial condyle of the tibia is connected to the medial condyle of the femur by the tibial collateral ligament.
Within the knee joint is a cartilage padding which helps cushion the
femur and the tibia from the stresses placed upon them. This cartilage
forms two depressions, each of which accepts a condyle of the articular
surface of the femur. The lateral meniscus is the slight concavity
on the outer side of the joint, upon which rests the lateral condyle, and
the medial meniscus is a
similar depression which accepts the medial condyle of the femur.
The patella (kneecap) is a small bone of the knee joint which resembles an inverted teardrop. The patella is connected to the joint by the medial and patellar retinaculum ligaments and to the tuberosity of the tibia by the patellar ligament. It is not visible in the posterior (rear) view and is removed in the anterior (front) view to show the articulation and connective tissues of the bones beneath.
The femur is the longest bone in the body, and composes the upper leg, or thigh. Articulating with the acetabulum of the pelvis at its head, and the tibia, fibula, and patella to form the knee joint at its lower end, each femur directly bears the weight of the upper body.
anterior
ligaments
posterior
ligaments
lateral
restraints
menisci
SCOI
SCOI
2
Cyberclinic:
knee joint
Virtual
Hospital and fully
labeled knee joint
Jumper's
knee