Articular capsule of the knee joint

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Articular Capsule of the Knee Joint

The Articular Capsule of the Knee Joint, also known as the capsular ligament, is a complex structure that encloses the knee joint. It plays a crucial role in the stability and function of the knee, providing both passive and active mechanisms of support. The capsule is composed of fibrous tissue and synovial membrane, which work together to protect and lubricate the joint.

Structure

The articular capsule of the knee is a spacious and loose-fitting envelope that surrounds the knee joint. It is attached proximally to the margins of the femur and distally to the tibia and fibula. The capsule is thicker and stronger on the sides than in the front and back, reflecting the need for lateral stability in the knee. It is divided into two layers: an outer fibrous layer and an inner synovial membrane.

Fibrous Layer

The fibrous layer of the capsule is made up of dense connective tissue. It is reinforced by the tendons of muscles around the knee, including the quadriceps femoris in the front and the hamstrings at the back. This layer provides mechanical strength to the capsule and serves as an attachment site for other knee ligaments.

Synovial Membrane

The synovial membrane lines the inner surface of the capsule, excluding the areas where the articular cartilages and menisci are found. It secretes synovial fluid, a lubricating liquid that reduces friction between the moving parts of the knee joint and nourishes the articular cartilage.

Function

The primary function of the articular capsule of the knee is to enclose and protect the knee joint. It maintains the joint's stability by restricting excessive movements and by its intrinsic tension. The capsule also plays a role in proprioception, helping the body to sense the position of the knee in space.

Clinical Significance

Injuries to the articular capsule of the knee, such as sprains or tears, can lead to instability, pain, and swelling. Conditions like osteoarthritis can also affect the capsule, leading to stiffness and reduced mobility. Treatment for capsule-related issues may include physical therapy, medication, or surgery, depending on the severity of the condition.

See Also

• Knee Ligaments
• Synovial Joint
• Knee Injuries