Ledkapsel

Ledkapsel, in English commonly referred to as the joint capsule, is the tough fibrous envelope that surrounds a synovial joint. It consists of an outer fibrous layer and an inner synovial membrane, and it forms and maintains the joint cavity. The capsule attaches to the articular margins of the bones participating in the joint and is often reinforced by extracapsular ligaments.

Anatomy and components: The fibrous layer is dense connective tissue that provides mechanical stability and protection. The inner synovial membrane lines the capsule’s inner surface, except where articular cartilage covers the articulating bones. The synovial membrane produces synovial fluid, which fills the joint cavity and lubricates, nourishes, and cushions the articular cartilage. The capsule is supplied with nerves, especially those involved in proprioception and pain, and with blood vessels that support the synovial membrane.

Function: The ledkapsel stabilizes the joint by containing and guiding movement while allowing some flexibility. It helps limit extreme ranges of motion to prevent dislocation and injury. The synovial fluid within the capsule reduces friction between moving surfaces and provides nutrients to avascular articular cartilage.

Clinical notes: Conditions affecting the joint capsule include synovitis (inflammation of the synovial membrane) and capsulitis (inflammation or fibrosis of the capsule), which can impair mobility and cause pain. Capsular thickening or adhesions may contribute to restricted motion, as seen in adhesive capsulitis in the shoulder.

In summary, the ledkapsel is a key structural and functional component of diarthrodial joints, balancing stability with mobility through its fibrous and synovial layers.