Articular recess

An articular recess is a normal anatomical extension or outpouching of a synovial joint cavity, formed by the joint capsule and synovial membrane, which extends beyond the main articular surfaces. These recesses are filled with synovial fluid and can vary in size, shape, and location depending on the specific joint. They are commonly found in joints such as the metacarpophalangeal (MCP) joints, knee, and zygapophysial (facet) joints, and are visible on imaging modalities like MRI, ultrasound, and arthrography.

Articular recesses serve as reservoirs for synovial fluid and can be sites where joint effusions accumulate, which is clinically relevant in the assessment of joint pathology. For example, the dorsal recess of the MCP joints is a prominent site for fluid collection in inflammatory or traumatic conditions. In the knee, recesses such as the suprapatellar and infrapatellar (suprahoffatic and infrahoffatic) recesses are important anatomical variants that may be mistaken for pathological findings if not recognized.