gewrichtsuitsteeksels
Gewrichtsuitsteeksels, also known as articular processes or zygapophyseal joints, are pairs of bony projections found on the vertebrae of the spinal column. Each vertebra typically has four such processes: two superior articular processes that point upwards and two inferior articular processes that point downwards. These processes articulate with the corresponding processes of adjacent vertebrae, forming the zygapophyseal joints. The primary function of these joints is to limit excessive movement between vertebrae, providing stability to the spine while allowing for a controlled range of motion such as flexion, extension, and rotation. The orientation and shape of the articular facets, the smooth cartilaginous surfaces of these processes, vary along the spinal column, influencing the type and degree of movement possible in different regions. In the cervical spine, the facets are more horizontally oriented, facilitating greater rotation. In the thoracic spine, they are more vertically oriented, restricting rotation but allowing for more lateral flexion. In the lumbar spine, the facets are curved and oriented in a sagittal plane, primarily allowing for flexion and extension. Inflammation or degeneration of these joints, known as zygapophyseal joint osteoarthritis or facet joint syndrome, can lead to chronic back pain.