The pars interarticularis is the region of a vertebra located between the superior and inferior articular processes. It's essentially the bony segment connecting the facet joints on the back of the spine.
Essentially, think of it as the section of bone that sits between the upper and lower joints which connect the vertebrae together. It's located on both sides (bilaterally) at each vertebral level.
Here's a breakdown:
- Location: Between the superior and inferior articular processes of a vertebra. This area is the bridge connecting the facet joints.
- Function: It plays a crucial role in spinal stability and load bearing.
- Significance: It's a common site for stress fractures, especially in the lower back (lumbar spine), leading to a condition called spondylolysis.
A helpful analogy is to think of vertebrae as building blocks. The pars interarticularis is part of the connection between those blocks, specifically relating to the joints on the back side.
