The posterior ligamentous complex acts to stabilize the vertebral column against flexion and rotation by holding the posterior elements of the neighboring vertebrae in fixed relation with each other. It is sometimes referred to as the posterior tension band although the latter also includes the bony posterior vertebral elements.
The posterior ligamentous complex comprises the following structures:
facet joint capsule
ligamentum flavum
interspinous ligament
supraspinous ligament
Some sources also include the cervical or thoracolumbar fascia
The importance of the posterior ligamentous complex/posterior tension band is highlighted in the most commonly used spinal fracture classifications systems: AO classification of subaxial cervical injuries, AO classification of thoracolumbar injuries, and the thoracolumbar injury classification and severity score (TLICS).