The changes in the spine can cause disc herniations or growth in the ligaments in the back of the spine. Other causes include hardening of the posterior longitudinal ligament or the ligamentum flavum, ...

The nucleus pulposus is posterior in the annulus and the posterior longitudinal ligament (PLL) is midline, creating a somewhat weak point in the annulus on either side of the PLL (Fig 5).

The ligament sutures are secured proximally ... or augmented MCL element only needs to prevent straight distal or distal posterior, longitudinal type distraction and not direct valgus deformation.