Cervical Spine Instability

Atlanto-axial subluxation

  • In rheumatoid arthritis, atlanto‐axial subluxation can occur due to destruction of the synovial joint between the atlas and the dens and rupture of the transverse ligament
  • Subluxation can result in cord compression which can be fatal

Management

  • Less severe cases (seen on flexion‐extension views) may be treated with a collar to prevent flexion
  • More severe cases may require surgical fusion

Lower cervical subluxations

  • Lower cervical subluxations can occur due to destruction of the synovial facet joints and uncovertebral joints by RA
  • There is potential for cord compression (myelopathy) with upper motor neuron signs (wide based gait, weakness, increased tone, upgoing plantar response)
  • Measurements are taken from flexion‐extension xrays

Management

  • If instability does not involve/threaten neurological structures - conservative management (analgesia, physio)
  • More severe cases may require stabilization/fusion

Other causes of atraumatic cervical spine instability

  • Atraumatic cervical spine instability can also occur in Down's syndrome