Lumbar iatrogenic spinal instability

Stability of the spine is achieved through a dynamic interaction of several structural systems within the body. One definition of clinical instability was proposed by White and Panjabi as follows: “The loss of the ability of the spine under physiologic loads to maintain its pattern of displacement so that there is no initial or additional neurological deficit, no major deformity, and no incapacitating pain.” Iatrogenic instability may occur due to discectomy and laminectomy and due to adjacent segment degeneration. The following chapter discusses the possible causes of iatrogenic instability and potential treatments for these occurrences.