External fixation in lumbar segmental instability.

Identification of the source of pain in patients with chronic low back pain remains a challenging subject. The non-invasive investigations lack specificity. The value of invasive tests has also been controversial. At one time discograms used to be considered as the only specific investigation identifying the source of pain prior to fusion surgery; many studies however proved that this is not true. Recently, external fixation of the spine has become a popular invasive investigation in patients with low back pain. In the current review, published articles in the field are discussed. There is unfortunately not enough data to support the use of spinal external fixation.