MANAGEMENT OF SPONDYLOLISTHESIS

Abstract

There is strong evidence that unilateral instrumentation leads to a better outcome regarding the reduction of adjacent motion segment abnormalities, than bilateral technique in the treatment of short segment lumbar spondylolisthesis. This is supported by the fact that most studies either statistically or non-statistically showed that the less rigid construct offered by unilateral instrumentation performs less hazardous biomechanical effect on the adjacent motion segment, than does the more stiff bilateral instrumentation . However, the fusion rate and bony union as an evidence of successful instrumentation was noticed to be better in bilateral instrumentation than in the unilateral one. In summary, unilateral fixation and fusion are reasonable in active, healthy, young patients with spinal stenosis associated with degenerative spondylolisthesis who have relatively few degenerative changes promoting stability at the level of the slip. Consequently, the more the degenerative changes at the listhetic level, the better to use bilateral fixation to promote stability. Unilateral fixation is also of benefit in cases where it offers a biomechanical solution of instability at the listhetic level as in traumatic spondylolisthesis due to unilateral fracture pars. Also those elderly with proven poor bone quality as osteoporosis may benefit from unilateral fixation to reduce the adjacent motion segment abnormalities .However, more detailed studies concentrating on more specific pathophysiological situations should be done with longer follow up periods.

CONCLUSION The key to success in managing lumbar spondylolisthesis is to know in whom, when and how to intervene. The best results are obtained in a symptomatic patient in good general health who does not have psychological overlay. The surgical team performing spondylolisthesis surgery must be conversant with more than one method of doing surgery but need not necessarily be capable of doing every conceivable procedure in the literature. The wise surgeon would desist from trying out every new spinal implant introduced by a commercially motivated industry. Results improve when the team does the same procedure again and again over the years. (Ramakrishna E.2012)