Abstract
Introduction: The reduction of severe spondylolisthesis remains controversial and is not without risk. The reduction should aim, primarily, to restore the lumbosacral angle.
Aim: To review the principle author’s experience with reduction of severe lumbosacral spondylolisthesis with emphasis on the restoration of the lumbosacral alignment.
Methods: Thirty patients have undergone reductions of severe lumbosacral spondylolistheses. All were treated by two-staged operations with variation. The anterior operations involved subtotal disc clearances with leverage to distract the discs and restore the lumbosacral angulation. Posteriorly, ala-transverse fusions and L5 laminectomies were performed. More recently pedicle screws were used. Initially hyperextension traction was employed between operations, but this was subsequently abandoned.
Results: Significant reductions (p< 0.01) of displacements were achieved at each stage but significant improvements in slip-angles only occurred with the initial operations. Loss of sagittal and angular corrections were noted at the one-year follow-up. Loss of angular corrections were significantly less with internal fixation (p=0.03). The final alignments were significantly improved when compared with the initial positions.
Conclusions: Satisfactory restoration of the lumbosacral alignment was achieved in severe spondylolisthesis by staged anterior and posterior procedures. Leverage to restore lumbosacral angulation during the anterior procedure facilitated reduction. Post-operative loss of correction was limited by pedicle screw fixation.
The abstracts were prepared by Professor A. J. Thurston. Correspondence should be addressed to him at the Department of Surgery, Wellington School of Medicine, PO Box 7343, Wellington South, New Zealand
