gms | German Medical Science

54. Jahrestagung der Norddeutschen Orthopädenvereinigung e. V.

Norddeutsche Orthopädenvereinigung

16.06. bis 18.06.2005, Hamburg

Clinical results after microsurgical bilateral decompression of lumbar spinal stenosis in 'over-the-top' technique through a unilateral approach

Meeting Abstract

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  • corresponding author C. Siepe - Orthozentrum München, Orthopädische Klinik, Wirbelsäulenzentrum, München
  • A. Korge - München
  • K. Wiechert - München
  • M. Mayer - München

Norddeutsche Orthopädenvereinigung. 54. Jahrestagung der Norddeutschen Orthopädenvereinigung e.V.. Hamburg, 16.-18.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05novW2.09

The electronic version of this article is the complete one and can be found online at:

Published: June 13, 2005

© 2005 Siepe et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Operative decompression of lumbar spinal stenosis has become a routinely performed procedure in the treatment of predominantly elderly patients after conservative treatment has failed. Considering the advanced age of patients with its necessity of earliest possible mobilisation, microsurgical techniques offer various advantages. In this study we evaluated whether clinical results could benefit from our modified surgical technique.

Materials and Methods

275 patients underwent bilateral microsurgical decompression of the lumbar spinal canal through a monolateral approach in ´over-the-top-technique´. Indications included symptoms of predominant leg-pain with spinal claudication and accompanying lower back pain that were unresponsive to nonoperative management. Postoperative improvement of walking distance and subjective findings were evaluated using the visual analog scale (VAS) as well as the modified Oswestry-disability-score.


568 segments were decompressed in 275 Patients. Time of operation averaged 42 minutes/segment, blood-loss 57ml/segment. Over 80% of patients with sciata and more than 40%of patients with lower back pain reported significant improvement following the operation. Walking distance improved 20x. Patients with spinal claudication showed better improvement than patients with a higher degree of lower back pain. Whilst 92 % of operations were uncomplicated, however, duralesions (5%) were found to be the highest source of intraoperative complications.


Bilateral microsurgical decompression of the lumbar spinal canal through a monolateral approach in ´over-the-top´-technique provides a sufficient and safe surgical technique. Considering the low rate of complications, elderly patients were able to benefit significantly. -Sciata and symptoms of spinal claudication improved to a greater extent than accompanying lower back pain.