gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Comparison of soft tissue trauma in microsurgical nucleotomy to a new technique: microscopically assisted percutaneous nucleotomy. An MRI study

Vergleich des Zugangstraumas bei mikrochirurgischer und mikroskopisch assistierter perkutaner Nukleotomie. Eine MRT-Studie

Meeting Abstract

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  • corresponding author R. Greiner-Perth - Klinik für Wirbelsäulenchirurgie, orthopädische Chirurgie und Neurotraumatologie, SRH Waldklinikum Gera
  • Y. Allam - Klinik für Wirbelsäulenchirurgie, orthopädische Chirurgie und Neurotraumatologie, SRH Waldklinikum Gera
  • J. Franke - Kilinik für Orthopädie, Otto-von-Guericke Universität, Magdeburg

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocP 12.190

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

Published: May 8, 2006

© 2006 Greiner-Perth 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.



Objective: Microsurgical nucleotomy (MC) currently is regarded as „gold standard“ in the operative treatment of lumbar disc herniation. This prospective randomised study aims at comparing the trauma of the approach of the standard technique to a newer method working through a working channel under control of the surgical microscope: “microscopically assisted percutaneous nucleotomy” (MAPN).

Methods: This is a prospective, randomized and blinded study examining fifty patients. Two subgroups were randomly selected for either of the treatment options. Magnetic resonance imaging with application of contrast medium (Gd-DTPA) was performed on every patient immediately before surgery and within the first 48 hours after the intervention. Enhancement of the nerve roots, edema of the paravertebral muscles, as well as the maximum extension of seroma/haematoma were assessed on axial T1-weighted and T2-weighted magnetic resonance images. To compare the size of edema between both groups we measured the angle between the route of surgical access and the lateral margin of edema.

Results: There was no relevant difference of enhancement of the nerve roots between both groups. However a significantly (p<0.001) smaller angle of edema extension could be measured in MAPN (22.36°; SD 7.8) when compared to MC (38.6°; SD 9.3). The maximum extension of seroma/hematoma in the approach area with a mean value of 33.4mm2 in MAPN did also show a statistically significant (p<0.05) difference to MC, where the average amounted to 134.8 mm2. These findings go parallel with a distinctly (p<0.001) smaller need for analgesics (in the early postoperative course: 1.3mg morphine equivalents in MAPN and 5.4mg in MC during the first 48 hours after surgery.

Conclusions: Noninvasive assessment of muscle trauma imposes substantial problems. Certainly changes in the signals of Magnetic Resonance cannot be equalled with surgical trauma, but they denote an alteration of the tissue due to the intervention. So it seems justified, to draw conclusions from different areas affected in a two-dimensional study. The 4 fold bigger area altered due to the microsurgical approach and the significantly smaller need for pain killers seems to justify the conclusion, that the working channel technique of MAPN is less invasive and may be a proper alternative. Further investigations in other institutions are under way to increase the data basis.