gms | German Medical Science

64th Annual Meeting of the German Society of Neurosurgery (DGNC)

German Society of Neurosurgery (DGNC)

26 - 29 May 2013, Düsseldorf

In vivo temperature measurement during decompression for treatment of lumbar spinal stenosis: randomized, single-blind comparison of high-speed diamond high-speed drill (HSD) and ultrasonic bone cutting device (USD)

Meeting Abstract

  • Marc Matthes - Klinik und Poliklinik für Neurochirurgie, Ernst-Moritz-Arndt-Universität Greifswald
  • Dirk Thomas Pillich - Klinik und Poliklinik für Neurochirurgie, Ernst-Moritz-Arndt-Universität Greifswald
  • Jörg Baldauf - Klinik und Poliklinik für Neurochirurgie, Ernst-Moritz-Arndt-Universität Greifswald
  • Henry Schroeder - Klinik und Poliklinik für Neurochirurgie, Ernst-Moritz-Arndt-Universität Greifswald
  • Jan-Uwe Müller - Klinik und Poliklinik für Neurochirurgie, Ernst-Moritz-Arndt-Universität Greifswald

Deutsche Gesellschaft für Neurochirurgie. 64. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Düsseldorf, 26.-29.05.2013. Düsseldorf: German Medical Science GMS Publishing House; 2013. DocDI.08.05

doi: 10.3205/13dgnc231, urn:nbn:de:0183-13dgnc2319

Published: May 21, 2013

© 2013 Matthes 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: Spinal decompression techniques differ in terms of the risk profile for controllability, applied pressure and generated heat. USD and HSD are both highly controllable and work at low pressures. Temperatures up to 90°C have been described for classic HSD. However, the peak temperature for spine surgery in vivo is not known for any of the methods. The goal of the study was to compare the bone decompression via diamond high-speed drilling with manual (DM) and automatic (DA) flushing and ultrasonic bone removal with automatic flushing (US).

Method: In a randomised study, the temperature maxima occurring during HSD using a diamond bit (8mm, single use, Microspeed Uni, Aesculap AG) and a piezoelectric USD (Sonoca 350, Söring GmbH) were compared. The study included 90 patients with absolute spinal stenosis (verified using MRT and myelo-CT) who were randomised for one of the three study arms. The pre- and postoperative clinical data were acquired and analysed in terms of group homogeneity. The intraoperative measurement of heat generation was carried out by means of a thermal imaging camera (FLIR T335, FLIR Systems) mounted close to the optical element of the operating microscope (OPMI Pentero, Carl Zeiss Meditec AG). A video stream of the thermographic measurements was captured and the maximum temperatures in the individual images were then determined. For each surgery the maximum temperature and the mean of the ten highest temperatures were determined. The peak temperatures used for determining the mean temperatures had to be at least 15 seconds apart.

Results: The clinical results in the three groups did not differ in terms of preoperative data, postoperative pain reduction, improvement in neurological findings or frequency of complications. Significant differences (p<0.05) were found for the measured mean temperature maxima (58.6°C for US, 74.2°C for DA and 88.2°C for DM) as well as the absolute temperature maxima (74.5°C (US), 106.8°C (DA) and 129.4°C (DM)).

Conclusions: For all systems the local temperatures exhibited maximum values which could lead to osteonecrosis and upon contact with neural structures to neurological deficits. The highest probability of thermal damage to the bones and neural structures was obtained using HSD with manual flushing. Ultrasonic bone removal led to the lowest amount of heat generation. This aspect should be taken into consideration in the selection of suitable decompression techniques.