gms | German Medical Science

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

German Society of Neurosurgery (DGNC)

26 - 29 May 2013, Düsseldorf

A multicenter, prospective, randomized study to demonstrate the superiority of a bone-anchored prosthesis for annular closure used in conjunction with limited discectomy to limited discectomy alone for primary lumbar disc herniation

Meeting Abstract

  • Peter Douglas Klassen - St. Bonifatius Hospital, Department of Neurosurgery, Lingen, Germany
  • Robert Hes - ZNA Middelheim, Department of Neurosurgery, Antwerp, Belgium
  • Gerrit J. Bouma - Sint Lucas-Andreas Ziekenhuis and Academic Medical Center, Department of Neurosurgery, Amsterdam, The Netherlands
  • Sandro Eustacchio - Medical University Graz, Department of Neurosurgery, Graz, Austria
  • Martin Barth - University Hospital, Department of Neurosurgery, Mannheim, Germany
  • Stefan Rath - Klinikum Deggendorf, Department of Neurosurgery and Interventional Neuroradiology, Deggendorf, Germany
  • H. Maximilian Mehdorn - University Hospital, Department of Neurosurgery, Kiel, Germany
  • Volkmar Heidecke - Klinikum Augsburg, Department of Neurosurgery, Augsburg, Germany
  • Richard Bostelmann - University Hospital, Department of Neurosurgery, Dusseldorf, Germany
  • Claudius Thomé - Innsbruck Medical University, Department of Neurosurgery, Innsbruck, Austria
  • Peter Vajkoczy - Charité Universitätsmedizin, Department of Neurosurgery, Berlin, Germany
  • Hans-Peter Köhler - Asklepios Westklinikum Hamburg, Department of Neurosurgery, Hamburg, Germany
  • Frederic Martens - OLV Ziekenhuis, Department of Neurosurgery, Aalst, Belgium

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. DocMO.03.10

doi: 10.3205/13dgnc027, urn:nbn:de:0183-13dgnc0270

Published: May 21, 2013

© 2013 Klassen 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: Same-level reherniation and progressive degeneration with disc height loss are main causes of poor outcome after discectomy and may necessitate reoperation. A novel prosthesis for anular closure was developed to address these causes. The design of a multicenter, prospective, randomized, post-market superiority trial comparing limited posterior lumbar discectomy augmented with this device (intervention group) with limited posterior lumbar discectomy alone (control group) is presented.

Method: Patients with single-level (L1-S1) posterior or posterolateral disc herniation and radiologic confirmation of neural compression for whom at least six weeks of conservative treatment has failed are eligible. Patients must have posterior disc height ≥5 mm at index level and baseline Oswestry and VAS leg pain scores of ≥40/100. Intraoperatively, subjects meeting anular defect size criteria post-discectomy (4–6 mm tall and 6–10 mm wide) will be randomized to study groups in a 1:1 ratio using centralized, web-based software. A Bayesian statistical approach will be used to enroll 400 to 800 subjects who will be followed for at least 24 months. Two co-primary endpoints will be assessed at 24 months: 1) a composite of leg pain, clinical function, disc height maintenance, and absence of reherniation, reoperation, and device failure; and 2) absence of reherniation based upon independent radiologic analysis. Trial subgroups include subjects blinded to group allocation and those who contribute additional cost data to determine cost-effectiveness of treatment.

Results: Demonstrate superiority of limited discectomy augmented with the device compared with limited discectomy alone in preventing recurrent pain, dysfunction, and herniation.

Conclusions: To our knowledge, this is the first randomized, controlled trial evaluating a bone-anchored prosthesis for anular closure and the largest multi-country, prospective discectomy study.