gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

Result presentation of a series of 13 lumbar implantations of the B-Twin Expandable Spinal System (B-Twin ESS) by a posterior approach

Meeting Abstract

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  • S. Terwey - Neurochirurgie, Clemenshospital Münster
  • B. Prümer - Radiologie, Clemenshospital Münster
  • A. Sepehrnia - Neurochirurgie, Clemenshospital Münster

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocP11-04

doi: 10.3205/09dgnc367, urn:nbn:de:0183-09dgnc3671

Published: May 20, 2009

© 2009 Terwey 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.



Introduction: In patients with severe spondylosis and accompanying (pseudo-)spondylolisthesis vertebral fusion promises pain relief along with the stabilization of vertebral shifting. In this study we evaluated the outcome after implantation of the “B-Twin Expandable Spinal System” (B-Twin ESS) through an open posterior approach.

Materials and Methods: 13 consecutive patients (6 males & 7 females) with a mean age of 67 years, presenting with degenerative disc disease and (pseudo-)spondylolisthesis grade 1 according to Meyerding were treated with a B-Twin ESS in the involved spinal segment.

The analyzed five parameters: (1) number of sequel operations, (2) wound infection, (3)procedural complications, (4) segment stability, (5) ease of handling, and (6) patient satisfaction.

Results: Unfortunately, the results were very disappointing. 6/13 patients (46%) underwent a sequel operation (revision) because of wound infections and a spinal liquor leakage. A bland aseptic spondylodiscitis was observed in 3 patients (23%), while 6 patients (46%) revealed a fracture of the adjacent end plates and a dislocated cage bulging into the vertebral body.

Because of the unsatisfactory results we stopped the implantation of the (lumbar) B-Twin Expandable Spinal Systems.

Conclusions: Only 2/13 patients (15%) had a favorable outcome, while 85% suffered from side effects and complications like inflammation, liquor leak and endplate erosion. In our opinion these results have to be regarded as unfavorable and dissatisfying, driving us to end the series at this point. Hypothetically, the reason for this poor outcome may be seen in the inadequately small interlaminar access for maneuvering the bulky device into the shrunk disk space.