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

Posterior fusion in atlantoaxial instability: a new compression clamp for easy and safe fixation. Technical note and first experience

Posteriore Fusion bei atlantoaxialer Instabilität: neue Kompressionsklammer zur einfachen und sicheren Fixierung. Technische Beschreibung und erste Erfahrungen

Meeting Abstract

  • corresponding author C. Doenitz - Department of Neurosurgery, University of Regensburg
  • R. Rothoerl - Department of Neurosurgery, University of Regensburg
  • A. Brawanski - Department of Neurosurgery, University of Regensburg
  • C. Woertgen - Department of Neurosurgery, University of Regensburg

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 11.184

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

Published: May 8, 2006

© 2006 Doenitz 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: A variety of surgical treatments are available for posterior stabilization in atlantoaxial instability. A new technique for posterior fusion in atlantoaxial instability is illustrated and the initial experience in treating seven patients with posterior atlantoaxial instability with the new DCS clamp (Dynamic Compression System) for indications of polyarthritis and trauma is reviewed.

Methods: In seven patients (29 - 70 y, mean 53 y, m:f = 3:4) solid laminary osteosynthesis C1-C2/3 was achieved by insertion of an autogenous cortico-cancellous bone graft into the interlaminar space and by bilateral application of a newly developed clamp distributed by PINA Medizintechnik, Neuhausen, Switzerland. Indications included C1/2 four cases of pseudarthrosis in polyarthritis and C1/2-3 instability in three trauma patients. The DCS clamp is a 2-clip hinge technique with central spindle in synchronized lengths. Compression is achieved by swivelling the central spindle (milled hexagon) with a ratchet screwdriver. Simultaneously the turnable glide clips are automatically rear catching the vertebra bows which have to be stabilized.

Results: Seven patients were treated successfully. The DCS clamps could be fixed easily and fast. No intraoperative complications occurred. There was one case of deep wound infection, which led to revision, but clamps could remain after refixation. A fracture of a lamina occurred in one patient due to an unlucky maneuver of an assistant during the postoperative X-ray. The fracture was fixed by a screw fixation and bony fusion. Mean follow-up time was two months. Neck pain was relieved in all cases. All of the postoperative control X-rays showed stable conditions.

Conclusions: Seven patients were treated successfully with the newly developed DCS clamps. Surgical technique is safe and fast without danger of injuring the vertebral artery or the nerve root. The technical principles of the clamp guarantee a permanent pressure on the graft and a solid initial stability in the segment. The axial compression strengths allow an immediate strain and mobilization of the patient without external fixation.