Two asymmetric contoured plate-rods for occipito-cervical fusion.

The author presents a retrospective clinical study addressing the outcome after posterior stabilisation of the occipital-cervical spine using a new cranio-spinal implant. The range of surgical methods for operative treatment of occipito-cervical instability remains wide, and it is still a demanding technique that frequently requires improvisation by the surgeon. No previous studies have been published of occipito-cervical reconstructions using two contoured asymmetrical occipital plates interdigitating in the midline at the occiput and allowing various methods of cervical fixation, by means of different hooks, a claw device or screws. Nine patients with severe occipito-cervical instability and/or subaxial malalignment underwent reconstructive surgery with the new implants between 1998 and 2001. Seven patients suffered from rheumatoid arthritis (RA) including cranial settling. Two patients had widespread cervical metastases. All patients suffering RA were treated by preoperative cervical traction for up to 28 days, and intraoperative traction, to try to restore the malalignment. Traction was also used, to diminish pain and to improve neurological symptoms. The lowest vertebra fused was T3. All patients were immobilised with an external orthosis or brace for 6 weeks or 3 months. A solid fusion was achieved in all patients. None of the patients deteriorated postoperatively. No serious complications occurred. One occipital screw broke and one hook loosened, needing a re-fixation. The simplicity of applying these cranio-cervical implants makes them practical for every orthopaedic or neurosurgeon with a special interest in cervical spine surgery.