Abstract
Many devices have been developed to enhance fusion and alignment of the spine in anterior spinal fusions. The Ulrich ‘Ivory’ interbody cage was introduced in 2000, and this report examines the results of the first 50 patients in whom it was used.
The mean age of the 21 men and 29 women was 50.8 (24 to 74). A total of 82 cages were inserted. In 39 patients the indications for surgery were failed posterior fusions. One patient, who had undergone three previous surgical procedures, had post-laminectomy syndrome. Primary anteroposterior fusion for spondylolisthesis was performed in six patients. The remaining four had surgery for other reasons, including sagittal malalignment and failed Dynesys fixation.
Evaluated radiologically, the fusion mass was good. Complications included one vascular injury, which required repair of the iliac artery. One patient developed pancreatitis and deep vein thrombosis. The posterior surface of S1 fractured in one patient. From six weeks to one year postoperatively, we saw five broken cages, three associated with grade II spondylolisthesis and two that had broken after trauma. Since then, the lateral supports of the cages have been strengthened.
The cage is easy to insert, either laterally or anteriorly. The large contact surface makes for good bony ingrowth and no stress shielding. It is a useful alternative to other cages on the market, but should not be used as a ‘stand alone’ device.
The abstracts were edited by Prof. M.B.E. Sweet. Correspondence should be addressed to him at the Department of Orthopaedic Surgery, Medical School, University of the Witwatersrand, 7 York Road, Parktown, 2193 South Africa
