C1-C2 POSTERIOR CERVICAL FUSION - LONG-TERM EVALUATION OF RESULTS ANDEFFICACY

POSTERIOR WIRING TECHNIQUES are the most commonly used methods of achi eving C1-C2 arthrodesis. Recently, transarticular screw fixation and i nterlaminar clamping have been advocated to achieve more secure fixati on. A retrospective review of patients undergoing C1-C2 fusion for non neoplastic disease was undertaken at the University of Toronto Hospita l, with the aim of determining the long-term outcome of the selected p rocedures. Thirty-two patients underwent 36 procedures from 1986 to 19 92, with a mean follow-up of 4.7 +/- 2 years (range, 2.0-8.0 yr). The most common disease processes were odontoid fracture (18 patients), tr ansverse atlantal ligament injury (5 patients), os odontoideum (5 pati ents), and rheumatoid C1-C2 instability (3 patients). Thirty-one Galli e fusions, one Brooks-Jenkins fusion, two transarticular screw fusions , and two Halifax clamp applications were performed. Six (19%) of Gall ie/Brooks-Jenkins fusions failed. These occurred with os odontoideum ( three patients), Type II odontoid fracture (two patients), and transve rse atlantal ligament injury (one patient). All transarticular screw a nd Halifax clamp procedures resulted in successful fusions, Two proced ures (6%) resulted in new neurological deficit; both of these patients underwent posterior wiring for os odontoideum. This study suggests th at Type II odontoid fractures may be successfully managed by a posteri or wiring technique alone. Rheumatoid C1-C2 instability may be managed by posterior wiring supplemented with halo immobilization. Transartic ular screw fixation has several potential advantages as a technique fo r C1-C2 arthrodesis and, in particular, may be appropriate for os odon toideum that had a high failure rate (75%) with conventional posterior wiring, even when this was supplemented with halo bracing.