G. Graziano et al., A COMPARATIVE-STUDY OF FIXATION TECHNIQUES FOR TYPE-II FRACTURES OF THE ODONTOID PROCESS, Spine (Philadelphia, Pa. 1976), 18(16), 1993, pp. 2383-2387
Primary screw fixation of a Type II odontoid fracture or non-union is
an attractive alternative to posterior atlanto-axial arthrodesis in th
at normal cervical motion can be maintained. Eight cervical cadaver sp
ines, ranging in age from 17-90 years, were used for study. Type II fr
actures of the dens were created using an osteotome. Simulated fractur
es were fixed using one or two 3.5-mm bone screws. After testing each
screw fixation technique, the screws were removed and a posterior C1-C
2 brooks sublaminar wiring was performed using four 18-gauge wires wit
h wooden blocks to simulate bone graft. No significant differences wer
e found between bending and torsional stiffnesses for the one-screw an
d two-screw specimens. No significant differences were found between o
ne- and two-screw fixation when compared with primary C1-C2 wiring in
torsion. One- or two-screw fixation was as stiff as primary C1-C2 wiri
ng in bending. One or two screws offers similar stability for fixation
for a dens fracture. One- and two-screw fixation is at least as stiff
as primary C1-C2 wiring in torsion and one- or two-screw fixation is
stiffer than primary C1-C2 wiring in bending.