STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The aim of this study was to compare the @entity1347 ( @entity1347 ) with a guide tube or with a straight probe. SUMMARY OF BACKGROUND DATA: @entity1347 associates with several complications, including malpositioning, fixation loss, and screw breakage. Screw pull-out from the C2 body is the most common complication. METHODS: All consecutive @entity1 with type II or rostral shallow type III odontoid @entity174 who underwent AOSFs during the study period were enrolled retrospectively. The guide-tube @entity1347 method followed the standard published method except C3 body and C2-3 disc annulus rimming was omitted to prevent @entity130 ; instead, the guide tube was anchored at the @entity1605 . After 2 screw pull-outs, the guide-tube cohort was analyzed to identify the cause of instrument failure. Thereafter, the straight-probe method was developed. A guide tube was not used. A small pilot hole was made on the most anterior side of the inferior endplate, followed by insertion of a 2.5mm straight probe through the C2 body. Non-union and instrument failure rates and screw-direction angles of the guide-tube and straight-probe groups were recorded. RESULTS: The guide-tube group (n=13) had 2 screw pull-outs and 1 non-union. The straight-probe group (n=8) had no complications and significantly larger screw-direction angles than the guide-tube group (60.5  4.63 vs. 54.8  3.82 degrees; P=0.047). CONCLUSION: Straight-probe @entity1347 yielded larger direction angles without injuring bone and disc. Complications were absent. The procedure was easier than guide-tube @entity1347 and assured sufficient engagement, even in horizontal @entity174 orientation cases. LEVEL OF EVIDENCE: 3.

Advantages of Direct Insertion of a Straight Probe Without a Guide Tube During Anterior Odontoid Screw Fixation of Odontoid XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity1605 :: ('OMIM:217000', 'Disease') :: ['anterior inferior C2 vertebra corner'] @entity174 :: ('MESH:D050723', 'Disease') :: ['fractures', 'fracture'] @entity1347 :: ('MESH:C537775', 'Disease') :: ['AOSF', 'anterior odontoid screw fixation'] @entity130 :: ('MESH:D014947', 'Disease') :: ['disc injury']
@entity174 :: (MESH:D050723,Disease) :: ['Fractures']
