Introduction Direct anterior screw fixation of the dens preserves C1-C2 rotation, and the reported fusion rates range from 88% to 100%.
Step 1: Positioning of the Patient Exact positioning of the patient and use of image intensifiers are mandatory to obtain perfect anteroposterior and lateral views of the axis.
Step 2: Surgical Approach The surgical approach is standardized, and the pretracheal layer can be exposed without violating any essential anatomic structures.
Step 3: Entry Point of the Screw The perfect entry point is directly anterior-inferior at the base of C2; therefore, the anterior rim of the C2-C3 intervertebral disc must be penetrated.
Step 4: Screw Insertion We use a single cannulated screw in most cases: insert the screw in the center of the dens with its tip perforating the cranial, cortical bone of the dens just posterior to the apex.
Step 5: Wound Closure Precise and anatomic closure of the platysma determines the quality of the scar that will be visible after the operation.
Step 6: Follow-up The patient wears a rigid collar for six weeks, removing it for body care; radiographic evaluations should be performed regularly.
Results In a study of sixty-nine patients with a fracture of the dens, three of the thirteen patients who underwent direct anterior screw fixation had persistent instability and nonunion of the dens four months after surgery.
Pitfalls & Challenges
Direct anterior screw fixation of the dens preserves C1-C2 rotation, and the reported fusion rates range from 88% to 100%1, 2.
Appropriate patient selection is essential to the success of the technique; only Anderson and D’Alonzo3 type-II fractures are suitable for direct anterior screw fixation. Positioning the patient in a way that reduces the fracture and opens the corridor above the sternum is a key point for this …
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