Pediatric atlantoaxial instability: management with screw fixation

Sixteen pediatric patients (age range 3-15 years; mean 9.4 years) with atlantoaxial instability underwent screw fixation at Columbus Children's Hospital between 1992 and 1998. Three patients with type II odontoid fractures underwent odontoid screw fixation. The remaining group of 13 patients had posterior C1-2 transarticular screw fixation and Sonntag C1-2 fusion. The group included 3 patients with rotatory C1-2 fixation, 4 patients with os odontoideum, 4 patients with congenital atlantoaxial instability and 2 patients with traumatic C1-2 instability. Postoperatively, all patients were placed in a Miami-J collar only. At 3 months follow-up, all patients achieved fusion. Bony fusion across the fracture line was clearly evident in patients with odontoid screws. The only complications in this series were a transient swallowing difficulty that resolved spontaneously in 2 weeks, and another patient's C1-2 fusion had extended to C2-3 at 9 months follow-up. This study demonstrates that children at 3 years of age and older, who sustain a type II odontoid fracture with an intact transverse ligament, can be safely managed with odontoid screws if the fracture is less than 4 weeks old. Posterior C1-2 transarticular screw fixation can be done safely and results in a high fusion rate in children older than 4 years of age. The technical difficulties of screw fixation in children are discussed.