Structural Allograft versus Autograft for Instrumented Atlantoaxial Fusions in Pediatric Patients: Radiologic and Clinical Outcomes in Series of 32 Patients

BACKGROUND: Allograft with wire techniques showed a low fusion rate in pediatric atlantoaxial fusions (AAFs) in early studies. Using allograft in pediatric AAFs with screw/rod constructs has not been reported. Thus we compared the fusion rate and clinical outcomes in pediatric patients who underwent AAFs with screw/rod constructs using either a structural autograft or allograft. METHODS: Pediatric patients (aged <= 12 years) who underwent AAFs between 2007 and 2015 were retrospectively evaluated. Patients were divided into 2 groups (allograft or autograft). Clinical and radiographic results were collected from hospital records and compared. RESULTS: A total of 32 patients were included (18 allograft, 14 autograft). There were no significant group differences in age, sex, weight, diagnosis, or duration of follow-up. A similar fusion rate was achieved (allograft: 94%, 17/18; autograft: 100%, 14/14); however, the average fusion time was 3 months longer in the allograft group. Blood loss was significantly lower in the allograft group (68 +/- 8.5 mL) than the autograft group (116 +/- 12.5 mL). Operating time and length of hospitalization were slightly (nonsignificantly) shorter for the allograft group. A significantly higher overall incidence of surgery-related complications was seen in the autograft group, including a 16.7% (2/14) rate of donor-site-related complications. CONCLUSIONS: The use of allograft for AAF was safe and efficacious when combined with rigid screw/rod constructs in pediatric patients, with a similar fusion rate to autografts and an acceptable complication rate. Furthermore, blood loss was less when using allograft and donor-site morbidity was eliminated; however, the fusion time was increased.