Atlanto-Axial Dislocation Surgery in Infants: Age and Size Parameters
Direct Answer
The youngest infant to undergo surgery for atlanto-axial or atlanto-occipital dislocation documented in the available evidence was 13 months old, weighing approximately infant size (specific weight not documented), who underwent successful occiput-C2 and C6-7 instrumented fusion in 2024. 1
Historical Context and Age Range
The literature on pediatric atlanto-occipital and atlanto-axial dislocation surgery demonstrates that:
Infants as young as newborns have been included in surgical case series, though specific operative details for the youngest patients are limited. A comprehensive series from 1991-2011 included patients "ranging in age from newborn to sixteen years old" who underwent posterior occipitocervical fusion with internal fixation. 2
The 13-month-old case from 2024 represents the most detailed technical description of instrumented fusion in an infant of this age, using occipital keel and C2 pedicle screws with sublaminar C1 polyester tape for occiput-C2 stabilization. 1
A 5-year-old child survived traumatic atlanto-occipital dislocation with posterior occipitoatlantoaxial fusion in 1980, representing one of the earliest documented survivals with surgical intervention. 3
Technical Considerations for Infant Surgery
Posterior instrumented fusion is technically feasible in infants despite significant anatomical challenges, including smaller bone dimensions and incomplete ossification. 1
Key technical adaptations for infant surgery include:
- Occipital keel fixation with C2 pedicle screws provides adequate purchase in small anatomy 1
- Sublaminar polyester tape at C1 can be used when screw fixation is not feasible 1
- Laminar hooks may be employed for subaxial fixation in very small patients 1
- Halo immobilization is critical for postoperative stabilization in infants 1, 2
Outcome Data
Survival and neurological outcomes in pediatric atlanto-occipital dislocation show:
- 34% mortality rate 4
- 41% survive with neurological deficits 4
- 25% achieve complete neurological recovery 4
- All patients in the largest pediatric series achieved spinal fusion by 4-6 months postoperatively 2
Critical Pitfalls
Hydrocephalus is the most common postoperative complication, occurring in approximately 29% of pediatric patients (4 of 14 in the largest series), and should be suspected if neurological decline occurs after spinal fixation. 2
Associated injuries are nearly universal, with brain injury occurring in 79% of patients (11 of 14) and spinal cord injury in approximately half, requiring comprehensive trauma evaluation beyond the spinal injury. 2
Anterior column stabilization may be deferred in infants when posterior stabilization with halo placement is achieved, particularly if complications such as CSF leak are present. 1