Long-term growth and alignment after occipitocervical and atlantoaxial fusion with rigid internal fixation in young children

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>The long-term consequences of atlantoaxial (AA) and occipitocervical (OC) fusion and instrumentation in young children are unknown. Anecdotal reports have raised concerns regarding altered growth and alignment of the cervical spine after surgical intervention. The purpose of this study was to determine the long-term effects of these surgeries on the growth and alignment of the maturing spine.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>A multiinstitutional retrospective chart review was conducted for patients less than or equal to 6 years of age who underwent OC or AA fusion with rigid instrumentation at 9 participating centers. All patients had at least 3 years of clinical and radiographic follow-up data and radiographically confirmed fusion. Preoperative, immediate postoperative, and most recent follow-up radiographs and/or CT scans were evaluated to assess changes in spinal growth and alignment.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Forty children (9 who underwent AA fusion and 31 who underwent OC fusion) were included in the study (mean follow-up duration 56 months). The mean vertical growth over the fused levels in the AA fusion patients represented 30% of the growth of the cervical spine (range 10%–50%). Three different vertical growth patterns of the fusion construct developed among the 31 OC fusion patients during the follow-up period: 1) 16 patients had substantial growth (13%–46% of the total growth of the cervical spine); 2) 9 patients had no meaningful growth; and 3) 6 patients, most of whom presented with a distracted atlantooccipital dislocation, had a decrease in the height of the fused levels (range 7–23 mm). Regarding spinal alignment, 85% (34/40) of the patients had good alignment at follow-up, with straight or mildly lordotic cervical curvatures. In 1 AA fusion patient (11%) and 5 OC fusion patients (16%), we observed new hyperlordosis (range 43°–62°). There were no cases of new kyphosis or swan-neck deformity, evidence of subaxial instability, or unintended subaxial fusion. No preoperative predictors of these growth patterns or alignment were evident.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>These results demonstrate that most young children undergoing AA and OC fusion with rigid internal fixation continue to have good cervical alignment and continued growth within the fused levels during a prolonged follow-up period. However, some variability in vertical growth and alignment exists, highlighting the need to continue close long-term follow-up.</jats:p></jats:sec>

Traumatic Occipitocervical Distraction Injuries in Children: A Systematic Review

“…Eighteen patients (21%) from 1 study underwent a combined OC wiring and screw-rod construct [12]. Fourteen (16%) from 2 studies underwent an unspecified form of OC screw-rod construct, including occipital screws and C1–2 transarticular instrumentation, C1 lateral mass and C2 pars screws, and occipital and C2 pars screws alone [13]. Seven patients (8%) underwent an OCF with C1–2 transarticular screw placement only.…”

Radiographic Outcomes of Upper Cervical Fusion for Pediatric Patients Younger Than 10 Years

“…Regarding cervical alignment, a previous study demonstrated that most young children undergoing upper cervical fusion continue to have good alignment and continued growth within the fused levels after surgery 24) . In the present study, O-C2 and C2-7 angles were maintained and C2-7 ROM was surprisingly increased at final follow-up, which might be a result of the specific population of syndromic patients with ligamentous laxity.…”

Pediatric Craniovertebral Junction Surgery

“…The fusion rate is reportedly as high as 95% and long-term follow up revealed preserved cervical lordosis in 85% of young children who underwent CVJ rigid internal fixation. 27,32) Interestingly, even after rigid internal fixation, the fixed occipitocervical and atlantoaxial distances increase in close to half and nearly all children treated, respectively. 32) …”

“…27,32) Interestingly, even after rigid internal fixation, the fixed occipitocervical and atlantoaxial distances increase in close to half and nearly all children treated, respectively. 32) …”