Secondary Suture Craniosynostoses following Spring-assisted Cranioplasty for Sagittal Synostosis: An Underrecognized,but Clinically Significant Phenomenon

Abstract

Background and purpose:

Spring-assisted cranioplasty has been established as an effective technique for minimally invasive correction of single suture sagittal craniosynostosis. However, the potential for secondary suture synostosis following spring placement remains unclear. This case series represents our institutional experience with spring-assisted cranioplasty and highlights 5 patients with progression to secondary suture craniosynostosis necessitating surgical intervention following initial spring placement.

Method and description:

IRB-approved data from all patients undergoing spring-assisted cranioplasty for sagittal craniosynostosis (2021-2025) were retrospectively reviewed.

Results:

Fifty-five patients over the 4-year interval underwent spring-assisted cranioplasty. Fifty-four patients presented with a diagnosis of single suture sagittal craniosynostosis, while one patient had sagittal and unilateral lambdoid craniosynostosis. All patients had 2 springs placed except for the one with concomitant lambdoid synostosis, who received a third. Mean age at spring placement was 3.7 months with a mean interval to removal of 3.8 months. The average operative duration was 80.3 minutes, and the mean length of stay was 1.5 days. Eighteen (32.7%) of patients had an intensive care unit stay and 14 (25.5%) of patients required a blood transfusion. Nine of the 55 patients required an unplanned secondary procedure. Two patients experienced hardware migration with the need for operative adjustment/replacement. Six patients (10.9%) necessitated subsequent CVR: 4 due to the development of secondary unicoronal synostosis and 2 due to inadequate expansions and residual cranial deformities. One patient developed bilateral coronal and right lambdoid synostosis and subsequently underwent suturectomy and helmet therapy.

Conclusion:

This series highlights the observation of secondary suture craniosynostosis following spring-assisted cranioplasty for sagittal synostosis. Whether the progression is a direct sequelae of underlying spring force mechanics/provider placement or a reflection of natural synostotic evolution remains uncertain. Its clinical significance warrants further investigation and discussion within the broader craniofacial surgical community.