The Negative Impact of External Activation Ports on Cranial Distraction: Systematic Review of the Literature and Proportional Meta-Analysis

ObjectivesWe aimed to quantify the prevalence of perioperative complications attributable to external activation ports in pediatric posterior cranial vault distraction osteogenesis (PCVDO) and to evaluate the influence of distraction protocol parameters on complication risk.MethodsFollowing PRISMA 2020 guidelines, six databases (2009-2025) were searched for studies reporting complications in children (<18 years) undergoing PCVDO.ResultsAcross 25 eligible studies, 154 adverse events were reported, yielding a pooled overall complication rate of 28.1%. Wound infection was most common (13.7%), followed by broken external activation ports (4.5%) and loosened footplates (3.1%). Mechanical failures accounted for 35.7% of all adverse events and frequently necessitated unplanned surgical intervention: 40% required intraoperative adjustment or premature removal of the distraction system. Each additional day of active distraction increased the risk of footplate loosening by 17%, while each additional day of consolidation increased the risk of breakage of the external activation ports by 1%, indicating cumulative mechanical stress on the distraction. External activation ports were associated with an elevated risk of wound infection, mechanical failure, and unplanned return to the operating room in pediatric PCVDO. The mechanical analyses demonstrated that off-axis loading, torque transmission through skin exits, and cumulative cyclic forces during prolonged distraction and consolidation phases could negatively impact device stability and vector fidelity.ConclusionsThese findings highlight the inherent mechanical limitations of externalized subcutaneous craniofacial distraction systems and underscore the need for next-generation, fully internalized, external port-free distraction technologies that optimize biomechanical alignment, reduce soft-tissue morbidity, and enhance clinical reliability.