Consolidation Time and Relapse: A Systematic Review of Outcomes in Internal Versus External Midface Distraction for Syndromic Craniosynostosis.

A. A. Bertrand
K. J. Lipman
J. P. Bradley, Zucker School of Medicine at Hofstra/Northwell
J. Reidhead
J. C. Lee


BACKGROUND:The choice between internal versus external distraction osteogenesis for midface advancement in patients with syndromic craniosynostosis is primarily based on surgeon preference and expertise. However, differences in outcomes between the two techniques have been sparingly compared. In this work, we performed a systematic review to compare outcomes between internal versus external midface distraction. METHODS:A systematic review was performed of studies published between 1998 and 2018 (61 studies included, n=689 patients). Operative characteristics, early reoperations, complications, and relapse rates were extracted. Bias evaluation was performed using the Newcastle-Ottawa instrument. Statistical analyses were performed with independent samples t tests and linear regression analyses (p<0.05 considered significant). RESULTS:We found that external distraction was associated with more Le Fort III osteotomies and hardware adjustments (p=0.023), whereas internal distraction was associated with more monobloc osteotomies and longer consolidation times (p=0.008). No significant differences in the distance of midface advancement, reoperations, complications, or relapse rates were noted between internal versus external distraction, although external distraction trended towards a slightly higher relapse rate. Regardless of distraction protocol, consolidation time was found to be a strong negative predictor for relapse (beta=-0.792, p=0.02). CONCLUSIONS:Internal and external distraction for midface advancement do not demonstrate significant differences in advancement distance, reoperative rates, complication rates, or relapse rates. Regardless of distraction type, consolidation time was strongly inversely associated with relapse rates. The trend towards higher relapse in external distraction is potentially explained by the significantly lower consolidation times.