Distraction Osteogenesis for Unicoronal Craniosynostosis Results in Decreased Rates of Postoperative Strabismus

Background: Traditional fronto-orbital advancement (FOA) is the standard of care for patients with isolated unicoronal craniosynostosis (UCS), however it is associated with significant intraoperative blood loss and high rates of strabismus, both of which have been shown to be lessened by fronto-orbital distraction. This study will describe our current experience with distraction osteogenesis (DO) in the treatment of UCS with regards to perioperative morbidity and the resultant development of new-onset strabismus (are we sure they didn’t have strabismus preoperatively?). 

Method: All patients undergoing DO for isolated UCS at our institution (13 patients) were examined and compared to the most recent 11 patients undergoing traditional FOA for UCS. Patient age, operative time, blood loss, blood replacement, technical details of the surgery, length of stay (LOS), complications, and the development of new onset strabismus following surgery were documented and compared statistically.

Results: A chi-square analysis and student’s t test with a significance value of .05 was utilized for analysis. Mean follow-up time was 21.7 months in the DO group and 31 months in the FOA group (p=0.32). Patients undergoing DO compared to FOA trended towards being younger (6.3 and 9.1 months, p = 0.05), experienced significantly less operative time for the initial procedure (115 vs 192 minutes, p < 0.01), significantly less blood loss (26 vs. 55 % of total blood volume, p < 0.05), and significantly less blood replacement (40 vs. 63 % of total blood volume, p < 0.05). DO also trended towards a decreased LOS (3.1 and 4.5 days, p = 0.10). The mean age of distractor removal was 8.9 months with a mean operative time of 32 minutes, blood loss of 18cc, and length of stay of 24 hours. The mean distance distracted was 36mm. One patient in the DO group experienced a new-onset strabismus postoperatively compared with 5 in the FOA group (p < 0.05). There were no complications requiring a return to the operating room in either group.

Conclusion: DO for the treatment of isolated UCS provides a favorable perioperative morbidity profile and decreased incidence of post-operative strabismus compared with traditional FOA. These positive factors are tempered by the need for an additional procedure for removal of the device and lack of long-term follow-up data on the stability of the advancement. Further investigation is warranted on both of these fronts.