Correction of Complex Neurofibromatosis Orbital and Globe Malposition Using the Orbital Box Segmentation Osteotomy With Patient-Specific Internal Orbit Reconstruction.

ABSTRACT

INTRODUCTION: Correction of severe orbital and globe malposition from neurofibromatosis remains a significant clinical challenge. Current techniques including zygoma osteotomy, bone grafting, or placement of orbital implants do not adequately address aberrant anatomy, under-correct the deformity, and are prone to relapse. The authors have developed the orbital box segmentation osteotomy to reduce vertical orbital height and translocate the orbit and use patient-specific custom internal orbital titanium implants to close the cranio-orbital communication-reestablishing both the external orbital shape and internal orbital volume. METHODS: Virtual surgical planning with contralateral mirror imaging was used to design symmetrical repositioning of the external orbit and to determine segmentation required to reduce the vertical excess and inferior rim malposition as well as for manufacturing patient-specific titanium implants. Orbital volume was measured from preoperative, virtual surgical simulation, and postoperative imaging using stereotactic software. Globe position was assessed using pre- and postoperative 3-dimensional photography software (Canfield). RESULTS: All patients (n = 3, mean age 12 years) demonstrated improved globe position and orbital contour with resolution of globe pulsatility. Virtual surgical planning predicted postoperative volumes within 0.8 cm ±â€Š0.5. Mean volume orbital change was 4.5 cm, change in conformation and distribution of orbital volume was present in all patients. Vertical globe position improved from 11.5 mm preoperatively to within 1 mm of the unaffected side postoperatively. One patient had surgical site infection, there is no evidence of relapse at mean 24-months follow-up. CONCLUSION: Segmental box osteotomy with internal orbital reconstruction redistributes orbital volume safely and accurately addresses globe malposition from neurofibromatosis.