Does intraoperative navigation restore orbital dimensions in traumatic and post-ablative defects?

Background: The outcomes of the reconstruction of post-ablative and post-traumatic orbital defects are often unpredictable when considering the restoration of the orbital dimensions. Intraoperative navigation offers the surgeon visualization of bony landmarks via comparison to preoperative computed tomography, aiding in bony reduction and implant placement. The purpose of this study was to assess whether intraoperative navigation-guided orbital reconstruction re-establishes orbital volume and globe projection in subjects with post-ablative and post-traumatic orbital defects. Material and methods: The investigators initiated a retrospective cohort study and enrolled a sample of subjects that underwent primary or secondary reconstruction for unilateral orbital deformities secondary to traumatic injury or tumour surgery. Pre- and post-operative orbital volume and globe projection were measured using Analyze (Mayo Clinic Biomedical Imaging Resource, Rochester, MN, USA). A matched pairs t-test was used to assess the difference in pre- and post-operative orbital volume and globe projection. Results: Twenty-three subjects underwent intraoperative navigation-guided orbital reconstruction. The mean difference in orbital volume and globe projection between the non-operated orbit and operated orbit in the post-operative period was -1.3 cm ³ and 2.4 mm respectively. Both final measurements were within the margin of error of clinically noticeable enophthalmos. The mean absolute difference in orbital volume and globe projection between the pre- and post-operative period was 5.1 cm ³ (p = <0.001) and 4.1 mm (p = <0.001) respectively. Conclusion: The results of this study suggest that orbital reconstruction using intraoperative navigation is effective in establishing normal orbital volume and globe projection in post-traumatic and post-ablative defects, therefore restoring the orbit and globe to pre-traumatic and pre-ablative conditions.