Accuracy of intraoperative navigation for orbital fracture repair: A retrospective morphometric analysis

In this retrospective case series, patients undergoing surgery to treat isolated orbital floor fractures were morphometrically analyzed. Cloud Compare was used to compare mesh positioning with a virtual plan, using the distance-to-nearest-neighbor method. To assess the accuracy of mesh positioning, a mesh area percentage (MAP) parameter was introduced and three distance ranges were defined as the outcome measures: the ‘high-accuracy range’ included MAPs at a distance of 0–1 mm from the preoperative plan; the ‘intermediate-accuracy range’ included MAPs at a distance of 1.1–2 mm from the preoperative plan; the ‘low-accuracy range’ included MAPs at a distance of >2 mm from the preoperative plan. To complete the study, morphometric analysis of the results was combined with clinical judgment (‘excellent’, ‘good’, or ‘poor’) of mesh positioning by two independent blind observers. In total, 73 of 137 orbital fractures met the inclusion criteria. In the ‘high-accuracy range’ the mean, minimum, and maximum MAP values were 64%, 22%, and 90%, respectively. In the ‘intermediate-accuracy range’, the mean, minimum, and maximum values were 24%, 10%, and 42%, respectively. In the ‘low-accuracy range’, the values were 12%, 1%, and 48%, respectively. Both observers classified 24 cases of mesh positioning as ‘excellent’, 34 as ‘good’, and 12 as ‘poor’. Within the limitations of the study, it seems that virtual surgical planning and intraoperative navigation has the potential to add quality to the repair of the orbital floor and, therefore, should be taken into consideration whenever appropriate.