Predictability in orbital reconstruction: A human cadaver study. Part II: Navigation-assisted orbital reconstruction

Abstract

Preformed orbital reconstruction plates are useful for treating orbital defects. However, intraoperative errors can lead to misplaced implants and poor outcomes. Navigation-assisted surgery may help optimize orbital reconstruction. We aimed to explore whether navigation-assisted surgery is more predictable than traditional orbital reconstruction for optimal implant placement. Pre-injury computed tomography scans were obtained for 10 cadaver heads (20 orbits). Complex orbital fractures (Class III-IV) were created in all orbits, which were reconstructed using a transconjunctival approach with and without navigation. The best possible fit of the stereolithographic file of a preformed orbital mesh plate was used as the optimal position for reconstruction. The accuracy of the implant positions was evaluated using iPlan software. The consistency of orbital reconstruction was lower in the traditional reconstructions than in the navigation group in the parameters of translation and rotation. Implant position also differed significantly in the parameters of translation (p = 0.002) and rotation (pitch: p = 0.77; yaw: p < 0.001; roll: p = 0.001). Compared with traditional orbital reconstruction, navigation-assisted reconstruction provides more predictable anatomical reconstruction of complex orbital defects and significantly improves orbital implant position.

Feasibility of Single Folded Unsintered Hydroxyapatite Particles/Poly-L-Lactide Composite Sheet in Combined Orbital Floor and Medial Wall Fracture Reconstruction

“…This is because, as discussed in this report, larger and more complicated orbital fractures (types III and IV) with "combined orbital floor and medial wall fractures" are highly complex with regard to anatomy, surgical technique, and ophthalmology and require special consideration of both contour and biocompatibility [10][11][12][13][14]16) . In this respect, a single u-HA/PLLA sheet was then fabricated, shaped, and prepared by folding, achieving an optimal angle between the orbital floor and medial walls using computer-assisted 3D morphological individual customization.…”

“…Computer-assisted surgery (CAS) can improve outcomes in complicated maxillofacial trauma surgeries 11,16,18) . The use of 3D CT imaging reconstruction and virtual planning provides accurate and individualized assessment for the restoration of orbital walls, orbital volume, and orbital fractures with bony defects as reported here 11,16,18) .…”

“…The use of 3D CT imaging reconstruction and virtual planning provides accurate and individualized assessment for the restoration of orbital walls, orbital volume, and orbital fractures with bony defects as reported here 11,16,18) . Proper implant sizing and shaping is critical to the success of this technique.…”

“…Proper implant sizing and shaping is critical to the success of this technique. Given the relatively large surface area of the implant, the rigidity of the material, and the close proximity of the implant to vital orbital structures, seemingly small deviations in contour and shape can result in significant complications 11,16,18,19) .…”

“…Additionally, 3D intraoperative final positioning of the implant on stable ledges of bone is critical, as no implant (no matter how well designed or shaped) will function properly if not placed in an anatomically correct position 11,16,18,19) .…”