Comparing Pre-adaptation of In-stock Mesh Over In-house 3D Patient Specific Model to Reconstruct Unilateral Primary Orbital Fracture With and Without Intraoperative Navigation vs Conventional Intraoperative Free-hand Mesh Bending

• 3D printed patient specific model (Procedure): An in-house three-dimensional patient-specific model is produced from preoperative computed tomography imaging to assist surgical planning for unilateral orbital fracture reconstruction. The model depicts the orbital defect and the surrounding available bony ledges, allowing direct visualization of the defect boundaries and identification of the bony support that the mesh must reach and rest upon. This distinguishes the model from models that reproduce only the intended reconstructed orbital contour. Before surgery, an available stock mesh is shaped using the model to achieve the planned orbital contour and adequate coverage of the defect, extending to the identified bony ledges. During surgery, the pre-adapted mesh is placed to reconstruct the orbital defect, with adjustments as required to achieve an appropriate fit and support.
• Conventional (Procedure): intraoperative visualization of orbital defect, freehand shaping and bending of available mesh
• Brainlab navigation system (Device), also known as Intraoperative navigator: intraoperative quality control check using navigation as an additive step to identify surrounding boney ledges for better accuracy of the pre-adapted mesh position

Primary outcomes

• accuracy of restoration of orbital volume [immediate postoperatively]: preoperative and postoperative assessment in the difference between the volume of the fractured orbit and the unaffected contralateral orbit, measured using computed tomography. Orbital volume discrepancy is expressed in cubic centimetres. A reduction in the magnitude of the discrepancy indicates closer restoration to the orbit.

Secondary outcomes

• Operative time [intraoperative]: Duration of mesh insertion in minutes, using the same defined start and end points in both groups.
• Sequence of clinical outcome (Enophthalmos, Diplopia, Limited ocular motility) [preoperatively and 1,3,6 months postoperatively]: Difference in globe projection between the affected and unaffected eyes, measured in millimetres using the hertles exophthalmometer. Diplopia and ocular motility by examination
• Mesh position [radiologically: immediate, Clinically: 1,3 and 6 months postoperatively]: Assessed radiologically by fusing postoperative CT over preoperative plan, and clinically by assessment of any palpable mesh or screws

Sex: All, ages: 18 Years to 55 Years

Inclusion Criteria:

* Fracture orbital wall:
* Timing: Recent (<3 weeks from trauma) Age: 18-55 years Sex: Both

Clinical Findings:

± Globe malposition, Enophthalmos ≥ 2 mm or Diplopia CT Findings

* Fracture Pattern: unilateral fractures medial wall or floor of the orbit.
* Defect Size critical sized defects proved by CT

  * Herniation of soft tissue, and/or muscle entrapment.
  * associated non-comminuted zygomatic fracture.

Exclusion Criteria:

* Timing Delayed (> 3 weeks from trauma)
* Pattern : Bilateral orbital fractures
* Associated with Comminuted zygomatic fracture or pan-facial fracture Ocular Manifestations
* Patients with ruptured globe or associated soft tissue injury Associated conditions
* Other life-threatening condition
* Presence of systemic diseases affecting the globe position (e.g Hyperthyroidism, Horner's syndrome)
* Presence of craniofacial anomalies and Facial asymmetries.
* History of other old facial fractures Patients refusing surgery or implant.

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