Comparison of the Outcomes of Complex Orbital Fracture Repair with and without a Surgical Navigation System: A Prospective Cohort Study with Historical Controls

Does Integration of Technology and Customization of Implants Produce Better Outcomes in Post-Traumatic Orbital Reconstruction? A Systematic Review and Meta-Analysis

PURPOSE

This review aims to compare and evaluate the outcomes achieved by integrating technological aids and the influence of different implant designs in the reconstruction of post-traumatic orbital defects.

METHODS

Electronic searches of the MEDLINE, Embase, Cochrane Library, and Google Scholar databases until March 2023 were conducted. Clinical controlled trials, observational studies, cohort studies, and retrospective studies were identified and included. The predictor variables were the integration of technological aids namely, computer-assisted surgical planning, mirror image overlay, and intraoperative navigation with the utilization of different orbital implant designs (standard orbital meshes, preformed implants, prebent implants, and patient-specific implant [PSI]) during post-traumatic orbital reconstruction. The primary outcome variables were orbital volume, diplopia, and enophthalmos. Weighted or mean difference and risk ratios at 95% confidence intervals were calculated, where P ＜ .05 was considered significant and a random effects model was adopted.

RESULTS

This review included 7 studies with 560 participants. The results indicate that the difference in postoperative orbital volume between affected and nonaffected eye showed no statistically significant difference between PSI and prebent group (mean difference, -0.41 P = .28, I2 = 46%). PSI group resulted in diplopia 0.71-fold less than that of the standard orbital mesh group but was not statistically significant (P = .15). Standard orbital mesh group is 0.30 times at higher risk of developing enophthalmos as compared to PSI group (P = .010). The literature suggests PSIs are preferred for patients with large defects (Jaquiéry's III-IV), whereas prebent implants are equally effective as PSIs in patients with preserved infraorbital buttress and retrobulbar bulge.

CONCLUSION

PSIs are associated with improved outcomes, especially for correcting enophthalmos. The data suggests the potential efficacy of prebent implants and PSIs in orbital volume corrections. There is a lack of randomized studies. This review should serve as a recommendation for further studies to contribute to the existing literature.

Intraoperative Image Guidance in Orbital and Lacrimal Surgery: A Report by the American Academy of Ophthalmology

PURPOSE

To review the efficacy and safety of the use of intraoperative image guidance (IIG) in orbital and lacrimal surgery.

METHODS

A literature search of the PubMed database was last conducted in November 2023 for English-language original research that assessed the use of any image guidance system in orbital and lacrimal surgery that included at least 5 patients. The search identified 524 articles; 94 were selected for full-text analysis by the panel. A total of 32 studies met inclusion criteria. The panel methodologist assigned a level II rating to 2 studies and a level III rating to 30 studies. No study met the criteria for level I evidence.

RESULTS

Procedures reported on were as follows: fracture repair (n = 14), neoplasm and infiltrate biopsy or excision (n = 6), orbital decompression for Graves ophthalmopathy (n = 3), dacryocystorhinostomy (n = 1), and mixed etiology and procedures (n = 8). Four studies used more than one IIG system. One study that met level II evidence criteria compared the outcomes of orbital fracture repair with IIG (n = 29) and without IIG (n = 29). Borderline better outcomes were reported in the IIG group: 2% versus 10% with diplopia (P = 0.039) and 3% versus 10% with enophthalmos (P = 0.065). The other level II study compared the repair of fractures with navigation (n = 20) and without (n = 20). The group in which navigation was used had a measured mean volume reduction of 3.82 cm3 compared with 3.33 cm3 (P = 0.02), and there was a greater measured reduction in enophthalmos in the navigation group of 0.72 mm (P = 0.001). Although the remaining 30 assessed articles failed to meet level II criteria, all alleged a benefit from IIG. No complications were reported.

CONCLUSIONS

A small number of comparative studies suggest that there are improved outcomes when IIG is used in orbital fracture repair, but each study suffers from various limitations. No high-quality comparative studies exist for the management of lacrimal surgery, neoplastic disease, or decompression. Complications attributable to the use of IIG have not been identified, and IIG has not been analyzed for cost savings.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

A retrospective analysis of the management and surgical treatment of orbital lesions: Outcomes and rationale

The orbital cavity is a subject of interest for various specialists, and achieving optimal outcomes requires comprehensive, multidisciplinary management. This study aims to report 10 years of experience in the preoperative, surgical, and postoperative care of patients with orbital lesions, examining their clinical, radiological, and anatomopathological features and outcomes. A retrospective review of 125 patients who underwent surgical treatment for intraorbital masses between January 2012 and December 2021 was performed. Outcome measures included postoperative diplopia, exophthalmos, decimal visual acuity, eyeball position, ocular motility, operative time, complications, and aesthetic results. A total of 107 patients were included. All cases were discussed with a neuroradiologist to determine the best therapeutic approach based on preoperative imaging. Preoperative diplopia was linked to extraconal (p = 0.03) and anterior (p = 0.001) lesions, and exophthalmos and visual acuity deterioration were associated with intraconal (p = 0.02; p = 0.03) and retrobulbar (p = 0.001; p = 0.02) lesions. Complications (11.2%) included diplopia, worsened visual acuity, postoperative blepharoptosis, and postoperative ectropion. Of the patients, 80.4% reported an "excellent" aesthetic outcome. This study underscores the importance of a multidisciplinary approach based on a thorough analysis of preoperative imaging. Periorbital approaches tailored to the lesion's three-dimensional location enables safe access to most intraorbital lesions, resulting in minimal complications and good aesthetic results.

Accuracy of surgical navigation for patient-specific reconstructions of orbital fractures: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to review the recent literature on the technical accuracy of surgical navigation for patient-specific reconstruction of orbital fractures using a patient-specific implant, and to compare surgical navigation with conventional techniques.

MATERIALS AND METHODS

A systematic literature search was conducted in PubMed (Medline), Embase, Web of Science, and Cochrane (Core Collection) databases on May 16, 2023. Literature comparing surgical navigation with a conventional method using postoperative three-dimensional computed tomography imaging was collected. Only articles that studied at least one of the following outcomes were included: technical accuracy (angular accuracy, linear accuracy, volumetric accuracy, and degree of enophthalmos), preoperative and perioperative times, need for revision, complications, and total cost of the intervention. MINORS criteria were used to evaluate the quality of the articles.

RESULTS

After screening 3733 articles, 696 patients from 27 studies were included. A meta-analysis was conducted to evaluate volumetric accuracy and revision rates. Meta-analysis proved a significant better volumetric accuracy (0.93 cm3 ± 0.47 cm3) when surgical navigation was used compared with conventional surgery (2.17 cm3 ± 1.35 cm3). No meta-analysis of linear accuracy, angular accuracy, or enophthalmos was possible due to methodological heterogeneity. Surgical navigation had a revision rate of 4.9%, which was significantly lower than that of the conventional surgery (17%). Costs were increased when surgical navigation was used.

CONCLUSION

Studies with higher MINORS scores demonstrated enhanced volumetric precision compared with traditional approaches. Surgical navigation has proven effective in reducing revision rates compared to conventional approaches, despite increased costs.

Image-guided navigation in posterior orbital tumour surgery: a comparative cohort study

PURPOSE

The posterior orbit is a confined space, harbouring neurovascular structures, frequently distorted by tumours. Image-guided navigation (IGN) has the potential to allow accurate localisation of these lesions and structures, reducing collateral damage whilst achieving surgical objectives.

METHODS

We assessed the feasibility, effectiveness and safety of using an electromagnetic IGN for posterior orbital tumour surgery via a comparative cohort study. Outcomes from cases performed with IGN were compared with a retrospective cohort of similar cases performed without IGN, presenting a descriptive and statistical comparative analysis.

RESULTS

Both groups were similar in mean age, gender and tumour characteristics. IGN set-up and registration were consistently achieved without significant workflow disruption. In the IGN group, fewer lateral orbitotomies (6.7% IGN, 46% non-IGN), and more transcutaneous lid and transconjunctival incisions (93% IGN, 53% non-IGN) were performed (p = .009). The surgical objective was achieved in 100% of IGN cases, with no need for revision surgery (vs 23% revision surgery in non-IGN, p = .005). There was no statistically significant difference in surgical complications.

CONCLUSION

The use of IGN was feasible and integrated into the orbital surgery workflow to achieve surgical objectives more consistently and allowed the use of minimal access approaches. Future multicentre comparative studies are needed to explore the potential of this technology further.

Patient Specific Implants for Orbital Reconstruction in the Treatment of Silent Sinus Syndrome: Two Case Reports

Silent sinus syndrome is a rare disorder characterized by ipsilateral enophthalmos and hypoglobus following a collapse of the orbital floor, in the presence of asymptomatic long-term maxillary sinusitis. It results in enophthalmos, hypoglobus and deepening of the superior palpebral sulcus. A standardized treatment protocol for this infrequent syndrome has not yet been established. The management includes restoration of maxillary sinus ventilation with functional endoscopic sinus surgery and orbital reconstruction, either concurrently or separately. In this paper, the authors presented two patients successfully treated with patient-specific implants, and intraoperative navigation. These cases highlight the benefit of computer-assisted planning and titanium patient-specific implants in the management of silent sinus syndrome. To the best of our knowledge, this is the first report that described the use of PSI with titanium spacers performed with the aid of intraoperative navigation for SSS treatment. Advantages, drawbacks of this technique and treatment alternatives currently available in the literature were also discussed.

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.

Technical considerations of computer-aided planning in severe orbital trauma: A retrospective study

The aim of this study was to evaluate the clinical outcomes of linear and orbital volume measurements in severe orbital trauma. Patients with severe orbital trauma that involved more than two walls and entailed a marked degree of comminution were included in this retrospective analysis. However, patients with incomplete clinical records and a simple blowout or zygmatico-orbital fractures were excluded. All the cases underwent surgical correction guided by virtual surgical planning and 3D-printed templates. The measurement protocol depended on assessing orbital dimensions, orbital volumetry, and the zygomatic bone's position in the three-dimensional planes. All patients' preoperative 3D CT scans were obtained, and DICOM files were imported into a three-dimensional image processing software. Data were then converted for 3D reconstruction in the axial, coronal, and sagittal views. A total of 18 patients with a mean age was 39.28 ± 6.28 were included in this study. The results revealed a significant difference between the pre and postoperative differences in distances in relation to the FHP (Frankfurt Horizontal Plane) (P = 0.0014) and sagittal planes (P < 0.0001). The orbital width and height of the traumatized orbit were significantly decreased from 45.26 ± 6.72 mm and 45.30 ± 2.89 mm to 39.74 ± 3.91 mm (P = 0.0022), and 40.34 ± 0.86 mm (P < 0.0001), respectively. Clinically, there was a satisfactory degree of symmetry regarding the zygomatic bones' position and orbital dimensions postoperatively. Moreover, the mean orbital volume on the traumatized side decreased significantly from 23.16 ± 1.91 cm³ preoperatively to 20.7 ± 1.96 cm³ postoperatively (P < 0.0001). These findings were associated with a low incidence of complications. Within the limitations of the study it seems that the described methodology is a relevant addition to clinical treatment options. It incorporates all the latest technology to plan virtual reconstruction surgery in the treatment of complex orbital trauma and should be adapted accordingly in cases of severe displacement and comminution.

"6 Anatomical Landmarks" Technique for Satisfactory Free-Hand Orbital Reconstruction With Standard Preformed Titanium Mesh

Study Design

Retrospective study.

Objective

Resolution of clinical signs and symptoms following orbital fractures depends on the accurate restoration of the orbital volume. Computer-Assisted procedures and Patient Specific Implants represent modern solutions, but they require additional resources. A more reproducible option is the use of standard preformed titanium meshes, widely available and cheaper; with their use quality of results is proportional to the accuracy with which they are positioned. This work identifies 6 reproducible and constant anatomical landmarks, as an intraoperative guide for the precise positioning of titanium preformed meshes.

Methods

90 patients treated at the Maxillofacial Surgery Department, Niguarda Trauma Center, Milan, for unilateral orbital reconstruction (January 2012 to December 2018), were studied. In all cases reconstruction was performed respecting the 6 proposed anatomical landmarks. The outcomes analyzed are: post-operative CT adherence to the 6 anatomical markers and symmetry achieved respect to controlateral orbit; number/year of re-interventions and duration of surgery; resolution of clinical defects (at least 12-months follow-up); incidence of complications.

Results

Satisfactory results were obtained in terms of restoration of orbital size, shape and volume. Clinical defects early recovered with a low incidence of complications and re-interventions. Operating times and radiological accuracy have shown a progressive improvement during years of application of this technique.

Conclusions

The proposed "6 anatomical landmarks" is an easy free-hand technique that allows everyone to obtain high levels of reconstructive accuracy and it should be a skill of all surgeons who deal with orbital reconstruction in daily clinical activity.

Is the Mirroring Technology Reliable in the Use of Computer-Aided Design for Orbital Reconstruction? Three-Dimensional Analysis of Asymmetry in the Orbits

BACKGROUND

Reconstruction of the orbital area remains a challenge in many cases. The recently introduced mirroring technology provides surgeons with patient-specific information for accurate orbital reconstruction; its premise is that the three-dimensional anatomy of craniofacial bone is symmetric. The purpose of this study was to verify this premise of the mirroring technology by assessing three-dimensional asymmetry.

METHODS

Facial computed tomographic data of 104 patients were imported into iPlan software. Four reference points (i.e., zygomaticofrontal suture, frontomaxillary suture, infraorbital foramen, and optic canal) were set, and the three-dimensional distances from these points to the anterior nasal spine on the mirroring plane were calculated. In addition, the orbital cavity volume and the three-dimensional distances from point optic canal to the other reference points were calculated for the assessment of the orbit anatomy. Three plastic surgeons performed these processes independently.

RESULTS

No statistically significant difference was found in the three-dimensional distances between anterior nasal spine and the four reference points bilaterally. Also, no statistically significant difference in the three-dimensional distances between the point representing the optic canal and other reference points was detected bilaterally. Orbital cavity volume showed a mild asymmetry, but the discrepancy was acceptable for computer-aided design applications. For all reference points, the maximum value of the 95 percent CI was less than 1.4 mm.

CONCLUSIONS

The three-dimensional location of the orbits and the three-dimensional anatomy of the orbit were symmetric. Thus, the mirroring technology could be a reliable first step in computer-aided design, computer-assisted surgery, and navigation-assisted surgery.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

A Novel Patient-specific Titanium Mesh Implant Design for Reconstruction of Complex Orbital Fracture

Complex orbital fractures, including orbital rims and walls, require precise reconstruction. A titanium-based patient-specific implant (PSI) benefits over other implants when challenged with narrow surgical space and designable implant fixation point.

In Search of Excellence: From a Small Clinical Unit to an Internationally Recognized Center for Orbital Diseases Research and Surgery at the Department of Ophthalmology, Shanghai Ninth People's Hospital, China

ABSTRACT

"Where there is a will, there is a way." It is never easy to make progress and development but with full dedication and firm commitment, many aspirations can still be realized. We would like to share with the readers the story of how we develop our division of orbital diseases and surgery from scratch to strengths over a period of 2 decades at the Department of Ophthalmology of Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China.

A Novel Precise Optical Navigation System for Craniomaxillofacial Surgery Registered With an Occlusal Splint

BACKGROUND

An augmented reality tool allows visual tracking of real anatomical structures and superimposing virtual images, so it can be used for navigation of important structures during surgery.

OBJECTIVES

The authors have developed a new occlusal splint-based optical navigation system for craniomaxillofacial surgery. In this study, the authors aim to measure the accuracy of the system and further analyze the main factors influencing precision.

METHODS

Ten beagle dogs were selected and a three-dimensional model was established through computed tomography scanning, dental model making, and laser scanning, and then registration was performed according to the tooth marking points. The bilateral mandibular osteotomy was performed on Beagle dogs under navigation system based on the occlusal splint. The left side was taken to compare the deviation between the preoperative plan and the surgical results, and the accuracy of distance and angle and the stability of the system were analyzed.

RESULTS

The average position deviation between the preoperative design and intraoperative navigation was: 0.01 ± 0.73 mm on the lateral height of the mandibular ramus, 0.26 ± 0.57 mm on the inner height of the mandibular ramus, and 0.20 ± 0.51 mm on the osteotomy length. The average angle deviation is 0.94° ± 1.38° on the angle between the mandibular osteotomy plane and ramus plane and 0.66° ± 0.97° on the angle of the retained mandibular angle. And most of the data showed good consistency.

CONCLUSIONS

In summary, the accuracy of the system can meet clinical requirements and can be used as a useful tool to improve the accuracy of craniomaxillofacial surgery.

Implant malposition and revision surgery in primary orbital fracture reconstructions

The aim of the study was to assess factors leading to revision surgery and implant position of primary orbital fracture reconstructions. A retrospective cohort included patients who underwent orbital floor and/or medial wall fracture reconstruction for recent trauma. Demographics, fracture type, surgery and implant-related variables, and postoperative implant position were analyzed. The overall revision surgery rate was 6.5% (15 of 232 surgeries). The rate was highest in combined midfacial fractures with rim involvement (14.0%), lower in zygomatico-orbital fractures (8.7%), and lowest in isolated blowout fractures (3.8%). Fracture type, orbital rim fixation and implant malposition predicted revision. The best positioning was achieved with patient-specific milled titanium implants (mtPSI) and resorbable materials, whereas the poorest with preformed three-dimensional titanium plates. Combined midfacial fractures with rim involvement in particular have a high risk for orbital revision surgery. Within the limitations of the present study, mtPSIs should be preferred in the reconstruction of primary orbital fractures if possible.

Surgical instrument to improve implant positioning in orbital reconstruction: a feasibility study

Adequate positioning of an orbital implant during orbital reconstruction surgery is essential for restoration of the pre-traumatised anatomy, but visual appraisal of its position is limited by the keyhole access and protruding soft tissues. A positioning instrument that attaches to the implant was designed to provide feedback outside the orbit. The goal of this study was to evaluate the accuracy of placement with the instrument and compare it with the accuracy of placement by visual appraisal. Ten orbits in five human cadaver heads were reconstructed twice: once using visual appraisal and once using the instrument workflow. No significant improvement was found for the roll (5.8° vs 3.4°, respectively, p=0.16), pitch (2.1° vs 1.5°, p=0.56), or translation (2.9 mm vs 3.3 mm, p=0.77), but the yaw was significantly reduced if the instrument workflow was used (15.3° vs 2.9°, p=0.02). The workflow is associated with low costs and low logistical demands, and may prevent outliers in implant positioning in a clinical setting when intraoperative navigation or patient-specific implants are not available.

A retrospective study to compare the treatment outcomes with and without surgical navigation for fracture of the orbital wall

PURPOSE

To evaluate the outcomes with and without aid of a computer-assisted surgical navigation system (CASNS) for treatment of unilateral orbital wall fracture (OWF).

METHODS

Patients who came to our hospital for repairing unilateral traumatic OWF from 2014 to 2017 were included in this study. The patients were divided into the navigation group who accepted orbital wall reconstruction aided by CASNS and the conventional group. We evaluated the surgical precision in the navigation group by analyzing the difference between actual postoperative computed tomography data and preoperative virtual surgical plan through color order ratios. We also compared the duration of surgery, enophthalmos correction, restoration of orbital volumes, and improvement of clinical symptoms in both groups systemically. Quantitative data were presented as mean ± SD. Significance was determined by the two-sample t-test using SPSS Version 19.0 A p < 0.05 was considered statistically significant.

RESULTS

Seventy patients with unilateral OWF were included in the study cohort. The mean difference between preoperative virtual planning and actual reconstruction outcome was (0.869 ± 0.472) mm, which means the reconstruction result could match the navigation planning accurately. The mean duration of surgery in the navigation group was shorter than it is in the control group, but not significantly. Discrepancies between the reconstructed and unaffected orbital-cavity volume and eyeball projection in the navigation group were significantly less than that in the conventional group. One patient had remnant diplopia and two patients had enophthalmos after surgery in the navigation group; two patients had postoperative diplopia and four patients had postoperative enophthalmos in the conventional group.

CONCLUSION

Compare with the conventional treatment for OWF, the use of CASNS can provide a significantly better surgical precision, greater improvements in orbital-cavity volume and eyeball projection, and better clinical results, without increasing the duration of surgery.

Role of Plain Radiographs in Assessing Appropriate Placement of Orbital Implants for Repair of Floor Fractures

Intraoperative imaging is becoming increasingly common in repair of facial fractures. Many institutions do not have access to intraoperative advanced 3D imaging but have the capability of obtaining plain radiographs intraoperatively. At institutions where advanced 3D imaging is available, scout radiographs are usually obtained prior to a complete scan. These scout images can provide some information about the placement of radiopaque implants before a complete scan is performed. The aim of this study is to examine the correct anatomic positioning of an orbital floor implant using lateral plain radiographs. Titanium orbital fan implants were molded and secured to orbital floor of 14 adult dry skulls (7 males and 7 females). Lateral radiographs were obtained for both the left and the right orbits individually. The antero-posterior angle of inclination that the implant makes relative to the Frankfort horizontal plane was measured, and results were compared in the male versus female radiographs. The mean angle that the implant made with the Frankfort horizontal plane was 20.1±2.4° in the male orbits (95% CI 18.8-21.5°) and 22.6 ± 2.0° in the female orbits (95% CI, 21.4-23.7°). We found no statistically significant differences between the male and female angles (P-value 0.62). For the combined specimens (i.e., 28 sides in 14 skulls), the overall mean angle was 21.4 ± 2.5° (95% CI, 20.4-22.3°). Based on these findings, the angle that the implant makes with the Frankfort horizontal plane on lateral cross-table plain radiographs can be used intraoperatively to assist the surgeon in confirming the appropriate placement of the implant.

Self-Made Rapid Prototyping Technique for Orbital Floor Reconstruction: Showcases for Technical Description

BACKGROUND

Restoring the orbital cavity integrity in orbital floor defects is a challenging issue due to the anatomical complexity of the floor's surface. This is a showcase for technical description of a novel "in house" rapid prototyping protocol aimed to customize implant for orbital floor reconstruction.

METHODS

The authors present 4 cases to show our Computer-aided-design and Computer-aided-manufacturing digital workflow. The system was based on a 3D-printed press that; through a virtually designed mold, was used to conform a patient specific titanium mesh for orbital floor reconstruction.

RESULTS

The merging procedure analysis by iPlan Cranial 3.0 (Brainlab, Munich, Germany) highlighted a 0.71 ± 0.23 mm (P <0.05) discrepancy in a point-to-point superimposition between the digital planned reconstruction and the real in vivo result.

CONCLUSIONS

The authors expect that this technique will reduce operative time and cost however further study and larger series may better define the applicability in everyday surgical practice.

Implant-oriented navigation in orbital reconstruction part II: preclinical cadaver study

In orbital reconstruction, the acquired position of an orbital implant can be evaluated with the aid of intraoperative navigation. Feedback of the navigation system is only obtained after positioning of the implant: the implant's position is not tracked in real time during positioning. The surgeon has to interpret the navigation feedback and translate it to desired adjustments of the implant's position. In a previous study, a real-time implant-oriented navigation approach was introduced and the system's accuracy was evaluated. In this study, this real-time navigation approach was compared to a marker-based navigation approach in a preclinical set-up. Ten cadavers (20 orbital defects) were reconstructed twice, by two surgeons (total: 80 reconstructions). Implant positioning was significantly improved in the real-time implant-oriented approach in terms of roll (2.0° vs. 3.2°, P=0.03), yaw (2.2° vs. 3.4°, P=0.01) and translation (1.3mm vs. 1.8mm, P=0.005). Duration of the real-time navigation procedure was reduced (median 4.5 min vs. 7.5 min). Subjective appreciation of the navigation technique was higher for real-time implant-oriented navigation (mean 7.5 vs. 9.0). Real-time implant-oriented navigation feedback provides real-time, intuitive feedback to the surgeon, which leads to improved implant positioning and shortens duration of the navigation procedure.

Orbital Trauma

The orbit is contained within a complex bony architecture with overlying soft tissue that involves many important anatomical structures. Orbital trauma is a frequent cause of damage to these structures. The authors review the literature on reconstructive techniques focusing on fractures of the orbital rim, orbital roof, orbital floor, medial orbital wall, and naso-orbito-ethmoid complex. A thorough literature review was conducted using PubMed analyzing articles relevant to the subject matter. Various search terms were used to identify articles regarding orbital trauma presentation, diagnosis, management, as well as postoperative complications. Articles were examined by all authors and pertinent information was gleaned for the purpose of generating this review. Orbital trauma can result in a wide variety of complications in form and function. Not all orbital fractures require operative repair. However, bony disruption can cause enophthalmos, hypophthalmos, telecanthus, epiphora, cerebrospinal fluid leaks, orbital hematoma, and even blindness to name a few. Timing of operative repair as well as reconstructive method is dictated by the patient's individual presentation. Successful fracture management requires a detailed understanding of the anatomy and pathophysiology to ensure restoration of the patients' preoperative state. Orbital trauma encompasses a wide variety of mechanisms of injury and resulting fracture patterns. A variety of surgical approaches to the orbit exist as has been discussed allowing the surgeon access to all area of interest. Regardless of the fracture complexity, the principles of atraumatic technique, anatomic reduction, and stable fixation apply in all cases.

Treatment of Zygomatic Complex Fractures with Surgical or Nonsurgical Intervention: A Retrospective Study

Objective:

Evaluate the 1-year treatment outcome of zygomatic complex fractures with surgical or nonsurgical intervention.

Materials and Methods:

One hundred and forty-two consecutive patients with a zygomatic complex fracture were enrolled. Sixty-eight patients underwent surgical intervention and 74 patients nonsurgical intervention. The 1-year examination evaluated cosmetic and functional outcome including malar symmetry, ocular motility, occlusion, mouth opening, neurosensory disturbances, and complications.

Results:

Forty-six patients allocated to surgical intervention responded to the 1-year follow-up examination. Satisfying facial contour and malar alignment was observed in 45 patients. All patients presented with identical position of the eye globe without enophthalmos and normal ocular movement. A habitual occlusion was seen in all patients with a mean interincisal mouth opening without pain of 49 mm. One patient presented with minor ectropion. Wound infection occurred in five patients. Persistent infraorbital neurosensory disturbance was described by 19 patients. The 1-year radiographic examination showed adequate fracture alignment in all patients with satisfying facial contour. However, dissimilar position of the orbital floor was seen in three patients having orbital reconstruction. None of the patients were re-operated or needed secondary correction of the zygomatic complex or orbital floor.

Conclusion:

Surgical intervention is an effective treatment modality of depressed zygomatic complex fractures, whereas a nonsurgical approach is often used for nondisplaced fractures. Most zygomatic complex fractures can be treated solely by an intraoral approach and rigid fixation at the zygomaticomaxillary buttress. Further exposure of the zygomaticofrontal junction or inferior orbital rim is necessary for severely displaced fractures, which require additional fixation.