Orbital reconstruction: a systematic review and meta-analysis evaluating the role of patient-specific implants

Assessment of the Correlation Between Types of Orbital Fractures and Ocular Symptoms, and the Effect of Manual Preformed and Patient-Specific Mesh Implants: A Retrospective Study

OBJECTIVE

Although certain orbital fractures are associated with specific clinical symptoms, these relationships should be reviewed comprehensively. The optimal choice between manual preformed mesh implants (MPIs) and patient-specific mesh implants (PSIs) for orbital reconstruction remains undetermined due to inconclusive evidence regarding their effectiveness.

METHODS

This retrospective study investigated 280 patients with unilateral orbital fractures to explore the correlation between clinical ocular symptoms, including diplopia, enophthalmos, limitation of ocular movement, blindness, and the specific type of orbital fracture. The effects on orbital volume (OV) and orbital volume ratio (OVR) of MPI and PSI with and without the use of navigation were also evaluated in this study. Patients were categorized into 4 groups: MPI, PSI, navigation-assisted MPI, and navigation-assisted PSI. After this categorization, alterations in OV and OVR were analyzed before and after surgical intervention.

RESULTS

Significant correlations were observed between the orbital fracture type and diplopia, enophthalmos, and limitation of ocular movement ( P < 0.05). Patients in the MPI group exhibited a notable difference in the postoperative OV between the injured and normal sides ( P < 0.05), but no statistically significant difference was found in the postoperative OV between the injured and normal sides among the patients in the other 3 groups ( P > 0.05). Moreover, the MPI group demonstrated significantly higher postoperative OVR than the other groups ( P < 0.05). Notably, PSI remained effective with or without navigation, MPI combined with navigation technology achieved a reconstruction quality similar to that of PSI by rectifying positioning errors during surgery.

CONCLUSION

The authors found significant correlations ( P < 0.05) between orbital fracture type and diplopia, enophthalmos, and limitations of ocular movement. Patient-specific mesh implant plays an important role in orbital reconstruction. It is also a good method for reconstructing orbital fractures using MPI assisted by navigation technology.

PSI: Planner-specific, physician-specific, or patient-specific implant for orbital reconstruction?

This study aimed to identify and quantify the variations in PSI designs intended for an identical patient. Records from 10 patients with an orbital fracture involving two walls, for which a primary orbital reconstruction was indicated, were retrospectively included. Clinical engineers from two centers independently generated proposal designs for all patients. Following web meeting(s) with the surgeon from the same institute, the PSI designs were finalized by the engineer. A cross-over of the engineer with the surgeon of the other center created two new design teams. In total, 20 proposal and 40 final PSI designs were produced. A three-dimensional comparison between different PSI designs for the same patient was performed by computing a difference score. Initially, the design proposals of the two engineers showed a median difference score of 37%, which was significantly reduced to a median difference score of 26% for the final designs with different engineers. The median difference score of 22% between surgeons demonstrated that both parties introduced notable user variations to the final designs. Evidence supporting the advantages of an experienced design team was found, with significantly fewer modifications, fewer meetings, and less time required to complete the design (up to 40% time reduction). The findings of the study underline the dependency of PSI design on the surgeon and engineer, and support the need for a more evidence-based protocol for PSI design.

Guidelines for Orbital Defect Assessment and Patient-Specific Implant Design: Introducing OA2 (Orbital Assessment Algorithm)

Study Design

This study presents a review of the evolutionary development in reconstructive orbital surgery over the past 3 decades. Additionally, it proposes the Orbital Assessment Algorithm (OA2) to enhance decision-making for intraorbital reconstruction of post-traumatic orbital deformities.

Objective

The objective of this paper is to provide insights into modern post-traumatic orbital reconstruction from a surgeon's perspective, with a specific focus on adult patients. It aims to highlight the advancements in computer-aided design and manufacturing techniques, particularly in the field of reconstructive orbital surgery, and to introduce the OA2 as a tool for improved decision-making in this context.

Methods

The study conducts a comprehensive review of the evolution of reconstructive orbital surgery, focusing on the integration of 3D technology into surgical practices. It also outlines the development and rationale behind the proposed OA2, emphasizing its potential to enhance the accuracy and efficacy of intraorbital reconstruction procedures for post-traumatic deformities.

Results

The review demonstrates the significant progress made in reconstructive orbital surgery, particularly in leveraging 3D technology for virtual modeling, navigation, and the design and manufacturing of patient-specific implants. The introduction of the OA2 provides a structured approach to assessing and addressing post-traumatic orbital deformities, offering potential benefits in decision-making and surgical outcomes.

Conclusions

In conclusion, this paper underscores the pivotal role of computer-aided design and manufacturing in advancing reconstructive orbital surgery. It highlights the importance of integrating innovative design concepts into implant manufacturing processes and emphasizes the potential of the OA2 to guide surgeons in the management of post-traumatic orbital deformities, ultimately contributing to improved patient outcomes.

Does a Point-of-Care 3-Dimensional Printer Result in a Decreased Length of Surgery for Orbital Fractures?

BACKGROUND

Utilization of point-of-care 3-dimensional printing (3DP) has decreased length of surgery in facial trauma. Little is known regarding 3DP's impact on length of surgery in orbital fracture.

PURPOSE

The purpose of this study was to compare length of surgery between 3DP/preadapted (3DPPA) orbital plates and intraoperative adapted plates (IOAP) for orbital fracture reconstruction.

STUDY DESIGN, SETTING, SAMPLE

This was a prospective, non-blinded, randomized clinical study of consecutive subjects with orbital fractures presented to Grady Memorial Hospital in Atlanta, Georgia, between January 2018 and June 2021. Subjects ≥ 18 years, unilateral fracture, no previous orbital surgery, and/or congenital craniofacial anomaly were included. We excluded subjects <18 years and bilateral fractures.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

Primary predictor variable was the treatment approach. Randomization software was used, and subjects were randomized to 3DPPA or IOAP groups.

MAIN OUTCOME VARIABLE(S)

Primary outcome variable was length of surgery in minutes. Secondary outcomes were the time required for plate insertion and fixation in minutes, operating room (OR) charges, and orbital volume (OV) calculation.

COVARIATES

Age, sex, race, etiology, laterality, location, dimension, indication for surgery, postoperative enophthalmos, and diplopia.

ANALYSES

Univariate and bivariate analyses were calculated. Statistical significance was P < .05.

RESULTS

Twenty-five subjects met the inclusion criteria. Mean ages in 3DPPA and conventional IOAP groups were 41.5 (±9) and 38.2 (±10, P = .31), respectively. The mean length of surgery was 32.6 (±13.7) in 3DPPA and 53.3 (±12.8, P < .001) in conventional IOAP. The mean time required for plate insertion and fixation was 15.8n (±14.4) in 3DPPA and 41.4 (±9.4, P < .001) in conventional IOAP. The mean OR charges were $1,072.5 (±524.6) in 3DPPA and $1,757.3 (±422.6, P ≤ 0.001) in conventional IOAP. The mean calculated OV of uninjured and reconstructed orbit for the 3DPPA was 23.5 (±3.2)cm3 and 23 (±3.5, P = .37)cm3, respectively. The mean calculated OV of uninjured and reconstructed orbit for conventional IOAP was 28.6 (±3.6)cm3 and 22.8 (±2.6, P < .001)cm3, respectively.

CONCLUSION AND RELEVANCE

Using 3DP to produce a model that enables preoperative plate bending/adaptation reduces the length of surgery, decreases OR charges, and results in predictable OV.

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.

A stepwise approach to chainsaw kickback injury of the nasoorbital complex: a case-based meta-narrative review

PURPOSE

This article outlines the management of a rare and severe nasoorbital injury resulting from a chainsaw kickback accident in a 60-year-old male. A meta-narrative review of English, French, and German literature indexed in PubMed, Embase, and the Cochrane Library up to January 8, 2024, accompanies the case report.

METHODS

This was a case report combined with a comprehensive review based on the 2011 Oxford Centre for Evidence-Based Medicine's highest and most recent level of evidence (LoE) and highest recommendation grade (RG). Rigorous selection criteria were applied.

RESULTS

The patient had an open nasal fracture, complex lacerations, and avulsion of the left eyelid, lateral orbital wall and lateral rectus muscle. Staged surgical interventions comprised repositioning and fixation of the fractured nose, buccal mucosal grafting for nasal mucosa and conjunctiva repair, titanium mesh and polydioxanone sheet for lateral orbital wall reconstruction, and subsequent muscle and eyelid repair. The second intervention 3 months postsurgery addressed lateral ectropion, nasal dorsal hump, and nasolacrimal system issues. Despite the rarity of such injuries, evidence-based discussions were conducted.

CONCLUSIONS

Complex nasoorbital trauma resulting from chainsaw kickback necessitates a meticulous, staged surgical approach. The inside-out technique proved effective in addressing various challenges. This article concludes with evidence-based recommendations, highlighting the importance of adapting established principles to unique nature of these injuries.

Clinical application of biomaterials in orbital implants: a systematic review

PURPOSE

Various materials have been proposed for reconstructing orbital fractures. The materials used must meet certain criteria to ensure their suitability for restoring the structure and function of the organ. These criteria include biocompatibility, ease of application, non-toxicity, hypo-allergenicity, and non-carcinogenicity. In this study, we systematically reviewed the studies regarding the biomaterials in orbital implants and their clinical application.

METHODS

A comprehensive search across various databases, including PubMed, Scopus, EMBASE, Cochrane Library, and Web of Science, was conducted until April 10th, 2023. After retrieving the search results and eliminating duplicates, final studies were included after screening through defined criteria. Human and animal studies assessing the clinical application of biomaterials in orbital implants were included. The quality of the case series and controlled intervention studies were evaluated using the NIH tool, and for animal studies, the risk of bias was assessed using SYRCLE's tool.

RESULTS

Seventeen studies were included according to defined criteria. These studies aimed to explore the clinical application of biomaterials and examine the associated complications in orbital implants.

CONCLUSION

We found that using biomaterials did not result in elevated intraocular pressure (IOP). However, we did observe certain complications, with infection, residual diplopia, and enophthalmos being the most frequently reported issues.

Comparison of patient specific implant reconstruction vs conventional titanium mesh reconstruction of orbital fractures using a novel method

To compare the reconstruction of orbital fractures using patient-specific implants (PSI) and conventional pre-formed titanium mesh; to develop a method of three-dimensional (3D) superimposition and analysis of the reconstructed orbits; and to present the pitfalls in 3D planning of orbital PSI and how to avoid them. This was a retrospective study of patients with orbital fractures who were treated in our institution between the years 2022 and 2023 using PSI or conservative prefabricated titanium mesh. Three different methods for virtual reconstruction of orbital fractures were used and are detailed with advantages, disadvantages and indications. Data acquired included age, gender, method of reconstruction, functional outcomes and aesthetic outcomes. 3D analysis for accuracy of reconstruction was performed. A total of 23 patients were included; 12 were treated using PSI and 11 using prefabricated titanium meshes. There were 8 male and 4 female patients in the PSI group comparted to 5 and 6 in the prefabricated group. All three virtual methods for reconstruction were used successfully, each with the proper indications. When comparing PSI reconstruction to conventional mesh, a significant difference in accuracy was observed; PSI cases showed an inaccuracy of 0.58 mm compared to 1.54 mm with the conventional method. Complications are presented, and tips for avoiding them are detailed. Three different methods for virtual reconstruction were used successfully; automated computerized reconstruction is used for small defects, repositioning is the superior method for non-comminuted cases while mirroring is the method of choice in comminuted fractures. 3D analysis can be performed using a novel method detailed in this report. PSI reconstruction showed superior results, indicating it should be the method of choice when possible. Pitfalls are presented and approaches to prevent them are discussed. Orbital reconstruction is a very important entity in maxillofacial surgery with crucial functional and esthetical implications, and one should use virtual planning and PSI implants, as they significantly improve outcomes.

Customized orbital implant versus 3D preformed titanium mesh for orbital fracture repair: A retrospective comparative analysis of orbital reconstruction accuracy

This study aimed to compare the accuracy of inferomedial orbital fracture restoration using customized orbital implant versus 3D preformed titanium mesh. Patients were divided into two groups. Group 1 underwent surgery with customized orbital implants and intraoperative navigation, while group 2 was treated using 3D preformed titanium meshes with preoperative virtual surgical planning (VSP) and intraoperative navigation. Reconstruction accuracy was assessed by: (1) comparing the postoperative reconstruction mesh position with the preoperative VSP; and (2) measuring the difference between the reconstructed and unaffected orbital volume. Pre- and postoperative diplopia and enophthalmos were also evaluated. Fifty-two patients were enrolled (25 in group 1 vs 27 in group 2). The mean difference between final plate position and ideal digital plan was 0.62 mm (SD = 0.235) in group 1 and 0.69 mm (SD = 0.246) in group 2, with no statistical difference between the groups (p = 0.282). The mean volume differences between the reconstructed and unaffected orbits were 0.95 ml and 1.02 ml in group 1 and group 2, respectively, with no significant difference between the groups (p = 0.860). Overall clinical improvements, as well as complications, were similar. 3D preformed titanium meshes can reconstruct inferomedial fractures with the same accuracy as customized implants. Therefore, in clinical practice, it is recommended to use 3D preformed meshes for this type of fracture due to their excellent results and the potential for reducing time and costs.

Orbital Fractures Treated in Auckland From 2016 to 2020: Review of Patient Outcomes

Orbital reconstruction is a complex procedure demanding accurate placement of implants to restore volume and anatomic shape to the orbits. Intra-operative computed-tomography (CT) and rapid-prototype (RP) biomodels have been recently introduced as surgical aids to improve outcomes. Investigation is required to determine if there is a reduction in post-operative ophthalmic complications.

Study Design

Retrospective cohort study.

Objective

To evaluate the impact of intra-operative CT and RP biomodels on the incidence of post-operative diplopia, paraesthesia, cosmetic issues and ability to return to work following orbital reconstruction surgery.

Methods

Adult (>18 years) patients treated at Counties Manukau District Health Board, Auckland, by the Department of Oral and Maxillofacial Surgery for isolated orbital fractures were retrospectively enrolled into this study. An audit of clinical records was undertaken to determine incidences of diplopia, altered sensation, cosmetic concerns and ability to return to work. These findings were compared against our previous audit which documented these findings in patients treated between 2010 and 2015, prior to the introduction of intra-operative CT and RP biomodels.

Results

Routine use of intra-operative CT and RP biomodels was associated with a reduced incidence of post-operative diplopia. No significant difference was observed with regards to paraesthesia and cosmetic deficits.

Conclusions

The relatively low radiation exposure and cost associated with intra-operative CT and RP biomodels is justified with improved outcomes in subjective diplopia. Titanium as a material for orbital reconstruction was confirmed to be associated with low complication rates.

Augmented and Virtual Reality for Preoperative Trauma Planning, Focusing on Orbital Reconstructions: A Systematic Review

BACKGROUND

This systematic review summarizes recent literature on the use of extended reality, including augmented reality (AR), mixed reality (MR), and virtual reality (VR), in preoperative planning for orbital fractures.

METHODS

A systematic search was conducted in PubMed, Embase, Web of Science and Cochrane on 6 April 2023. The included studies compared extended reality with conventional planning techniques, focusing on computer-aided surgical simulation based on Computed Tomography data, patient-specific implants (PSIs), fracture reconstruction of the orbital complex, and the use of extended reality. Outcomes analyzed were technical accuracy, planning time, operative time, complications, total cost, and educational benefits.

RESULTS

A total of 6381 articles were identified. Four articles discussed the educational use of VR, while one clinical prospective study examined AR for assisting orbital fracture management.

CONCLUSION

AR was demonstrated to ameliorate the accuracy and precision of the incision and enable the better identification of deep anatomical tissues in real time. Consequently, intraoperative imaging enhancement helps to guide the orientation of the orbital reconstruction plate and better visualize the precise positioning and fixation of the PSI of the fractured orbital walls. However, the technical accuracy of 2-3 mm should be considered. VR-based educational tools provided better visualization and understanding of craniofacial trauma compared to conventional 2- or 3-dimensional images.

Personalized Medicine Workflow in Post-Traumatic Orbital Reconstruction

Restoration of the orbit is the first and most predictable step in the surgical treatment of orbital fractures. Orbital reconstruction is keyhole surgery performed in a confined space. A technology-supported workflow called computer-assisted surgery (CAS) has become the standard for complex orbital traumatology in many hospitals. CAS technology has catalyzed the incorporation of personalized medicine in orbital reconstruction. The complete workflow consists of diagnostics, planning, surgery and evaluation. Advanced diagnostics and virtual surgical planning are techniques utilized in the preoperative phase to optimally prepare for surgery and adapt the treatment to the patient. Further personalization of the treatment is possible if reconstruction is performed with a patient-specific implant and several design options are available to tailor the implant to individual needs. Intraoperatively, visual appraisal is used to assess the obtained implant position. Surgical navigation, intraoperative imaging, and specific PSI design options are able to enhance feedback in the CAS workflow. Evaluation of the surgical result can be performed both qualitatively and quantitatively. Throughout the entire workflow, the concepts of CAS and personalized medicine are intertwined. A combination of the techniques may be applied in order to achieve the most optimal clinical outcome. The goal of this article is to provide a complete overview of the workflow for post-traumatic orbital reconstruction, with an in-depth description of the available personalization and CAS options.