Implant malposition and revision surgery in primary orbital fracture reconstructions

Computed Tomography-based Measurement of Herniated Orbital Volume Following Acute Orbital Fractures

Background

To predict which patients will develop more than 2 mm of enophthalmos and require surgery after orbital fracture is challenging. Although high herniated orbital volume (HV) might be a predictor, its measurement can be complex and time-consuming. This study aimed to identify a simple, reliable, and clinically applicable method for measuring herniated orbital volume.

Methods

This single-center retrospective study examined HV and approximate volume in 42 patients with an orbital floor fracture (OF group) and 56 patients with a medial wall fracture (MW group). Approximate herniated volume (AV) was calculated as a rectangular parallelepiped, quadrangular pyramid, or hemiellipsoid. The correlation between HV and AV was analyzed quantitatively. Receiver operating characteristic curve analysis was performed to compare AV and HV cutoff values.

Results

AV calculated as a hemiellipsoid (AVhe) provided the closest approximation to HV. Correlation analysis showed a positive linear relationship between HV and AVhe in both the OF group (r = 0.818) and the MW group (r = 0.84). The optimal AVhe cutoff value was 1.013 mL in the OF group (positive and negative predictive values, 96.3% and 66.7%, respectively; area under the curve, 0.925) and 1.13 mL in the MW group (positive and negative predictive values, 90.0% and 69.2%, respectively; area under the curve, 0.956). High HV was defined as greater than 1.0 mL in the OF group and greater than 0.9 mL in the MW group.

Conclusions

A simplified method that approximately calculates the volume of herniated orbital contents in a hemiellipsoid pattern model proved to be practical, easy, and reliable.

Need for Redo Surgery of Maxillofacial Fractures

The purpose of the present study was to describe the demographic and clinical features of patients having undergone redo surgery for mandibular and/or midfacial fractures and to identify factors that increase the odds of redo surgery. Included were the files of all patients who had undergone open reduction and fixation of one or more mandibular and/or midfacial fracture or orbital reconstructions at the Department of Oral and Maxillofacial Surgery, Helsinki University Hospital, Helsinki, Finland, between 1 January 2013-31 October 2020. Patients having undergone redo surgery were identified, and descriptive characteristics were calculated. In the data analysis, the association between redo surgery and explanatory variables was analyzed. Altogether, 1176 patients were identified for the analysis. Of these, 25 (2.1%) underwent redo surgery for 28 fracture sites. The most common reasons for redo surgery were inadequate fracture reductions of the zygomatic process or the mandible (19 patients) and inadequate orbital reconstructions (four patients). Compared with surgery of only the mandible, combined surgery of the mandible and midface had almost four times greater odds of redo surgery (95% CI 3.8, 0.8-18.4), but the finding was not statistically significant. Although redo surgery was required fairly infrequently, the findings highlight the relevance of surgical competence to treatment success; suboptimal surgical procedure was the most common reason for redo surgery. The literature supports the use of intraoperative CT scanning as a useful tool in association with the treatment of complex midfacial fractures in general and orbital fractures in particular. The success of orbital reconstruction can be promoted by using patient-specific implants.

Long-term clinical outcomes of isolated orbital floor fracture reconstruction using nonresorbable implants

PURPOSE

There are no universally established guidelines for material selection in orbital wall fracture reconstruction. With an increasing preference for permanent implants, this study aimed to compare the long-term clinical outcomes of three different non-resorbable materials in reconstructing isolated orbital floor fractures.

DESIGN

A retrospective, interventional comparative study.

METHODS

The medical records of patients with unilateral pure orbital floor fractures who underwent orbital reconstruction using non-resorbable alloplastic implants at two tertiary referral centers between January 2017 to December 2021 were reviewed. Cases with non-pure orbital floor blowout fractures and/or <2 years of follow-up were excluded. Patients were separated into three groups according to the implant material type: porous polyethylene (PPE) sheet, polypropylene (PP) mesh, and titanium (Ti) mesh. These groups were then retrospectively analyzed for clinical outcomes, implant-related complications, and patient's satisfaction.

RESULTS

Sixty-six patients met the inclusion criteria. Twenty-four patients (36.36%) received PPE sheets, 20 patients (30.3%) had PP mesh, and 22 patients (33.33%) received Ti mesh. At the 6-month postoperative visit, nine patients (40.9%) in the Ti mesh group experienced postoperative diplopia compared to six patients (30.0%) in the PP group and one patient (4.2%) in the PPE group (P < 0.047). Following the initial 6-month postoperative period, the PP group had more frequent postoperative enophthalmos compared to the other 2 groups. The total ocular motility restriction score was significantly lower in the Ti mesh group compared to the other 2 groups at all follow-up visits. Patient's satisfaction was significantly higher in the PPE group (median = 10, IQR = 1) compared to the PP (median = 8.5, IQR = 3) and Ti groups (median = 8, IQR = 3), P < 0.001. Reoperation was needed in seven patients (31.8%) in the Ti group, two patients (10%) in the PP group, and none in the PPE group.

CONCLUSIONS

The use of PPE orbital implants for the repair of isolated orbital floor fracture provides better long-term clinical outcomes compared to PP or Ti mesh and reduces the need for reoperation across all fracture sizes. Ti mesh has been associated with a higher frequency of unfavorable clinical outcomes and implant removal.

Primary surgery of subcondylar mandibular fracture using patient-specific implant: the Helsinki protocol

PURPOSE

Preoperative virtual planning and osteosynthesis with patient-specific implants (PSIs) have become a quotidian approach to many maxillofacial elective surgery setups. When a process is well-organized, a similar approach can be harnessed to serve the needs of exact primary reconstructions, especially in midfacial trauma cases. PSI osteosynthesis of the mandible is, however, more challenging because a mirror technique of the facial sides is often unreliable due to inherent lack of symmetry, and movement of the mandible increases the risk of loosening of the osteosynthesis. The purpose of this study was to present clinical results of the Helsinki protocol concept of utilizing PSIs in the primary surgery of unilateral mandibular subcondylar fractures as the first publication on the subject.

METHODS

A single-center study of a new Helsinki protocol is presented for surgical treatment of subcondylar mandibular fractures using patient-specific, titanium-milled repositator plates. Ten patients with dislocated subcondylar mandibular fractures received surgery and osteosynthesis with PSI via a retromandibular approach.

RESULTS

Clinical and radiological outcomes were excellent; none of the patients had fixation-related major complications or developed postoperative malocclusion.

CONCLUSIONS

Study results show that the Helsinki protocol, treating mandibular condylar fractures primarily with PSI plates, is a viable treatment option.

The Association of Same-Day CT Scan with Postoperative Outcomes in Isolated Orbital Fracture Repair

The potential benefits to surgical outcomes of intraoperative and/or same-day computed tomography (CT) during isolated orbital fracture reconstruction are debatable, and previous research on this topic is limited by small sample size. This retrospective IBM MarketScan Commercial and Medicare Supplemental research database study examined patients undergoing isolated orbital reconstruction from January 1, 2012 to December 31, 2018, to assess whether same-day CT affected postoperative outcomes. The average age of the 5,023 participants was 37 (standard deviation [SD]: 16) years and 63% were males. The data revealed that 16.2% (815 of 5,023) patients underwent a same-day CT. Those who underwent a same-day CT scan exhibited reduced odds of postoperative enophthalmos (adjusted odds ratio [aOR]: 0.269; 95% confidence interval [CI]: 0.167-0.433) and diplopia (aOR: 0.670; 95% CI: 0.495-906). Interestingly, these patients also displayed a higher rate of revision surgeries (aOR: 2.721; 95% CI: 1.893-3.912). In summary, while same-day CT scans diminish certain postoperative complications of orbital fracture repair, they are also associated with an increased likelihood of subsequent surgical revision.

Analysis of postoperative complications of orbital fracture

OBJECTIVE

To analyze the types and causes of complications following orbital fracture reconstruction and enhance clinicians' capacity to manage or prevent such complications.

METHODS

We conducted a retrospective case series analysis, retrospectively collecting and analyzing clinical data of patients with orbital fractures who received surgical treatment at the Affiliated Eye Hospital of Nanchang University from May 2012 to May 2022. Descriptive statistics were employed to document common postoperative complications, and we recorded complications persisting after a minimum 6-month follow-up period.

RESULTS

Among the 227 patients who underwent orbital fracture surgery, they were followed up for 6 to 36 months, and complications occurred in 15 cases, resulting in an incidence rate of 6.61%. These complications included implant material infections and rejections (4 cases), persistent diplopia (3 cases), intraorbital hematomas (2 cases), epiphora (2 cases), lower eyelid eversion or retraction (2 cases), and skin scars (2 cases). The primary cause of postoperative infection was chronic inflammation in the paranasal sinuses or closed cavities within the fracture area. Postoperative complications in orbital fractures were associated with various factors, including the timing of surgery, surgical approach, repair materials, surgical skills, and auxiliary techniques.

CONCLUSION

Standardizing surgical techniques and implementing precise auxiliary technologies may reduce the incidence of complications and enhance the operation's success rate.

Surgical Outcomes of Revision Orbital Reconstruction in Patients With Inadequate Primary Orbital Fracture Repair

OBJECTIVE

This study aimed to investigate the clinical characteristics of patients with complications following inadequate primary orbital fracture repair and to evaluate surgical outcomes of secondary revision orbital reconstruction.

METHODS

The authors retrospectively reviewed data from 41 patients who underwent revision orbital reconstruction by a single surgeon following complications from primary orbital fracture repair performed elsewhere. Clinical characteristics, including enophthalmos, exophthalmos, diplopia, ocular motility limitation, epiphora, infraorbital hypoesthesia, infection, eyelid malposition, lagophthalmos, hypoglobus, and compressive optic neuropathy, were assessed. Surgical outcomes of revision surgery were evaluated to determine improvements in clinical deficits and postoperative patient satisfaction.

RESULTS

The most common postoperative complications of primary orbital fracture repair were enophthalmos (n=20/41) and diplopia (n=20/41). The mean time between primary and revision surgeries was 67.2 months (range: 1-276 mo). Revision surgery significantly improved enophthalmos, diplopia (Hess area ratio), epiphora (Munk score), periorbital pain, and exophthalmos ( P =0.003, P =0.001, P <0.001, P <0.001, and P =0.007, respectively) compared to the pre-revision state. In addition, 6 patients experienced improved infraorbital hypoesthesia. Among the 41 patients, 23 were very satisfied, 17 were satisfied, and 1 was neutral after revision orbital reconstruction.

CONCLUSIONS

Our study highlights the positive impact of revision orbital reconstruction in addressing complications from inadequate primary orbital fracture repair. Surgeons should consider revision surgery to address clinical deficits following prior surgery, especially when anatomic abnormalities are evident in imaging studies, regardless of the time lapse since the initial surgery or concerns about tissue fibrosis and fat atrophy.

Patient-specific implants made of 3D printed bioresorbable polymers at the point-of-care: material, technology, and scope of surgical application

BACKGROUND

Bioresorbable patient-specific additive-manufactured bone grafts, meshes, and plates are emerging as a promising alternative that can overcome the challenges associated with conventional off-the-shelf implants. The fabrication of patient-specific implants (PSIs) directly at the point-of-care (POC), such as hospitals, clinics, and surgical centers, allows for more flexible, faster, and more efficient processes, reducing the need for outsourcing to external manufacturers. We want to emphasize the potential advantages of producing bioresorbable polymer implants for cranio-maxillofacial surgery at the POC by highlighting its surgical applications, benefits, and limitations.

METHODS

This study describes the workflow of designing and fabricating degradable polymeric PSIs using three-dimensional (3D) printing technology. The cortical bone was segmented from the patient's computed tomography data using Materialise Mimics software, and the PSIs were designed created using Geomagic Freeform and nTopology software. The implants were finally printed via Arburg Plastic Freeforming (APF) of medical-grade poly (L-lactide-co-D, L-lactide) with 30% β-tricalcium phosphate and evaluated for fit.

RESULTS

3D printed implants using APF technology showed surfaces with highly uniform and well-connected droplets with minimal gap formation between the printed paths. For the plates and meshes, a wall thickness down to 0.8 mm could be achieved. In this study, we successfully printed plates for osteosynthesis, implants for orbital floor fractures, meshes for alveolar bone regeneration, and bone scaffolds with interconnected channels.

CONCLUSIONS

This study shows the feasibility of using 3D printing to create degradable polymeric PSIs seamlessly integrated into virtual surgical planning workflows. Implementing POC 3D printing of biodegradable PSI can potentially improve therapeutic outcomes, but regulatory compliance must be addressed.

Presurgical Virtual Planning and Intraoperative Navigation with 3D-Preformed Mesh: A New Protocol for Primary Orbital Fracture Reconstruction

PURPOSE

This pilot study aims to evaluate the feasibility and effectiveness of computer-assisted surgery protocol with 3D-preformed orbital titanium mesh (3D-POTM), using presurgical virtual planning and intraoperative navigation in primary inferomedial orbital fracture reconstruction.

METHODS

Between March 2021 and March 2023, perioperative data of patients undergoing surgery for unilateral inferomedial orbital fracture treated with 3D-POTM were analyzed. Presurgical virtual planning with a Standard Triangle Language file of preformed mesh was conducted using the mirrored unaffected contralateral side as a reference, and intraoperative navigation was used. The reconstruction accuracy was determined by: correspondence between postoperative reconstruction mesh position with presurgical virtual planning and difference among the reconstructed and the unaffected orbital volume. Pre- and postoperative diplopia and enophthalmos were assessed.

RESULTS

Twenty-six patients were included. Isolated orbital floor fracture was reported in 14 (53.8%) patients, meanwhile medial wall and floor one in 12 (46.1%) cases. The mean difference between final plate position and ideal digital plan was 0.692 mm (95% CI: 0.601-0.783). The mean volume difference between reconstructed and unaffected orbit was 1.02 mL (95% CI: 0.451-1.589). Preoperative diplopia was settled out in all cases and enophthalmos in 19 (76.2%) of 21 patients.

CONCLUSION

The proposed protocol is an adaptable and reliable workflow for the early treatment of inferomedial orbital fractures. It enables precise preoperative planning and intraoperative procedures, mitigating pitfalls and complications, and delivering excellent reconstruction, all while maintaining reasonable costs and commitment times.

Clinical and radiographic assessment of patient-specific transantral reconstruction of orbital floor fractures: A case series

To clinically and radiographically evaluate patient-specific titanium meshes via a trans-antral approach for correction of enophthalmos and orbital volume in patients with recent unilateral orbital floor fracture. Seven patients with unilateral orbital floor fractures received patient-specific titanium meshes that were designed based on a mirror-image of the contralateral intact orbit. The patient-specific implants (PSIs) were inserted via a trans-antral approach without endoscopic assistance. The patients were evaluated clinically for signs of diplopia and restricted gaze as well as radiographically for enophthalmos and orbital volume correction. Diplopia was totally resolved in two of the three patients who reported diplopia in the upward gaze. Whereas enophthalmos significantly improved in all but two patients, with a mean value of 0.2229 mm postoperatively compared to 0.9914 mm preoperatively. CT scans showed excellent adaptation of the PSIs to the orbital floor with a mean reduction of the orbital volume from 29.59 cc to 27.21 cc, a mean of 0.6% smaller than the intact orbit. It can be concluded that the proposed PSI can offer good reconstruction of the orbital floor through an isolated intraoral transantral approach with minimal complications. It could of special benefit in extensive orbital floor fractures.

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.

Intraoperative computed tomography for orbital reconstruction: a systematic review

Orbital reconstruction is a common procedure with inherent challenges and important consequences. Intraoperative use of computed tomography (CT) is an emerging application that facilitates accurate intraoperative evaluation to improve clinical outcomes. This review aims to investigate the intraoperative and postoperative outcomes of intraoperative CT use in orbital reconstruction. PubMed and Scopus databases were systematically searched. Inclusion criteria were: clinical studies investigating intraoperative CT use in orbital reconstruction. Exclusion criteria were: duplicates; non-English publications; non-full-text publications; studies with insufficient data. Of the 1022 articles identified, seven eligible articles representing 256 cases were included. The mean age was 39 years. Most cases were male (69.9%). With regards to intraoperative outcomes, the mean revision rate was 34.1%, with plate repositioning being the most common type (51.1%). Intraoperative time was variably reported. With regards to postoperative outcomes, there were no revisions, and only one case that had a complication (transient exophthalmos). Mean volumetric difference between the repaired and contralateral orbits was reported in two studies. The findings of this review present an updated evidence-based summary of the intraoperative and postoperative outcomes of intraoperative CT use in orbital reconstruction. Robust longitudinal comparisons of clinical outcomes between intraoperative and non-intraoperative CT cases are required.

Intraoperative Computed Tomography Use in Orbital Fracture Repair: A Systematic Review and Meta-Analysis

Background: Intraoperative computed tomography (CT) allows surgeons to make adjustments during orbital fracture repair that may impact postoperative outcomes. Learning/Study Objectives: To determine the impact of intraoperative CT use on intraoperative revision and surgical outcomes for orbital fracture repair. Methods: A systematic review was performed in concordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines: the population was patients undergoing orbital fracture repair; intervention was use of intraoperative CT; comparison was patients not undergoing intraoperative CT; and outcomes were intraoperative revision rate, postoperative complications, and secondary revision surgeries. Meta-analysis was performed on the rate of intraoperative revision. Results: The search criteria yielded 790 articles, 377 were eligible for review, and 20 articles met criteria for analysis. In 19, intraoperative imaging led to immediate surgical corrections, with a random pooled effect size of 0.27 (0.20-0.35). Six studies reported secondary revision surgery rates (range 0-10.5%), and six studies reported postoperative complication rates (range 10-30%). Conclusions: Intraoperative imaging helps surgeons make precise, real-time adjustments in 27% of orbital fracture repair cases, which may improve surgical outcomes; however, more research is needed to investigate its impact on health care costs, operating time, and radiation exposure.

Reconstruction of Medial Orbital Wall Using Autologous Perpendicular Plate of Ethmoid

The aim of this study is to investigate the feasibility of perpendicular plate of ethmoid as material for the reconstruction of medial orbital wall. The main outcome measurement was preoperative and postoperative orbital volume. The authors performed a study including 17 patients who have isolated medial orbital wall fracture (blow-out fracture). All the patients were fixed the defect using autologous perpendicular plate of ethmoid under endonasal approach. The authors compared the preoperative and postoperative orbital volume difference (unaffected orbit, affected orbit) of all the patients, and observed the improvement of diplopia or ocular motility disorders after operation. All 17 medial orbital wall reconstruction surgeries were successful with no severe postoperative ophthalmic complications. Statistically significant differences were found between the preoperative and postoperative orbital tissue volumes for the affected orbit. There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction. And postoperative computed tomography showed the implant is in place and there is no medial rectus incarceration. Autologous perpendicular plate of ethmoid proved to be safe and effective in the reconstruction of medial orbital wall under endonasal approach with cost-effectivence, low complication rate, high biocompatibility, and minimally invasion.

Comparison of Anatomical Preformed Titanium Implants and Patient-Specific CAD/CAM Implants in the Primary Reconstruction of Isolated Orbital Fractures-A Retrospective Study

BACKGROUND/AIM

Reconstruction of the fractured orbit remains a challenge. The aim of this study was to compare anatomical preformed titanium orbital implants with patient-specific CAD/CAM implants for precision and intraoperative applicability.

MATERIAL AND METHODS

A total of 75 orbital reconstructions from 2012 to 2022 were retrospectively assessed for their precision of implant position and intra- and postoperative revision rates. For this purpose, the implant position after digital orbital reconstruction was checked for deviations by mirroring the healthy orbit at 5 defined points, and the medical records of the patients were checked for revisions.

RESULTS

The evaluation of the 45 anatomical preformed orbital implant cases showed significantly higher deviations and an implant inaccuracy of 66.6% than the 30 CAD/CAM cases with only 10% inaccuracy. In particular, the CAD/CAM implants were significantly more precise in medial and posterior positioning. In addition, the intraoperative revision rates of 26.6% vs. 11% after 3D intraoperative imaging and the postoperative revision rates of 13% vs. 0 for the anatomical preformed implants were significantly higher than for patient-specific implants.

CONCLUSION

We conclude that patient-specific CAD/CAM orbital implants are highly suitable for primary orbital reconstruction. These seem to be preferable to anatomical preformed implants in terms of precision and revision rates.

Is the Pre-Shaping of an Orbital Implant on a Patient-Specific 3D-Printed Model Advantageous Compared to Conventional Free-Hand Shaping? A Systematic Review and Meta-Analysis

This study aimed to perform a systematic review and meta-analysis to compare pre-shaped implants on a patient-specific 3D-printed (3DP) model to manual free-hand shaping (MFS) for orbital wall reconstruction. The PRISMA protocol was followed in this study, and the review was registered in the PROSPERO database (CRD42021261594). A search was conducted in MEDLINE (PubMed), Embase, Cochrane Library, Clinicaltrials.gov, Google Scholar, and the grey literature. Ten articles were included, and six outcomes were analyzed. In total, 281 patients were in the 3DP group and 283 were in the MFS group. The studies had an overall high risk of bias. 3DP models resulted in a better accuracy of fit, anatomical angle reproduction, and defect area coverage. The correction of orbital volume was also superior with statistical significance. There was a higher percentage of the correction of enophthalmos and diplopia in the 3DP group. Intraoperative bleeding and hospital stay were reduced in the 3DP group. The meta-analysis of operative time showed a reduction in the average operative time by 23.58 min (95% CI: -43.98 to -3.19), which was statistically significant (t(6) = -2.8299, p = 0.0300). The 3DP models appear advantageous for an accurate orbital wall reconstruction, with fewer complications than those for conventional free-hand-shaped implants.

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.

'Frozen eye' - Post blowout fracture surgical correction - A case report

The Rationale

"Frozen Eye" is a very uncommon sequel after treatment of orbital blowout fractures requiring implant placement.

Patient Concerns

The implant may faultily impinge on the ocular and extra-ocular muscle(s), causing the abnormality in the movement of the eye.

Diagnosis

We present a 56-year-old male whose ocular implant impinged on muscle, causing "frozen eye" and had an infected implant.

Treatment Outcomes

The same was removed and surgically corrected. The manuscript describes the details and discusses the possible mechanism that led to the "Frozen Eye".

Virtual Planning and 3D Printing in the Management of Acute Orbital Fractures and Post-Traumatic Deformities

Virtual surgical planning (VSP) and three-dimensional (3D) printing have advanced surgical reconstruction of orbital defects. Individualized 3D models of patients' orbital bony and soft tissues provide the surgeon with corrected orbital volume based on normalized anatomy, precise location of critical structures, and when needed a better visualization of the defect or altered anatomy that are paramount in preoperative planning. The use of 3D models preoperatively allows surgeons to improve the accuracy and safety of reconstruction, reduces intraoperative time, and most importantly lowers the rate of common postoperative complications, including over- or undercontouring of plates, orbital implant malposition, enophthalmos, and hypoglobus. As 3D printers and materials become more accessible and cheaper, the utility of printing patient-specific implants becomes more feasible. This article summarizes the traditional surgical management of orbital fractures and reviews advances in VSP and 3D printing in this field. It also discusses the use of in-house (point-of-care) VSP and 3D printing to further advance care of acute orbital trauma and posttraumatic deformities.

Ageing increases risk of lower eyelid malposition after primary orbital fracture reconstruction

Lower eyelid malposition (LEM) is a common sequela after orbital fracture reconstruction. This study aimed to analyse the development of LEM, specifically ectropion and entropion, following primary orbital fracture reconstruction, to identify predictive factors for LEM, and to assess the effect of the eyelid complication on patients' daily lives. The retrospective cohort comprised patients who had undergone orbital floor and/or medial wall fracture reconstruction for recent trauma. Demographics, fracture type and site, surgery and implant-related variables, follow-up time and number of visits, type and severity of LEM, subsequent surgical correction, and patient satisfaction, were analysed. The overall occurrence of LEM was 8%, with ectropion in 6% and entropion in 2% of patients. Older age, complex fractures, transcutaneous approaches, preoperative traumatic lower lid wounds, and implant material were associated with the development of LEM. Of all patients, 3% needed surgical correction of LEM. Six of the 13 patients (46%) who developed LEM required surgical correction. The transconjunctival approach and patient-specific implants should be preferred, especially in elderly patients and those with more complex fractures. LEM often requires subsequent surgical correction, and the treatment period is substantially prolonged, with multiple extra visits to the clinic.

Primary reconstruction of combined orbital and zygomatic complex fractures with patient-specific milled titanium implants - A retrospective study

The aim of this retrospective study was to compare mid-facial symmetry and clinical outcomes between patients treated with patient-specific and standard implants in primary fracture reconstructions of combined orbital and zygomaticomaxillary complex fractures. Patients who underwent primary reconstruction of orbital and zygomaticomaxillary complex fractures during the study period were identified and background and clinical variables and computed tomography images were collected from patient records. Zygomaticomaxillary complex dislocation and orbital volume were measured from pre- and postoperative images and compared between groups. Out of 165 primary orbital reconstructions, eight patients treated with patient-specific and 12 patients treated with standard implants were identified with mean follow-up time of was 110 days and 121 days, respectively. Postoperative orbital volume difference was similar between groups (0.2 ml for patient-specific vs 0.3 ml for standard implants, p = 0.942) despite larger preoperative difference in patient-specific implant group (2.1 ml vs 1,5 ml, p = 0.428), although no statistical differences were obtained in symmetricity or accuracy between the reconstruction groups. Within the limitations of the study it seems that patient-specific implants are a viable option for primary reconstructions of combined zygomaticomaxillary complex and orbital fractures, because with patient-specific implants at least as symmetrical results as with standard implants can be obtained in a single surgery.

Pitfalls of Surgeon-Engineer Communication and the Effect of In-House Engineer Training During Digital Planning of Patient-Specific Implants for Orbital Reconstruction

PURPOSE

The use of patient-specific implants for reconstruction of complex orbital floor defects is increasing and requires communication with an industry partner, which warrants investigation. Therefore, the aim of this study was to evaluate the effects of in-house training of engineers on such communication as well as to identify frequent sources of problems and their solutions for improvement of the implant-planning workflow.

METHODS

We conducted a retrospective cross-sectional study and enrolled a sample of patients who had undergone orbital reconstruction with patient-specific implants between 2017 and 2020. The predictor variables were in-house training (additional training completed in hospital or not) and implant complexity (complex [multiwalled implants] vs less complex [isolated orbital floor reconstructions]). The outcome variables were duration of communication, message length, and need for synchronous communication or modifications to the original design. Descriptive, univariate, and multivariate statistics were computed, and statistical significance was set at a P value of < 0.05.

RESULTS

This study included the data of 66 patients (48 men and 18 women, average age: 42.27 years). The complexity of the implant statistically significantly increased the duration of the communication (8.76 vs 16.03 days; P = .004). In 72.73%, the initial design had to be changed. Engineers trained in house required less communication to plan less-complex implants and generally needed fewer corrections to the original design (P = .020 and P = .036, respectively). Problems during planning were observed in 25.76% of the cases, with an insufficient diagnostic 3-dimensional data set being the most common (15.15%).

CONCLUSIONS

In-house training of engineers is time-saving while planning the workflow for patient-specific implants, especially in less-complex cases, given that design changes are not needed often. The high rate of data sets that were insufficient for planning patient-specific implants suggests that diagnostic 3-dimensional data sets should already meet the requirements for such planning.