Computer-aided Volume Measurement of Posttraumatic Orbits Reconstructed With AO Titanium Mesh Plates: Accuracy and Reliability

Matrixmidface Preformed Orbital Implants for Three-Dimensional Reconstruction of Orbital Floor and Medial Wall Fractures: A Prospective Clinical Study

Study Design

Prospective Interventional study.

Objective

To evaluate the efficiency of Matrixmidface preformed Orbital plates for three-dimensional reconstruction of orbital floor and medial wall fractures.

Methods

This prospective institutional clinical study was conducted on a group of 14 patients who underwent repair of orbital floor and medial wall fracture defects using Matrixmidface Preformed Orbital plates and open reduction and internal fixation of associated fractures. The following parameters were studied preoperative and postoperative enophthalmos, hypoglobus, orbital volume; correction of diplopia, intraoperative and postoperative complications.

Results

All 14 patients were males aged between 19 and 42 years. The most common mode of injury was found to be road traffic accidents (RTAs) followed by self-fall and trauma at workplace. Orbital fractures were associated with other concomitant maxillofacial fractures in 12 patients (85.7%) while 2 patients (14.3%) had pure blowout fractures. Significant improvement of enophthalmos was noted from preoperative period to 1 week, 6 weeks, and 6 months postoperatively (P value .02, .01, and .01, respectively). Out of 11 patients with preoperative hypoglobus, 5 patients (45.45%) had persistent hypoglobus in the immediate postoperative period which reduced to 4 patients (36.36%) at 6 weeks postoperatively (p value .00). The postoperative orbital volume of fractured side ranged from 20.3 cm3 to 26.76 cm3 with a mean of 23.50 cm3 ± 1.74. The mean difference between the volumes of the repaired and uninjured sides was found to be .27 cm3 ± .39 (P value .02) denoting that the reconstruction of the orbit closely approximated that of the uninjured side.

Conclusions

The Matrixmidface Preformed Orbital plate provides exceptional reconstruction of the orbital blowout fracture defects and ensures satisfactory results clinically and radiographically. The plate ensures an approximate recreation of topographical anatomy of the orbit and adequately restores the orbital volume. It provides adequate correction of asymmetry, hypoglobus, enophthalmos and attempts to restore eye movements, without causing any significant postoperative complication.

Semi-supervised segmentation of orbit in CT images with paired copy-paste strategy

The segmentation of the orbit in computed tomography (CT) images plays a crucial role in facilitating the quantitative analysis of orbital decompression surgery for patients with Thyroid-associated Ophthalmopathy (TAO). However, the task of orbit segmentation, particularly in postoperative images, remains challenging due to the significant shape variation and limited amount of labeled data. In this paper, we present a two-stage semi-supervised framework for the automatic segmentation of the orbit in both preoperative and postoperative images, which consists of a pseudo-label generation stage and a semi-supervised segmentation stage. A Paired Copy-Paste strategy is concurrently introduced to proficiently amalgamate features extracted from both preoperative and postoperative images, thereby augmenting the network discriminative capability in discerning changes within orbital boundaries. More specifically, we employ a random cropping technique to transfer regions from labeled preoperative images (foreground) onto unlabeled postoperative images (background), as well as unlabeled preoperative images (foreground) onto labeled postoperative images (background). It is imperative to acknowledge that every set of preoperative and postoperative images belongs to the identical patient. The semi-supervised segmentation network (stage 2) utilizes a combination of mixed supervisory signals from pseudo labels (stage 1) and ground truth to process the two mixed images. The training and testing of the proposed method have been conducted on the CT dataset obtained from the Eye Hospital of Wenzhou Medical University. The experimental results demonstrate that the proposed method achieves a mean Dice similarity coefficient (DSC) of 91.92% with only 5% labeled data, surpassing the performance of the current state-of-the-art method by 2.4%.

Insights into Orbital Symmetry: A Comprehensive Retrospective Study of 372 Computed Tomography Scans

Background: The operation planning and production of individualized implants with the help of AI-based software after orbital fractures have become increasingly important in recent years. This retrospective study aimed to investigate the healthy orbitae of 372 patients from CT images in the bone and soft tissue windows using the Disior™ Bonelogic™ CMF Orbital software. (version 2.1.28). Methods: We analyzed the variables orbital volume, length, and area as a function of age and gender and compared bone and soft tissue windows. Results: For all variables, the intraclass correlation showed excellent agreement between the bone and soft tissue windows (p < 0.001). All variables showed higher values when calculated based on bone fenestration with, on average, 1 mL more volume, 0.35 mm more length, and 0.71 cm2 more area (p < 0.001). Across all age groups, men displayed higher values than women with, on average, 8.1 mL larger volume, a 4.78 mm longer orbit, and an 8.5 cm2 larger orbital area (p < 0.001). There was also a non-significant trend in all variables and both sexes toward growth with increasing age. Conclusions: These results mean that, due to the symmetry of the orbits in both the bone and soft tissue windows, the healthy orbit can be mirrored for surgical planning in the event of a fracture.

Are Magnetic Resonance Imaging-Generated 3Dimensional Models Comparable to Computed Tomography-Generated 3Dimensional Models for Orbital Fracture Reconstruction? An In-Vitro Volumetric Analysis

BACKGROUND

Magnetic resonance imaging (MRI) is being increasingly considered as an alternative for the evaluation and reconstruction of orbital fractures. No previous research has compared the orbital volume of an MRI-imaged, three-dimensional (3D), reconstructed, and virtually restored bony orbit to the gold standard of computed tomography (CT).

PURPOSE

To measure the orbital volumes generated from MRI-based 3D models of fractured bony orbits with virtually positioned prebent fan plates in situ and compare them to the volumes of CT-based virtually reconstructed orbital models.

STUDY DESIGN

This retrospective in-vitro study used CT and MRI data from adult patients with orbital trauma assessed at the Royal Brisbane and Women's Hospital Outpatient Maxillofacial Clinic from 2011 to 2012. Only those with orbital blowout fractures were included in the study.

PREDICTOR VARIABLE

The primary predictor variable was imaging modality, with CT- and MRI-based 3D models used for plate bending and placement.

MAIN OUTCOME VARIABLE

The primary outcome variable was the orbital volume of the enclosed 3D models.

COVARIATES

Additional data collected was age, sex, and side of fractured orbit. The effect of operator variability on plate contouring and orbital volume was quantified.

ANALYSES

The Wilcoxon signed rank test was used to assess differences between orbital volumes with a significance level P < .05.

RESULTS

Of 11 eligible participants, six patients (four male and two female; mean age 31 ± 8.6 years) were enrolled. Two sets of six CT-based virtually restored orbits were smaller than the intact contralateral CT models by an average of 1.02 cm3 (95% CI -0.07 to 2.11 cm3; P = .028) and 0.99 cm3 (95% CI 0.07 to 1.91 cm3; P = .028), respectively. The average volume difference between the MRI-based virtually restored orbit and the intact contralateral MRI model was 0.97 cm3 (95% CI -1.08 to 1.94 cm3; P = .75). Imaging modality did affect orbital volume difference for 1 set of CT and MRI models (0.63 cm3; 95% CI -0.11 to 1.29 cm3; P = .046) but not the other (0.69 cm3; 95% CI -0.11 to 1.23 cm3; P = .075). Single operator variability in plate bending did not result in significant (P = .75) volume differences.

CONCLUSIONS

MRI can be used to reconstruct orbital volume with a clinically acceptable level of accuracy.

3D printing for orbital volume anatomical measurement

PURPOSE

The aim was to develop a method for reproducible orbital volume (OV) measurement in vivo based on 3D printing.

METHODS

Twelve orbits were obtained from dry skulls of the Human Anatomy Department of Lille University. Computer tomography (CT) slice images of these orbits were transformed into stereo-lithography (STL) format and 3D-printed. Bone openings were closed using either putty and cellophane after printing (3D-Orb-1) or at the printing stage in silico using MeshMixer (3D-Orb-2). The results were compared with those of the conventional water-filling method as a control group (Anat-Orb).

RESULTS

The observers reported a mean orbital volume of 21.3 ± 2.1 cm³ for the open-skull method, 21.2 ± 2.4 cm³ for the non-sealed 3D-printing method, and 22.2 ± 2.0 cm³ for the closed-print method. Furthermore, the intraclass correlation coefficients (ICCs) showed excellent intra-rater agreement, i.e., an ICC of 0.994 for the first observer and 0.998 for the second, and excellent interobserver agreement (ICC: 0.969). The control and 3D-Orb-1 groups show excellent agreement (ICC: 0.972). The 3D-Orb-2 exhibits moderate agreement (ICC: 0.855) with the control and appears to overestimate orbital volume slightly.

CONCLUSION

Our 3D-printing method provides a standardized and reproducible method for the measurement of orbital volume.

A deep learning method for automatic segmentation of the bony orbit in MRI and CT images

This paper proposes a fully automatic method to segment the inner boundary of the bony orbit in two different image modalities: magnetic resonance imaging (MRI) and computed tomography (CT). The method, based on a deep learning architecture, uses two fully convolutional neural networks in series followed by a graph-search method to generate a boundary for the orbit. When compared to human performance for segmentation of both CT and MRI data, the proposed method achieves high Dice coefficients on both orbit and background, with scores of 0.813 and 0.975 in CT images and 0.930 and 0.995 in MRI images, showing a high degree of agreement with a manual segmentation by a human expert. Given the volumetric characteristics of these imaging modalities and the complexity and time-consuming nature of the segmentation of the orbital region in the human skull, it is often impractical to manually segment these images. Thus, the proposed method provides a valid clinical and research tool that performs similarly to the human observer.

CLINICAL APPLICATION OF 3D PRINTING TECHNOLOGY FOR PREOPERATIVE PLANNING OF THUMB RECONSTRUCTION

Objective:

This study aimed to explore the clinical application of preoperative precise design for 3D printing and thumb reconstruction, which could help manage the patients with thumb defect and achieve better function and appearance.

Methods:

This was a retrospective study of 20 patients who underwent the surgery of harvesting toe transplant and thumb reconstruction between January 2015 and December 2016. The 3D model of the thumb defect was created and printed. The dimensions of skin and bones from donor site were precisely designed as reference for surgical operation. The surgery was performed according to the model.

Results:

Perfect repair of defects was achieved with satisfying appearance and function. The reconstructed thumbs all survived (survival rate of 100%). Follow-up was 3-9 months. The maximum dorsiflexion was 8-30° and the maximum flexion was 38-58°. The two-point sensory discrimination was 9-11 mm. In total, 17 patients reposted “Excellent” satisfaction and three “Good”, each for the reconstructed thumb and hand function, respectively. The satisfaction rate was 85%.

Conclusion:

Preoperative digital design and 3D printing according to the donor and recipient sites allowed a tailored operation. The operation was more precise, the appearance of the reconstructed thumb was good. Level of Evidence II, Retrospective Study.

Quality of life after reconstruction of traumatic orbital floor defects using titanium mesh and medpore: A randomised controlled trial

AIM AND OBJECTIVES

The aim of this study was to analyse the outcomes of orbital floor reconstruction with two types of orbital implants and assess patients' quality of life.

MATERIAL AND METHODS

39 sequential patients with clinical and radiological evidence of orbital floor fracture, presenting diplopia, enophthalmos, paraesthesia or a post traumatic residual orbital deformity were included in this study and randomised for orbital floor reconstruction using porous polyethylene sheet (Biopore™) or preshaped titanium mesh on a 3D model. Their pre and postoperative quality of life were compared. Success rate was assessed and scored with a minimum of zero (none) and a maximum of ten (excellent) for improvement in the signs of diplopia, enophthalmos, hypoglobus, paraesthesia and aesthetics.

RESULTS

Both QOL scores and Success score was greater in cases which reconstruction of orbital floor was performed with preshaped titanium mesh as compared to those with Biopore™.

CONCLUSION

Preshaped titanium mesh shows better results than reconstruction with Biopore™. However a large sample size and a long term follow up is needed for generating the best evidence. Quality of life extensively improves after orbital floor reconstruction motivating the patients desire to live.

Reliability of orbital volume measurements based on computed tomography segmentation: Validation of different algorithms in orbital trauma patients

PURPOSE

To compare the most common methods of segmentation for evaluation of the bony orbit in orbital trauma patients.

MATERIALS AND METHODS

Computed tomography scans (before and after treatment) from 15 patients with unilateral blowout fractures and who underwent orbital reconstructions were randomly selected for this study. Orbital volume measurements, volume difference measurements, prolapsed soft tissue volumes, and bony defect areas were made using manual, semi-automated, and automated segmentation methods.

RESULTS

Volume difference values between intact and damaged orbits after surgery using the manual mode were 0.5 ± 0.3 cm³, 0.5 ± 0.4 cm³ applying semi-automated method, and 0.76 ± 0.5 cm³, determined by automated segmentation (р = 0.216); the mean volumes (MVs) for prolapsed tissues were 3.0 ± 1.9 cm³, 3.0 ± 2.3 cm³, and 2.8 ± 3.9 cm³ (p = 0.152); and orbital wall defect areas were 4.7 ± 2.8 cm², 4.75 ± 3.1 cm², and 4.9 ± 3.3 cm² (p = 0.674), respectively.

CONCLUSIONS

The analyzed segmentation methods had the same accuracy in evaluation of volume differences between two orbits of the same patient, defect areas, and prolapsed soft tissue volumes but not in absolute values of the orbital volume due to the existing diversity in determination of anterior closing. The automated method is recommended for common clinical cases, as it is less time-consuming with high precision and reproducibility.

Magnetic resonance imaging for three-dimensional printing of the bony orbit: is clinical use imminent?

The aim of this study was to examine the accuracy of three dimensionally (3D) printed models of the bony orbit derived from magnetic resonance imaging (MRI) for the purpose of preoperative plate bending in the setting of orbital blowout fracture. Retrospective computed tomography (CT) and MRI data from patients with suspected orbital fractures were used. Virtual models were manually generated and analysed for spatial accuracy of the fracture margins. 3D-printed models were produced and orbital fan plates bent by a single operator. The plates were then digitized and analysed for spatial discrepancy using reverse engineering software. Seven orbital blowout fractures were evident in six orbits. Analysis of the virtual models revealed high congruence between blowout fracture margins on CT and MRI (n=7, average deviation 0.85mm). Three zygomaticomaxillary complex fractures were seen, for which MRI did not demonstrate the same accuracy. For plates bent to the 3D-printed models of blowout fractures (n=6), no significant difference was found between those bent to CT versus those bent to MRI when compared for average surface and average border deviation (Wilcoxon signed rank test). Orbital blowout fractures can be defined on MRI with clinically acceptable accuracy. 3D printing of orbital biomodels from MRI for bending reconstructive plates is an acceptable and accurate technique.

Navigation-Assisted Isolated Medial Orbital Wall Fracture Reconstruction Using an U-HA/PLLA Sheet via a Transcaruncular Approach

Purpose: We investigated the feasibility of isolated medial orbital wall fracture reconstruction using an unsintered hydroxyapatite particles/poly L-lactide (u-HA/PLLA) sheet implant with the assistance of intraoperative navigation via the transcaruncular approach. Patients and methods: Ten consecutive patients (5 males and 5 females; mean age, 57.5 years) were included based on the clinical and imaging criteria. All patients underwent surgical treatment of the isolated medial orbital wall fracture using transcaruncular incision and the u-HA/PLLA implant under navigation. The follow-up time was greater than 6 months. Preoperative and postoperative clinical data regarding the presence of diplopia, eye motility restriction, and enophthalmos were assessed. The orbital volumes of the injured and uninjured orbit were also evaluated using computed tomography images. Results: All patients had improved ophthalmologic functional and esthetic outcomes and were successfully treated without any long-term complications arising during follow-up. There was a significant difference between the preoperative and postoperative injured orbits due to herniation of the orbital contents. Moreover, the orbital volume of the postoperative injured side following surgery was the same as that of the unaffected side, indicating that anatomically good reconstruction had been obtained. Conclusions: Surgical treatment using the transcaruncular approach and u-HA/PLLA materials with intraoperative navigation is a safe, promising, and effective technique for isolated medial orbital wall fracture reconstruction.

Three-Dimensional Printed Model and Transantral Endoscopy to Orbital Fracture Repair

Orbital fractures are high prevalent and result in several complications such as diplopia, muscular entrapment, visual impairment, and enophthalmos. The goal of orbital reconstruction is to restore orbital anatomy, volume, and globe symmetry. This case report aims to describe the use of transantral endoscopy and 3D printed model for treatment of an orbital floor fracture. A 54-year-old woman presented orbital floor fracture with diplopia and extraocular muscle entrapment. The surgical treatment was performed using a standard titanium mesh bended over 3D printed model, and transantral endoscopy to verify fracture extension and implant adaptation. The postoperative evaluation demonstrates correction of diplopia and ocular motility restriction. Computed tomography scan showed reestablishment of the orbital anatomy. The association of transantral endoscopy and 3D printed models is a feasible technique to improve orbital reconstruction.

Is There a Difference in Orbital Volume Between Affected and Unaffected Sides in Patients With Unilateral Craniofacial Microsomia?

PURPOSE

Craniofacial microsomia (CFM) is characterized by malformations of structures derived from the first and second pharyngeal arches. The orbit is variably affected. The purpose of this study was to determine whether there is a difference in orbital volume between affected and unaffected sides in patients with unilateral CFM. The specific aims were to 1) measure orbital volume, 2) compare affected and unaffected sides, 3) evaluate the correlation between clinical evaluation of orbital size and volumetric measurement, and 4) determine whether there is a correlation between orbital volume and severity of mandibular deformity.

MATERIALS AND METHODS

This study is a retrospective case series of patients with unilateral CFM from Boston Children's Hospital (Boston, MA) who had a computed tomographic (CT) scan. Manual segmentation of the orbit using Mimics software (Materialise, Leuven, Belgium) was performed on CT images of the 2 orbits. The predictor variable was laterality (affected vs unaffected side) and the primary outcome variable was orbital volume. Wilcoxon signed rank test was used to compare these measurements and determine whether the affected side differed from the unaffected side. The correlation between orbital volume and Pruzansky-Kaban type of mandibular deformity, as documented in the medical record, was determined using the Spearman rank correlation coefficient.

RESULTS

Thirty-nine patients were included. Orbital volume was 10% smaller on the affected side (P = .001) in 80% of patients. There was no correlation between orbital size and severity of mandibular involvement.

CONCLUSION

The results of this study showed a marked difference in orbital volume between affected and unaffected sides in patients with unilateral CFM. These differences were small and might not be clinically relevant. Orbital volume did not correlate with severity of mandibular deformity.

Is there an ideal implant for orbital reconstructions? Prospective 64-case study

The aim of this study was to compare the effectiveness of porous polyethylene, titanium mesh, and castor oil-derived biopolymer randomized in orbital reconstructions of defects larger than 1 cm in length on the inferior and medial walls. A total of 63 patients (64 orbits) were evaluated to determine the presence of diplopia, enophthalmos ocular motility, and infraorbital nerve paraesthesia in both the preoperative and postoperative periods. The surgeons' opinions of the ease in handling the implants were also obtained after each procedure. The patients were divided into 3 groups: 17 received porous polyethylene, 21 received castor oil-derived biopolymer, and 26 received titanium mesh. In the preoperative period, 30 patients experienced enophthalmos, 11 experienced diplopia, and 12 experienced ocular motility. Ninety days after the orbital reconstruction, 6 cases of enophthalmos persisted, as did 2 cases of diplopia and 2 cases of ocular motility. Ten patients developed some type of postoperative complication. Material removal was required in only 1 case. Regardless of the size of the defect, the materials used were found to be effective for reconstructing orbital volume; they were also found to offer ease in handling and stabilization.

Virtual Surgical Planning for Orbital Reconstruction

The advent of computer-assisted technology has revolutionized planning for complex craniofacial operations, including orbital reconstruction. Orbital reconstruction is ideally suited for virtual planning, as it allows the surgeon to assess the bony anatomy and critical neurovascular structures within the orbit, and plan osteotomies, fracture reductions, and orbital implant placement with efficiency and predictability. In this article, we review the use of virtual surgical planning for orbital decompression, posttraumatic midface reconstruction, reconstruction of a two-wall orbital defect, and reconstruction of a large orbital floor defect with a custom implant. The surgeon managing orbital pathology and posttraumatic orbital deformities can benefit immensely from utilizing virtual planning for various types of orbital pathology.

Inaugural Survey on Practice Patterns of Orbital Floor Fractures for American Oral and Maxillofacial Surgeons

PURPOSE

In recent years, several studies have reported on practitioners' preferences for the treatment of orbital floor fractures, showing widely varying practice patterns. The purpose of the present study was to identify the practice patterns among oral and maxillofacial surgeons involved in the management of orbital floor fractures in the United States and compare them with the available published data.

MATERIALS AND METHODS

An anonymous survey was created and electronically mailed to surgeons. We also reviewed the published data on orbital floor fractures using a PubMed and MEDLINE search. The responses to the survey were analyzed using descriptive statistics.

RESULTS

The factors that had the greatest influence on the surgeon's decision to operate were a defect size > 2 cm2, enophthalmos, entrapment, and persistent diplopia. The most common surgical approach reported was a preseptal transconjunctival approach (32.0%), followed by the subciliary (27.9%) and postseptal transconjunctival (26.2%) approaches. The most commonly reported implant for orbital reconstruction was titanium (65.4%), followed by Medpor (43.7%) and composite Medpor and titanium (26.4%). The review of the published data showed a consensus among many of the operative indications mentioned, including a large defect size, enophthalmos, clinical entrapment, and persistent diplopia.

CONCLUSIONS

Oral and maxillofacial surgeons in the United States have a wide range of practice habits in the management of orbital floor fractures. Although the quality of the available evidence is poor, it supports a consistent approach to the management of orbital floor fractures in terms of the indications and surgical approach. The choice of reconstructive material and timing of repair remain more controversial. A clear need exists for improvement in the available data to help guide and set standards of care for the specialties managing orbital floor fractures.

Biomaterials for repair of orbital floor blowout fractures: a systematic review

PURPOSE

To evaluate the reported use and outcomes of implant materials used for the restoration of post-traumatic orbital floor defects in adults.

MATERIALS AND METHODS

A systematic search of the English literature was performed in the databases of PubMed, Cochrane Library, and EMBASE. The study selection process was adapted from the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement, and 55 articles complied with the study inclusion criteria. The primary outcome measures were diplopia, enophthalmos, graft extrusion/displacement, and infection related to the graft material. The secondary outcome measures were infraorbital paresthesia, orbital dystopia, orbital soft tissue entrapment, and donor-site complications.

RESULTS

Of 55 articles, 41 (74.5%) evaluated were retrospective case series, 9 (16.4%) were retrospective case-control studies, 3 (5.5%) were controlled trials, and 2 (3.6%) were prospective case series. Autogenous graft materials were predominantly used in 19 studies, alloplastic materials were used in 33 studies, and the remaining 3 articles reported on allogeneic materials. Overall, 19 different types of implant materials were used in 2,483 patients. Of 827 patients with diplopia before surgery, 151 (18.3%) had diplopia postoperatively. Of 449 patients with enophthalmos before surgery, 134 (29.8%) had enophthalmos postoperatively. Only 2 patients (0.1%) and 14 patients (0.6%) had graft extrusion/displacement and infection related to the graft material, respectively; alloplastic biomaterials were used in all of these cases.

CONCLUSIONS

All graft materials used were successful to variable degrees because all studies reported improvement in terms of the recorded outcome measures. A guideline for choice of implant material based on defect size was developed.

Preformed vs intraoperative bending of titanium mesh for orbital reconstruction

OBJECTIVE

The most accurate orbital reconstructions result from an anatomic repair of the premorbid orbital architecture. Many different techniques and materials have been used; unfortunately, there is currently no optimal method. This study compares the use of preformed vs intraoperative bending of titanium mesh for orbital reconstruction in 2-wall orbital fractures.

STUDY DESIGN

Cadaver-based study.

SETTING

University hospital.

SUBJECTS AND METHODS

Preinjury computed tomography scans were obtained in 15 cadaveric heads (30 orbits). Stereolithographic (STL) models were fabricated for 5 of the specimens (10 orbits). Two wall fractures (lamina papyracea and floor) were then generated in all orbits. Surgical reconstruction was performed in all orbits using 1 of 3 techniques (10 orbits each): (1) patient-specific implant molded from the preinjury STL model, (2) titanium mesh sheet bent freehand, and (3) preformed titanium mesh. Each technique was evaluated for orbital volume correction, contour accuracy, ease of use, and cost.

RESULTS

No difference in volume restoration was found between the 3 techniques. Patient-specific implants had the greatest contour accuracy, poor ease of use, and highest cost. Freehand bending implants had the poorest contour accuracy, acceptable ease of use, and lowest cost. Preformed mesh implants had intermediate contour accuracy, excellent ease of use, and low cost.

CONCLUSION

All 3 techniques provide equivalent orbital volume correction. However, preformed mesh implants have many advantages based on contour accuracy, ease of use, and relative cost.

Radiologic and long-term clinical outcome from treatment of isolated medial orbital wall blowout fractures

Blowout fractures in the medial orbital wall may lead to enophthalmos, ocular dysmotility, and diplopia. Ten consecutive patients with unilateral, isolated fractures of the medial orbital wall were retrospectively studied. The radiologic accuracy of the medial orbital wall reconstructions and the long-term clinical outcomes were assessed. All cases were treated through a bicoronal approach and by use of porous polyethylene-titanium implants. The total fracture area and the orbital volume increase from the blowout were measured on computed tomographic scans. Next, we evaluated the reconstruction in the posterior part of the medial wall. This was done by calculating the ratio between the defect area and the implant area located behind the anterior ethmoidal canal. The patients were examined at least 1 year after the operation, and the rates of enophthalmos and diplopia were evaluated. The mean fracture defect area was 2.45 cm2 (range, 0.41-4.16 cm2), and the mean volume increase from the blowout fractures was 1.82 cm3 (range, 0.53-2.76 cm3). The orbital volume was accurately restored in all patients. However, the ratio of implant to defect area behind the anterior ethmoidal canal ranged from 0% to 100% (mean, 47.3%). None of the patients had enophthalmos or diplopia at the long-term follow-up. The results confirm that restoration of orbital volume is important to prevent postoperative enophthalmos in isolated medial orbital blowout fractures. Complete reconstruction of the most posterior part of the medial orbital wall seems to be of lesser importance.

[Post-traumatic orbital reconstruction comparing preformed versus non preformed titanium mesh plates]

AIM

We compared, clinically and radiologically, the accuracy and reliability of two types of titanium mesh plates used for orbital reconstruction. The first were non-preshaped mesh plates (NPMP) and the second were three-dimensionally preformed mesh plates (PMP).

METHODS

Two groups were created, each including 15 patients treated with NPMP and the second formed by 15 patients treated with PMP. The volume of each orbit was computed from coronal CT-scans using the OsiriX medical imaging software (version 3.3.2, www.osirix-viewer.com). Measurements were done for both, healthy and reconstructed sides. The other studied parameters were: sex, age, fracture distribution, and complications (diplopia and enophthalmia).

RESULTS

The orbital volume difference between the reconstructed and the healthy contralateral side was not statistically significant in either group (NPMP: p=0.991 PMP: p=0.200). The mean orbital volume of reconstructed orbits was not statistically significant in either group (NPMP: 21.76 cm(3) and PMP: 20.28 cm(3), p=0.441).

DISCUSSION

There is no difference in orbital volume reconstructions measured by the OsiriX software between non-preshaped and three-dimensionally preformed titanium mesh plates.

Update on orbital reconstruction

PURPOSE OF REVIEW

Orbital trauma is common and frequently complicated by ocular injuries. The recent literature on orbital fracture is analyzed with emphasis on epidemiological data assessment, surgical timing, method of approach and reconstruction materials.

RECENT FINDINGS

Computed tomographic (CT) scan has become a routine evaluation tool for orbital trauma, and mobile CT can be applied intraoperatively if necessary. Concomitant serious ocular injury should be carefully evaluated preoperatively. Patients presenting with nonresolving oculocardiac reflex, 'white-eyed' blowout fracture, or diplopia with a positive forced duction test and CT evidence of orbital tissue entrapment require early surgical repair. Otherwise, enophthalmos can be corrected by late surgery with a similar outcome to early surgery. The use of an endoscope-assisted approach for orbital reconstruction continues to grow, offering an alternative method. Advances in alloplastic materials have improved surgical outcome and shortened operating time.

SUMMARY

In this review of modern orbital reconstruction, several controversial issues such as surgical indication, surgical timing, method of approach and choice of reconstruction material are discussed. Preoperative fine-cut CT image and thorough ophthalmologic examination are key elements to determine surgical indications. The choice of surgical approach and reconstruction materials much depends on the surgeon's experience and the reconstruction area. Prefabricated alloplastic implants together with image software and stereolithographic models are significant advances that help to more accurately reconstruct the traumatized orbit. The recent evolution of orbit reconstruction improves functional and aesthetic results and minimizes surgical complications.

Combined mycophenolate mofetil and prednisone therapy in tamoxifen- and prednisone-resistant Reidel's thyroiditis

BACKGROUND

Mycophenolate mofetil is a recently identified therapy for disorders associated with systemic fibrosis, but has never been reported in the treatment of Reidel's thyroiditis. We report the first case of Reidel's thyroiditis that became resectable after treatment with mycophenolate and prednisone.

SUMMARY

A 27-year-old woman presented to an outside hospital with thyromegaly associated with compressive symptoms. The patient underwent a neck exploration with thyroid biopsy that revealed evidence of fibrosing variant Hashimoto's thyroiditis. The patient was then treated with tamoxifen and prednisone at an outside hospital without resolution. After initial evaluation she underwent an open thyroid wedge biopsy that revealed Reidel's thyroiditis. She was subsequently treated with both 1 g mycophenolate twice daily and 100 mg prednisone daily. The patient experienced immediate subjective improvement of compressive symptoms and objective decrease in mass size at 30 days, as seen by serial computed tomography examination. By 90 days of therapy the mass had decreased to a size small enough to allow subtotal thyroidectomy, which was completed over two staged procedures.

CONCLUSIONS

Reidel's thyroiditis remains a primarily surgical disease. Patients who are not surgical candidates have been treated with tamoxifen and prednisone with equivocal results. Our report is the first to suggest the combination of mycophenolate and prednisone as a viable treatment option for patients with Reidel's thyroiditis.