Comparison of the supporting strength of a poly-L-lactic acid sheet and porous polyethylene (Medpor) for the reconstruction of orbital floor fractures

Controversies and Contemporary Management of Orbital Floor Fractures

Substantial controversy exists regarding the timing of intervention and management of patients with orbital floor fractures. Recent advances in computer-aided technology, including the use of 3-dimensional printing, intraoperative navigational imaging, and the use of novel implants, have allowed for improvement in prospective management modalities. As such, this article aims to review the indications and timing of repair, surgical approaches, materials used for repair, and contemporary adjuncts to repair. Indications for orbital floor fracture repair remain controversial as many of these fractures heal without intervention or adverse sequelae. Intraoperative navigation and imaging, as well as endoscopic guidance, can improve visualization of defects mitigating implant positioning errors, thereby reducing the need for secondary corrective procedures. Patient-specific implants may be constructed to fit the individual patient's anatomy using the preoperative CT dataset and mirroring the contralateral unaffected side and have been shown to improve pre-operative efficiency and minimize postoperative complications. With increased data, we can hope to form evidence-based indications for using particular biomaterials and the criteria for orbital defect characteristics, which may be best addressed by a specific surgical approach.

Blowout Fracture Assessment Based on Computed Tomography and Endoscopy: The Effectiveness of Endoscopy for Fracture Repair

ABSTRACT

The purpose of this study was to compare the configuration of blowout fracture observed through orbital computed tomography (CT) and endoscopy, then present the effectiveness of using an endoscope in reconstruction surgery of blowout fracture. We retrospectively reviewed the clinical records of 337 patients who underwent reconstruction surgery of blowout fracture between January 2017 and December 2020 in the Department of Ophthalmology at Korea University Guro Hospital. The patients were categorized into 3 groups based on preoperative CT findings as follows: combined orbital medial and floor wall fractures, trapdoor fractures, and large blowout fractures. The images obtained through CT and endoscopy were compared among the 3 groups. Endoscopy helped identify herniated soft tissue and posterior fracture margins, and it also provides better magnification and a brighter view of the posterior aspects of the fracture site. Furthermore, endoscopy can also provide educational opportunities to visualize the fracture site and help trainees understand the surgical procedure approach or orbital anatomy. Based on our results, we suggest using an endoscope during blowout fracture surgery as an effective approach to reduce postoperative complications due to endoscopy's advantages in clear visualization of the fracture site during operation.

A Multi-Criteria Assessment Strategy for 3D Printed Porous Polyetheretherketone (PEEK) Patient-Specific Implants for Orbital Wall Reconstruction

Pure orbital blowout fractures occur within the confines of the internal orbital wall. Restoration of orbital form and volume is paramount to prevent functional and esthetic impairment. The anatomical peculiarity of the orbit has encouraged surgeons to develop implants with customized features to restore its architecture. This has resulted in worldwide clinical demand for patient-specific implants (PSIs) designed to fit precisely in the patient's unique anatomy. Material extrusion or Fused filament fabrication (FFF) three-dimensional (3D) printing technology has enabled the fabrication of implant-grade polymers such as Polyetheretherketone (PEEK), paving the way for a more sophisticated generation of biomaterials. This study evaluates the FFF 3D printed PEEK orbital mesh customized implants with a metric considering the relevant design, biomechanical, and morphological parameters. The performance of the implants is studied as a function of varying thicknesses and porous design constructs through a finite element (FE) based computational model and a decision matrix based statistical approach. The maximum stress values achieved in our results predict the high durability of the implants, and the maximum deformation values were under one-tenth of a millimeter (mm) domain in all the implant profile configurations. The circular patterned implant (0.9 mm) had the best performance score. The study demonstrates that compounding multi-design computational analysis with 3D printing can be beneficial for the optimal restoration of the orbital floor.

Comparison of Nasoseptal Cartilage Graft Versus Titanium Mesh in Reconstruction of Pure Orbital Blowout Fractures

PURPOSE

To compare the efficacy of nasoseptal cartilage grafts versus titanium mesh implants in pure orbital blowout fractures.

METHODS

A retrospective review was performed on 48 patients who had surgical repair of an orbital fracture. Patients who underwent pure orbital blowout fracture repair with either nasoseptal cartilage grafts or titanium mesh implants and at least 1 year postoperative follow-up were included in the study. The clinical features and treatment outcomes were analyzed.

RESULTS

Twenty-five patients fulfilled our study criteria and were included in the analyses. Nasoseptal graft was used in 12 patients (48%) while titanium mesh was preferred in 13 patients (52%). Preoperative clinical features including age, size of the floor defect, and preoperative clinical findings (enophthalmos, diplopia, and restriction of ocular motility) were similar between 2 groups. Mean postoperative follow-up was 14.7 ± 2.3 months in the nasoseptal group while it was 16.1 ± 2.5 months in the titanium group (P = 0.84). Diplopia and ocular motility limitation were resolved in all patients at the last postoperative follow-up visit, while 1 patient in each group had enophthalmos (8.3% versus 7.6%, P = 1.0). No patient in the nasoseptal group experienced postoperative complications while 2 patients in the titanium group (15.3%) developed material-related complications (P = 0.48).

CONCLUSIONS

Long-term clinical results of nasoseptal cartilage grafts and titanium mesh implants in pure orbital blowout fractures with preoperative floor defects smaller than 4 cm2 were comparable. Nasoseptal cartilage grafts may be preferred in patients with septal deviation and no spurs or turbinate hypertrophy.

Recurrent Orbital Trauma Following Repaired Orbital Floor Fracture

A study of a 22-year-old male who was assaulted and sustained a left orbital floor blowout fracture was presented in this study. The orbital floor was repaired with a titanium-reinforced porous polyethylene implant. Two years postoperatively, the patient sustained repeated left orbital trauma. The orbital floor implant remained stable while the medial wall blew out.

Correction of post-traumatic enophthalmos with anatomical absorbable implant and iliac bone graft

BACKGROUND

Trauma is one of the most common causes of enophthalmos, and post-traumatic enophthalmos primarily results from an increased volume of the bony orbit. We achieved good long-term results by simultaneously using an anatomical absorbable implant and iliac bone graft to correct post-traumatic enophthalmos.

METHODS

From January 2012 to December 2016, we performed operations on seven patients with post-traumatic enophthalmos. In all seven cases, reduction surgery for the initial trauma was performed at our hospital. Hertel exophthalmometry, clinical photography, three-dimensional computed tomography (3D-CT), and orbital volume measurements using software to calculate the specific volume captured on 3D-CT (ITK-SNAP, Insight Toolkit-SNAP) were performed preoperatively and postoperatively.

RESULTS

Patients were evaluated based on exophthalmometry, clinical photographs, 3D-CT, and orbital volume measured by the ITK-SNAP program at 5 days and 1 year postoperatively, and all factors improved significantly compared with the preoperative baseline. Complications such as hematoma or extraocular muscle limitation were absent, and the corrected orbital volume was well maintained at the 1-year follow-up visit.

CONCLUSION

We present a method to correct enophthalmos by reconstructing the orbital wall using an anatomical absorbable implant and a simultaneous autologous iliac bone graft. All cases showed satisfactory results for enophthalmos correction. We suggest this method as a good option for the correction of post-traumatic enophthalmos.

Restoration of the inferomedial orbital strut using a standardized three-dimensional printing implant

The inferomedial orbital strut (IOS) is the thin bony junction of the orbital medial wall and floor. Its fracture is common and leads to serious complications, including enophthalmos, globe dystopia and diplopia. However, anatomical restoration of the IOS is challenging owing to reduced structural support; sound anatomical background and accurate implants are therefore essential. The aim of the present study was to incorporate data from cadaveric orbit anatomy into three-dimensional (3D) printing technology and to reconstruct the complex orbital fracture elaborately. After averaging the data from computed tomography (CT) images of 100 adult cadavers, the dimensions of the IOS were extracted, and a tangent sphere was created using a computer-aided design program. The curves were compared with the CT data of 10 adult patients from the simulation test. Based on these data, a standardized 3D implant, 1.15 mm thick, was designed using polycaprolactone. The implant was placed in five patients with complex orbital fractures. The radius of the sphere in contact with the orbit, measuring 33.54 mm, was confirmed to be appropriate. A comparison between the normal side volume (V0) and the postoperative volume (V_post ) showed that they were statistically similar. Furthermore, a comparison between V0 and the preoperative volume (V_pre ), and V_post compared with V_pre also showed a statistically significant difference (P < 0.05). On follow-up, the preoperative ocular symptoms were resolved. The orbital data obtained from 100 cadavers provided standardized orbital anatomy, and 3D printed implants were created. The implants were anatomically accurate with regard to the orbital cavity and adequately covered the simulation model. The implant also showed satisfactory results when applied clinically in actual patients.

Permanent Versus Bioresorbable Implants in Orbital Floor Blowout Fractures

PURPOSE

To compare the outcomes of bioresorbable and permanent implants in the reconstruction of isolated orbital floor blowout fractures.

METHODS

Retrospective series of all patients who had orbital floor fracture repair in a single tertiary trauma center from January 2005 to December 2014. The authors reviewed the case notes and CT scans of patients with orbital floor fracture repair with either bioresorbable or permanent implants. Main outcome measures were enophthalmos, diplopia, and ocular motility restriction 1.5 years after fracture repair. Implant-related complications were collected for analysis.

RESULTS

There were a total of 88 patients in our study. Bioresorbable implants were used in 48 patients (54.5%) while 40 patients had permanent implants (45.5%). The authors analyzed the implants used in various sizes of orbital fractures: small (<13.3 mm), medium (13.3-20 mm), and large (>20 mm). One and a half years after fracture repair, both groups had comparable clinical outcomes (n = 2 and n = 0 for diplopia for permanent and bioresorbable implant groups, respectively, n = 0 for enophthalmos for both groups and n = 1 for ocular motility limitation for both groups) overall and across all fracture sizes.

CONCLUSION

Bioresorbable implants degrade after fracture healing through hydrolysis and promote the gradual transfer of functional forces to healing bone during its disintegration. The clinical outcomes of diplopia, enophthalmos, and ocular motility restriction associated with the use of resorbable implants are comparable to that of permanent implants for all fracture sizes. Their study shows that bioresorbable and permanent implants are equally safe and effective for the treatment of patients with isolated orbital floor blowout fractures.

High-Density Polyethylene Material versus Autogenous Grafts in Craniofacial Augmentation Procedures

AIM

The objective was to do a comparative study and to evaluate the outcome in overall acceptance for correction of residual facial deformity with autogenous graft versus porous polyethylene implants.

MATERIALS AND METHODS

A total of 16 patients in the age group of ≥15 years irrespective of sex, caste, religion, and socioeconomic status presenting with signs and symptoms of residual facial deformities and who were declared fit for surgery were included in the study. The study patients were further divided into two groups, of eight each. Deformity correction using autogenous grafts was performed in Group A and using high-density polyethylene (HDPE) alloplastic implants was performed in Group B. During the follow-up period, patients' and doctor rating of overall acceptance between autogenous and alloplastic (HDPE) bone grafts was recorded on 100-mm visual analog scale (VAS) on the 2nd day and 7th day and at 3, 6, and 12 weeks.

RESULTS

The unpaired t-test is used for evaluation. VAS score at all the follow-up periods above stated was significantly higher in alloplastic group than in the autogenous group for both in patients and doctor evaluation.

CONCLUSION

From the present study, it can be concluded that porous HDPE implants are an effective alternative to autogenous grafts in accordance of overall acceptance for correction of residual facial deformity when proper case selection, exclusion of negative prognostic factors, and meticulous surgical procedure are followed.

Orbital wall restoring surgery with resorbable mesh plate

BACKGROUND

Orbital resorbable mesh plates are adequate to use for isolated floor and medial wall fractures with an intact bony buttress, but are not recommended to use for large orbital wall fractures that need load bearing support. The author previously reported an orbital wall restoring surgery that restored the orbital floor to its prior position through the transnasal approach and maintained temporary extraorbital support with a balloon in the maxillary sinus. Extraorbital support could reduce the load applied on the orbital implants in orbital wall restoring surgery and the use of resorbable implants was considered appropriate for the author's orbital wall restoring technique.

METHODS

A retrospective review was conducted of 31 patients with pure unilateral orbital floor fractures between May 2014 and May 2018. The patients underwent transnasal restoration of the orbital floor through insertion of a resorbable mesh plate and maintenance of temporary balloon support. The surgical results were evaluated by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR) values.

RESULTS

The OVR decreased significantly, by an average of 6.01% (p< 0.05) and the preoperative and postoperative Hertel scale measurements decreased by an average of 0.34 mm with statistical significance (p< 0.05). No complications such as buckling or sagging of the implant occurred among the 31 patients.

CONCLUSION

The use of resorbable mesh plate in orbital floor restoration surgery is an effective and safe technique that can reduce implant deformation or complications deriving from the residual permanent implant.

Evidence-based medicine: Orbital floor fractures

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Explain the epidemiology, anatomy, and pathophysiology of orbital floor fractures. 2. Select the optimal timing of--and understand the indications for-operative repair of orbital floor fractures. 3. List advantages and disadvantages of the surgical approaches and materials available for orbital floor reconstruction. 4. Identify special considerations in treating pediatric patients presenting with orbital floor fractures.

SUMMARY

This maintenance of certification module reviews the anatomy, pathophysiology, diagnosis, and management of orbital floor fractures in addition to special considerations for pediatric patients. The shows the evidence rating scale used for the literature review in creating this maintenance of certification article.

Comparison of Absorbable Mesh Plate versus Titanium-Dynamic Mesh Plate in Reconstruction of Blow-Out Fracture: An Analysis of Long-Term Outcomes

Background

A blow-out fracture is one of the most common facial injuries in midface trauma. Orbital wall reconstruction is extremely important because it can cause various functional and aesthetic sequelae. Although many materials are available, there are no uniformly accepted guidelines regarding material selection for orbital wall reconstruction.

Methods

From January 2007 to August 2012, a total of 78 patients with blow-out fractures were analyzed. 36 patients received absorbable mesh plates, and 42 patients received titanium-dynamic mesh plates. Both groups were retrospectively evaluated for therapeutic efficacy and safety according to the incidence of three different complications: enophthalmos, extraocular movement impairment, and diplopia.

Results

For all groups (inferior wall fracture group, medial wall fractrue group, and combined inferomedial wall fracture group), there were improvements in the incidence of each complication regardless of implant types. Moreover, a significant improvement of enophthalmos occurred for both types of implants in group 1 (inferior wall fracture group). However, we found no statistically significant differences of efficacy or complication rate in every groups between both implant types.

Conclusions

Both types of implants showed good results without significant differences in long-term follow up, even though we expected the higher recurrent enophthalmos rate in patients with absorbable plate. In conclusion, both types seem to be equally effective and safe for orbital wall reconstruction. In particular, both implant types significantly improve the incidence of enophthalmos in cases of inferior orbital wall fractures.

Orbital floor reconstruction considering orbital floor slope

Orbital floor fractures are among the more challenging injuries faced by plastic surgeons. Enophthalmos is defined as backward, usually downward, displacement of the globe into the bony orbit. We describe reconstruction of the orbital floor slope in orbital floor fractures that prevents postoperative complications, especially posttraumatic enophthalmos. Thirty-three patients with orbital floor fractures were treated using reconstruction of the orbital floor slope between April 2009 and July 2010. The patients ranged in age from 12 to 54 years. There were 31 males and 2 females. All patients were operated on using a transconjunctival approach under general anesthesia. The orbital floor was reconstructed with poly-l/d-lactide sheets in all cases. Preoperatively, 23 [Float1]patients (69%) had enophthalmos, and 12 patients (36%) had symptomatic diplopia. The enophthalmos was corrected in 20 patients (86%), and the diplopia resolved in 10 (83%). Extrinsic ocular movement was impaired preoperatively in 1 patient (3%), but resolved after surgery. No patient had impaired visual acuity preoperatively or postoperatively. The results suggest that orbital floor reconstruction considering the orbital floor slope is a safe, reliable method with fewer complications that is more effective at preventing posttraumatic enophthalmos.

Biomaterial guides for lymphatic endothelial cell alignment and migration

Axillary dissection during breast cancer surgery produces extensive lymphatic vessel damage that often leads to lifelong secondary lymphedema of the arm. We have developed a biodegradable material conduit for lymphatic vessel reconstruction where fibers electrospun along the conduit lumen promote endothelial cell alignment and migration in vitro. The diameter and density of the electrospun fibers were optimized for cell migration and direction on two-dimensional substrates by seeding human lymphatic endothelial cells (LECs) onto aligned fibers of varying diameters and densities, randomly oriented fibers, and film substrates with no fibers. We found that LECs became aligned in the fiber direction, with cells seeded on the randomly oriented fibers becoming oriented in random directions, whereas cells seeded on the highly aligned fibers became highly aligned. Cell migration was dependent upon fiber alignment and density, with optimal migration found on 1300 nm diameter aligned fibers of low density. Blood endothelial cells seeded on the fibers exhibited similar behavior as the LECs. Fiber alignment was preserved upon rolling the two-dimensional substrate into the tubular geometry of a lymphatic vessel. The data suggest that aligned electrospun fibers may promote endothelial migration across the conduit in a manner that is independent of lymphatic growth factors.