Hospital Universiti Sains Malaysia Experience in Orbital Floor Reconstruction: Autogenous Graft Versus Medpor

Delayed Orbital Floor Reconstruction Using Mirroring Technique and Patient-Specific Implants: Proof of Concept

Enophthalmos is a severe complication of primary reconstruction following orbital floor fractures, oncological resections, or maxillo-facial syndromes. The goal of secondary orbital reconstruction is to regain a symmetrical globe position to restore function and aesthetics. In this article, we present a method of computer-assisted orbital floor reconstruction using a mirroring technique and a custom-made titanium or high-density polyethylene mesh printed using computer-aided manufacturing techniques. This reconstructive protocol involves four steps: mirroring of the healthy orbit computer tomography files at the contralateral affected site, virtual design of a customized implant, computer-assisted manufacturing (CAM) of the implant using Direct Metal Laser Sintering (DMLS) or Computer Numerical Control (CNC) methods, and surgical insertion of the device. Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography measures in 13 treated patients and compared to a control group treated with stock implants. An improvement of 3.04 mm (range 0.3-6 mm) in globe protrusion was obtained for the patients treated with patient-specific implants (PSI), and no major complications have been registered. The technique described here appears to be a viable method for correcting complex orbital floor defects needing delayed reconstruction.

Orbital Fractures: A New CT-Based Protocol to Guide the Surgical Approach and Reconstruction Material Decision-Making

Preoperative computer-assisted planning and intraoperative navigation are becoming popular for orbital fracture treatment. However, not all institutions currently have access to these computer-aided applications. The authors present a simple and intuitive operative algorithm to guide orbital fracture reconstructions. The operative algorithm was based on linear measurements of orbital defects on high-resolution Computer tomography (CT) scans using specific axial, coronal, and sagittal plane images. The fractures were then divided into 3 types based on site and defect-size area. For each type, the authors suggested a surgical approach and material reconstruction. Between February 2022 and January 2023, 57 patients were treated according to the described CT-based protocol. The quality of reconstruction was classified as ideal, satisfactory, acceptable, and poor based on postoperative CT. Diplopia, enophthalmos, and postoperative complications were assessed. Fifty-seven patients were included. Forty-four (77.2%) patients were included in the type 1 group, 4 (7.01%) in the type 2 group, and 9 (15.79%) in the type 3 group. The reconstruction was considered ideal in 54 (94.7%) cases, satisfactory in 2 (3.5%), and acceptable in 1 (1.8%). No revision surgery was required. In all cases, preoperative diplopia was settled out, and only 1 patient reported postoperative enophthalmos. No complications occurred, with good clinical results and orbital symmetry. The linear CT measurement-based protocol is a simple and reliable workflow to guide the surgeon's choice of reconstruction material and surgical approach for primary orbital reconstruction. It allows good management of orbital trauma and could help standardize treatment decisions with an imaging technique available in all institutions.

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.

Clinical evaluation of the efficacy of materials used for primary reconstruction of orbital floor defects: Meta-analysis

BACKGROUND

The aim of this network meta-analysis (NMA) was to compare the clinical results obtained after primary reconstruction of orbital floor fractures (OFF) using different materials.

METHODS

PubMed, Cochrane, and Google Scholar databases were screened from 1989 to 2019. For a study to be eligible, it had to evaluate two or more materials and report the following clinical parameters: diplopia and/or enophthalmos and/or other complications.

RESULTS

Nine studies involving 946 patients presenting with an OFF were included. After the surgical procedure, 105 patients (11%) had diplopia, while 43 patients (4.5%) suffered from enophthalmos. The NMA revealed that less postoperative diplopia and enophthalmos were obtained either by using polydioxanone (PDS), or a polymer of l-lactic acid and dl-lactic acid (P[L/DL]LA), or porous polyethylene, or titanium mesh compared with the use of autologous bone grafts.

CONCLUSION

P(L/DL)LA and PDS seem to be the best options for small and intermediate defects, whereas the association of porous polyethylene and titanium should be preferred for larger defects.

Reconstruction of Orbital Floor With Auricular Concha

Orbital floor fractures of varying sizes commonly occur after orbital injuries and remain a serious challenge. Serious complications of such fractures include enopthalmos, restriction of extraocular movement, and diplopia. There is a dearth of literature that can be applied widely, easily, and successfully in all such situations, and therefore there is no consensus on the treatment protocol of this pathology yet. Autogenous grafts and alloplastic and allogenic materials with a wide variety of advantages and disadvantages have been discussed. The value of preoperative and postoperative ophthalmological examination should be standard of care in all orbital fracture patients. An ideal reconstructed orbital floor fracture should accelerate the restoration of orbital function with acceptable cosmetic results. Management parameters of orbital fractures such as timing of surgery, incision type, and implant materials, though widely discussed, remain controversial. In this study, 55 patients with orbital floor fractures surgically reconstructed with conchal cartilage grafts between 2008 and 2014 were retrospectively evaluated. Complications and long-time follow-up visit results have been reported with clinical and radiographic findings. The aim of this study was to present the authors' clinical experiences of reconstruction of blow-out fractures with auricular conchal graft and to evaluate the other materials available for use.

Postoperative Complications in Craniomaxillofacial Reconstruction With Medpor

Bone reconstruction in craniofacial surgery is a challenge for surgeons, who most commonly adopt the autogenous bone grafting and alloplastic implants in such procedures. Among the alloplastic materials, the high-density porous polyethylene is highlighted-Medpor (Medpor, Porex Surgical Inc, Newman, GA), considered to be pure polyethylene, with only 1 manufacturing process and standard pore size. The purpose of the current study has been to present through a review of literature and the types of complications derived from the use of Medpor in craniomaxillofacial bone surgery. A specific and sensitive database was initially created via PubMed, focusing on studies published in English peer-reviewed journals between 2004 and 2014, including case reports, experimental studies in humans, and prospective and retrospective studies. Forty articles were found at PubMed database. After analyzing their abstracts, 19 were selected, totaling 1453 patients and 121 complications, being the most commonly reported diplopia with 56 patients and infection with 6 patients. Most of the complications reported in the articles used for the development of the current review are not directly related to the use of the Medpor implant. The only complications directly related to the use of this biomaterial were cases of infection.

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.

Reconstruction of Orbital Floor Fractures with Porous Polyethylene Implants: A Prospective Study

PURPOSE

The main aim of our study was to assess and evaluate the efficacy, long standing outcome and infection of porous polyethylene implants in treatment of orbital floor fractures.

PATIENT AND METHODS

Twelve patients with fractures of orbital floor were included in the study. The cause of fracture was road traffic accident, self fall and cow hit respectively. They also complained of enophthalmos (n = 9), diplopia (n = 3), restricted eye movement (n = 2), impairment of infraorbital nerve (n = 3) and dystopia (n = 6). All the fractures were reconstructed with thin porous polyethylene sheets.

RESULTS

No implants were extruded and there were no signs of inflammatory reactions against porous polyethylene implant. In all nine patients with pre-op enophthalmos it was corrected post-operatively with p value = 0.000 and was statistically significant; diplopia in one patient was corrected; persistence of double vision was noted in two patients. Restricted eye movement was corrected in all patients, dystopia was corrected in four patients and in two patients have persisting dystopia. Paresthesia persisted in all three patients.

CONCLUSION

Our experience was that reconstruction of orbital floor fracture using porous polyethylene implant is reliable, safe and effective and may be used for reconstruction of the orbital floor fracture with no donor site morbidity.

Controversies in orbital reconstruction--I. Defect-driven orbital reconstruction: a systematic review

In the 1980s, computed tomography was introduced as an imaging modality for diagnosing orbital fractures. Since then, new light has been shed on the field of orbital fracture management. Currently, most surgeons are likely to repair orbital fractures based on clinical findings and particularly on data obtained from computed tomography scans. However, an important but unresolved issue is the fracture size, which dictates the extent and type of reconstruction. In other fields of trauma surgery, an increasing body of evidence is stressing the importance of complexity-based treatment models. The aim of this study was to systematically review all articles on orbital reconstruction, with a focus on the indication for surgery and the defect size and location, in order to identify the reconstruction methods that show the best results for the different types of orbital fractures.

Reconstruction of orbital floor blow-out fractures with autogenous iliac crest bone: a retrospective study including maxillofacial and ophthalmology perspectives

This is a 10-year retrospective study of patients with an isolated unilateral orbital floor fracture reconstructed with an autogenous iliac crest bone graft. The following inclusion criteria applied: isolated orbital floor fracture without involvement of the orbital rim or other craniofacial injuries, pre-/post-operative ophthalmological/orthoptic follow-up, pre-operative CT. Variables recorded were patient age and gender, aetiology of injury, time to surgery, follow-up period, surgical morbidity, diplopia pre- and post-operatively (Hess test), eyelid position, visual acuity, and the presence of en-/or exophthalmos (Hertel exophthalmometer). Twenty patients met the inclusion criteria. The mean age was 29 years. The mean follow up period was 26 months. No patient experienced significant donor site morbidity. There were no episodes of post-operative infection or graft extrusion. Three patients had diplopia in extremes of vision post-operatively, but no interference with activities of daily living. One patient had post-operative enophthalmos. Isolated orbital blow-out fractures may be safely and predictably reconstructed using autogenous iliac crest bone. The rate of complications in the group of patients studied was low. The value of pre- and post-operative ophthalmology consultation cannot be underestimated, and should be considered the standard of care in all patients with orbitozygomatic fractures, in particular those with blow-out fractures.

Comparison of efficacy of mandible and iliac bone as autogenous bone graft for orbital floor reconstruction

OBJECTIVE

This study evaluated and compared the efficacy of mandible and iliac bone as autogenous bone graft for correction of orbital floor fractures.

PATIENTS AND METHODS

Twenty patients who suffered orbital floor fractures took part in the study. The subjects enrolled in the study sustained both isolated orbital floor fracture and orbital floor fracture associated with fracture of zygomatico-maxillary complex. Each inferior orbital wall was reconstructed using either a mandible bone graft or an iliac graft. Mandibular symphysis was opted as a donor site for graft harvest from mandible and anterior iliac crest for the iliac group. CT scans were taken before the operation. Inclusion criteria consisted of at least 2 months postsurgical follow-up, pre- and post-surgical photographic documentation, and complete medical records regarding inpatient and outpatient data. To describe the distribution of complications and facilitate statistical analysis, we categorized our findings into diplopia, enophthalmos, and restriction of ocular movements before and after treatment. We also considered the time required for the harvest of the grafts and the donor site complications. A comparative study was carried out using Chi square test and student t test. We considered P value <0.05 to be statistically significant.

RESULTS

Ten iliac crest grafts and ten mandible bone grafts were placed. The mean age of the patients was 33.1 years. 80 % of the patients were males. The most common complication of orbital floor fracture was diplopia, followed by enophthalmos and restriction of ocular movements. The post operative results were compared after 2 months of the surgery. In iliac crest group, diplopia got corrected in six out of seven patients (85 %), enophthalmos in four out of five patients (80 %) and restricted ocular movement showed 100 % correction. While in mandible group, diplopia and ocular movement showed 100 % correction and enophthalmos got corrected in five out of six patients (83 %). No statistically significant differences were found between the two groups on comparing these variables. On the other hand the mean time required for the harvest of iliac graft and mandible graft was 30.2 ± 3.52 min and 16.8 ± 1.75 min respectively. The difference was statistically significant.

CONCLUSION

There is no difference in the ability of mandible and anterior iliac crest bone grafts to correct post-traumatic diplopia, enophthalmos and restricted ocular movements. But the time and ease of harvest of the graft from mandible was comparatively less and easy especially when the treating doctor was an oral and maxillofacial surgeon. Secondly the post-operative morbidity was low and the quality and contour of the bone graft was very adaptable for the reconstruction of the orbital floor.

Computer-aided orbital wall defects treatment by individual design ultrahigh molecular weight polyethylene implants

Despite of well-known advantages of high molecular weight polyethylene (Medpor, Synpore) in orbital reconstructions, the thickness of those implants significantly exceeds 0.5 mm and precise modification of thickness is limited. The aim of this study was to present the application of a self-developed method of treatment orbital wall fracture by custom implant made of ultrahigh molecular weight polyethylene (UHMW-PE).

MATERIAL AND METHOD

First, the test of influence of sterilization process upon implant deformation was performed (autoclaving, ethylene oxide, gas plasma, irradiation). Next, ten cases for delayed surgical treatment of orbital fracture were included into this study (7 males, 3 females). Based on CT scan and mirrored technique, a CAD model of virtual implant for repairing orbital wall was made. Then, an implant was manufactured with a computer numerical controlled milling machine from UHMW-PE block, sterilized and used during a surgical procedure. Clinically used implants had thickness from 0.2 to 4.0 mm.

RESULTS

The best method of sterilization is ethylene oxide process, and the worst is autoclaving. In this series of delayed surgical cases, functional results of orbital surgery are worse than in simpler, early treated cases, but long-term subsidence of diplopia is noticeable [10% poor results]. The results of the treatment depend on the initial level of diplopia where severe initial diplopia to be corrected requires thicker implants (p < 0.01). It also leads to longer surgical procedures (p < 0.01), but prolongation of the surgery had no negative influence upon results of any investigated follow-up examinations. Obviously, the orbital destruction intensity is related to injury-evoked initial diplopia but it also influences whole results of treatment up to 12 months post-op. Interesting result is presented by the relation of maximal implant thickness to 12-month diplopia evaluation. Thicker implants used result in lower residual diplopia (p < 0.05). This is important because of the correlation between the higher orbital destruction intensity with a thicker UHMW-PE implant (p < 0.05) applied in this series.

CONCLUSION

Patient-specific ultrahigh molecular weight polyethylene implants enable precise reconstructions of orbital wall. One should not be afraid of a significant eye globe reposition caused by these thickness modulated implants, as such repositioning is essential for an efficient correction of enophthalmos.