Reconstruction Of Orbital Floor Defects Research Articles

Virtual reconstruction of orbital floor defects using a statistical shape model.

PurposeThe current standard in reconstructing defects of the orbital floor, by using the concept of mirroring, is time‐consuming and ignores the natural asymmetry of the skull. By using a statistical shape model (SSM), the reconstruction can be automatized and improved in accuracy. The present study aims to show the possibilities of the virtual reconstruction of artificial defects of the orbital floor using an SSM and its potentials for clinical implementation.MethodsBased on 131 unaffected CT scans of the midface, an SSM was created which contained the shape variability of the orbital floor. Nineteen midface CT scans, that were not included in the SSM, were manually segmented to establish ground truth (control group). Then artificial defects of larger and smaller sizes were created and reconstructed using SSM (Group I) and the gold standard of mirroring (Group II). Eventually, a comparison to the surface of the manual segmentation (control group) was performed.ResultsThe proposed method of reconstruction using an SSM leads to more precise reconstruction results, compared with the conventional method of mirroring. Whereas mirroring led to the reconstruction errors of 0.7 mm for small defects and 0.73 mm for large defects, reconstruction using SSM led to deviations of 0.26 mm (small defect) and, respectively, 0.34 mm (large defect).ConclusionsThe presented approach is an effective and accurate method for reconstructing the orbital floor. In connection with modern computer‐aided design and manufacturing, individual patient‐specific implants could be produced according to SSM‐based reconstructions and could replace current methods using manual bending techniques. By acknowledging the natural asymmetry of the human skull, the SSM‐based approach achieves higher accuracy in reconstructing injured orbits.

English

Maxilla can be considered a hexahedrium with close relationship to surrounding critical anatomic structures, and thereby invariably involved in the resection process of tumours that arise from maxillary sinus, palate, nasal cavity, orbital contents, or intro-oral mucosa.1 Maxillary defects created after tumour ablation can cause severe functional and aesthetic deficits. Orbital floor defects with displacement of the eyeball results in deformities with possible consequences of enophthalmos, diplopia and impaired visual acuity. The eyeball can become displaced either due to alteration in the position of the orbital walls caused by trauma, or due to loss of support of the orbital floor during resection of a lesion. The role of the suspensory ligament of Lockwood in maintaining the superio - inferior position of the visual apparatus is recognized. The preservation of this ligament, which acts like a hammock holding the eyeball in position, prevents any drastic downward displacement except for the small limit which the slack of the ligament allows. Surgical reconstruction of orbital floor defects is the primary treatment modality, but remains nonetheless a challenge for surgeons. Currently various types of materials such as titanium meshes, hydroxyapatite, silica gel, Teflon, Medpor and autogenous bones are used for orbital reconstruction.2,3 Prosthetic rehabilitation of maxillary surgical defects is so predictable and effective that reconstructive surgery is not indicated in most instances.4,5 Prosthetic management of defects with orbital floor resection is usually obturators with extensions to support the visual apparatus.6 In clinical situations involving the resection of the orbital floor and maxillary sinus, without the sacrifice of the floor of maxilla, no oro-antral communication is created. This eliminates the need for an obturator prosthesis. In this scenario the support for the visual apparatus will be solely dependent on surgical reconstruction. However, when dealing with invasive and progressive diseases of fungal and bacterial origin, immediate surgical reconstruction is not generally recommended till complete resolution of the disease is achieved. The potential for recurrence of tumours varies from 10 - 30 % with benign tumours and over 50 % with malignant tumours. This creates a need for long term follow up, to assess the resection margins for signs of recurrence.4

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

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. 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. 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. 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.

CLINICAL EVALUATION OF USING CORTICAL LAMINA XENOGRAFT IN RECONSTRUCTION OF ORBITAL FLOOR

Background: The orbital floor is one of the most frequently injured areas during facial trauma. Their proper treatment is crucial for prevention of orbital complications as diplopia, limitation of ocular motility and enophthalmos. Cortical lamina is a collagenated cortical bone of heterologous origin that is used in grafting of non-load-bearing areas. Objective: To evaluate clinically the use of cortical lamina in the reconstruction of orbital floor defects. Materials and Methods: Ten patients with orbital floor defects less than 2cm were associated with one or more of the following complications; binocular diplopia, enophthalmos, limitation of ocular motility or infra orbital nerve dysfunction, were indicated for orbital reconstruction using cortical lamina xenograft. The follow-up schedule was 1week and 1, 3, 6 months postoperatively. Results: Orbital complications had been resolved in all patients. Only infra orbital nerve dysfunction continued in 7 patients where 3 of patients recovered after 3 months and the other 4 have recovered after 6 months. Conclusions: Cortical lamina xenograft is a good alternative for the reconstruction of orbital floor defects less than 2cm due to its plasticity and biocompatibility without any donor site morbidity.

Reconstruction of orbital floor defect with preserved orbital contents after advanced maxillary sinus cancer resection

Objective: To analyze the method and effect of reconstruction of the orbital floor defect with preserved orbital contents after advanced maxillary sinus cancer resection. Methods: Thirty-three patients of T3/T4 stage maxillary sinus cancer with orbital invasion who were treated in Shandong Provincial Hospital from January 2010 to October 2016 were retrospectively analyzed, including 20 males and 13 females, aged from 12 to 80 years old. Patients were treated with appropriate surgical methods according to their clinical manifestation, imaging finding, invasion range, preoperative and intraoperative pathology. Surgical approaches such as maxillectomy, expanded maxillectomy and superstructure maxillectomy were used for patients with Medpor orbit floor repairment. Patients were followed up regularly after surgery, and the surgical efficacy was discussed by descriptive statistical method. Results: Of those 33 cases, 19 were squamous cell carcinoma, 8 were adenoid cystic carcinoma, 5 were inverted papilloma malignant transformation, and 1 was myoepithelial carcinoma in our study. After tumor resection and orbital floor repair, the orbital contents and eyeball function of all patients remained intact. During follow-up time ranged from 3 to 8 years, a total of 6 patients relapsed at 3 years and died of ineffective treatment. The survival rate was 81.8% (27/33). Conclusion: Tumor resection and Medpor orbital floor repair in maxillary sinus cancer patients with orbital invasion can preserve the function of the eyeball well, greatly improve the quality of patient's life.

CLINICAL AND RADIOGRAPHIC EVALUATION OF THE USE OF ANTERO-LATERAL WALL OF MAXILLARY SINUS FOR RECONSTRUCTION OF ORBITAL FLOOR DEFECT

INTRODUCTION: The orbital floor fracture results in disruption of bony continuity, enophtalmos, diplopia and herniation of orbital content which lead to a restriction in eye movement. Auotogenous bone graft remains as the gold standard for reconstruction of orbital floor defects, the anterolateral wall of maxillary sinus is considered as one of the donor site used in the reconstruction of the orbital floor defects, which has many advantages such as biocompatibility, strength, vascularization and has no immune reaction. In addition, its contour fits exactly the orbital floor defect, a simple harvesting technique from an intraoral donor site which minimizes its morbidity. OBJECTIVE: We aimed in the present study to evaluate the use of anterolateral wall of maxillary sinus clinically and radiographically in the reconstruction of orbital floor defects in ten patients. MATERIALS AND METHODS: All operated patients had more or less one or more signs and symptoms of orbital floor fracture as diplopia, enophthalmos, limitation of eye movements and progressive infraorbital nerve hypoesthesia. The graft harvested with peizosurgery from contralateral side of the fracture, the donor site is covered by a collagen membrane to prevent soft tissue infiltration. The harvested bone graft is adapted to the defect with no other means of fixation. The follow-up schedule was 3 days postoperatively then once weekly for two weeks and then monthly for 3 months. RESULTS: All patients with preoperative diplopia had significant improvement postoperatively. 8 patients out of 9 with preoperative ocular restriction had improvement in the postoperative follow up visits. 6 patients with preoperative enophthalmos showed improvement in the postoperative follow up visits. 7 patients with infra orbital nerve paresthesia preoperatively, all of them showed improvement in the follow up visits. CONCLUSION: The study concluded that the anterolateral wall of the maxillary sinus is a suitable material for orbital floor reconstruction, especially in cases of small to medium defects (< 3 cm2).

The Application of Autogenous Bone for the Reconstruction of Traumatic Defect of Orbital Floor

To study the effects of reconstruction of orbital floor defects with autogenous bone, 20 patients with orbital floor fractures were treated via peri-orbital mini-incision, and orbital floor defects were reconstructed with autogenous bone. The results showed that 20 cases recovered well. There was no infection, optic neuropathy, diplopia and enophthalmos. In general, the data of the study suggest that collagen membrane is an ideal material for orbital reconstruction.

Micro‐porous composite scaffolds of photo‐crosslinked poly(trimethylene carbonate) and nano‐hydroxyapatite prepared by low‐temperature extrusion‐based additive manufacturing

Complex bony defects such as those of the orbital floor are challenging to repair. Additive manufacturing techniques open up possibilities for the fabrication of implants with a designed macro‐porosity for the reconstruction of such defects. Apart from a designed macro‐porosity for tissue ingrowth, a micro‐porosity in the implant struts will be beneficial for nutrient diffusion, protein adsorption and drug loading and release. In this work, we report on a low‐temperature extrusion‐based additive manufacturing method for the preparation of composite photo‐crosslinked structures of poly(trimethylene carbonate) with bone‐forming nano‐hydroxyapatite and noricaritin (derived from bone growth stimulating icariin). In this method, we extrude a dispersion of nano‐hydroxyapatite and noricaritin particles in a solution of photo‐crosslinkable poly(trimethylene carbonate) in ethylene carbonate into defined three‐dimensional structures. The ethylene carbonate is subsequently crystallized and extracted after photo‐crosslinking. We show that this results in designed macro‐porous structures with micro‐pores in the struts. The dispersion used to fabricate these structures shows favorable properties for extrusion‐based processing, such as a sharp crystallization response and shear thinning. The formed photo‐crosslinked materials have a micro‐porosity of up to 48%, and the E modulus, ultimate tensile strength and toughness are in excess of 24 MPa, 2.0 N/mm2 and 113 N/mm2 respectively. A sustained release of noricaritin from these materials was also achieved. The results show that the technique described here is promising for the fabrication of micro‐porous photo‐crosslinked composite structures of poly(trimethylene carbonate) with nano‐hydroxyapatite and that these may be applied in the reconstruction of orbital floor defects. Copyright © 2016 John Wiley &amp; Sons, Ltd.

A New Option for the Reconstruction of Orbital Floor Defects

Orbital floor fractures are one of the most commonly encountered maxillofacial fractures due to its weak anatomic structure. Autogenous bone is a commonly used option for the reconstruction of orbital floor defects by many authors and institutions. This article introduces the olecranon bone graft as a new option for orbital floor reconstruction. The study is based on the analysis of 13 patients with orbital floor fracture operated on by using the olecranon bone graft. The mean age of the patients was 34 years 6 months. The physical examination of 5 (38.5%) patients revealed diplopia, 3 (23%) patients gaze restriction, 3 (23%) patients infraorbital nerve paresthesia, and 7 (53.8%) patients enophthalmos with various degrees. The mean defect size was 21.15 × 14.08 mm and the mean defect field was 2.98 cm2. All patients were operated on under general anesthesia and the orbital floor defect was exposed subperiosteally. The olecranon bone graft was harvested in 10 cases using a 3-cm incision over the olecranon and in 3 cases using the bone biopsy trephine and placed to the orbital floor defect after shaping with cottle cartilage crusher. Both clinical and radiological follow-up examinations were carried out in the postoperative period. The mean follow-up period of the patients was 7.92 months. The mean size of the grafts was 24.85 × 17.54 mL. The mean field of the grafts was 4.26 cm2. Among the 7 patients who had enophthalmos before the surgery, complete resolution was observed in 6 (85.7%) patients and in the remaining 1 (14.3%) patient, the degree of enophthalmos was found to be significantly reduced at the postoperative sixth month examination. All patients with preoperative diplopia and gaze restriction showed complete healing in the postoperative period. Eleven (84.6%) patients showed mild pain at the olecranon donor area with complete relief in the postoperative 3 days and the remaining 2 (15.4%) patients had moderate pain sensation which completely passed away at the postoperative fifth day. The olecranon bone graft is a suitable autogenous option for orbital floor reconstruction due to its considerable strength and molding capacity with low rates of complications and donor area morbidity.

CLINICAL EVALUATION OF THE USE OF PROCEED ® MESH IN RECONSTRUCTION OF ORBITAL FLOOR FRACTURES: CLINICAL TRIAL

Abstract: Introduction: Orbital fracture is a common type of midfacial trauma. Its proper treatment is considered a challenging situation. Otherwise orbital complications; as diplopia, limited ocular motility, enophthalmos, hypoglobus and infraorbital dysesthesia; may occur. Proceed® mesh consists of polypropylene soft mesh encapsulated with polydioxanone (PDS) and layered with oxidized regenerated cellulose (ORC). It is a widely used mesh in hernia repair which is proved to be safe and suitable. The ORC component provides the mesh with some properties differ from other materials. It provides a physical barrier to decrease the adhesion between the mesh and orbital tissue. It is a commonly used hemostatic agent. In addition, it is proved to be antibacterial against many resistant species. The PDS component attaches the ORC with polypropylene soft mesh.Objectives: We aimed in this study to evaluate Proceed® mesh clinically in reconstruction of orbital floor defects in seven patients. Materials and Methods: Indications for intervention were diplopia, enophthalmos, minimal clinical improvement over time under drug therapy, ocular limited motility, dystopia, defect more than 50% of the orbital floor and progressive infraorbital hypoesthesia. The ORC side of the mesh was placed facing orbital soft tissue, while polypropylene side was placed towards orbital bony wall. The follow-up schedule was 3 days postoperatively then once weekly for two weeks and then monthly for 6 months. Results: Clinically, most patients recovered from diplopia, dystopia, ocular restriction and enophthalmos. Two patients had transitory postoperative diplopia (for 1 week), that may be due to postoperative muscle weakness. One patient out of four suffered from preoperative ocular restriction, had no or slight improvement postoperatively. Two patients complained from inflammatory reaction within 2-4 weeks postoperatively, resolved by anti-inflammatory and antibiotic administration. Conclusion: The study concluded that Proceed® mesh is a suitable material for orbital floor reconstruction, especially in cases of small to medium defects (< 3 cm2). Key words: orbital floor, Proceed® mesh, implant material, prolene mesh.

Use of anteriolateral wall of maxilla for reconstruction of orbital floor fracture: A clinical study

Purpose:The aim of the present study was to assess the utility of anterolateral wall of maxilla as a bone graft to reconstruct the continuity of orbital floor.Materials and MethodsThis study was carried out at Datarkar Institute of Maxillofacial Surgery, Pratap Nagar, Nagpur. Out of five patients selected, three were male and two were female. All the patients had intact anterolateral wall of maxilla on contralateral side. In all the patients the reduction of the zygomatic complex fracture was done by Keen's approach. The fractures were stabilized by miniplates. From the contralateral sides,bone graft of 1.5 × 2 cm size was harvested from which were intact in all the patients. All the patients were reviewed at regular interval, initially once every week for 1 month, followed by once in every month for next 6 months postoperatively.Results:Five patients with orbital floor defects of medium size average 1.16 cm size (range 0.8-1.5 cm) were grafted by using autogenous bone graft harvested from anterolateral wall of maxilla. All the patients were successfully reconstructed with restoration of the orbital wall continuity. We have not come across any complications like infection, exposure, and extrusion of the graft. Only one patient did not show much improvement in enopthalmous where the size of the defect was large.Conclusions:The use of harvested bone graft from the anterolateral wall of the maxilla is better option for the reconstruction of orbital floor defects.

Biomechanical properties of novel biodegradable poly ε‐caprolactone–chitosan scaffolds

To investigate the biomechanical properties of poly ε-caprolactone (PCL)-chitosan (CS) scaffolds fabricated by the melt stretching and multilayer deposition technique. The PCL-CS scaffolds containing CS at 0% (pure PCL), 10%, and 20% by weight were prepared. For the monolayer scaffolds, shear and blending tests simulating the reconstruction of orbital floor defects (situation A) and mandibular defects (situation B) were conducted. For the 3-D scaffolds, compression tests of their superior and lateral aspects were done. For the monolayer scaffolds, the pure PCL group had remarkably lower shear strength than the other groups (P > 0.05). In situation A, all groups withstood the forces without any significant difference. In situation B, the pure PCL group could withstand the forces remarkably lower than those of the other group (P < 0.05). The 3-D scaffolds of all groups could withstand compressive forces directed towards their superior aspects. However, they could not withstand the forces directed towards their lateral aspects at the limited strain. The monolayer scaffolds were suitable for reconstruction of the orbital floor and mandibular defects under light load-bearing conditions. The 3-D scaffolds could be used in the high load bearing-areas only if the forces were directed at their superior aspects.

The Use of Detachable Flanges on Customized Titanium Orbital Implants: A Technical Note

The combined use of three-dimensional reformatted images, stereolithographic models, and rapid prototyping allows the construction of an accurate, individually made titanium implant for the reconstruction of orbital floor defects. Despite the perfect fit of the custom-made plate to the model, there might be several locations on the bone where the plate may reside intraoperatively. Most titanium orbital plates therefore contain extensions over the inferior orbital rim to help locate and stabilize the plate in its position on the bone. Such over-the-rim extensions may be palpable and can cause discomfort postoperatively. We describe the use of two small detachable flanges that help to accurately locate the orbital plate in place and allow its fixation. The locating flanges are then detached and discarded, leaving a smooth implant surface within the confines of the bony orbit.

Reconstrução de assoalho orbital com polietileno de alta densidade

&lt;div&gt;Justifica-se intervir cirurgicamente em fraturas do tipo blow out naqueles casos em que haja alterações da função orbital,&lt;/div&gt;&lt;div&gt;como a diplopia, ou mesmo por razões estéticas, como a enoftalmia. Clinicamente, as fraturas do tipo blow out revelam&lt;/div&gt;&lt;div&gt;alterações estéticas e funcionais que, associadas aos exames complementares por imagem, como a tomografia&lt;/div&gt;&lt;div&gt;computadorizada, indicam o procedimento cirúrgico reparador. A utilização do polietileno de alta densidade (PAD) na&lt;/div&gt;&lt;div&gt;reconstrução do assoalho orbital reduz a morbidade do enxerto autógeno, apresentando estabilidade e biocompatibilidade.&lt;/div&gt;&lt;div&gt;Este artigo discute um caso cirúrgico de evolução favorável após seis meses de reconstrução do assoalho orbital com PAD.&lt;/div&gt;

Treatment of orbital floor fracture using a periosteum–polymer complex

Various materials for the reconstruction of bone defects in orbital floor fractures have been developed and applied clinically. Recently, reconstruction using polymers, in place of autologous bone and artificial materials, has been actively introduced, but there are problems, such as the size of reconstructable bone defects and the decomposition rate of polymers. A basic study was performed on bone regeneration using a periosteum-polymer complex produced by attaching periosteum to a biodegradable polymer sheet. In this study, patients with orbital floor fractures were evaluated clinically who had undergone reconstruction of orbital floor defects of the using a periosteum-polymer complex produced by applying periosteum to an Hydroxyapatite-[poly (l-lactide-epsilon-caprolactone)](HA-P (CL/LA)) sheet and the ilium in the previous 3 years. A bone defect of less than 2.5cm(2) area was defined as small, that of 2.5-4cm(2) as intermediate, and that of more than 4cm(2) as a large bone defect. For small bone defects, hypoaesthesia in the infraorbital nerve was observed in one patient each of the periosteum-polymer complex and ilium groups. Regarding intermediate bone defects, diplopia and hypoaesthesia in the infraorbital nerve were observed in one patient in each of the two groups. For large bone defects, diplopia was observed in one patient each for the periosteum-polymer complex and ilium groups, and hypoaesthesia of the infraorbital nerve was only detected in one patient of the former group. Not more than 2mm of enophthalmos was detected in any patient. The anatomical eyeball position and eyeball movement were normal after surgical treatment using the periosteum-polymer complex, just as in reconstruction using autologous bone.

Resorbable Mesh Plate in the Treatment of Blow-out Fracture Might Cause Gaze Restriction

Selection of the material for the reconstruction of orbital floor defects is controversial. There are both autogenous and alloplastic materials, each having its own benefits and disadvantages. Resorbable mesh plate is one of the alloplastic implants. Although it has many advantages, the considerable complication related to the mesh is local inflammatory reaction along the infraorbital rim.We present a patient treated using resorbable mesh plate for the orbital floor fracture, in whom gaze restriction in the eye movements was detected because of some fibrotic bands passing through holes of the resorbable mesh.

Reconstruction of orbital floor defect with polylacticglycolide acid/recombinant human bone morphogenetic protein 2 compound implanted material in sheep

To study the effect and safety of polylacticglycolide acid copolymer (PLGA) and recombinant human bone morphogenetic protein 2 (rhBMP-2) as implanted biomaterials for reconstruction orbital floor defects in sheep and find the relationship between implant materials degradation and orbital floor defects restoration. Nine sheep (eighteen eyes) with orbital floor defect were divided into three groups randomly. Group A was the control without treatment. Group B was treated with PLGA and group C was received PLGA/rhBMP-2. Cosmetic appearances and complications were observed after surgery. CT scan, 3D reconstruction, defect area measurement and histological examination were performed on a week, three months and six months after operation. No complication was observed. The CT examinations showed that orbital floor defect in group C was almost disappeared by six months, however in group A and group B only partially orbital floor defect was repaired. Histological examinations showed that all materials were absorbed on six months. The orbit defects in group A were replaced by fiber tissue. The defect areas in group B were consisted of bone tissue in the peripheral and fiber tissue in the center. In group C the reconstructed areas were replaced by bone tissue, loose connective tissue and mucosal epithelia layers. The thick of 0.5 mm PLGA/rhBMP-2 sheet is a good substitute material of bone graft and may be used for orbital fracture defect reconstruction in clinic in the future.

Long-Term Outcomes of Ultra-Thin Porous Polyethylene Implants used for Reconstruction of Orbital Floor Defects

The objective of this article is to present the long-term outcomes of ultra-thin polyethylene implants used for orbital floor reconstruction in facial trauma patients. From 1998 to 2004, 38 patients underwent orbital floor reconstruction with porous polyethylene implants with a mean follow-up of 4 years. A subciliary incision and preexisting facial wounds or scars were used. The boundaries of the maxillofacial injury and the orbital volumes of both orbits were assessed by computed tomography images obtained pre- and postoperatively. In all patients, ultra-thin porous polyethylene implants in various sizes were used to reconstruct the orbital floor defect. None of the patients needed removal of the implants during the follow-up. The volume increase of the traumatized orbits ranged from 0.04 to 6.18 (average 3.12 +/- 1.48) mL compared with the intact orbit (P < 0.01). This difference was not significant postoperatively (P > 0.01). Postoperative ectropion in three cases was corrected under local anesthesia. Persistence of complications were as follows: enophthalmos, 3 in 28; diplopia, 1 in 16; dystopia, 1 in 4; and infraorbital nerve hypoesthesia, 3 in 31. One patient underwent late enucleation of the globe because of initial penetrating trauma. We recommend the use of ultra-thin porous polyethylene implants in the reconstruction of the orbital floor defects in facial trauma patients. The implants are durable in the long-term and mimic the anatomy of the thin orbital floor and avoid the morbidity of autogenous bone grafts.

Management of an isolated orbital blow-out fracture

Fracture of the orbital floor (57.4%) can occur from zygomatico-maxillary complex fracture in middle third facial skeletal injuries. However, isolated orbital floor fracture-the term coined as ‘blow out fracture’ represents upto 21.4% [1]. Anatomically, the antero-medial 3rd of the floor is formed by orbital surface of maxilla, where as the postero-medial part is formed by palatine bone and lateral 3rd is formed by zygoma. The medial wall of the orbit is formed anterior to posterior, by frontal process of the maxilla behind its lacrimal crest, lacrimal bone, orbital plate of ethmoid and body of sphenoid. The ‘blow out’ fracture of orbit usually involves the medial wall and floor of the orbit being the thinnest. Absolute indications for reconstruction of orbital floor are diplopia with muscle entrapment, enopthalmos and large defect [2]. Many materials have been described for the reconstruction of orbital floor defects with varying rate of success. They include autogenic, allogenic and alloplastic material. This article reports management of a case of orbital blow-out fracture using autogenous iliac crest bone graft to reconstruct the defect of the orbital floor.

The efficacy of Gore-Tex vs. hydroxyapatite and bone graft in reconstruction of orbital floor defects

Fractures of the orbital floor often need to be reconstructed with rigid materials that provide a stable orbital floor and reestablish the correct orbital volume. In addition to autologous bone grafts, many alloplastic materials are available such as hydroxyapatite and, recently, expanded polytetrafluoroethylene reinforced with fluorinated ethylene propylene also known as reinforced SAM Gore-Tex. This study compared the efficacy and biocompatibility of reinforced and nonreinforced SAM Gore-Tex to those of hydroxyapatite and autogenous bone graft for reconstructing the orbital floor. A defect measuring 1.5×1.0 cm was created in the left orbital floor in 24 short-hair cats while the right side served as the control. The cats were divided into four groups, the defect being reconstructed with an autogenous iliac crest corticocancellous bone graft (group A), hydroxyapatite (group B), nonreinforced Gore-Tex (group C), or reinforced Gore-Tex (group D). Computed tomography was performed postoperatively at 1 and 8 weeks, and at the conclusion of the study specimens from the left orbit were harvested to evaluate the histological biocompatibility of each material. Reinforced SAM Gore-Tex possessed excellent physical properties. It was malleable yet firm enough and therefore easily contoured during repair of the defect while strong enough to support the orbital contents. It could even be sutured to the orbital rim or a fixating plate to ensure further stabilization, if necessary. Additionally, the material demonstrated exemplary biocompatibility as it initiated a minimal inflammatory response. As healing progressed, a growth of host tissue into the material was noted in all histological specimens, thereby augmenting the stability of the implant and reducing the incidence of extrusion.