Epidemiology and Outcome of Orbital Floor Fractures in Children at the Research Institute of Ophthalmology

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1 Med. J. Cairo Univ., Vol. 84, No. 2, December: , Epidemiology and Outcome of Orbital Floor Fractures in Children at the Research Institute of Ophthalmology AYMAN F. ELSHIATY, M.D.*; HISHAM A. HASHEM, M.D.**; SAMEH H. ABDEL BAKY, M.D.*; HESHAM F. KAMEL, M.Sc.** and OMAR M. SOLYMAN, M.Sc., F.R.C.S.** The Department of Ophthalmology, Faculty of Medicine, Cairo University* and The Department of Oculoplastics & Ocular Oncology, Research Institute of Ophthalmology, Giza**, Egypt Abstract Purpose: To study the epidemiology of orbital floor fracture in children and evaluate the safety and effectiveness of different alloplastic materials used for its repair at the Research Institute of Ophthalmology (RIO) from January 2012 to December Methods: This study is a retrospective, interventional, case series of patients aged 16 years or less with orbital floor fracture who presented to the department of oculoplastics at RIO from January 2012 to December Patient records were reviewed to confirm a diagnosis of orbital floor fractures, the underlying etiology, classification, associated injuries, surgical technique used in the reconstructive surgery including the implant material, the outcome of surgical reconstruction and any postoperative complications. Results: A total of 22 patients with confirmed diagnosis of orbital floor fracture were identified. Four patients did not require surgery. The age of patients at presentation ranged from 7 to 16 year with a mean of 11.4 years. Only three patients were females (13.6%) and the rest of patients were males (86.4%). Accidental normal daily activity related trauma was the most common underlying cause and was responsible of 9 cases (40.9%), followed by interpersonal violence (5 cases, 22.7%). Eighteen cases required surgical reconstruction. Porous polyethylene was used as orbital floor implant in ten cases and porous polyethylene with embedded titanium mesh was used in eight cases. Follow-up period ranged between 6 and 28 months with average of 14.5 months. Complete resolution of diplopia in primary position and down gaze was achieved in 14 (87.5%) out of 16 children that presented with diplopia preoperatively. No patient developed postoperative diplopia worse than preoperatively. Enophthalmos was corrected in 4 (80%) out of 5 cases and partially improved in one case. No major or sight threatening complications were reported in this series. Conclusion: Orbital floor fractures are much more common in boys compared to girls. The peak age in our series was around eleven years and it was uncommon in children under the age of 7 years. When presenting with oculocardiac reflex, Correspondence to: Dr. Omar M. Solyman, o.solyman@rio.edu.eg orbital floor fractures should be considered as an emergency and urgent surgical repair should be performed. Imaging techniques may fail to show entrapment of extraocular muscle. When the clinical picture is suggestive of entrapment, surgical exploration should not be delayed so as to confirm the diagnosis and to prevent muscle damage that may happen with late management. Key Words: Orbital floor fracture Children Porous polyethylene Porous polyethylene with embedded titanium mesh. Introduction THE orbital floor is also the roof of the maxillary sinus and is mainly composed from the orbital plate of maxilla with contributions from the orbital plate of zygomatic bone and the orbital process of palatine [1]. In very early childhood, because of incomplete pneumatization of maxillary sinus and the protective effect of the thickened malar fat pads, orbital floor fractures are rare and orbital roof fractures are more common. As midface outgrows the forehead after the age of seven years orbital floor fractures become the most common orbital fractures as in adults [2]. Compared to adults, orbital bones in children are elastic and the periosteum is stronger. This explains why orbital floor fractures in children tend to be linear and hinged with possibility to result in trapdoor fractures. In adults, the orbital floor bones are densely mineralized and more brittle and tend to fragment and displace into the maxillary sinus when fractured [3]. However, neither of both fracture patterns is very specific for each age group and both types can occur in any age [4]. Clinically, children with orbital floor fractures are less likely to present with subconjuctival hemorrhage, periocular edema and ecchymosis compared to adults. Diplopia and limitation of ocular 161

2 162 Epidemiology & Outcome of Orbital Floor Fractures in Children motility are the most common presenting features and are usually more severe than adults. Enophthalmos, orbital and periorbital emphysema and infraorbital hypoesthesia are other common clinical features [5]. Vagal hyperstimulation in the form of vomiting, bradycardia, and attacks of syncope may present in combination with other features or it may be the sole presenting feature of orbital floor fracture in children. It results from incarceration of extraocular muscle in the fracture site and may be life threatening and requires urgent surgical intervention to free the incarcerated muscle and reconstruct the floor of the orbit [6]. Indications for orbital floor fracture reconstruction in children are similar to adults and include enophthalmos more than 2mm compared to the opposite side, hypoglobus, diplopia in the primary or down gaze and/or radiographic evidence of entrapment [7,8,9]. Compared to adults, there is evidence that early surgical intervention carries a better prognosis in children presenting with diplopia [5]. Orbital floor fracture reconstruction surgery involves exploration of the orbital floor through an inferior anterior orbitotomy approach, reduction of the herniated and/or incarcerated orbital contents and spanning of the orbital floor defect with a plate implant [8,9]. Many autologous and alloplastic implant materials have been reported to be effective in the reconstruction of orbital floor fractures. The use of alloplastic implants saves time during surgery and spares donor sites from potential morbidity, however they are at a little increased risk of inducing postoperative complications like infection and migration [10-12]. Patients and Methods This is a retrospective, case series study of patients aged 16 years or less who presented with orbital floor fracture at RIO from January 2012 to December Patient records were reviewed and 22 patients with confirmed orbital floor fractures were studied regarding patient characteristics, the underlying etiology, classification of orbital floor fracture, associated injuries, surgical technique of the reconstructive surgery including the implant material used, the outcome of surgical reconstruction and postoperative complications. Results Patients' characteristics: A total of 22 children with unilateral orbital floor fracture were identified of which 19 (86.4%) were males and three (13.6%) were females. The ages of the patients ranged between 7 and 16 years with a mean of 11.4 years ±2.68. The underlying trauma and type of fractures: The right orbit was affected in 10 patients (45.5%) and the left side in 12 cases (54.5%). There were no cases with bilateral orbital floor fractures reported in this series. Accidental injuries of normal daily activity were the most common underlying cause (9 cases, 40.9%), followed by interpersonal violence (5 cases, 22.7%). Other causes are listed in Table (1). Isolated orbital floor fractures were the most common type of orbital fracture in this series accounting for 18 cases. Further classification of types of fractures in this series is shown in Table (2). Table (1): Injuries associated with orbital floor fractures in this study. Frequency Percent Accidental Violence MVA Sports Occupational Total MVA = Motor Vehicle Accident. Table (2): Classification of orbital floor fractures in this study. Type of fracture Frequency Percent Isolated: Pure (Blow-out) Impure Multiwall: OF+ZMC OF+MW Four wall fracture Total OF = Orbital floor. MW = Medial wall. ZMC = Zygomatic maxillary complex. Clinical presentation and associated injuries: Diplopia was the presenting feature in 13 cases (59.1%), enophthalmos in 2 cases (9.1%) and combined diplopia and enophthamos in 3 cases (13.6%) (Fig. 1). Other features included infraorbital hypoesthesia in 12 patients (54.5%), periorbital emphysema in 4 patients (18.2%) and oculocardiac reflex in the form of vomiting and fainting in combination with diplopia in one patient (4.5%) that required urgent surgery. Associated ocular injuries are listed in Table (3). Non contrast orbital computed tomography scan did not show evidence

3 Ayman F. Elshiaty, et al. 163 of entrapment of extraocular muscle in one case with evident clinical picture of entrapment and positive forced duction test. Surgical exploration revealed incarcerated inferior rectus muscle in a trapdoor fracture and repair was performed. Table (3): Associated injuries. Associated injuries Frequency Percent Traumatic NLDO Choroidal rupture Commmotio retinae Iridodialysis+Hyphema Traumatic mydriasis Surgical procedure and outcome: Four children did not meet the requirements of surgical repair and were treated conservatively with one week course of prophylactic antibiotics and warned against blowing the nose. Eighteen patients underwent orbital floor fracture reconstruc- tion with alloplastic orbital floor plate implant. Interval to surgery ranged from two to 21 days with mean of 13±4.5. The transconjuctival preseptal approach was employed in all eighteen cases. Trasncaruncular approach was added in two cases with associated medial orbital wall fractures. Lateral canthotomy and cantholysis of lower eye lids to improve visualization were used in 11 cases in which wider exposure was needed (Fig. 1). Herniated and or incarcerated orbital contents were then gently freed and reduced into the orbital cavity using malleable retractors (Fig. 2). Porous polyethylene, Medpor (Stryker, Kalamazoo, Michigan, U.S.A.) was used as implant material in ten cases out of 18 cases that underwent surgical repair. Porous polyethylene with embedded titanium mesh Medpor Titan (Stryker, Kalamazoo, Michigan, U.S.A.) was used in the other eight cases (Fig. 3). the periosteum was then closed with 6/0 vicryl sutures and the conjunctiva was left sutureless Follow-up periods ranged from 6 to 28 months with mean of 14.5 months ±6.3. Fig. (1): Intraoperative photos of transconjunctival preseptal approach to the orbital floor showing Conjunctival incision and Lateral canthotomy and cantholysis. Fig. (2): Intraoperative photos showing orbital floor defects after reduction of herniated orbital contents with malleable retractors in Impure and Pure isolated orbital floor fractures.

4 164 Epidemiology & Outcome of Orbital Floor Fractures in Children Fig. (3): Intraoperative photos showing sheets of : Porous polyethylene, and Porous polyethylene with embedded titanium mesh during their implantation. Complete resolution of diplopia in primary position and down gaze was achieved in 14 out of 16 children who presented with diplopia preoperatively (Figs. 4,5). Two patients had partial improvement of diplopia after surgery that required strabismus surgery. No patient had postoperative diplopia worse than preoperatively. One patient out of five patients with preoperative enophthalmos had residual enophthalmos after surgery (Fig. 6). No major or sight threatening intraoperative of postoperative complications were reported. Post operative complications are listed in Table (4). (C) (D) (E) Fig. (4): (A&B) Preoperative clinical photos showing limited left upgaze and sown gaze respectively in 12 years old boy. (C) Coronal CT scan confirming the diagnosis of left orbital floor fracture. (D&E) Postoperative clinical photos showing improvement of left upgaze and downgaze.

5 Ayman F. Elshiaty, et al. 165 Fig. (5): Preoperative and Postoperative clinical photos showing improvement of right supraduction after repair of right orbital floor fracture. (C) Preoperative coronal orbital CT scan showing entrapment of right inferior rectus muscle in right orbital floor fracture site (tear drop sign). (C) (C) (D) Fig. (6): Preoperative clinical photo of 11 years old boy with left orbital floor fracture showing left enophthalmos. Postoperative clinical photo showing partial improvement of left enophthalmos. (C) Coronal orbital CT scan showing left orbital floor, medial wall and roof fractures. (D) Postoperative coronal orbital CT scan showing the porous polyethylene sheet with embedded titanium mesh implant and flat inferior rectus muscle.

6 166 Epidemiology & Outcome of Orbital Floor Fractures in Children Table (4): Postoperative complications. Implant material Number Residual enophthalmos Overcorrection Reoperation Other complications Porous polyethylene (20.0%) 0 Infraorbital anaethesia. (one case) (10.0%) Porous polyethylene with embedded titanium mesh 8 1 (12.5%) 0 1 Palpable micro screw. (one case) (12.5%) Discussion Isolated orbital floor fractures not involving the orbital rim are known as pure or blow-out orbital floor fractures and are the most common type to affect children [5]. Because of the elastic nature of orbital wall bones in children, the fractured bone my snap back after relieve of the inciting trauma, resulting in entrapment of an extraocular muscle in a trapdoor fracture line. Muscle entrapment in trapdoor orbital floor fractures may not be evident on computed tomography of the orbit and may represent a clinical challenge [13]. In this series pure orbital floor fracture was the most frequently reported and represented 13 cases (59.1%). Impure orbital floor fractures in which the orbital rim is involved was the second most common type (5 cases, 22.7). Also it was noted in this series that boys were affected almost six times as frequent as girls. Accidental normal daily activity related trauma was the most common underlying cause of injury followed by interpersonal violence. Agricultural occupation related injury was responsible for orbital floor fracture in two boys. Diplopia was the most common indication for surgical repair (16 cases, 72.7%). Orbital floor fracture reconstruction surgery involves exploration of the orbital floor, reduction of the herniated and or incarcerated orbital contents and spanning of the orbital floor defect with a plate implant. The Transconjunctival preseptal approach is our preferred approach for reconstruction of orbital floor fractures because it provides excellent exposure and fast access to the orbital floor. Compared to the transcutaneous approaches, the transconjunctival approach also spares skin incisions which may result in scars and avoid the potential complication of lower eyelid retraction [14]. The choice of the implant material used in each case of this series depended on the preference of the surgeon and the available resources. Porous polyethylene has micopores that allow fibrovascular ingrowth and integration with surrounding tissues. This provides stability of the implant and may explain the low infection rate of these implants [7]. Porous polyethylene with embedded titanium mesh can be bent to conform to the curves of the orbital floor and can be easily fixated to orbital bones with microscrews when indicated. It is also radio-opaque and can be visualized on postoperative CT scans (Fig. 7). Both implant materials proved effective and safe throughout the follow-up period. Fig. (7): Saggital and Coronal CT scans of reconstructed orbital floor fractures using porous polyethylene with embedded titanium mesh. The radio-opacity of the implant enables postoperative assessment of its position and orientation.

7 Ayman F. Elshiaty, et al. 167 Computed tomography of the orbit failed to show entrapment in 9 year old boy with presenting with diplopia and limited left ocular motility in up and down gaze. In such cases surgical exploration is recommended [13,15]. Forced duction test was performed under general anesthesia and was positive and exploration showed incarcerated left inferior rectus muscle. Surgical repair was performed in the same setting. Reoperation was performed in another case that previously received porous polyethylene with embedded titanium mesh implant for postulated adhesions between the implant and inferior rectus because of markedly restricted ocular motility up gaze and positive forced duction test. Exploration showed tight inferior rectus with no adhesions to the implant material and the patient later underwent strabismus surgery. Conclusion: Orbital floor fractures are much more common in boys compared to girls. The peak age in our series was around eleven years and it was uncommon in children under the age of 7 years. When presenting with oculocardiac reflex, orbital floor fractures should be considered as an emergency and urgent surgical repair should be performed. Imaging techniques may fail to show entrapment of extraocular muscle. When the clinical picture is suggestive of entrapment, surgical exploration should not be delayed so as to confirm the diagnosis and to prevent muscle damage that may happen with late management. References 1- PATNAIK V.G., SANJU B. and SINGULA R.K.: Anatomy of the bony orbit some applied aspects. J. Anat. Soc. India., 50: 59-67, KOLATI P.J., AMJAD I., MEYER D., et al.: Orbital fractures in children. Arch. Otolaryngol. Head Neck Surg., 121: , STOTLAND M.A. and DO K.D.: Pediatric orbital fractures. J. Craniofac. Surg., 22 (4): , ETHUNANDAN M. and EVANS B.: Linear trapdoor or white-eye blowout fracture of the orbit: Not restricted to children. Br. J. Oral Maxillofac. Surg., 49: , WEI L.A. and DURAIRAJ V.D.: Pediatric orbital floor fractures. J. AAPOS, 15 (2): , WORTHIGTON J.: Isolated posterior orbital floor fractures, diplopia and oculocardiac reflexes: A 10-year review. Br. J. Oral Maxillofac. Surg., 48: , BOYETTE J.R., PEMBERTON J.D. and BONILLA- VELEZ J.: Management of orbital fractures: Challenges and solutions. Clin. Ophthalmol., 9: , BURUNSTINE M.: Clinical recommendations for repair of isolated orbital floor fractures: An evidence-based analysis. Ophthalmology, 109 (7): , De MAN K.: Fractures of orbital floor: Indications for exploration and for the use of a floor implant. J. Maxillofac. Surg., 12: 73-77, BAINO F.: Biomaterials and implants for orbital floor repair. Acta. Biomaterialia., 7: , MOK D., LESSARD L., CORDOBA C., et al.: A review of materials currently used in orbital floor reconstruction. Can. J. Plast. Surg., 12 (3): , WAJIH W.A., SHAHARUDDIN B. and Razak N.H.: Hospital University Sains Malaysia experience in orbital floor reconstruction: Autogenous graft versus Medpor. J. Oral Maxillofac. Surg., 69 (6): , PARBHU K.C., GALLER K.E., LI C., et al.: Underestimation of soft tissue entrapment by computed tomography in orbital floor fractures in the pediatric population. Ophthalmology, 115 (9): , NUNU H., Bell A., McHUDG S., et al.: 3D assessment of morbidity associated with lower eyelid incisions in orbital trauma. Int. J. Oral Maxillofac. Surg., 36 (8): , PHAN L., PILEUK W. and McCULLEY T.: Orbital trapdoor fractures. Saudi J. Ophthalmol., 26: , 2012.

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