Orbital Floor “Blowout” Reconstruction

Fractures

Using Autogenous Maxillary Wall Bone Grafts

Mark A. Mandel, MD, FACS, Cleveland, Ohio

Orbital floor fractures have increased in number, in great part due to automobile accidents and personal injuries [I-3]. These fractures, when severe, have the inherent danger of causing permanent visual disability and deformity, such as enophthalmus and diplopia. Early recognition of the problem and prompt institution of therapy has resulted in diminution of the above sequelae [4,5]. The creation of medical grade prosthetic implants has resulted in the stabilization of the orbital floor in many cases but has not totally resolved the reconstructive problems, especially in the more severe types of “blowout” fractures. This report describes the use of autogenous bone grafts, harvested from the anterior maxillary wall, in the reconstruction of orbital floor defects. Eight patients have been studied with a minimal follow-up of eighteen months. Material and Methods Patient Selection. Orbital floor fractures were treated in 194 patients at either University Hospitals of Cleveland or the Cleveland Veterans Administration Hospital from July 1971 to June 1974. Each patient received a thorough physical examination and basic facial bone x-ray examination (Waters, anteroposterior, and lateral views). Laminography was employed in patients in whom physical examination suggested, but basic radiologic examination did not confirm, disruption of the orbital floor. A broad spectrum of pathologic features is represented by the term “orbital floor fracture,” ranging from simple linear floor defects without displacement to gross disruption of the midface bony components. After stabilization of the patient’s overall condition, the diagnosis of fracture and need for surgery were determined [3,571. Symptoms indicative of significant floor disruption include diplopia, numbness in the infraorbital nerve dis-

Division of Plastic Surgery, University Hospitals of Cleveland, 2065 Adelbert Road, Cleveland, Ohio. Reprint requests shouM be addressed to Mark A. Mandel. MD, Division of Plastic and Reconstructive Surgery, University Hospitals of Cleveland, 2065 Adelbert Road, Cleveland, Ohio 44106.

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tribution, displacement of the eye, bloody expectoration, and orbital swelling after blowing the nose. Physical examination yields the following signs: edema and ecchymosis of the periorbital region, hyperesthesia in the infraorbital nerve distribution, enophthalmus due to gross ocular displacement, abnormal ocular motility with limitation in upward gaze (confirmed by a forced duction duct [3]), and associated ocular injuries (hyphema or traumatic cataract). Definite indications for surgery include diplopia and enophthalmus in the presence of radiographic evidence of a fracture [5]. Diplopia is due to entrapment of soft tissues (either the inferior rectus or inferior oblique muscles or supporting elements such as the suspensory ligaments of Lockwood or periorbital fascial structures) within the fracture site. A forced duction test will help differentiate between entrapment and direct injury to the extraocular muscles or their nerve supply. Unless the entrapped tissues are released from the fracture site, diplopia will persist. Late reduction of the fracture may not correct the diplopia since the additional problem of muscle contracture becomes superimposed upon the correction. Enophthalmus results from either the relative or absolute increase in the size of the orbital cavity; it is usually associated with larger fractures of the “blowout” type and is considered significant when it exceeds 2 mm. As described by Converse and Smith [8,9], enophthalmus may be caused by several factors including (1) enlargement of the orbital cavity by the fracture, (2) escape of periorbital fat into the maxillary sinus, and (3) retroposition of the globe due to entrapment. If the fracture remains unreduced, contracture of soft tissue elements occurs with an increase in the severity of the enophthalmus. Other indications for surgery with pure orbital floor fractures include a high degree of clinical suspicion as evidenced by the signs and symptoms and the presence of displacement on radiographic examination. Certainly when significant floor disruption is suggested with maxillary or zygomatic fractures, direct exploration of the orbital floor is required to prevent the late development of enophthalmus. Classification of Orbital Floor Fractures. Orbital floor fractures have been divided into those with or without a “blowout” component [3]. The term “blowout” fracture implies a specific etiologic feature with the trauma resulting in the disruption of the orbital floor and protrusion of the contents into the maxillary sinus.

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Journal 01 Surgery

Orbital Floor Blowout Fractures

Figure 1. Orbital Anatomy. Transiiium/nation of the skull reveals the salient points concerned with orbital anatomy and explains why fractures occur in certain iocatlons. The anterior orbital rims consist of thkk buttresses and are quite strong. ‘Blowout” fractures occur through the thin areas, which include the floor (the maxillary component is further weakened by the passage of the infraorbitai nerve) and the medial wail (iamina papyracea of the ethmoid); force directed to the eye would be transmitted to these weakened areas that then fracture as a physiologic safety valve.

In pure “blowout” fractures the thin areas of the floor (or medial wall) are displaced and the integrity of the orbital rim is maintained. Thus, the trauma causes dramatic rise in intraorbital pressure, with the weakest wall, usually the floor, being “blown out” as a physiologic safety valve. The anatomic reasons for the varying strength of the bones in the periorbital area are seen in Figure 1. The impure “blowout” is associated with a fracture of the orbital rim and continued transmission of the traumatizing force to produce a secondary “blowout” of the orbital floor. Orbital fractures without “blowout” components are associated with either linear or cornminuted fractures of the floor due to fracture of the maxilla and/or zygoma. Surgical Technic. The correction of the “blowout” fracture should be attempted within ten days of injury to circumvent the problem of fibrosis and scarring. The procedure can be performed using either local or general (endotracheal) anesthesia. The direct approach to the orbital floor is preferred, using an incision that parallels the natural horizontal folds of the eyelid, as described by several authors [3,5,6]. The incision is deepened through the skin and orbicularis oculi muscle. The periosteum on the anterior surface is incised 2 to 3 mm below the rim, to prevent the release of orbital fat. A subperiosteal exploration of the floor is performed. The entrapped tissues are gently released from the fracture site and bony fragments retrieved. If the fragments bridge the bony gap, this may suffice for floor reconstitution. This repair may be supplemented by an alloplastic implant, usually Silastic@, to provide a smooth nonadherent floor surface. If the floor defect is large, or if the potential for infection is present, then a Silastic sheet will not provide the patient with an adequate floor. In these instances, autogenous maxillary bone grafting may be useful.

Volwne 130, Novcmbor 1975

The Caldwell-Luc approach is used to harvest the bone graft from the anterior maxillary wall. An incision is made through the mucosa overlying the canine fossa. A subperiosteal dissection of the soft tissues over the anterior maxillary wall can be performed; the infraorbital nerve can be directly visualized and preserved. A small osteotome and mallet are used to remove the anterior wall. A bone graft as large as 2 by 3 cm can be obtained, as seen in Figure 2. The graft is denuded of soft

Figure 2. Anterior Maxillary Wail Bone Graft. A skull preparation outlines the area that can be obtained from the anterior maxillary wail to be used as a bone graft. An osteotome and mallet are utilized to harvest the graft. The infraorbitai nerve foramen can be palpated and/or visualized to obviate damage to the nerve.

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Figure 3. Pure “Blowout” Fracture. A, preoperative photograph indicates the periorbitai trauma to the left skie in this f/fty year oki woman and the deficiency in upward gaze, this patient has a right eye prosthesis that was removed prior to tirgery. 6, the depression of the left orbital floor, as well as the right prosthesis, can be seen in the pretreatment Waters view. C, follow-up examination at one year reveals the absence of enophthaimus and normal left sided upward gaze; the lack of movement in the prosthetic right eye is demonstrated. 0, Waters view at one year.

tissue and used in reconstitution of the orbital floor. The maxillary antrum can be explored, with removal of bony fragments, and the integrity of the floor delineated in conjunction with the direct infraorbital approach. This has been useful in several of the complicated impure “blowout” fractures. The sinus is packed with gauze permeated with bacitracin; the pack is brought out into the nasal cavity via an antrostomy beneath the inferior turbinate. The oral wound is closed with absorbable sutures. The maxillary bone is used to bridge the orbital floor defect; its thinness and shape approximate that of the destroyed bone. Interosseous fixation is not necessary. The orbital contents are positioned over the graft and a multilayered wound closure is performed. Postoperative management includes antibiotics and removal of the antral pack by seven days.

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Results

Eight patients with “blowout” fractures have been treated with anterior maxillary wall bone grafts with a minimum follow-up period of eighteen months. Patients treated for pure and impure “blowout” fractures are presented. Pure “Blowout” Fracture. The patient (GG), a fifty year old white woman bookkeeper at an automobile repair dealership, was struck in the left periorbital area by an irate customer. Remarkable in the history was that the right eye had been previously enucleated because of malignancy and was replaced by a prosthesis. Physical examination revealed sensory loss in the infraorbital nerve distribution, inferior rectus muscle entrapment, and

The American Journal of Surgery

Orbital Floor Blowout Fractures

multiple periorbital lacerations. (Figure 3A.) The orbital floor “blowout” fracture was demonstrated on the Waters view. (Figure 3B.) The operation was performed using local anesthesia. Multiple cornminuted fragments were retrieved and the floor defect corrected with a maxillary bone graft. The postoperative course was unremarkable. The patient, now twenty-four months after injury, has a persistent small anesthetic patch in the infraorbital area but is otherwise asymptomatic. (Figures 3C and D.) Impure “Blowout” Fracture. The patient (JM), a twenty-four year old female college student sus-

tained severe facial trauma when she was involved in an automobile accident. A large oblique laceration of the midface, with fractured maxilla and zygoma in the wound, was present. (Figure 4A.) On ophthalmologic examination, diplopia and muscle entrapment were prominent. No systemic injuries were noted. With the patient under general anesthesia, the orbital floor was examined and a large defect was detected. The anterior maxillary wall, displaced into the antrum, was used to reconstruct the floor defect. The comminuted zygomatic fracture was reduced and immobilized by interosseous fixation. A multilayered wound closure was per-

Figure 4. impure ‘Blowout” Fracture. A and B, a preoperative photograph indkates the severity of damage to the midface; a kng oblique full thkkness laceratkn is present. combined w/th damage to the orbftai floor, the maxilla, and xygoma. The anterior maxillary wall was retrieved and used to bridge the orbItal floor defect. C and D, follow-up photograph and x-ray f//m at four years.

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TABLE

I Complications

of Orbital

Floor Bone Grafting Number of Patients _~

Complications Functional or cosmetic Enophthalmus Diplopia (especially superior Inflammatory Extrusion Fistula Chronic sinusitis Others Persistent pain Persistent numbness -____________------_------

lateral gaze)

0 0 0 0 2 0 2

formed. In the postoperative course, transient weakness in the buccal branches of the facial nerve were noted. The patient is now asymptomatic some four years after injury. (Figure 4C.) The above cases are examples of those treated by anterior wall maxillary bone grafts. A total of eight patients have now been treated and followed for more than eighteen months. In each case, the grafts were performed because of the severity of the floor defect and to diminish the risk of infection that might occur if alloplastic reconstructive materials were used. The complications of this technic are listed in Table I. Enophthalmus and diplopia were not detected in any patients, whereas only two patients each had chronic sinusitis or persistent numbness in a portion of the infraorbital nerve distribution. Comments Autogenous bone grafting has been successfully used in treating large “blowout” fractures of the orbital floor. This technic, originally described by Kaye [IO], has now been extended to a larger group of patients and a long-term follow-up is reported. The procedure is not necessary for all “blowout” fractures since many can be reconstructed with the original fracture components or the gap can be bridged with alloplastic materials. For the severe defect in a potentially infected wound the use of a thin alloplastic material such as Silastic sheeting would be dangerous since it provides little support [II] and would be extruded if infection developed. In these cases, autogenous materials are best since they have a high degree of resistance to infection. The purpose of orbital floor reconstruction is to separate the orbital and antral cavities. In essence, this will restore the volume of the orbital cavity and provide a smooth surface over which the globe and its motors will glide. The requisite for success-

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ful therapy is a material to bridge the orbital gap in a stable fashion. Numerous materials, both autogenous (iliac bone, rib graft, maxillary wall, perpendicular plate of the ethmoid) and alloplastic (Silastic products, Teflon@, polyethylene, Vitallium@, stainless steel, and tantalum) have been utilized in this reconstructive procedure (3,10-141. For the large contaminated defect, autogenous materials are safest. The ideal graft would be one of appropriate thickness and contour with a low extrusion rate; the anterior maxillary wall appears to meet these requirements. Further advantages of this maxillary graft are (1) the safety of the technic, (2) the ability to perform the operation under local anesthesia, (3) the absence of an additional skin incision to harvest the graft, as would be needed to obtain a rib or iliac bone, and (4) the low morbidity of the operative procedure. Although Converse [3] points out the need to use iliac grafts for extremely large defects, a graft of such size was not required in the 194 patients reviewed for this study. The results obtained with autogenous maxillary bone grafting compare favorably with other reported series. Browning [12], reporting on alloplastic materials in the orbital repair of ninty-nine patients, had four cases of infection and three of extrusion. Goldman and Hessburg [15] noted a high incidence of enophthalmus (14 per cent) and diplopia (16 per cent) as well as extrusion (7 per cent) and fistula formation (7 per cent) in forty-four patients treated with silicone and Teflon sheets; they recommend primary repair by the Caldwell-Luc approach. I recommend a flexible approach. Since the incidence of ocular injury is significant [3,5,14], a cooperative venture, with plastic and ophthalmologic surgeons participating, is best in treating extensive fracture. The transfacial (or conjuctival) approach is deemed best for most orbital fractures since it allows for the direct inspection of the floor and permits disengagement of entrapped tissue. The Caldwell-Luc approach is useful in severely cornminuted fractures but is not satisfactory for reconstruction of the floor. When combined with the transfacial approach, and maxillary bone grafting, the Caldwell-Luc approach facilitates the accurate reduction of fractures and stabilization of the orbital floor. Summary The use of autogenous anterior maxillary wall bone grafts is described as an alternative approach to reconstruction of the orbital floor. Eight patients with severe “blowout” fractures have been

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Orbital Floor Blowout Fractures

followed for a minimal period of eighteen months. The technic can be performed under local or general anesthesia and has a low complication rate. Acknowledgment. The assistance of Doctor Clifford L. Kiehn in outlining this project is gratefully acknowledged.

6. 7.

8. 9.

References 10. 1. Schultz RC: Facial injuries from automobile accidents: a study of 400 consecutive cases. Plast Reconst Surg 40: 415. 1967. 2. Cornell University Automotive Crash Injury Research: The injury producing accident: a primer of facts and figures. New York, Cornell Press, 1961. 3. Converse JM: Kazanian and Converse’s “Surgical Treatment of facial Injuries.” 3rd ed. Baltimore, Williams and Wilkins, 1974. 4. Converse JM, Smith B, Obear MF. Wood-Smith D: Orbital blowout fracture: a ten year survey. P&M Reconsb Surg 39.20, 1967. 5. Natvig P. Dortzbach RK: Facial bone fractures. Plastic Sur-

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11. 12. 13. 14.

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gery: A Concise Guide to Clinical Practice. (Grabb WC, Smith JW, ed). Boston, Little, Brown, 1973. Dingman RO. Natvig P: Surgery of facial fractures. F’hiladelphia, WB Saunders, 1964. Gwvn PP. Carrawav JH. Horton CE. Adamson JE. Mladick RA: Facial fractires-associated injuries and complications. P&M Reconstr Surg47: 225, 1971. Converse JM, Smith B: Enophthalmus and diplopia in fractures of the orbital floor. Br J Plast Surg 9:265, 1957. Converse JM, Smith B: Blowout fracture of the floor of the orbit. Trans Am Acad Ophthaimol Otolatyngol 64: 676, 1960. Kaye BL: Orbiil floor repair with antral wall bone grafts. Plast Reconstr Surg 37: 62, 1966. Fryer MP, Brown JB, Bin JW: Repair of trauma about the orbit. J Trauma 12: 290, 1972. Browning CW: Alloplastic materials in orbital repair. Am J Ophthalmol63: 955, 1967. Milauskas AT: Blowout fractures of the orbit. Springfield, Illinois, Thomas, 1969. Emery JM, Von Noorden GK, Schlernitzauer DA: Manage ment of orbital floor fractures. Am J Ophfha/mo/ 74: 299, 1972. GoMman RJ, Hessberg PC: Appraisal of surgical correction in 130 cases of orbital floor fracture. Am J Ophtha/mo/ 76: 152, 1973.

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Orbital floor "blowout" fractures. Reconstruction using autogenous maxillary wall bone grafts.

Orbital Floor “Blowout” Reconstruction Fractures Using Autogenous Maxillary Wall Bone Grafts Mark A. Mandel, MD, FACS, Cleveland, Ohio Orbital flo...
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