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Two lethal cases of penetration injury of the orbita are reported. The injuries were caused directly by the point of an umbrella (accident or homicide), leading to canalicular destruction of the frontal lobe of the cerebrum. The mechanism of injury with cerebral involvement was not determinable except by autopsy, and the importance of a thorough clinical examination is therefore emphasized.

One year after trauma, diplopia, limitation of ocular movements on the left side, orbital asymmetry, and a growing skull fracture on the orbital roof were reported in an extraordinary case. While presenting this extraordinary localization of growing skull fractures, the anatomy, pathogenesis and the natural evolution of these lesions still remain obscure.

Before reconstruction of the orbital walls and other surgical procedures concerning the orbits leading to a modification of pathologically altered orbital volumes, it is useful to measure these volumes in order to allow preciser correction. Orbital volumetric studies on 22 patients and 6 dry skulls were performed using high resolution computer tomography. 14 patients presented enophthalmos of various origin, 3 patients fibrous dysplasia involving the orbits and 5 patients showed no orbital pathology. In 10 patients with unilateral posttraumatic enophthalmos an increase of the bony orbital volume of 20.1% in the average was found corresponding to an enophthalmos of 3.5 mm in the average. Correlation between the severity of the enophthalmos and the increase in orbital volume was found. Enophthalmos could not be correlated to the intraorbital fat volume, especially no atrophy of orbital fat could be demonstrated in these patients. Normal orbital volume measurements of patients and dry skulls were compared to those found in the literature. Planning of the surgery was therefore facilitated before correction of enophthalmos, reconstruction of bony orbital contour after tumor resection and in patients with fibrous dysplasia. Results suggest that the bony orbital enlargement, followed by a change in soft-tissue shape and position is the usual cause for posttraumatic enophthalmos. Changes in volume of soft-tissues themselves are less significant.

Recent developments of medical imaging such as CT scanning with three dimensional reconstruction (3D-CT) and magnetic resonance imaging (MRI), have had a profound impact on the diagnosis of maxillo-facial trauma, including orbital blow-out fractures. The authors discuss the pathology of orbital blow-out fractures, the current views concerning the etiopathogenesis and nowadays clinical and technical investigations. Some important aspects of the assessment of the physical damages according to the Belgian law are discussed.

With the recent advent of accurate orbital volume assessment by computed tomography, a retrospective analysis was made of 31 patients with 'pure' blowout fracture of the orbital floor, managed either surgically or conservatively, to determine whether orbital volume measurement could provide an additional parameter of use in the management of such fractures. There was a significant difference in orbital volume discrepancy between patients managed surgically or conservatively suggesting that this investigation may be of use in decision making on surgical intervention in patients with orbital blowout fractures.

Avulsion of the optic nerve is an infrequent traumatic event which results in a permanent and usually devastating loss of vision. We present two cases which highlight the salient features of partial and complete optic nerve avulsion. The clinical findings, including the results of B-scan ultrasonography, fluorescein angiography, and computed tomography (CT) are discussed. In addition, the past two decades of literature pertaining to optic nerve avulsion are reviewed and summarized.

Great progress has been made in both the basic science and the clinical knowledge base used in orbital reconstruction. With this, increasing complex orbital reconstructive problems are better managed. The diagnosis, treatment plan, and the actual reconstruction have evolved to a higher level. Several areas of progress are of note: the greater appreciation of the intimate relation between the bony orbit's shape and the position of the globe; application of computer technology in orbital injuries; effect of rigid fixation on autogenous and alloplastic graft; and the use of advanced biocompatible synthetic materials in orbital reconstruction. Although this progress has great impact on treatment of orbital injuries, there are many unanswered challenges in the treatment of the fragile frame of the window to the human soul.

Where there has been displacement or removal of the lateral orbital rim or zygomaticomaxillary complex secondary to trauma or surgery, the measure of globe position by the Hertel exophthalmometer is problematic and inaccurate. A modification of Hertel's instrument that uses the external auditory canal (EAC) rather than the orbital rim as reference point has been developed. Measurement of globe position of 120 normal volunteers was obtained with the Hertel and the modified EAC-fixated exophthalmometer. Although the mean absolute difference between right and left measurements for both methods (Hertel mean, 0.36 mm; modified mean, 0.51 mm; n = 120) differed statistically from 0 (p = 0.0001), that difference was not clinically significant. A more meaningful comparison was that of the variability of the two methods. The variance of the Hertel method (0.32) did not differ from the variance of the modified method (0.40; p = 0.06). No statistically significant difference was noted for sex (p = 0.33) or for race (p = 0.11). We believe this instrument to be of practical use in the assessment of enophthalmos or exophthalmos in patients whose facial deformity, trauma, surgery, or disease precludes the use of a rim-based exophthalmometry.

Globe position was assessed by both the Hertel exophthalmometer and the modified external auditory canal (EAC)-fixated device in 27 patients with complex orbital fractures (18 tripod and 9 Le Fort fractures). Although 94% of the patients with tripod fractures had relative exophthalmos on the fracture side or no difference between eyes by Hertel exophthalmometry, greater than 30% of the same patients showed relative enophthalmos when measured by the EAC-fixated device. In three of four patients undergoing surgical repair of the orbital floor, modified exophthalmometry showed exophthalmos of greater than or equal to 2 mm postoperatively on the fractured side. The relatively low incidence of enophthalmos in tripod fractures indicates a need for selective orbital floor repair; the uniform exploration of the orbital floor should be discouraged. Multiple comminuted facial fractures (Le Fort II and III) showed a greater variability in globe position and a high frequency (90%) of enophthalmos, suggesting a need for early orbital repair in these patients. EAC-fixated exophthalmometry can provide meaningful information regarding globe position in orbitofacial fracture patients in which orbital rim-based methods are precluded.

Techniques borrowed for the correction of congenital craniofacial deformities and acute traumatic reconstruction have improved the quality of secondary post-traumatic orbital reconstruction. These techniques include precise pre- and postoperative assessment made possible by thin section axial and coronal CT imaging. Wide exposure through remote incisions borrowed from aesthetic surgery allows access for repositioning or recontouring of malaligned structures without additional morbidity to the soft tissues. The use of osteotomy and camouflage techniques will depend on the severity of comminution and displacement. Most often, a combination of techniques is employed. Rigid fixation techniques, particularly the use of micro systems, allows the potential for complex configurational reconstruction with little morbidity. The lag microscrew technique allows in-place contouring of onlay grafts and increases volume persistence, thus decreasing the amount of relapse. These techniques taken together provide the potential for unparalleled sophistication in our secondary orbital reconstructions. The factor limiting the quality of the result is most often a function of the damage imparted to the soft tissues at the time of initial injury. The soft tissues are known to absorb more energy at the time of impact than the underlying bones. The resultant contraction of the soft-tissue envelope over the malaligned and compacted skeletal infrastructure can never be restored to its preinjury appearance. For this reason, reconstruction in the acute phase remains the ideal time to prevent or limit post-traumatic orbital deformity.

The aim of the study is to compare the effectiveness of computerised tomography (CT) and magnetic resonance (MR) imaging in diagnosing herniation and entrapment of orbital soft tissues in orbital fractures. 15 consecutive patients with clinical signs and symptoms of medial orbital wall injury were examined with CT and MR. The data were subsequently compared with the findings of the surgical exploration with regard to the extent of the wall fractures, the presence of soft tissue herniation and its entrapment. CT and MR were equally accurate in demonstrating or excluding orbital wall fractures but both modalities slightly underestimated their incidence. CT and MR underestimated the actual incidence of soft tissue herniation and entrapment when compared with the surgical findings but the extent of soft tissue herniation and entrapment were demonstrated more clearly by MR than by CT scanning. MR imaging when available should therefore be used as the initial imaging modality and CT held in reserve for confirmation as positioning in the MR unit is easier and more comfortable for recently injured patients who may well have other injuries.

A 10-year experience with surgical treatment of 813 zygomalateral orbital complex fractures is reviewed. Regardless of the type or severity of the fracture pattern, concomitant fractures of the orbital floor and rim were approached exclusively through the transconjunctival approach without a lateral canthotomy. The advantages of this approach compared with the subciliary access are the avoidance of a visible scar and markedly reduced incidence of postoperative lower eyelid complications such as ectropion and edema. Implants of lyophilized dura or cartilage and autogenous bone were used to reconstruct orbital floor defects. Malar asymmetry is a frequent complication of zygoma fractures resulting from inadequate three-dimensional reduction. Methods for accurate reduction and stabilization, indications for closed and open reduction, and management of the fractured infraorbital rim are emphasized. The indications for miniplates vs wire ligatures for the infraorbital rim are discussed. Long-term follow up and evaluation of the results with regard to the fracture pattern, complications, maxillary sinus dysfunction, and facial and orbital symmetry are presented.

The mechanism of healing of facial bone fractures was investigated in a rabbit model. Twelve New Zealand white rabbits underwent surgically induced fractures of the right infraorbital rim and fracture ostectomies (4 to 5 mm) of the left infraorbital rim. Animals were sacrificed 2, 4, and 8 weeks postfracture. Bone, including periosteum, obtained from each fracture or fracture osteoctomy site was divided longitudinally for hematoxylin and eosin staining, fluorescent microscopy, microangiography, and microradiography. Sequential fluorochrome labels of oxytetracycline (30 mg/kg), alizarin complexone (30 mg/kg), DCAF (20 mg/kg), and xylenol orange (90 mg/kg) were administered 24 hours preoperatively and at 1, 2, 4, and 8 weeks postfracture. All fracture and fracture ostectomy sites demonstrated vascular ingrowth, mineralization, and woven bone formation by 2 to 4 weeks postoperatively, beginning with a cartilage precursor. Subsequently, the woven bone was replaced with remodeled lamellar bone, resulting in complete bony healing by 8 weeks postoperatively. These steps were substantiated by microscopic, microradiographic, and radiologic examination of the specimens. This study demonstrates that fractures of the facial bones in a rabbit model heal by a process of new bone formation that resembles secondary union in endochondral bones.

A 26 year old patient with a LeFort III fracture after an automobile accident exhibited bilateral luxation of the globes. An avulsio imcompleta with an evulsion of the optic nerve posteriorly was noted on his right eye and an avulsio incompleta with evulsion of the optic nerve anteriorly was seen on his left eye as a cause for the luxation. The said locations may represent predilection sites for an evulsion of the optic nerve.

Two cases of unusual fronto-orbital fracture were encountered. In these cases, bone fragments containing orbital roof were detached from the wound in one piece. This injury was thought to occur by the application of tangential forces to the forehead. Laceration of the dura was noted, but there was no ocular or cerebral damage. This injury is thought to be characteristic in children. The mechanism of this injury is discussed.

Although much has been written regarding the treatment of facial bone fractures, at the present time there are no available investigations of human microscopic sections to verify the exact nature of the healing process. The consensus in the literature is that following fractures of the midface, the bone segments are united by fibrous union. Biopsies of the healed fracture sites were obtained in 10 consecutive patients who underwent secondary reconstructive procedures to correct residual deformities. Clinical assessment confirmed that the fractures were completely healed and stable. Histologic sections were obtained across the healed fracture sites, sent for H&E staining, and then examined by light microscopy. All specimens showed that the defects between the segments were obliterated by the formation of a mature compact bone. This bridging bone was characterized by concentric lamellae surrounded by a typical bony architecture. From this study it can be concluded that fractures of the midface heal by direct bony union.

Contrecoup fractures of the base of the skull are regarded as rare in the clinical literature. In our material (n = 171 falls on the same level and on or from stairs), the overall frequency of contrecoup fractures of the anterior cranial fossa in fatal cranio-cerebral trauma due to falls was 12%, as compared to 24% with occipital point of impact of the head. The relationships between the impact site on the head, form of fracture at the point of impact with involvement of the skull cap and/or the base of the skull, coup and contrecoup injuries of the brain, localization of contrecoup fractures in the anterior cranial fossa and the occurrence of monocle and spectacle haematomas display a major variability. Fractures occur in the form of simple fractures and as impression fractures (fracture fragments or fracture boundaries displaced to the inside). Clinical diagnosis is difficult because of the concealed position of the anterior skull base. Contrecoup fractures become of forensic medical significance when symptoms of a frontobasal injury occur for the first time after trauma which has occurred some time in the past and when the question arises as to the causal connection with the original trauma. In investigation of living persons, it may be difficult to decide whether haemorrhages in the region of the orbit and its vicinity result from a direct blunt force or derive from fractures of the base of the skull, especially contrecoup fractures.

Complex orbital fractures consist of fractures of the orbital rim and walls in two or more places and may be associated with more extensive facial fractures. Previously, delayed repair was the standard approach. Techniques of craniofacial surgery allow earlier reconstruction with more accuracy and stability. Enophthalmus, dystopia and facial contour deformities are avoided, and the final result improved. A new standard has been established. Three factors are important in attaining improved results. Three-dimensional CT scanning is used to obtain a comprehensive assessment of the injury, to plan reconstruction pre-operatively, and to assess the reconstruction post-operatively. Secondly, complete exposure of the facial skeleton is necessary and is achieved by the use of a coronal incision, frontal flap, infraorbital incision, and intraoral upper sulcus incision. Thirdly, cranial bone grafting is used to reconstruct orbital floors and severely comminuted or missing bones. Finally, the use of mini-plates and lag screws provides improved accuracy and stability of the reconstruction.

Current thought on the pathophysiology of orbital wall fractures postulates either a "hydraulic" or a "buckling" mechanism. Evidence from cadaver, dried skull, and theoretical model studies supports both theories. No in vivo data, human or nonhuman primate, are available that quantitate the force necessary to fracture the orbital floor by either of the two mechanisms. We developed an apparatus that delivers quantifiable force only to the globe, without occluding the orbital opening or striking the orbital rim. We used it on 11 anesthetized Macaca fascicularis monkeys. Following a single bilateral application, the orbits were exenterated, and the orbital walls and orbital contents were examined to determine the extent of injuries. Fractures were described, diagrammed, and photographed. Fracture of the orbital floor was consistently produced at and above a force of 2.08 J. Posterior ruptures of five eyes occurred over the same range. We provide the first accurate measurements of the force required to produce orbital blow-out fractures in a live primate model. We show that orbital floor fractures can occur at low energies with direct ocular trauma only ("pure" hydraulic mechanism). Orbital wall fractures failed to protect the globe from rupture in 23% of cases.

The protected childhood environment and the anatomy of the craniofacial skeleton largely protect children from experiencing facial fractures. However, when major trauma to the head and face is sustained, an oblique pattern of fractures has been observed, distinct from those common in adults and explicable in terms of the anatomic differences between the child's and the adult's head and face. This difference in pattern of facial fracturing is relevant in terms of the examination, investigation and treatment of the primary injury, and prevention of any subsequent facial growth disturbances.

Twenty-three patients aged 3.3 +/- 1.6 years (mean +/- SD) presented between January of 1984 and September of 1987 with fronto-orbital trauma resulting in fractures of one (N = 20) or both (N = 3) orbital roofs. All patients had computed tomography (CT) with axial and coronal sections that revealed three fracture patterns of the orbital roof (nondisplaced, superiorly displaced, and inferiorly displaced fractures). Orbital dystopia was exhibited in 35 percent (N = 8) of the patients. Exophthalmos was noted in 61 percent (N = 14) of the patients. Only 30 percent of the patients (N = 7) sustained associated maxillofacial fractures. Eight percent of fractures exhibited orbital encephaloceles. All patients lacked frontal sinus pneumatization. The majority of children with orbital roof fractures do not exhibit concomitant facial fractures. CT utilizing both axial and coronal sections is valuable in defining the extent and pattern of the fracture as well as in identifying associated neurologic injuries. Large, displaced orbital roof fractures, which occurred in 3 of 13 patients with displaced fractures in our series, should undergo early reduction to avoid late development of encephalocele.

The mechanisms of posttraumatic enophthalmos were evaluated to determine the interrelation between fat and ligaments in globe support. Anatomic studies demonstrate that the ligaments form an essential "sling" framework for the globe but are alone insufficient to maintain the globe's full forward position. Removal of extramuscular fat in cadavers and in patients undergoing blepharoplasty did not significantly change globe position. Loss of intramuscular cone fat (atrophy or displacement) in cadavers and patients produced enophthalmos. Fat atrophy is not a prominent feature in most patients with posttraumatic enophthalmos. Some loss of intramuscular cone fat from displacement outside the muscle cone is frequently present. The principal mechanism, however, of posttraumatic enophthalmos involves a displacement and change in the shape of orbital soft tissue. Loss of bone and ligament support permits posterior displacement and a reshaping of orbital soft tissue under the influence of gravity and the remodeling forces of fibrous scar contracture. The shape of the retrobulbar orbital contents changes from a modified cone to a sphere, and the globe sinks backward and downward. Given that the volume of orbital soft tissue is constant following trauma, procedures to restore the shape and position of the orbital soft tissue by mobilization and bone reconstruction will correct or significantly improve enophthalmos.

The diagnosis of scleral perforation of the globe following ocular trauma is often obvious on physical examination, but occult perforations occur frequently. In addition to locating intraorbital foreign bodies and associated facial bone fractures, computed tomography of the orbit can suggest an occult scleral rupture. Posterior collapse of the sclera causes flattening of the posterior contour of the globe, the "flat tire" sign. Other associated findings that are suggestive of scleral rupture are intraocular foreign body or gas, thickening of the sclera posteriorly, and a blood-vitreous fluid-fluid level.

Nineteen patients with orbital floor fractures were examined and underwent computed tomography of both orbits. By evaluating the amount of orbital expansion and soft tissue herniation, we were able to identify a group of patients at high risk for developing enophthalmos (3/7 in the group with the largest amount vs. 0/7 and 0/5 in the two other groups). By studying the appearance of the inferior rectus muscle, we were also able to identify a group of patients at high risk for developing persistent diplopia (5/5 with entrapped muscles, 0/2 with hooked muscles and 0/12 of patients with free inferior rectus positions).

Converse is using the term "interorbital space" for the ethmoid bone, especially its lateral wall. We added the frontal process of the upper jaw including spongy substance ("trajector"). Pathophysiology and clinical points of view of comminuted fractures are demonstrated.

The stiffness and strength of the orbital walls are proportionally dependent on the anatomical structures which support and strengthen these walls from the opposite side. The medial wall is therefore strong due to the support of ethmoid cells. The floor is stronger the less surface there is and the more supported it is by trabeculae of the maxillar sinus. The strength of the upper and lateral walls are proportional to their thickness. The orbital floor is on the average the weakest, followed by the medial and upper walls. The lateral wall is the stiffest and the most rigid. Computed tomography (CT) has improved structural analysis of the orbital contents and orbital walls enabling the visualisation of superficial and deep soft tissues and bone structures.

A method for the clinical evaluation of patients with orbital and midfacial fractures is presented. Pertinent anatomic relations, classification of fractures, and significant associated injuries are reviewed. Principles of treatment are offered.

A ten-year review of 2,067 cases of zygomatico-orbital fractures is presented. The age and sex distribution, anatomical types of fractures, associated maxillofacial and nonmaxillofacial trauma, and causes of the injuries are described. The majority of fractures were sustained by males and resulted from trauma inflicted in altercations. The most common associated facial fractures were mandibular; the most common associated nonmaxillofacial trauma was extremity fractures. Motorcycle accidents caused the most significant amount of associated trauma, followed by motor vehicle accidents in which no seat restraint was used by the victim. Treatment, when indicated, consisted of elevation via a temporal approach followed by fixation where necessary. The fixation methods used are presented and discussed.

Injuries to the inferior and lateral orbital walls are traditionally classified as either "blow-out" or trimalar fractures. This simplified system has helped considerably in the understanding of the causes of the two types of injury and methods of repair. Unfortunately, simultaneous occurrence can cause immediate and delayed problems that potentiate each other. Enophthalmos and globe ptosis, in combination with a depressed malar eminence, present a major challenge to the reconstructive surgeon's efforts to achieve satisfactory function and appearance. This paper reports the results of combined orbital floor and lateral wall injuries as an important clinical trauma syndrome. The interaction of the two fractures with regard to pathophysiology, sequelae, and methods of correction will be discussed. A review of cases will be used to describe the authors' techniques of repair, and to illustrate the preferred methods of bone grafting for correction of retrusion and depression of the globe, muscle entrapment and depression of the malar eminence.

A blow-in fracture is an inwardly displaced fracture of the orbital rim or wall resulting in decreased orbital volume. The purpose of this study is to classify orbital blow-in fractures, describe the distinguishing clinical and radiologic features, and review the result of treatment. The series consists of 41 patients with blow-in fractures (34 males and 7 females). The mean age of the patients was 36 years. All were treated between 1979 and December of 1986 at Sunnybrook Medical Centre in Toronto. Clinical features of blow-in fractures were primarily related to the decrease in volume of the orbital cavity. Proptosis was a consistent finding, and in 27 percent of patients, the globe was further displaced in a coronal plane. Restricted ocular motility and diplopia were documented in 24 and 32 percent of patients, respectively. Fracture fragments displaced into the orbit resulted in globe rupture in 12 percent of patients, superior orbital fissure syndrome in 10 percent, and optic nerve injury in 1 patient. Blow-in orbital injuries were classified as pure fractures, consisting of an isolated blow-in of a segment of the roof, floor, or walls, or impure fractures, where the orbital rim itself was disrupted. In all cases, early decompression of the orbit and open reduction of fractures was necessary. Late sequelae of blow-in fractures were primarily related to injuries of intraorbital contents. Twelve percent of patients underwent enucleation and 8 percent reported persistent diplopia. Despite the presence of superior orbital fissure syndrome and complete ophthalmoplegia in 10 percent of patients, early orbital decompression resulted in resolution of nerve palsies in all but one patient.

An unusual fracture of the facial skeleton has been described to show that an apparently simple injury to the lateral aspect of the orbit can lead to serious consequences. In this case, the consequence was progressive loss of vision, which possibly could have led to blindness. It is recommended that all diagnostic methods should be employed in assessing an injured patient. The patient's history, in conjunction with inspection, palpation, and clinical judgment and experience, will almost always lead to a diagnosis. Radiographic confirmation can then be obtained and special views employed when indicated. These methods must be used in the evaluation of even apparently simple injuries so that the patient can be properly treated.

Orbital floor fractures can result in herniation of orbital tissues and impairment of ocular function. In this experimental study, orbital defects were created surgically in cats. The gross and histologic healing of these defects was compared among animals implanted with silicone rubber sheeting or absorbable gelatin film and animals that received no implants. Both implanted animal groups demonstrated enhancement of healing. The absorbable gelatin film showed less migration, less inflammatory response, and improved healing. This animal study supports the use of absorbable gelatin film in the surgical management of orbital fractures.