Predictable outcomes of complex orbital fracture patterns may be achieved by a structured and evidence-based approach.
Full anatomic and physiologic assessment of the fracture pattern using computed tomographic data and quantitative orthoptic analysis allows for precise planning of the surgical technique.
Preseptal transconjunctival access with transcaruncular extension and lateral swinging lid technique allows for ultimate exposure of the fracture complex.
Incarcerated orbital tissues must be identified and planned for released without surgical duress to the musculature.
Surgical momentum is progressing toward patient-specific implants for larger and more strategic fracture patterns. Medial and floor reconstruction to the apex can now be achieved.
The nature of the problem
Fracture patterns of the anatomic orbit are common in contemporaneous oral and maxillofacial practice and exist in isolation or in concert with adjacent skeletal components. There is variance in complexity according to volume of energy transfer, and clinical heterogeneity in presentation because of soft tissue involvement, some of which may be vision threatening. Predicable outcomes therefore depend on prompt clinical diagnosis augmented by full anatomic description of the fracture configuration in conjunction with formal physiologic assessment. This full clinical data set then will inform prompt surgical management followed by evidence-based indications for surgery, approach, materials and methods used, together with prognostication to manage both surgeon and patient expectation.
Changes within the UK acute trust infrastructure have led to the adoption of major trauma centers, of which the Royal London Hospital was the prototype example, with 30 years of dedicated multidisciplinary trauma experience. This multidisciplinary trauma experience has led to proven increased survival rates in complex high-energy injury mechanisms, and greater survival rates resulting in higher numbers of complex facial injuries coming to surgery. The social demographic of East London, with a substantial history of criminal and even political violence, is well known. The UK Crime statistics indicate 30,000 violent crimes reported per year in East London, representing 19.5% of all crimes reported . The map of London in Fig. 1 demonstrates the significantly increased crime levels in the region.
Surgical pathologic condition
Classically, orbital fracture patterns were described as either pure or impure. Impure fractures follow failure of the orbital rim, which can either be localized to the inferior orbital rim and associated with the orbital floor or propagate to the orbit from an adjacent facial bone fracture ( Table 1 ).
|Floor||Segmental lower-orbital rim||Isolated|
The distinction of pure and impure of course has surgical significance but seems to be less important in the association with ocular damage, this born out clinically and by finite element analysis, which illustrates that the failure threshold for globe rupture is less than that of bone.
The surgical principle is to convert impure to pure orbital injuries and then treat the floor and medial walls accordingly. The size of the defect and position have both profound influence on surgical complexity and prognostic implications in terms of both aesthetics and function. Most surgeons will agree that fractures toward the posterior floor and upper medial third are more technically challenging and take longer to return to normal function postoperatively. Ahmad proposed a quantitative assessment of orbital fractures by splitting the floor and medial wall into separate thirds, as well as quantifying fracture severity in the rest of the facial skeleton, with recognition of the presence or absence of the posterior medial ledge. Jaquiery classified orbital fractures into 5 types according to surgical complexity, focusing on the size of defect and presence or absence of the posterior bone ledge medial to the infraorbital nerve, which facilitates anatomic dissection, and in addition, seating of the implant ( Table 2 ).
|Stage||Size of Defect (cm 2 )||Bone Ledge Medial To Orbital Fissure|
|IV||Entire orbital floor/medial wall||No|
|V||Extension to roof||No|
Facilitation of binocular single vision requires the integration of a complex neuromuscular system involving 4 cranial nerves and 6 extraocular muscles working in a highly coordinated syncytium. The nuclei of the cranial nerves supplying these muscles are linked by the medial longitudinal fasciculus, which allows coordination with integration of the vestibular nerve. Disruption by intracranial damage can cause internuclear ophthalmoplegia. The muscles themselves are easily damaged or trapped in certain fracture patterns ( Table 3 ).
|Trochlear nerve||Motor to superior oblique||
|Abducent nerve||Motor to lateral rectus||
|Medial longitudinal fasciculus||Linking all intracranial nuclei||
Fracture progression is influenced by the mechanism and biomechanics of the orbit itself. In paediatric mechanisms, energy transfer commonly produces a linear fracture resulting herniation of the orbital contents with entrapment due to the elastic biomechanical nature of the orbital floor. Linear fracture pattern may occur with comparatively low-energy transfer and produce the so-called white-eye blowout fracture, which could be initially missed in accident and emergency departments. One of the symptoms is persistent postinjury nausea and vomiting, so a computed tomographic (CT) scan of the brain could incidentally expose the orbital fracture. Nevertheless, experience shows that CT scan is not always conclusive, and a trapdoor fracture could be missed easily.
Indications for surgery
The decision to operate follows comprehensive assessment of the fracture pattern in concert with the patient, in which clinical, medical, anatomic, and functional considerations are supported by objective evidence from detailed imaging and formal quantified orthoptic examination. With the exception of a vision-threatening condition that demands immediate surgical treatment, all indications are relative. Ultimately, it is a balanced decision between the surgeon and the patient according to individualization of the risk-benefit ratio.
Restoration of anatomy
The aesthetic form of the orbit involves harmony between the soft and hard tissues.
The orbital floor and medial wall have several key strategic landmarks, which maintain globe position. These landmarks have been described by Hammer with reference to the posterior medial bulge ( Fig. 2 ). Note the normal left side in this low orbital axial view (blue arrow) and the fractured right side (right arrow), and the sigmoid nature of the floor in sagittal view ( Fig. 3 ). In this view, the blue zone maintains the vertical height of the globe, and the sigmoid green zone maintains projection.
The concept of orbital volume remains but is, of course, related to the geometry of the bone orbit. It should also be appreciated that the volume comprises all the orbital adnexae, which includes fat and muscle, but in addition, the globe itself.
Restoration of function
In order to facilitate free movement of the globe, any trapped tissue within linear fractures, or physical limitation by sharp bone fragments, needs to be removed.
Primary orbital trauma decision making
Decision making for Orbital Reconstruction should follow a logical and stereotypical process which includes appraisal of physical findings, and assessment of hard and soft tissue subunits, with didactic surgical treatment planning ( Fig. 4 ).
The orbit is described as a 4-walled pyramid contained by the orbital septum constrained by the lateral and medial canthal tendons, making the orbital contents vulnerable to compartment syndrome. Although an expanding retrobulbar hematoma is recognized, it must also be appreciated that intraorbital surgical emphysema, cerebrospinal fluid, and displaced bone fragments can be implicated.
Although medical management in the form of acetazolamide, mannitol, and hydrocortisone is described, lateral cantholysis in a timely manner is frequently vision saving.
Fig. 5 demonstrates an axial view of a medial wall fracture (red arrows) and a retrobulbar hematoma (blue arrows).
Physical signs of ocular compartment syndrome
Tense and proptosed globe
Loss of red vision
Loss of visual acuity
The risk of ocular damage in facial injuries has been described many times, and the famous mnemonic device of BAD ACT has been constructed to raise awareness:
B: Blow out
CT: Comminuted trauma
These injuries can frequently be difficult to assess because of acute periorbital swelling or may be masked by substance or alcohol abuse and a lowered level of consciousness. High-energy mechanism injured patients with multisystem injuries may mask orbital injuries that are not life threatening ( Box 1 ).
Significant volume of trauma
Orbital fracture: increased probability with increasing size
Multiple fractures: particularly involving orbital cancellous bone
Impaired consciousness: pain is less of a feature
Diagnosis, quantification, and prognostication of fracture pattern
CT scan analysis is central to diagnosis and planning treatment as well as to prognostication.
The sequential analysis of axial-coronal-sagittal formatted scans with measurement of bone loss and even angulation of fragments can be conducted near the patient with modern PACS systems.
Interpretation will influence the incision with the need for lateral and medial extensions to achieve predictable access, which materials to reconstruct, and risks to anatomic structures.
CT scans can also be interrogated to both diagnose and prognosticate functional deficits because of muscular involvement. The classic description of a trapdoor fracture typically seen in the pediatric or adolescent, otherwise known as the white-eye blowout fracture, is an example.
The CT scans visualized in coronal format demonstrate the region (blue square) of the fracture that is typically close to the infraorbital canal (green arrow) ( Fig. 6 ).
The sagittal view illustrates the small size of the fracture (T), and soft tissue windows may distinguish between muscle and fat prolapse ( Fig. 7 ).
This fracture pattern is not exclusively seen in young patients and is not always confined to the floor. The author has seen this pattern in older patients and affecting the medial wall involving medial rectus and superior oblique.
The scan, soft tissue windows, coronal format demonstrates the fracture (blue arrow) and the superior oblique (red arrows) ( Fig. 8 ).
CT scans may also support orthoptic diagnosis and prognosticate on the possibility of postoperative functional defect. Orthoptic examination is mandatory for all clinical diagnoses of diplopia and will help prognosticate ( Table 4 ).
Diplopia on downgaze is a predictor of the likelihood of postoperative diplopia, although it must be appreciated that the Hess chart only examines to 30° of elevation/depression, so type II and III may be more common than first appreciated.
Radiological predictors of postoperative diplopia included bone spurs in close proximity (blue arrow showing involvement with inferior rectus) ( Fig. 9 ).
Another prognostic indicator is the change in shape of the muscle bellies, seen in coronal section.
This can be seen in both the medial rectus and, in this case, the inferior rectus. Note the ribbon shape of the normal side (blue arrow) compared with the rounder fractured side (red arrow) ( Fig. 10 ).
Choice of material
The function of reconstruction material for primary repair has now become more objective. The choice of material depends on the anatomic and functional deficit ( Table 5 ).
|Single wall||Trapdoor||Polydiaoxanone sulfate|
|Single wall, loss contour||Anatomic loss||Preshaped titanium|
|Floor, medial wall||Anatomic loss||Preshaped titanium|
|Approach, apex||Anatomic loss||Custom-made||Navigation|
|Approach, skull base||Anatomic loss||Custom-made||Navigation|
|Large combined defect||Anatomic Loss||2-part custom-made||Navigation|
For simple defects, which in essence simply partition the orbit from adjacent anatomy, the polydiaoxanone sulfate (PDS) membrane is a very acceptable choice, easy to use, and well tolerated.
If the fracture size according to local anatomy and relationship to key structures is considered, then treatment planning becomes logical. In the schematic of the right orbit ( Fig. 11 ), floor (light blue defect) and medial wall (blue defect), which do not transgress the white line described by Jaquiery, are extremely predictable when reconstructed by preformed plates. The red areas of the apical third have close proximity to the optic nerve, and the high medial wall can be technically challenging to check plate positioning; for that reason, a custom plate with or without support by navigation is required.
The prefabricated plates are deficient laterally (purple zone), and for that reason a second plate (PDS), or alternatively a custom plate, is required.
The anterior ethmoidal and posterior ethmoidal foramina are illustrated but are anatomically inconsistent, and vessels are invariably thrombosed in primary surgery.
The dimensions of a typical prefabricated plate are illustrated in Fig. 12 in millimeters. The plate may be divided according to reconstructive requirements. Moderate defects floor (green), junctional zone (red), and medial wall (yellow) can be reconstructed, but lateral defects (blue) need further support. The footplate needs to remain in only the largest defects and can often be removed, simplifying plate placement.
Timing of surgery
There is anecdotal and published evidence to suggest that pediatric trapdoor defects are best operated on as soon as possible. Although this is the ideal, often presentation is delayed. The author has had good outcomes even in delayed cases. The surgical approach is easiest performed following resolution of chemises and lower-eyelid swelling, which occurs between 4 and 10 days after injury. The timeframe allows for treatment planning on a semielective pathway and also for fabrication of a custom plate if indicated. After 3 to 4 weeks, fibrous adhesions start to be noticeable, and by 6 weeks, the orbit begins to behave as a revision case.
Historical access to the orbit has undergone a significant evolution to achieve adequate surgical access in a cosmetically privileged region. Modern reconstructive principles have driven the development of more cosmetic incisions around the orbit that deliver at least equivalent, but, in fact, better surgical access. The eyelid can be divided anatomically and philosophically into 2 distinct zones:
Anterior lamella, which consists of skin and orbicularis oculi
Posterior lamella, which consists of conjunctiva and tarsal plate
Approaches to the orbit can be described in terms of the position of the initial incision; both techniques separate the anterior and posterior lamellae along the plane of the middle lamella, scarring of which is implicated in both the pathologic condition and the secondary correction of ectropion and entropion. Further subclassification of the approaches is indicated in Table 6 .
Although it is accepted that good results can be achieved by all the orbital approaches, there is increasing evidence that the posterior lamellar approaches provide for excellent surgical access with superb aesthetic outcomes. In view of the fact that there is no disturbance of the orbicularis oculi muscle, the postoperative bruising and swelling are very much reduced, as is the time to resolution.
Improved lateral exposure with an anterior lamellar approach requires a cutaneous extension that can be very visible postoperatively, and even compromises lymphatic drainage if extensive. In the case of the posterior lamellar approach, the addition of a McCord swinging lid greatly increases the surgical access to the whole orbital floor and lateral wall. Medial exposure through an anterior approach is difficult and may require an additional incision Lynch incision, whereas, in the posterior approach, extension into the transcaruncular zone will achieve a predictable exposure to the whole medial wall.
The surgical exposure resulting from a lateral cantholysis with transcaruncular extension is very satisfactory and highly predictable, allowing access from above the frontozygomatic suture laterally to the skull base medially and well into the posterior third of the orbital floor.
There has been debate about the relative merits of surgical incision of the orbital septum. It must be appreciated that the septum may be violated in more significant orbital trauma, and in those cases, surgical exploration is more challenging, and postoperative results are less predictable. There is increasing understanding in the literature to support this, and the author has practiced the preseptal approach for 15 years with a low-complication and returned-to-theater rate, in a significant quantitative and qualitative trauma practice. It is for this reason that this approach is presented.
Initial assessment of the approach requires testing the integrity of the medial and lateral canthal tendons ( Fig. 13 ). The shape and integrity of the lateral canthus (blue arrow) are demonstrated here. At this time, the presence or absence of a “crow’s foot” can be determined to site the position of the lateral canthal release (red line). Note that the length of the incision is short, and simply enough to access the lateral tarsal plate.
The cantholysis can be planned (blue arrow) ( Fig. 13 ) (red line) and made before the conjunctiva incision, or in a “cut as you go,” if during the subsequent dissection further access is required.
A 4/0 suture is placed through the midpoint of the lower eyelid ( Fig. 14 ), and evert the lid over a Desmarres retractor. This view demonstrates the tarsal plate (red arrows) nicely. Note that the tension within the eyelid causes an avascular zone; it is here that the incision is best sited (green arrows). The assistant applies gentle downward traction with both the Desmarres retractor and the suture.
It is extremely important to ensure that there is a low-power setting of the diathermy. The settings required are “10to 10 blend and spray.”
The initial incisions are mapped out using a postage-stamp technique ( Fig. 15 ) using the cutting setting. It is important to have the lightest touch on the surgical instrument until just the conjunctiva is incised.
This is then completed by joining each postage stamp, extending to the posterior aspect of the caruncle medially to the lateral canthus posteriorly.
The conjunctiva is then picked up with a small-toothed forceps, and tension is applied cranially (blue arrows) ( Fig. 16 ), leading to exposure of the middle lamella, which can be either incised with the diathermy or sharply cut with scissors.
The free edge of the conjunctiva can then be advanced cranially, and this acts as an eye shield. Note the integrity of the orbital septum (blue arrows) ( Fig. 17 ).
In this case, the skin incision is made with a number 15 scalpel ( Fig. 18 ).
The incision is then clipped with a mosquito forceps for a period of not less than 25 seconds, with the curve extending cranially ( Fig. 19 ).
The lateral tendon is then visualized, and this can be divided along the blue line ( Fig. 20 ). The downward traction (red arrows) allows the tendon to be tight, which greatly facilitates cutting the ligament with a pair of tenotomy scissors.
Downward traction of the lower eyelid is crucial to facilitate separation of the tendon (blue arrows) ( Fig. 21 ).
It is important to ensure that the tendon is freely mobile as demonstrated here ( Fig. 22 ).
A Lacks tongue retractor is then placed on the orbital margin to control the septum. It is crucially important that Lacks retractor remains stable and static. The soft tissues can then be scooped forward using a Mitchell’s trimmer to mobilize the orbicularis forward ( Fig. 23 ).
This allows full exposure of the orbital periosteum, which is sharply incised using diathermy ( Fig. 24 ).
The orbit can then be entered laterally, and initial dissection continues along the subperiosteal pocket. The lateral wall is robust, and this is an easily developed plane, “the lateral wall is your friend” ( Fig. 25 ).
One of the many advantages of the preseptal approach is that the surgical plane can readily be identified medially. The dissection is made easier by the use of multiple traction sutures (blue arrows). The mucosa can be cut with scissors along the green retrocaruncular line ( Fig. 26 ).
Subsequently, the orbital periosteum is incised along the rim and the soft tissue retracted along the green arrows and the medial orbit readily entered (blue arrow) ( Fig. 27 ).
The approach to the orbit follows a stereotypical route ( Fig. 28 ). Following subperiosteal access at the inferior orbital rim (1), the dissection proceeds laterally (2). The sphenozygomatic region allows a firm surface to develop the surgical plane. Following bipolar diathermy in the inferior orbital fissure (4), the posterior orbit is dissected to the palatine bone; this is the ledge that Jaquiery references.
The medial dissection then proceeds (6). The medial tissue can usually be delivered by traction (indicated by the dotted lines).
The clinical view shows the fracture margins (blue arrows) ( Fig. 29 ) and the herniated contents. Should there be a sharp bone edge, then this is best removed with a “Mitchell’s trimmer” to enlarge the hole. The contents should be delivered very gently.
The plate can then be gently insinuated between the bone and the soft tissues and fixed with screws.
Control of hemorrhage
Preseptal dissection is crucial to help avoid bleeding in a potentially closed space.
Operative bleeding can be managed according to the operating site ( Fig. 28 ).
Lateral bleed (blue zone): This is usually from the zygomaticofacial vessel; the vessel can be diathermied, and the foramen can be packed with bone wax.
Inferior orbital vessel tributary (yellow zone): This manifests as a small leak; the bleeding point can readily be identified, and bipolar cautery will normally arrest it.
Maxillary floor (green zone): This manifests as a persistent and slow ooze. This is managed by use of a ribbon gauze soaked in 1:1000 adrenaline placed in the bleeding point for 2 minutes. This allows for slowing of the bleeding point for diathermy to be used. Occasionally the maxillary antrum itself will need packing, if necessary with removal of the orbital floor to facilitate access. The packing with a saline soaked swab maintained for 2 minutes is usually all that is required.
Medial wall (red zone): This manifests as a persistent ooze that is complicated by reduced surgical vision due to the position. This is managed in a similar way to the maxillary sinus using an 1:1000 adrenaline soaked ribbon gauze. This area must be surgically dry to facilitate further surgery and patient safety.