Cranio-Maxillo-Facial

All Facial Fractures

Facial Fractures

The orbits are paired bony structures, conical or pyramidal in shape, and house safely the orbital contents, the most important of which being the eyes. The middle third of the orbit, particularly its floor and medial wall, are composed of relatively thin bones and are most liable to bony trauma.

Orbital fractures are of two types – Blow out fractures and Fractures without blowout of the thin medial wall or floor. A blow out fracture can again be a pure blow out or an impure one when associated with fractures of adjacent facial bones. Orbital fractures without blow out linear fractures, comminuted fractures or fractures with fronto-zygomatic separation.

A very thorough clinical examination and a proper documentation is a must in all orbital fractures. An ophthalmologic examination to document the presence of vision, light perception, visual acuity and presence of foreign bodies is a must. The globe should be examined for injuries and documented. A search for fractures should be made bone-wise and every facial bone should be individually examined and documented. Associated head injuries, particularly base of skull injuries and cervical spine injuries should not be overlooked.

A coronal and a sagittal CT scan of the facial skeleton are used to demonstrate orbital fractures. A 3D computerized reconstruction of the injured facial skeleton is also extremely informative.

Open reduction internal fixation of the fractures of the orbital rim by approaching through the facial lacerations or through the sub-conjunctival, subciliary or infraorbital incisions is routinely practiced. The internal fixation of fractures is done by 1.5mm or 2mm mini plates and screws. Blow out fractures with bone loss are treated preferably by calvarial, iliac or rib grafts, but silastic implants are also used on rare occasions. Associated naso-ethmoidal, basicranial, frontal, maxillary, zygomatic and mandibular fractures are all attended at the same time.

Prompt management of orbital fractures can reduce deformities and functional impairments. Complications like facial asymmetry, enophthalmos, diplopia and ocular muscle imbalance are preventable on most occasions. A wide variety of injury to the globe from simple corneal laceration to vitreous haemorrhage, retinal detachment, rupture of the globe and blindness can at times be associated, and prompt documentation and management by an ophthalmologist can avoid future complications and litigation.

Anatomy of Orbits

Orbits are conical and paired bony sockets occupying the middle third of the facial skeleton and contain Ocular globe in its anterior half, Extra-ocular muscles in the form of a muscle cone, the orbital fat – both outside and inside the muscle cone and Vessels and Nerves.

The bony box is composed of 4 walls and 2 Fissures. It can be conceptualized into anterior 1/3 and posterior  1/3 which are thick walled and middle 1/3 which is thin walled. Anterior 1.5 cm of its floor is concave and posteriorly it is convex.

The Lateral wall is limited by the superior orbital fissure above and the inferior orbital fissure below. It is adjacent anteriorly to the Temporal fossa and posteriorly to the middle cranial fossa. There are no borders between the floor and medial wall. This structure is weakest in its middle third where it is formed by the orbital plate of Maxilla and lamina papyraceae of Ethmoid. This is the commonest site for Blowout fractures.

The Roof is formed anteriorly by the Orbital plate of Frontal bone and posteriorly by the lesser wing of Sphenoid. Its fracture may cause Superior Orbital nerve compression, Trochlea / Superior Oblique pulley damage, Blow in fracture, Dural tear, Frontal lobe injury and Sup. Orbital fissure syndrome. It may also be involved in naso-ethmoidal, zygomatico-orbital and Le Fort II and III Maxillary fractures.  

HISTORY OF THE PATIENT

The history of  the patient is of vital importance in deciding about the type of Injury. If the diameter of the offending object is less than 5 cm like a marble, then a globe injury should be suspected but if it is more than 5 cm. Like a tennis ball then the injury is probably a blowout fracture. Visual disturbances like diplopia, blue ring or loss of vision should be documented. Episodes of bleeding from nose and loss of consciousness should also be noted.  

OPHTHALMIC EXAMINATION

A pre operative ophthalmologic examination by an ophthalmologist is a must prior to any orbital surgery. PL / PR, abrasions and lacerations of the eyelids, oedema, contusion, abrasion and laceration of the globe, movement of extra-occular muscles, intra-occular pressure, visual fields, fundoscopy, patency of Lachrymal system and intactness of the Canthal ligaments should be documented.  

CLASSIFICATION OF ORBITAL FRACTURES

• Orbital Blowout Fractures
• PURE - Orbital Rim intact 
• IMPURE - Associated with Fr. Orbital rim 

ORBITAL FRACTURE WITHOUT BLOWOUT

•    Linear Fractures - Zygomatic, Le Fort II, III Maxillary.    

•    Comminuted Fr. - Le Fort II, III + Herniation of Orbital contents into Maxillary Sinus 

•    Displaced Fr. - Fronto-Zygomatic separation + down and out displacement of Zygoma

BLOWOUT FRACTURES

Blowout fractures are caused by trauma to rim / soft tissue of Orbit. There is a sudden increase in intra-orbital pressure which causes the force transmitted to Orbital walls. The Lamina papyraceae in the floor / medial wall, being the weakest area of  the four walls, fractures. Soft tissue like orbital fat and extra- occular muscle herniates into the maxillary antrum and at times  incarceration of soft tissues can occur at this site. This in turn results in diplopia and enophthalmos.

CAUSES OF DIPLOPIA

• Muscle contusion

• Entrapment of Orbital fat

• Entrapment of muscle I.R, I.O

• Injury to Nerve to I.R, I.O

  –    Contusion

  –    Multiple bony fragmentation

• Injury to Cr. N. III, IV, VI

  –    Laceration by bone fragment

  –    Disruption of muscle attachment

  –    Contusion

  –    Haemorrhage

CAUSES OF ENOPHTHALMOS

• Orbital enlargement 

• Soft tissue herniation 

• Post. Retention of Globe by entrapped soft tissue 

• Fat necrosis 

• Fat atrophy - N. disruption 

• Dislocation of intra-conal fat to extra-conal site 

• Dislocation of trochlea and Sup. Oblique M. 

• Cicatrical contracture of retro-bulbar tissue  

INVESTIGATIONS

X - Ray - Caldwell, Water view and a 

C.T.Scan - Axial Coronal cuts will clinch the diagnosis. Various radiological appearances are seen:

• Hanging drop 

• Trap door - 2 bone fragments hang on a periosteal hinge 

• Med. wall - Lamina papyraceae symmetrically depressed / shattered

• Extensive fracture + massive extrusion of Orbital contents 

Forced Duction Test - The most important test is however the Forced duction test. We instill local anaesthesia in the conjunctival sac. After complete anaesthesia is achieved grasp the Inferior Rectus 7 mm from the limbus and rotate the globe superiorly, inferiorly, medially and laterally. This not only detects soft tissue entrapment but even cures minimal entrapment. This is the surest indication of Surgery.

INDICATIONS OF SURGERY 

1. Limitations of forced rotation of eyeball 

2. Radiographic evidence of extensive fracture 

3. Enophthalmos 

4. Significant positional change of globe 

5. Pediatric age group – as true muscle entrapment is more frequent  

TIMING OF SURGERY

This is not an easy decision. We have to avoid early surgery in Post trauma oedema, Retinal detachment, Hyphema, and when Clinical / Radiological indications are equivocal, and when other major injuries prevent us from operating on the orbit. However we have to do early surgery in major orbital fractures, positive Forced Duction Test, significant soft tissue herniation, Enophthalmos, and in children.  

SURGERY

Aim of Surgery

• Disengage entrapped structures 

• Restore oculo-rotatory functions 

• Replace orbital contents in anatomical position 

• Restore orbital size and volume  

APPROACH

• Eyelid

• Subciliary

• Transconjunctival + lateral canthotomy

• Preseptal

• Retroseptal

• Orbital rim - one stroke incision

• Canine fossa - through Maxillary sinus  

REPLACEMENT OF HERINATED CONTENTS

• Gentle tug, no strong tug

• Enlarge bone gap if needed

• Intra-operative Forced Duction Test

  –    before disengagement

  –    after disengagement

  –    after Orbital floor reconstruction

• Establish complete bone gap-intact bone all around

• Preserve Infra-orbital N  

RESTORATION OF ORBITAL FLOOR

• Indications 

  –    Bone defect 

  –   Malpositioned, Weak Comminuted floor

• Material 

  –   Bone - Calvarial, Rib 

  –   Cartilage - Ear, Septal 

  –   Inorganic - Silastic, Teflon, Metals, Polymers  

The bone graft is to be retained by itself or preferably by a lag screw or wire fixation. A mini plate bent to form a sauce pan handle can also be used. The grafting achieves two purposes, it re-establishes the orbital size and seals the maxillary sinus. Both floor and medial wall should  be grafted if needed.

ORBITAL FRACTURES WITHOUT BLOWOUT

INFERIOR ORBITAL RIM FRACTURES

These can be Isolated or Impure Blowout fracture. The aim is to restore the cheek convexity. This is achieved by reducing the fracture, realigning the rim and retaining it by wires / Mini plates. Two words of caution, we must avoid inferior and posterior displacement of rim and we must prevent vertical shortening of lower eyelid.

MEDIAL ORBITAL WALL FRACTURES

It is usually with fractures of floor or Naso-ethmoidal fractures. There is progressive increasing enophthalmos and increase enophthalmos on abduction. Narrow palpabral fissure, Horizontal diplopia, and Orbital emphysema are pointers to the diagnosis. Treatment is like the blowout fracture except for the fact that in very high medial wall fractures exposure through a bicoronal flap may be needed. Properly curved bone grafts that fit into the natural contour of floor and medial wall are necessary.

LATERAL ORBITAL WALL FRACTURES

It is usually caused by high energy trauma to Zygomatic area. The fractured zygomatic complex is displaced downwards and outwards and the orbital fat is prolapsed into the temporal fossa. The lateral canthus is dislocated downwards. There is ectropion of lower lid and rarely injury to the globe and loss of vision. Rarely the Greater wing of Sphenoid too is involved along with the inferior orbital fissure.

ORBITAL ROOF AND SUPERIOR RIM FRACTURES

Isolated fractures of the Orbital roof are uncommon. Usually they are seen with Zygomatic, Frontal, and Naso-ethmoidal fractures. Superior Orbital Nerve induced anaesthesia and Trochlea damage causing Superior Oblique muscle impairment are associated features. Superior Oblique Fissure syndrome – involvement of Cranial nerves III,IV,VI+V(Ophthalmic division) and Orbital  Apex syndrome – Involvement of Optic N. and resultant loss of Vision are rarely encountered.

FRONTO-TEMPORO-ORBITAL FRACTURES

High velocity trauma is the usual causative factor. Dural tear and Frontal lobe trauma are usually seen. The Orbital Roof is displaced downwards and  inwards, which in turn results in the Globe being displaced downwards and forwards. Trans-cranial repair of dura and calvarial bone grafting is required.

NASO-ETHMOIDO-ORBITAL FRACTURES

These can be Isolated as a result of blunt trauma or in association with Mid face fractures and Anterior Cranial fossa fractures. We have to watch for Head Injury and C.S.F. rhinorrhoea. The most frequently involved parts are the Lamina papyraceae, Lacrimal bone and the posterior part of the frontal process of maxilla. Neurological complications like Laceration of dura of frontal lobe, Laceration of tubular sheaths of Olfactory Nerves, perforation of brain by ethmoid or frontal bone chips and contusion or necrosis of Brain tissue are also encountered. Soft tissue complications like laceration of Levator.

Jaw Fracture

Malocculsion following mandible fracture	Intra oral view of fracture site

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