Orbital fractures

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Prepared by Dr. Anchal AgarwalOrbital Fracture

CONTENTS Anatomy of Orbit Bony Orbit, Floor, Medial wall, Lateral Wall, Roof ,Apex of Orbit Classification of fracture Pathophysiology of Fracture Blow In fractureBlow Out Fracture Pathophysiology & Clinical features.Superior Orbital Fissure Syndrome - Pathophysiology & Clinical features.CLINICAL EVALUATION Forced Duction Test , Hess Chart Management Incisions Subciliary , Transconjuctival Orbital Floor Dissection & Reconstruction. COMPLICATIONS

Anatomy of Orbit Orbit conical cavityBase AnteriorlyApex directed at Optic Foramen Orbital Volume 30cc ; Globe 7ccBy Age 5 years orbital growth is 85% complete , Finalised between 7 years of age

Bones 7 (Maxillary, Zygomatic, Frontal, Ethmoid, Larimal, Palatine, and Sphenoid )

Four Walls roof, lateral, medial, floorMedial wall & floor thin ;Lateral wall & Roof Stronger.Floor weakened due to Infraorbtal Canal passing through it

Medial wall Formed by Lamina Papyracea of Ethmoidal bone & Lacrimal bone Vital Contents Eyeball (Non Compressible)6 EXTRAOCULAR MUSCLES Originate from Common Tendinous fibrous ringAnnulus of Zinn Fibrous ring Common origin of 4 Rectus Muscle

OPTIC NERVE direct extension of Gray MatterVery sensitie to Compression and once damaged fails to regenerate

SUPERIOR ORBITAL FISSURE Transmits 3rd , 4th & 6th Cranial Nerves Opthalmic Division of 5th Cranial Nerve Opthalmic Artery & Vein

Cranial Nerves and its Supply

Occulomotor (C.N.-III)- Supplies Superior Rectus Medial Rectus Inferior Rectus Inferior Obliqus

Abducent Nerve Lateral Rectus (LR6 )Trochlear Nerve Superior Obliqus (SO4)

Theoretically, the mechanical load of the orbital floor is approximately 0.0005 N/mm2 (30 g orbital content onto 600 mm2 of orbital floor area), as indicated by several cadaver investigations.

CLASSIFICATION ORBITAL WALL FRACTURES Blow Out Fracture Pure Blow Out Fracture Impure Blow Out Fracture Blow In Fracture

ISOLATED ORBITAL WALL FRACTURE :RoofFloor Medial wall Lateral wall

ISOLATED FRACTURES OF THE ORBITAL RIM :SUPERIOR RIM INFERIOR RIM MEDIAL RIM LATERAL RIM

COMPLEX COMMINUTED FRACTURES : Nasoethmoidal and fronto-naso-orbital fractures

Anatomy of Bony Orbit

Floor Of Orbit

Extends Rim to approx. 2/3rd of the depth of the orbit Posteromedial aspect of Orbital floor transitions into Medial Orbital Wall to form Posterior Medial Bulge Only three of four orbital wall extend into the Apex Medial, Superior , Lateral Anterior third Diameter widens behind Superior Inferior margins Post Entry Concavity Saggital plane Lazy S shape

Petersons Principles of Oral and Maxillofacial Surgery ; 2nd Edition ; Page 463- 464

Floor of Orbit Surface Landmarks Infraorbital Groove bony sulcus Inferior Orbital Fissure converts into canal continues to Infraorbital Foramen Origin Of Inferior Oblique Muscle Posterior Lateral Promontry Posterior medial bulge ending in a raised Promontory shaped lateral plateau. Delineated junctional zone of Maxillary surface of orbital floor & Orbital process of Palatine bone

Orbital Fissures/Canals and Their Contents

MEDIAL WALLConvex Rectangular shape Runs Parallel to Saggital Plane Medial wall paper thin Lamina paprycea (0.2-0.4mm) Reinforced along the Maxillary-Ethmoidal suture --- forming an Internal Orbital Buttress.

Petersons Principles of Oral and Maxillofacial Surgery ; 2nd Edition ; Page 465

Surface Landmarks Lacrimal Fossa Anterior 1/3rd of the Medial WallFrontoethmoidal suture Roof of the ethmoid sinus at the level of the cribriform plate Ant. & Post. Ethmoidal Foramen along frontoethmoidal suture in midorbit Distances Medial orbital Rim Ant. Ethmoid Foramen 22-25mmPost. Ethmoid Foramen to Ant Ethmoid Foramen 12-15mm Post Ethmoid Foramen & Optic Canal 3-7mm


Formaina approx 2/3rd of the way up the medial orbital wall, within the frontoethmoidal suture line. IMPORTANT SURGICAL LANDMARK to identify the cribriform plate Orbital surgeons use these as landmarks for superior extent of orbital wall decompression 15

LATERAL WALL Forms Triangle with an anterior base Forms 45degree angle to its medial wall counterpart SURFACE LANDMARKS Whitnalls tubercle small bony projection actual insertion is Common lateral retinaculum.Lateral horn of lateral aponeurosisLateral canthal tendon of eyelids Inferior Suspensory (Lockwoods) Ligaments. Multiple fine check ligaments of Lateral Rectus Muscle. Superior & Inferior Orbital FissureZygomaticosphenoid suture imp. Landmark to verify proper reduction of complex ZMC fracture.

Petersons Principles of Oral and Maxillofacial Surgery ; 2nd Edition ; Page 464- 465

Roof Of Orbit Domed contour Comprised of Orbital plate of the Frontal Bone Extremely thin In Apex Roof terminates into Lesser Wing of Sphenoid where Oval shaped Optic foramen forms Optic canalSURFACE LANDMARKS:Trochlear fossa : Zone of attachment of tendon of Superior Oblique muscle Lacrimal Gland Fossa

Petersons Principles of Oral and Maxillofacial Surgery ; 2nd Edition ; Page. 464

Apex of Orbit Posterior third made by sphenoid bone Superior Orbital Fissure separates the Lesser wing of sphenoid & Greater Wing of Sphenoid Optic Canal within the lesser wing of sphenoid Annulus of Zinn all Extraocular muscles except Inf. Oblique arises from this tendinous ring

Limit of Dissection Inferiorly(Floor) Upto 28-30mm (safe limit) optic canal is at around 40mm Laterally Superior Orbital Fissure Superiorly Orbital roof dissection is stopped at periorbital surrounding Recurrent Meningeal Artery passing through bony canal within the Sphenofrontal suture lineMedially Posterior extent Posterior Ethmoidal vessels , running in the Fronto-Ethmoidal Suture line Anterior to Optic foramen.

Distance of Vital Orbital Structures from Bony LandmarksSTRUCTUREREFERENCE LANDMARK MEAN DISTANCE (mm)Midpoint of inferior orbital fissureInfraorbital foramen 24Anterior Ethmoidal ForamenAnterior Lacrimal crest 24Superior Orbital FissureZygomaticofrontal suture 35Superior orbital Fissure Supraorbital Notch 40Optic Canal (medial aspect)Anterior Lacrimal Crest 42Optic Canal (Superior Aspect)Supraorbital notch 45


Pathophysiology of Orbital Fractures

In the event of Trauma

Thick Rims protect the Eyeball

Absorb shock by Fracturing themselves

Orbital walls (especially Medial Wall & Floor) fracture in an isolated way

Gets displaces Inwards or Outwards

Called as Blow-In or Blow-Out fractures

PURE Blow Out OR Blow In Orbital Walls fracture in Isolation

IMPURE Blow Out or Blow In Fracture Walls + Rim

Blow Out Fracture

Blow Out Fracture Term coined by Smith and Regan 1957First described by MacKenzie in Paris in 1844PATHOPHYSIOLOGYBuckling Theory This theory states thatif a force was to strike any part of the orbital rim, it will cause walls to undergo a rippling effect & the force striking the rim-will transfer to the weaker portion especially the floor & cause them to distort & eventually fracture

Pathophysiology of blow out fracture of the orbit

Hydraulic Theory (Pfeiffer in 1943) he said that it is evident that the force of the blow received by the eyeball was transmitted by it to the walls of the orbit with fracture of the delicate portions. Therefore direct injury to the globe forcing it into the orbit was necessary.

Medial Wall & Floor Thin & Fragile Fracture readily provide natural compensation As they fracture Orbital Size increases, Itraorbital pressure compensated.Herniation of periorbital fat

Clinical Features Circumorbital Edema - Subconjunctival Bleeding due to fracture subperiosteal bleeding escapes in subconjuctival plane. Enopthalmous Increase in size of Orbit Eyeball sinks Periorbital Fat Herniates through fractured walls Hanging-drop AppearanceUnilateral Epistaxis bleeding into antrum Numbness in area of distribution of Infraorbital Nerve Diplopia or Vertical gage Inferior Rectus or Inferior Obliqus gets entrapped in fracture inability of eyeball to move in vertical direction.

Enopthalmus following Blow-Out Fracture

Retracting action of extraocular muscles Enopthalmus.

Diplopia Entrapment of Inferior Rectus & Inferior Obliqus

Superior Orbital Fissure SyndromeAlso k/as Rochon Duvigneaud SyndromeHirschfeld first described it.

Contents of Superior Orbital Fissure :3rd Cranial Nerve (Occulomotor)4th Cranial Nerve (Trochlear)6th Cranial Nerve (Abducent)5th Cranial Nerve (Trigeminal) Opthalmic Branch Opthalmic ArteryOpthalmic Vein

Superior Orbital Fissure Syndrome

Pathophysiology Raised Intraorbital Pressure (due to Hematoma/Displaced fractured segments)

Compression of contents of Sup. Orbital Fissure

Paresis of Nerve

Neurological deficit in their distribution

Occulomotor supplies SR , MR, IR , IO Abducent LR Trochlear SO

Due to paresis of these nerves all these extraocular muscles undergo paralysis eyeball fails to move External OpthalmoplegiaAs affected eye does not move whereas contralateral normal eyeball moves focal axis gets disturbed two images - Diplopia

Clinical Manifestations

External Opthalmoplegia Eyeball fails to moveDiplopia Two images of one object Internal Opthalmoplegia Fixed Dilated pupils (parasympathetic III cranial nerve Occulomotor )Ptosis of Upper Eyelid upper eyelid drops down like a curtain parasympathetic supply.Orbital Apex Syndrome If Optic Nerve Involvement is present.

Pre-ganglionic parasympathetic fibres from Edinger- Westphal nucleus in the mid brain , - relayed to --- ciliary ganglion situated in lateral rectus muscle ----- Post ganglionic fibres distributed paillary and ciliary muscles of the pupil through short ciliary nerve34

BLOW IN FRACTURE Fragmented bones of the orbital floor are displaced into the orbit.Proptosis Exopthalmous More commonly seen in fractures of orbital roof

CLINICAL EXAMINATION Initial Opthalmological evaluation 1. Periorbital Examination 2. visual acuity SNELLEN CHART 3. ocular motility FORCED DUCTION TEST 4. Pupillary responses ,- pupillary size, shape& symmetry, light reactivity,5. Visual fields HESS CHART6. Fundoscopic examination TONOMETRY to assess Intraocular pressure (Normal 10-20mmHg)7. Hertel Exopthalmometer measure exopthalmous

UNEQUAL PUPILS Anisocoria

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Forced Duction Test Prior to the performance of a forced duction test, a cotton-tipped applicator is soaked with topical anesthetic drops and held against the limbus for a few minutes. Fine-toothed forceps are then used to grasp the conjunctiva and Tenons capsule just posterior to the limbus. The patient is then asked to look in the direction of restriction of movement of the eye .

Snellen chart

Tonometer

HESS CHART

IMAGING CT Scan Orbit - To visualize the fractured segments CT Scan also helps evaluate the Intraorbital volume. By using a software to compare the normal orbital volume to the affected

MRI

Management

Strabismus surgery - Loosens or tightens the eye muscle which changes the alignmnet of eye related to each other .SURGERY ON THE EXTRAOCULAR MUSCLE TO CORRECT THE MISALIGNMENT OF THE EYES

Abnormal position of eye - dystopia

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In 1984 Smith and colleagues introduced the concept that Volkmanns contracture might occur as a result of elevated intraorbital compartmental pressure

Although this phenomenon was well known in orthopedic literature , to occur within extremities, it was unproven in orbit

Applying this concept to the orbit Smith and colleagues recommended surgical intervention in the elderly , in individuals who are hypotensive , and for small or linear orbital floor fracture with coexsisting diplopia.

They felt these pateints were at higher risk of developing Orbit Compartment syndrome.

Puttermans indications for surgical intervention 7 days of systemic corticosteroids to speed the resolution of diplopia within the first 3 weeks Persistent functional limitations clear indication for surgery

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Indications for surgical managmentUnresolving soft tissue entrapment with disabling diplopia Enopthalmous greater than 2mmCT scan evidence of a large fracture

SURGICAL MANAGEMENT : 1.CLOSED REDUCTION Transantrally.- Caldwell Luc Procedure Trannasally Through inferior turbinate foleys catheter

Hertel Exopthalmometer to measure enopthalmous

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Incisions

Existing lacerations

LowerEyelid 1)Subciliary 2) Subtarsal 3) Infraorbital approaches

Transconjuctival Approach Lower Eyelid

SAGITAL SECTION THROUGH ORBIT & GLOBE C- Palpebral Conjuntiva IO- Inferior Oblique muscleIR- Inferior Rectus MuscleOO- Orbicularis Oculi OS Orbital SeptumP - Periosteum/Periorbita TP- Tarsal Plate.

Orbicularis Oris Muscle Innervated by Cranial Nerve VII

Upper Eyelid Levator Palpebral Superioris Cranial Nerve III

Orbicularis Oculi - Orbital and Palpebral Portions

Palpebral Portion is divided into fibers - Pretarsal Portion - in front of the tarsus.Preseptal Portion - in front of the orbital septum.

LAYERS OF EYELID - Skin; Subcutaneous areolar tissue; Striated muscle (orbicularis oculi)Submuscular areolar tissue (contains main sensory nerves to lids)Fibrous layer with tarsal plates; Nonstriated smooth muscle; Mucous membrane or conjunctiva47

Subciliary Incision

The incision is approximately 2 mm below the eyelashesand can be extended laterally as necessary (top dashed line). It is made throug skin only.

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Subcutaneous dissection of skin, leaving pretarsal portion of orbicularis muscle attached to tarsus. Dissection 4-6mm inferiorly in this plane is adequate Subcutaneous dissection through the lid margin

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Use of scissors to dissect through orbicularis oculi muscle over lateral orbital rim to identifyperiosteum.

Incision through the bridge of orbicularis oculi muscle.

Sagital plane through orbit showing incision of the bridge of orbicularis oculi muscle.

- Incision through periosteum along anterior maxilla, 3 to 4 mm inferior to infraorbital rim.- Note the pretarsal muscle still remaining on the inferior tarsus and the orbital septum, which restricts the orbital fat from entering the field.

- Subperiosteal dissection of anterior maxilla and orbital floor. Note that the periosteal elevator entering the orbit is placed almost vertically as dissection proceeds behind the rim. -In the anterior region, the floor of the orbit is at a lower level than the crest of the rim, necessitating dissection inferiorly just behind the crest of the rim.

1-2mm below Inferior rim layers converge periosteal thickening ARCUS MARGINALIS

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Sagital plane through orbit showing subperiosteal dissection of the anterior maxilla and orbital floor.

TRANSCONJUCTIVAL APPROACH

Fig.1 - Incision of the conjuctiva below the tarsal plate

Fig 2 - Incision through periosteum. To facilitate this maneuver, a traction suture is placed through the cut end of the conjunctiva to retract the tissue and maintain the position of the corneal shield. Small retractors are placed so that the lower lid is retracted to the level of the anterior surface of the infraorbital rim. The intervening tissue along the infraorbital rim is the periosteum. The incision is made through the periosteum just posterior to the infraorbital rim.

TEISSER AND CONVERSE 1973RETROSEPTAL & PRE-SEPTAL APPROACH 54

Sagital plane through the orbit and globe demonstrating level and plane of incision. The conjunctiva and lower lid retractors are incised with scissors.

SUBPERIOSTEAL DISSECTION OF THE ORBITAL FLOOR. Note the traction suture placed through the cut end of the conjunctiva, which assists in retracting the conjunctiva and maintains the corneal shield in place.

Orbital Floor Dissection

Periorbital is elevated from the underlying bone As dissection continues posterolaterally, the inferior orbital fissure are visualized

The periorbital dissection along the orbital floor proceeds posteriorly in a twohanded technique using a malleable ribbon retractor with a wide rounded tip and a periosteal elevator.

In order to ensure a clean periosteal dissection, the bony contours must berespected

Surgical Exposure After periorbital dissection is performed, adequate exposure, (proper retraction) and illumination of the fractured area is imperative.

Malleable retractors, spoons and special orbital retractors designed for the globe

Transition between anterior mid orbit , the orbital floor slopes upwards giving rise to the posterior medial bulge & Slightly convex bony platform Elevator passed transversely along the inferior orbital fissure

Infraorbital neurovascular bundle can be visualized first shining through the thin bony roof of its canal

Then it becomes directly visible in the infraorbital groove Depending on the amount and severity of comminution around the course of theinfraorbital nerve, a bony decompression might be indicated.

EXTENT OF DISSECTIONTaking into account the extent of fracture, the periorbital dissection stops at the medial border of the inferior orbital fissure leaving the soft tissue invagination intact Laterally, the dissection is continued to the posterior edge of the floor to the orbital process of the palatine bone. The suture between the maxilla and the palatine bone is indistinguishable in the adult skull.Medially the periorbital dissection (as shown in the anatomic specimen) extends to the zone over the internal orbital buttress where the orbital floor blends into the medial wall.

In many cases a periorbital dissection of the floor with a tunnel medial to theinferior orbital fissure will be sufficient.

For an EXTENDED ACCESS to the posterior orbital floor, the contents of the inferior orbital fissure must be addressed and transected to allow for this additional access.

The transsection is prepared with a dissection along the inferior portion of the lateral orbital wall in order to create a second tunnel alongside the vertical softtissue partition

The intervening soft tissue invagination is transected in a stepwise fashion usingbipolar electrocautery and sharp dissection across the fissure above the level ofMllers vestigial muscle, stripping the periorbita along the lateral edge of theinferior orbital fissure.

This illustration demonstrates the stripping of the periorbital layer from the inferior lateral orbital wall immediately adjacent to the inferior orbital fissure with a sharp elevator proceeding posteriorly.

Limit of Dissection Inferiorly Upto 28-30mm. Laterally Superior Orbital Fissure Superiorly Orbital roof dissection is stopped at periorbital surrounding Recurrent Meningeal Artery passing through bony canal within the Sphenofrontal suture lineMedially Posterior extent Posterior Ethmoidal vessels , running in the Fronto-Ethmoidal Suture line Anterior to Optic foramen.

The subperiosteal dissection is continued using a periosteal or freer elevator in alateromedial direction and lifted up and retracted by and by with the ribbonretractor until the entrance of the apex is reached.

Reconstruction Material

Pre-formed Orbital Implant

ADVANTAGES : RadiopacitySmooth Surface Minimal or no countouring necessary DISADVANTAGE : Cost

Bone Graft

Disadvantages : Additional Donor site needed Possible contour and dimensional changes due to remodeling Difficult to shape according to patients anatomy

Porous Polyethylene Sheet (PPE)

Disadvantages : Not Radiopaque (Not visble on Post Operative Radiographs Lack of Rigidity when very thin wafer of PPE is used. When a more thick rigid wafer is used there is a risk of causing dystopia

COMPOSITE OF POROUS POLYETHYLENE AND TITANIUM MESH By combining titanium mesh with porous polyethylene Material becomes radioopaque More rigid than porous PPE.ADVANTAGE : Stability Contouring Adequate in large three wall fracturesRadiopacityNo Donor Site Needed DISADVANTAGES : Less Drainage from orbit than with titanium mesh

RESORBABLE MATERIALSThermoplastic and Non Thermoplastic Materials ADVANTAGES :Availability Handling/Contourability (only for thermoplastics) Smooth surface and smooth edges

Disadvantages: - No radiopacity- Degradation of material with possible contour loss Sterile infection / inflammatory response- Difficult to shape according to patients anatomy (only for non-thermoplastics)- Less drainage from the orbit than with uncovered titanium mesh.

COMPLICATIONS EARLY COMPLICATIONS :

1. Hemorrhagic or orbital hematoma treated by -lateral cathotomy immediately, lateral canthal Tendonlysis ,

Lateral canthotomy indicated when - Decreased visual acuity Introcular pressure more than 40mmHg Proptosis Opthalmoplegia

Retrobulbar hemorrhage Rare, rapidly progressive life threatening emergency that results in accumulation of blood in the retrobulbar space Increased IOP stretching of the optic nerve & blockage of ocular perfusion

Proptosis , marked subconjuctival ecchymosis & edema ,

Symptoms seen are pain , decreasing visual acuity, diplopia Treatment includes iv mannitol (used to treat raised intracranial pressure)Acteazolamide carbonic anhydrase inhibitor ; diuresis in PCT of kidney excretion of NA, K, Cl lowering BP, IOPMegadose Steroid Therapy 100mg Dexa as an i.v. bolus with 40mg 6 hourly in severe unresponsive cases ( Anderson et al 1982)

3. Blindness

4. Superior Orbital Fissure syndrome

OCULOCARDIAC REFLEX/ TRIGEMINOCARDIAC/ TRIGEMINOVAGAL REFLEX The oculocardiac reflex pathway begins with theafferent fibres of the long & short ciliary nerves that travel with the opthalmic division of the trigeminal nerve to the gasserion ganglion via the sensory nucleus of the trigeminal nerve. In the floor of the 4th ventricle short internuncial fibres in the reticular formation connect them with the efferent pathway from the motor nucleus of the vagus nerve to the depressor nerve ending in the mucle tissue of the heart.

CLINICAL FEATURES Bradycardia Faintness Further stimulation can lead to cardiac dysrhythmiasAtrioventricular blocks Asystole

Bradycardia has been attributed to Trigeminal derived vagal reflex

LATE COMPLICATIONS Altered vision Diplopia Ectropion lower eyelid turns outward Epiphora overflow of tears onto the face insufficient tear film drainage from eyed in that tears will drain down the face rather than through nasolacrimal system Enopthalmous

References ROWE & WILLIAMS Maxillofacial Injuries FONSECA - Petersons Textbook of Oral & Maxillofacial Surgery R.M. Borle

THANK YOU

Dissection between orbicularis oculi muscle and orbital septum. The dissection shouldextend completely along the orbital rim and superiorly to the level of subcutaneous dissection.

Sagital plane through orbit showing level and extent of dissection. Note the bridge oforbicularis oculi muscle remaining between the lid and skin/muscle flap.

Linear Fracture

Education

Orbital fractures