Grand Ward Round

1. Grand Ward Round Case Presentation: Mr QBZ

2. History • 17 Malay boy • Allegedly assaulted on 31 May 2008 • Awoke to find himself in hospital • Admittted under Neurosurgeons for head injury • C/O binocular vertical diplopia during admission • Referred as blue letter and first seen by us on 2 June 2008 • Otherwise well with no nausea or vomiting

3. Examination

4. R mild Enophthalmos • R gross Hypotropia -4 0 0 EOM 0 0 0 0 -3.5

5. CT ORBITS • Fracture involving the infero-medial wall of the right orbit posteriorly. Also Fracture of the medial wall of the right maxillary antrum seen • Surrounding soft tissue swelling and prolapse of a small amount of retrobulbar fat into the roof of the maxillary sinus • No significant prolapse of the R inferior rectus is seen, however it appears slightly swollen with surrounding fat stranding suggesting a contusion

6. Diagnosis • Right orbital floor fracture • With entrapment of orbital contents • “White-eyed blowout fracture”

7. MANAGEMENT • Underwent R Orbital Floor Fracture Repair with Osteomesh implant on 2 Jun 2008 1930 hrs in EOT (2 days post initial injury) • Intraop findings: • Posterior fracture 28 mm from orbital rim • 5 mm x 5mm in size • Entrapment of orbital contents- relieved during op

8. Postop • G Preforte Q1H RE • G Cravit Q3H RE • PO Prednisilone 60mg OM

9. 3 June 2006 ( POD 1) • LHT 40Δ • R Hypotropia ? due to R Inferior rectus: • Direct injury/ fibrosis • Entrapment 0 -4 0 0 0 0 -3 0

10. Postop CT Orbits • Previously noted blowout fracture had been reduced • The inferior rectus muscle is enlarged, with inflammatory change in adjacent fat • No evidence of entrapment • Findings suggest residual muscle swelling, edema and inflammation

11. 13 Jun 2008 (POD 11) • Subjectively: mild diplopia in primary gaze • LHT 6 Δ- Improved • HERTEL’s: 113 16 17 -2 0 EOM 0 0 0 0 -3 0

12. Orbital Blowout Fractures and the White-eyed Blowout fracture

13. Orbital Blowout Fractures • More common in males • Usually between the ages of 21 to 30 years • Result from an impact injury to the globe and eyelid • The object is usually • Large enough not to perforate the globe • And small enough not to fracture the orbital rim • E.g. fist, tennis ball, door knob

14. Mechanism of Injury 2 theories: • The fracture results from sudden increase in intraorbital pressure • The fracture is the result of buckling forces which are transmitted to the orbital bones by a transient deformity of the orbital rim .

15. Under these circumstances, fractures of the inferior orbital wall are most common because of a combination of factors, namely: • the thinness of the maxillary roof, • presence of the infraorbital canal, • and the curvature of the floor

16. Pertinent Signs & Symptoms • Restricted ocular movements and Diplopia • Enophthalmos, resulting from • Escape of orbital fat • Enlargement of bony orbital volume • Muscle entrapment causing a backward pull on the globe • Infraorbital nerve hypoesthesia • Numbness of the gums and skin of mid-face

17. Investigations • CT Orbits is gold standard • But critical to obtain coronal views • Might be difficult to obtain in patients with cervical spine injuries • As coronal imaging requires hyper-extention of the neck • In these cases, should be able to reconstruct coronal vies from axial images

18. General Rules of Management Conservative Rx • Suitable for: • Patients without significant enophthalmos • A lack of marked hypoglobus • Absence of entrapped muscle or tissue • Fracture less than 50% of floor • Lack of diplopia

19. In this group of patients, treat with: • IV or PO Antibiotics • A short course of PO Prednisilone may also benefit in reducing edema of the orbit and muscle, and may allow more thorough assessment later on • Discourage nose blowing to avoid creating or worsening orbital emphysema • Nasal decongestants can also be used

20. Surgical Management • Indications of surgery • Diplopia especially in the primary position • which does not improve after posttraumatic edema resolves • Large floor fractures (>50%) • Which may result in progressive enophthalmos • Significant globe dystopia • Hypoglobus or enophthalmos (>2mm)

21. Generally accepted ophthalmic guidelines suggest surgical intervention within 2 weeks of injury • This 2 week window allows for some resolution of tissue edema and hemorrhage

22. Important to bear in mind that these general guidelines are suitable and can be applied to the management of adult orbital floor fractures • However for such fractures in the paediatric population, the evaluation and management differs from that of the adult

23. White-Eyed Blowout Fractures (WEBOF) • Young patients • Less than or equal to 18 years of age • Significant trauma history • But little clinical signs of soft tissue injury • Extraocular movements are restricted in up and down-gaze • Giving rise to marked diplopia • Often pain on attempted vertical gaze • May complain of nausea and vomitting

24. Lane et al (2007) • Compared signs and symptoms of 16 patients with WEBOF • Versus 14 control patients with with large classic blowout fractures Lane et al. Orbit, 2007;26

25. CT scanning • Reveals either a small crack along the floor with little or no bony displacement • Or a small trap door defect (i.e., the bony orbital floor was attached or hinged at one edge), with a tear drop tissue herniation into the maxillary sinus

26. Example 1 Coronal CT Orbits: • Arrow points to a small soft tissue opacity within a narrow break in the orbital floor • Note that the inferior rectus is missing- • the muscle is in effect tightly tethered and distorted within the confines of the fracture

27. Pathophysiology of Orbital Fractures in Adults versus Children

28. Adults • In adults (>18 years of age) • The bones are more mature, brittle and less flexible • When a blow is sustained to the periocular region, the floor more commonly buckles, and breaks in several areas • And a portion of the floor blows out into the antrum, rather than staying hinged and springing back

29. Children • Conversely, children have softer, less calcified and more flexible bone • When a similar blow is sustained to the region • The floor is more likely to bend, crack, and form a flexible “trapdoor” that springs downwards initially • As the blow is finished, the floor returns to its normal position • Entrapping tissue in the process

30. Radiographically, if a considerable amount of tissue is entrapped, it will show up as a tear drop tissue herniation on CT scan • However if little tissue is entrapped, the floor will only appear to have a small crack • The trap door returning to its normal anatomic position impinges the herniated tissue • Potentially reduces blood flow to the muscle and the perimuscular tissue

31. Smith et al (1984) • First demonstrated that small orbital fractures were more likely to incarcerate extraocular muscle than large fractures • And this may lead to compartment syndrome (as described by Volkman) • Producing muscle ischaemia, fibrosis and restricted motility • If this Volkman syndrome was not relieved surgically, diplopia seemed to be persistent • They advocated early surgical release of entrapped muscles to prevent permanent damage and diplopia Smith et al, Plast Reconstr Surg. 1984;74

32. Hence waiting 2 to 3 weeks in this group of patients may be detrimental to the patient’s recovery • As the ischaemic process is prolonged, and could lead to fibrosis to the muscular and perimuscular tissue

33. Instead early repair (within days), returns the herniated tissue to its normal position, and relieves any compartment syndrome • Moreover a 2 week watch and wait period is not necessary in this group because the patients have little or no sign of soft tissue trauma • Thus allowing a thorough clinical assessment

34. Jordan et al (1998) • Reported on 20 individuals with characteristics of white-eyed blowout fracture • All patients were under 18 years of age • With history of significant blows to the periocular area • On clinical examination, they exhibited little signs of soft tissue injury • Little ecchymosis, lid swelling, ptosis or chemosis Jordan et al. Ophthal Plast and Recon Surg. 1998; 14(6)

35. There were significant complaints of diplopia in all cases • With motility restrictions in up and down-gaze in all patients • CT scanning typically showed a small crack on the orbital floor • Or trap door like defect with little bony displacement

36. The time of injury to the time of surgery ranged from 48 hours to 40 days • Some of the patients were managed according to the ‘2 week watch and wait grace period’ Whereas other underwent early surgery within days

37. Of the 20 patients, 6 (30%) underwent surgery within 5 days • In 5 (83%) of these 6 patients, symptoms resolved between 3 to 6 weeks after surgery • In 1 patient, symptoms resolved slowly over 1 year • In no patients was there felt to be permanent restriction

38. In the other 14 (70%) patients • Surgery was performed between 5 to 40 days (average 14.2 days) • Symptoms resolved in 3 (21%) of these patients within 4 weeks • In the other 11 • Symptoms resolved over 4 to 10 months in 8 (57%) patients • However 3 (21%) patients had continued restriction by 12 months

39. The authors concluded that WEBOF patients having surgery: • At 2 to 3 weeks tended to have slower resolution of symptoms (over months), and some had permanent restriction • Instead early surgery- within days of injury may be able to prevent ischaemic contracture of the entrapped muscle and persistent diplopia

40. However they acknowledged that with little clinical sign of soft tissue injury (white eye), the potential severity of the clinical problem is usually not appreciated • And these patients may by default simply be observed

41. Summary • The evaluation and management of orbital floor fractures differs between adults and children • In adults a 2 week wait and watch period is acceptable and appropriate • However in children, we need to be wary of WEBOF, and its management should be fracture repair with release of entrapped muscle within 72 hours • This affords this group of patients the best chance of full clinical recovery

42. Recommendations • In children/ teenagers who present with ocular trauma • Ask about nausea and vomiting • Ask about the presence and pattern of diplopia • Undergo an extraocular motility examination • If extraocular motility dysfunction is noted, then order a CT with axial and coronal views, along with brain imaging if indicated clinically

43. Thank you