AN ANALYSIS OF THE PATTERN OF ORBITAL FRACTURES AT TWO

REFERRAL TEACHING INSTITUTIONS IN NAIROBI

Principal Investigator: Dr. Wayne Manana BDS (UZ), BA (Zim)

Registration Number: V60/64610/10

A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT FOR THE

AWARD OF A MASTER OF DENTAL SURGERY DEGREE IN ORAL

AND MAXILLOFACIAL SURGERY

i

DECLARATION

This is my original work and has not, to my knowledge, been presented for degree at any other university.

Name: Wayne Manana …Signed…………….Date…………………………………………..

We declare that we have verified and approved the contents of this research proposal:

1. PROF. M. L. CHINDIA BDS (Nbi), MSc (London), FFDRCS (Ireland), FICD, FIAOMS

Professor, Dept. of Oral and Maxillofacial Surgery, Oral Pathology and Oral Medicine

University of Nairobi CHS, School of Dental Sciences

Signature…………………………………………Date……………………………………

2. DR W. A. ODHIAMBO BDS (Nbi), MDS OMFS (Nbi)

Senior Lecturer, Department of Oral and Maxillofacial Surgery, Oral Pathology and Oral

Medicine, University of Nairobi, CHS School of Dental Sciences

Signature…………………………………..Date……………………………………….

3. DR. K. KOECH BDS (Nbi), MDS OMFS (Nbi)

Consultant Oral and Maxillofacial Surgeon Kenyatta National Hospital, Honorary

Lecturer, Dept. of Oral and Maxillofacial Surgery, Oral Pathology and Oral Medicine,

University of Nairobi, CHS School of Dental Sciences

Signature……………………………………………Date………………………………..

i

DEDICATION

To all the victims of orbital fractures and their relatives whose lives have been affected in one way or the other.

To my parents, sisters and brothers.

To my lectures and fellow residents who inspired me in preparing this work.

ii

ACKNOWLEDGEMENT

“How far we climb up a mountain does not only depend on our efforts but it also depends on those who give us a push along the way.” I would like to acknowledge the tireless effort of my great and inspirational teachers: Prof Mark L. Chindia, Dr. Walter A. Odhiambo, and Dr. Kennedy Koech, for their indispensable support throughout this study. I am also greatly indebted to the following:

Mr. Joshua Simba and Mr. Desmond K’Owino for the tremendous statistical support plus bringing sense and meaning out of a huge volume of raw data; Miss Florence N. Mbugua for helping in translating from Swahili to English. Special thanks to Prof L. Gathece, Prof S.W. Guthua and Prof

M.M. Chidzonga for their inspiration throughout my residency.

Above all, I give thanks to God Almighty for giving me the strength and the ability to accomplish this work.

iii

TABLE OF CONTENTS DEDICATION ...... ii ACKNOWLEDGEMENT ...... iii TABLE OF CONTENTS ...... iv LIST OF TABLES ...... vi LIST OF FIGURES ...... vii LIST OF ABRREVIATIONS ...... viii ABSTRACT ...... x CHAPTER 1 ...... 1 1. INTRODUCTION AND LITERATURE REVIEW ...... 1 1.1. Introduction ...... 1 1.1.1. Background ...... 1 1.1.2. Relevant Surgical Anatomy of the ...... 1 1.2. Literature Review ...... 2 1.2.1. Classification of Orbital Fractures ...... 2 1.2.2. Socio-Demographic presentation of orbital fractures ...... 3 1.2.3. Etiology and Mechanisms of Orbital Fractures ...... 3 1.2.3.1. Etiology ...... 3 1.2.3.2. Mechanisms of blow-out Orbital Fractures ...... 5 1.2.4. Clinical presentation of orbital fractures ...... 6 1.2.6. Radiological findings ...... 8 1.2.7. Management ...... 11 1.3. Statement problem and Justification ...... 13 1.4. Objectives ...... 15 1.4.1. Broad Objective ...... 15 1.4.2. Specific objective ...... 15 CHAPTER 2 ...... 16 2. Material and Methodology ...... 16 2.1. Study area ...... 16 The study was conducted at two referral institutions in Nairobi; Kenyatta National Hospital ( ...... 16 2.2. Study population: ...... 16 2.3. Study Design: A 5-month descriptive prospective hospital based study commencing on 1st of July 2014 up to 30 th of November 2014 ...... 16

iv

2.4. Study instrument: ...... 16 2.5. Variables ...... 17 2.6. Inclusion criteria: ...... 17 2.7. Exclusion criteria: ...... 17 2.8. Sampling method ...... 17 2.9. Sample Size ...... 18 2.10. Data collection: ...... 18 2.11. Limitations and challenges of the study ...... 19 2.12. Minimizing errors and biases ...... 20 2.13. Data management and analysis ...... 20 2.14. Validation ...... 21 2.15. Ethical considerations ...... 21 CHAPTER 3 ...... 22 3. RESULTS ...... 22 3.1. Etio-Socio-demographics ...... 22 3.2. Clinical features of orbital fractures ...... 25 3.3. CT Scan findings ...... 28 3.4. Management of orbital fractures ...... 32 CHAPTER 4 ...... 35 1.6. DISCUSSION ...... 35 1.7. CONCLUSION ...... 42 1.8. RECOMMENDATIONS ...... 42 1.9. References ...... 43 APPENDIX I: DATA COLLECTION SHEET ...... 51 APPENDIX II: LETTER OF APPROVAL ...... 58

v

LIST OF TABLES

TABLE 1.1: ETIOLOGY OF ORBITAL FRACTURES ...... 4

TABLE 1.2: RADIOLOGICAL PATTERN OF ORBITAL WALL FRACTURES ...... 9

TABLE 1.3: TYPE OF IMPLANT MATERIAL ...... 12

TABLE 2.1: VARIABLES ...... 17

TABLE 3.1: DISTRIBUTION OF OCULAR AND PERI -OCULAR FINDINGS IN PATIENTS WITH ORBITAL

FRACTURES ...... 26

TABLE 3.2: DISTRIBUTION OF CONCOMITANT SOFT TISSUE INJURIES ...... 27

TABLE 3.3: DISTRIBUTION OF THE ORBITO -ZYGOMATIC FRACTURES ...... 28

TABLE 3.4: DISTRIBUTION OF IMPURE AND PURE ORBITAL FRACTURES ...... 29

TABLE 3.5: DISTRIBUTION OF BILATERAL ORBITAL FRACTURES ACCORDING TO ANATOMICAL SITE

...... 30

TABLE 3.6: DISTRIBUTION OF CONCOMITANT CRANIOMAXILLOFACIAL FRACTURES ...... 31

TABLE 3.7: INDIRECT CT SCAN FINDINGS ...... 32

Table 3.8: Distribution of surgical approaches used ……………………………………………34

vi

LIST OF FIGURES

FIGURE 1.1: ILLUSTRATION OF THE HYDRAULIC THEORY ...... 6

FIGURE 3.1: DISTRIBUTION OF ORBITAL FRACTURES ACCORDING TO THE AGE ...... 22

FIGURE 3.2: DISTRIBUTION OF ORBITAL FRACTURES ACCORDING TO OCCUPATION ...... 23

FIGURE 3.3: THE DISTRIBUTION OF INJURED PERSONS ACCORDING TO AETIOLOGICAL FACTORS ... 24

FIGURE 3.4: DISTRIBUTION OF AETIOLOGY ACCORDING TO GENDER ...... 25

vii

LIST OF ABRREVIATIONS

1. BDS ...... Bachelor of Dental Surgery

2. Cc ...... cubic centimeters

3. Cm ...... centimeters

4. CT ...... Computed Tomography

5. Dept ...... Department

6. EOMM ...... Extra-Ocular Muscle Motility

7. Etc ...... Et cetera

8. IPV………………………………………………………………….interpersonal violence

9. KNH ...... Kenyatta National Hospital

10. LE...... Left Eye

11. mJ………………………………………………………………………….……..millijoule

12. mm……………………………………………………………………...………millimeters

13. MCCs………………………………………………………………....motor cycle crashes

14. MVC………………………………………………………………..motor vehicle crashes

15. MRI………………………………...………………..……..Magnetic Resonance Imaging

16. NOE………………………………………………………….……..Naso-Orbital-Ethmoid

17. OMFS……………………………………………Oral and Maxillofacial Surgery/Surgeon

18. P(L/DL)LA………………………………………..………………..poly-L/DL-lactic Acid

19. PDS………………………………….……………………………………...Polydioxanone

20. PGA………………………………………………………………...……Polyglycolic Acid

21. PLLA…………………………………………………………..………Poly-L-Lactic Acid

22. RE………………………………………………………………………………..Right Eye

viii

23. RTCs…………………………………………………………………Road Traffic Crashes

24. SCH…………………………………………………………...subconjuctival haemorrhage

25. SDS………………………………………………………..,…...School of Dental Sciences

26. STIs…………………………………………………………………….Soft Tissue Injuries

27. UON………………………………………………………………....University of Nairobi

28. UNDH……………………………………………...University of Nairobi Dental Hospital

29. USS………………………………………………………………………..Ultrasound Scan

30. VF…………………………………………………………………………..….Visual Field

31. ZF……………………………………………………………….Zygomatic-Frontal Suture

32. ZM…………………………………………………………...Zygomatic-Maxillary Suture

33. ZMC……………………………………………………..Zygomatico-Maxillary-Complex

34. ZT…………………………………………………………….Zygomatic-Temporal Suture

ix

ABSTRACT

Background of the study

Orbital fracture is a common injury accompanying mid-face trauma. The incidence of isolated orbital fractures ranges from 4 to 16% of facial fractures. Combined with other injuries including those of the zygomatico-maxillary-complex (ZMC) and those of the naso-orbito-ethmoidal (NOE) complex, they account for 30 to 55% of all facial fractures. Orbital trauma can result in significant functional and cosmetic defects and hence can be significantly disabling. The modal age of 20-40 years leads to reduced productivity and loss of manpower. Patients with fractures involving the orbit often present with concomitant injuries of the eyeball and/or the surrounding extra-ocular structures. Misdiagnosis or delayed diagnosis may result in debilitating complications such as blindness, , permanent paresthesia, malocclusion and facial disfigurement.

Material and Methods

A descriptive prospective hospital-based study was carried out to determine the demographics, aetiology, clinico-radiological features and management modalities among patients presenting with orbital fractures (n=60) at the University of Nairobi Dental Hospital (UNDH) and Kenyatta

National Referral Hospital (KNH) in Nairobi, Kenya . A specially designed data collection tool which was tested and calibrated was completed for all patients with confirmed orbital fractures.

All data were coded and entered into the statistical package for social sciences (SPSS) software version 20 for analysis.

x

Results

Sixty patients (52 male, 8 females; p<0.05) with confirmed orbital fractures on CT scan were recruited into the study. Orbital fractures occurred most frequently in the 21-40-year old age group

(80%, p<0.05). The self-employed group was the most affected occupational group (40%) whilst the least affected was the formally employed group (3.3%). The distribution of orbital fractures according to occupation was statistically significant (X 2=23.500, p=0.000). The principal aetiological factor was motor cycle crashes (MCCs) at 30 % particularly riders (21.6%) followed by interpersonal violence (IPV) at 23.3%, public vehicle crushes (PVCs) at 20%, private vehicle crushes (PVCs) at 10%, injury from flying objects at 10% and falls at 8.3%. All the cases of IPV were male (n=14, p=0.071) particularly of the 20-30-yr old age (n=8) group. Clinical features noted included peri-orbital oedema, subconjuctival haemorrhage (SCH), step deformity on the rim, peri-orbital ecchymosis, trismus, eyelid laceration and avulsion, paresthesia, malar collapse and telecanthus, blindness, diplopia and entrapment of extra-ocular muscles, , vertical dystopia, exophthalmos and eyelid ptosis. The most commonly affected anatomical site was the floor (75%) followed by the lateral wall (71.7%), infra-orbital rim (66.7%), zygomatico-frontal suture (63.3%), medial wall (46.7%) and orbital roof (25%). Notably, 65% had zygomatic arch fractures whilst 51.7% had ZMC fractures. In this study 5 patients had pure blow-out orbital fractures whilst 55 patients had impure fractures. There were more fractures involving the left orbit

(n=28) than the right (n=14). Bilateral orbital fractures were seen in 18 patients. Indirect CT scan findings included haemosinus (air-fluid level) in 47 patients, tissue emphysema, teardrop and pneumocephalus. The relationship between haemosinus and orbital fractures was statistically significant (p<0.05). More of the patients were managed conservatively (60%).

xi

Conclusion

The present study has reaffirmed that RTCs, especially motor cycle crashes and IPV are the leading cause of orbital injuries most commonly in the young males in their third and fourth decades of life. Evidently, haemosinus as demonstrated on CT scanning together with peri-orbital oedema and SCH constitute the clinical features most consistent with orbital fractures, most of which were the impure variants. The left side was more affected than the right whilst the floor and the lateral wall being the commonest sites of orbital fractures. Impure variants particularly zygomatico- maxillary-complex fractures are by far more common than the pure variant. Depending on the severity of the injury, orbital fractures can be managed either surgically or conservatively.

xii

CHAPTER 1

1. INTRODUCTION AND LITERATURE REVIEW

1.1.1.1.1.1. Introduction

1.1.1. Background Orbital fracture is a common injury accompanying mid-face trauma. The incidence of isolated orbital fractures ranges from 4 to 16% of facial skeletal injuries 1. In combination with those of the zygomatico-maxillary (ZMC) and naso-orbito-ethmoid (NOE) complexes, they account for 30 to

55% of facial injuries 1. Orbital trauma can result in significant functional and cosmetic defects and hence can be significantly disabling 2. Patients with fractures involving the orbit often present with concomitant injuries of the eyeball and/or the surrounding extra-ocular structures. Orbital floor fractures have been associated with a 40% risk of ophthalmic complications 3. Blindness following facial fractures has been reported to occur in between 0.67 to 9% of the orbital wall fractures

1, 2, 4, 5 . Interestingly, the rate of missed diagnosis of orbital fractures is very high 5. In a study by

Liu Jun (2002), 42.6% of orbital fractures were missed 6. In another study conducted by Ashar

(1998) to assess the frequency of blindness associated with maxillofacial trauma, it was concluded that early diagnosis of the exact nature of the ophthalmic injury and treatment were important and the involvement of the ophthalmologist was mandatory 7.

1.1.2. Relevant Surgical Anatomy of the Orbit The orbit is made up of seven . The orbital shape varies with age, gender and race and between individuals but the volume is usually 29–30 cm3 with the eyeball occupying 7cc of the orbital volume 1, 8,9,10 . Important vital neurovascular structures are transmitted through the orbital foramina and fissures. These include structures such as the optic, oculomotor, trochlear, ophthalmic and abducent nerves in addition to the ophthalmic veins and artery. These structures are vulnerable to injury following trauma. Medial to the infra-orbital foramen the floor is about

1

0.27 to 0.5mm whilst the lamina papyracea is about 0.2 to 0.4mm. The lesser wing of the sphenoid bone is about 3 mm thick. The floor and the medial wall are, therefore, the thinnest portions of the orbit. This makes the medial wall and floor the most common sites of orbital fractures 1. The medial walls are parallel in the sagittal plane and the lateral walls form a 90º angle with each other

11,12 .There is evidence of inter-racial morphometric variations of the orbital anatomy hence the possibility of differences in the pattern of orbital fractures among different races 5. In a retrospective review of computed tomography (CT) scans and demographics in an unselected cohort of 152 patients with orbital blowout fractures, it was shown that most blowout fractures involve the orbital floor in Caucasians and Asians, whereas in Afro-Caribbeans the most common site for fracture was the medial wall 13 .

1.2.Literature Review

1.2.1. Classification of Orbital Fractures Orbital fracture classification systems vary widely and may even be confusing, which makes comparisons between studies difficult 9, 14 . For the purposes of this study orbital fractures were classified into 9, 15 :

• Pure/ Simple fractures

o Blow out fractures

° Medial wall

° Floor: trap door, tear drop

° Lateral wall

° Roof

° Any combination(s) of the medial, lateral, floor and roof

o Blow-in fractures

2

• Impure/Complex fractures

o Orbital rim fractures

° Tripod (Zygomatico-Maxillary Complex) or Tetrapod

° Lefort II

° Lefort III

° Naso-Orbito-Ethmoid (NOE) complex

° Simple orbital rim fractures

1.2.2. Socio-Demographic presentation of orbital fractures

Most authors agree that by far the most commonly affected age group is the 20-40 years with an

80% plus male predominance 1, 8, 14, 16 . In a retrospective analysis of 132 patients with orbital fracture, 84% males were affected vis-a-vis 16% females. In this study the most affected age group was the 31-40-year-old age range (24.2%), followed by the age groups of 21-30 years (22%) and

11-20 years (22%) 16 .

1.2.3. Etiology and Mechanisms of Orbital Fractures

1.2.3.1.Etiology

The commonest causes of facial fractures are motor vehicle crashes (MVCs), assaults, falls and sports injuries 17-21 . In a Swedish retrospective study investigating the injuries before the introduction of the seatbelt law in 1975, the main cause of zygomatico-orbital injuries was MVCs

22 . However, similar more recent studies have established assault (stoning, fists, kicks) as the commonest cause of orbital fractures 20, 21, 23 . Airbags, paradoxically, have been reported to cause ocular injuries and less frequently orbital fractures. In their study Lehto et al. (2003) reported a

2.5% frequency of ocular injuries but a low risk of severe eye injury from airbags (0.4%) 24 . The etiology of orbital fractures varies according to geographic region and occupation. In war zones

3

and mining regions, the predominant etiology includes high velocity missiles, bomb-blasts and gunshots. Sports, particularly boxing, cricket, rugby and soccer are associated with a high risk of orbital fractures 25 . In a review of ten papers on orbital trauma, Jatania (2012) broadly divided the etiology of orbital fractures into five main categories including MVCs, assaults, industrial accidents, sports and others (Table 1.1) 1. Evidently MVCs constituted by far the commonest cause of orbital fractures and assault being the second.

Table 1.1: Etiology of Orbital Fractures

Motor Assault Industrial Sports Other Vehicle Accident Accident First author N % % % % %

Abbas 772 24 1 0 0 75

Al-Qurainy 363 12 50 19 12 0

Amrith 104 32 13 20 10 20

Cook 365 40 31 0 0 29

Covington 243 80 5 0 0 15

Crumley 324 71 17 7 4 5

Gwny 567 35 37 5 9 18

Jayamanne 135 3 73 1