A STUDY OF THE PATTERN OF CERVICAL SPINE INJURIES IN HEAD INJURED PATIENTS AS SEEN AT THE KENYATTA NATIONAL HOSPITAL.

Transcription

1 1 1 A STUDY OF THE PATTERN OF CERVICAL SPINE INJURIES IN HEAD INJURED PATIENTS AS SEEN AT THE KENYATTA NATIONAL HOSPITAL. A DISSERTATION SUBMITTED IN PART FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTER OF MEDICINE IN SURGERY AT THE UNIVERSITY OF NAIROBI. BY DR PETER KAMAU NJOROGE MBChB(NBI) 2003

2 2 2 DECLARATION I certify that this dissertation is my original work and has not been presented for a degree in any other university Signed DR KAMAU P NJOROGE MBChB(NBI) This dissertation has been submitted for examination with my approval as the university supervisor. Signed MR VINCENT MUOKI MUTISO MBChB(NBI),MMED(NBI), FELLOW A-O INTERNATIONAL,ORTH&TRAUMA(UK). CONSULTANT ORTHOPAEDIC SURGEON, DEPARTMENT OF ORTHOPAEDIC SURGERY COLLEGE OF HEALTH SCIENCES UNIVERSITY OF NAIROBI

3 3 3 ACKNOWLEDGMENT I sincerely thank my supervisor Mr Vincent M Mutiso, Lecturer department of orthopaedic surgery for his encouragement, guidance and and able supervision during preparation for this dissertation. My sincere gratitude to Dr Othieno of radiology department KNH for assisting in the interpretation of radiographs. I m grateful to Mr Thiongo the head porter on the surgical floor and his team for their invaluable assistance in taking patients for X- rays. I m grateful to the Kenyatta National Hospital Ethical and Research Committee for their constructive corrections and allowing me to proceed with this study. Finally I am deeply indebted to my sister Wangui, my wife Mercy and my little son Mark for their constant encouragement.

4 4 4 DEDICATION This work is dedicated to my father Njoroge Gathua for his constant encouragement, support and advice through out my studies.

5 5 5 LIST OF ABBREVIATIONS AP View Anteroposterior view. C1, C2 First cervical vertebrae, Second cervical vertebra etc. CT Computer Tomography. H.D.U High Dependency Unit. I.C.U Intensive Care Unit. I.V Intravenous. KNH Kenyatta National Hospital. MRI Magnetic Resonance Imaging. RTA Road Traffic Accidents. SCIWORA Spinal Cord Injury Without Radiological Abnormality. SPSS Statistical Package for Social Sciences.

6 6 6 TABLE OF CONTENTS TITLE 1 DECLARATION 2 AKNOWLEDGMENT 3 DEDICATION 4 LIST OF ABBREVIATIONS 5 TABLE OF CONTENTS 6 LISTS OF TABLES AND FIGURES 8 SUMMARY 10 INTRODUCTION AND LITERATURE REVIEW 12 STUDY JUSTIFICATION AND RESEARCH QUESTION 60 MAIN AND SPECIFIC OBJECTIVES 61 MATERIALS AND METHODS 62 Study design 62 Area of study 62 Study population 63 Study instruments and methods 63 Eligibility criteria 64 Exclusion criteria 64 Constraints 65 Data 66 Ethical considerations 66 RESULTS 67 DISCUSSION 84 CONCLUSIONS 90 RECOMMENDATIONS 91 REFERENCES 92 APPENDIX 1; QUESTIONNAIRE 99

7 7 7 APPENDIX 2; INFORMED CONSENT FORM 102 APPENDIX 3 ; PATIENT INFORMATION FORM 103

8 8 8 LISTS OF TABLES AND FIGURES TABLE 1: Measurable parameters of the cervical spine 46 TABLE 2: Incidence of cervical spine injury 67 TABLE 3: Sex and frequency of cervical spine 70 TABLE 4: Causes of Cervical injury 73 TABLE 5: Cervical spine injury versus severity of head injury 74 TABLE 6: Region of scalp injured versus cervical spine injury 75 TABLE 7: Skull fracture versus cervical spine injury 76 TABLE 8: Type of skull fracture versus cervical spine injury 77 TABLE 9: Level of injury versus type of cervical spine injury 79 TABLE 10: Cervical spine protection on arrival at casualty 80 TABLE 11: Whether KNH primary or referral hospital 80 TABLE 12: Retropharyngeal widening versus cervical injury 82 TABLE 13: Loss of normal lordosis versus cervical injury 82 TABLE 14: Spinal cord injuries 83 TABLE 15: Treatment offered for cervical spine injury 83 FIGURE 1: Parts of typical cervical vertebrae 15 FIGURE 2: The three column spine 21 FIGURE 3: Blood supply to the spinal cord 24 FIGURE 4: Compressive flexion injuries 30 FIGURE 5: Stages of vertical compression 31 FIGURE 6: Stages of distractive flexion 31 FIGURE 7: Stages of compression extension 33 FIGURE 8: Stages of distractive extension 34 FIGURE 9: Stages of lateral flexion Injury 35 FIGURE 10: Schematic lateral view of the cervical spine 47 FIGURE 11: Sex distribution of head injuries 68 FIGURE 12: Sex distribution of cervical spine injuries 69

9 9 9 FIGURE 13: Age distribution of cervical and head injuries 71 FIGURE 14: Age distribution of head injuries 72 FIGURE 16: Vertebral level of injury 81 FIGURE 17: Unit X-rays ordered from 72

10 10 10 SUMMARY The study is a cross sectional prospective study was carried out on the pattern of cervical spine injury in head injured patients as seen at Kenyatta National Hospital (KNH). The aims and objectives of the study were to determine the relative frequency of cervical injury in head injured patients, the age and sex distribution, the pattern of cervical spine injuries as related to the cause and severity of head injury and the pre hospital care given to protect the cervical spine before arrival at KNH. All patients with head injury admitted to KNH, who qualified for the study, and consented to participate, were recruited. Demographic information (age, sex) and clinical information( cause of head injury, evidence of intoxication, pre-hospital care given, level of consciousness, neurological deficit, Neck pain or tenderness, Type and area of scalp injury, and all other relevant parameters) were then obtained. Investigations done were mainly plain radiography (three views for the skull and a lateral, antero-posterior and odontoid view for the cervical spine). CT scan was obtained where possible. Three hundred and sixty one cases were recruited over a period of 10 weeks. Of this number 19, (5.3%) were found to have cervical spine injury. Most of the head injuries were secondary to assault (51%), followed by road traffic accidents (41%) while fall from height was 7.8%. Road traffic accidents contributed 57% of all the cervical spine injuries seen. Most of those having heads injuries were male (90%) and 10% were female, however 26% of the cervical spine injuries seen were female while 74% were male. The peak age range for cervical spine

11 11 11 injury was 21 to 35 years. The youngest was 4.5 years and the oldest 65 years. KNH was the primary hospital for 94% of all head injuries seen. None had any form of cervical spine protection on arrival. Only 18%of those referred from other hospitals had cervical collars on arrival at the Accident & Emergency department of KNH. The majority (78%) of the cervical spine injuries were in the lower cervical spine (C3 to C7) with 22% in the upper cervical region (C1 to C2).Only one patient had spinal cord injury- which was mild. The incidence of cervical spine injury in head injured patients at KNH is 5.3%. For most of these patients (94%) KNH is the primary hospital; none of these patients at presentation have any cervical spine protection. Females with head injury were found to be significantly more at risk of having cervical spine injury compared to the males. There is very poor pre-hospital care of the cervical spine. A lot of emphasis on teaching the basic care of the injured and cervical spine immobilization, to the public, police and first aid providers is recommended. A post mortem study of fatal head injuries would reveal the incidence and severity of cervical spine injury in this group.

12 12 12 INTRODUCTION AND LITERATURE REVIEW INTRODUCTION Injuries of the cervical spine are among the most common and potentially devastating injuries involving the axial skeleton. It is a common associated injury in patients with head trauma. The force producing a serious head injury (e.g. a road traffic accident or a fall from a height onto the head) may also injure the neck. One should assume a cervical spine injury is present until proven otherwise in patients presenting at an emergency medical facility with a history of a high-velocity motor vehicle accident, significant head or facial trauma, a neurological deficit, or neck pain 1. While assessment of airway, breathing, and hemodynamic stability (A B C s of trauma) continue to be the highest priority in caring for the patient with multiple traumatic injuries, central nervous system evaluation follows closely behind. The central nervous system assessment begins in the field. The cervical spine should be protected until work-up proves that it is not injured. History of the injury: The Edwin Smith papyrus (2800 BC) referred to spinal cord injury as a disease not to be treated. Galen, in 177 AD, reported on his experiments in animals and described loss of movement and sensibility below the level of cord transection until breathing stopped at higher levels. Charles-Edouard Brown- Sequard did experimental work on hemisection of the cord and described his findings in papers in Operative stabilization of the cervical spine was introduced by Hadra in 1891, when he wired the spinous processes of a child who had a fracture dislocation with progressive neurologic deterioration. This was the first surgical procedure of its kind recorded in the

13 13 13 literature. Further refinement in the application of internal fixation was documented by Rogers in 1942 with a simple wire technique. Bohlman's technique involved using separate wires for fixation of the adjacent spinous processes and compression of two corticocancellous grafts against the spinous processes. Biomechanically, this was thought to provide better flexural and torsional stiffness than Rogers' simple wiring. Weiland and McAfee reported 100% fusion rates in 60 patients using this means of fixation in the subaxial cervical spine. 2 Roy-Camille pioneered the use of posterior cervical plates to manage a variety of injuries involving the posterior subaxial spine. Magerl and Anderson have proposed variations of screw insertion techniques. Skull traction using modified ice tongs was introduced by Crutchfield in Nickel and Perry pioneered the halo device in the late 1950s, primarily to immobilize the cervical spine affected by polio. Its application extended to trauma cases, providing a better means of immobilization 2. The incidence of cervical spine injuries is on the increase in many countries. This has been especially so in the last 40yrs due to an increase in both use and volume of motor vehicles 3,4. There is a proportional loss in valuable manpower as most of the injured patients are in the most productive years of their life. Few diseases or injuries have greater potential for causing death or devastating effects to the quality of life than cervical spine trauma. Head injuries primarily have a high rating in both mortality and morbidity. Together they create a devastating duo. It is therefore of paramount importance for surgeons and emergency unit workers to be conversant with the relationship and

14 14 14 management of these two conditions especially when they present together. RELEVANT ANATOMY The human spine comprises 24 movable presacral vertebrae, a sacrum and a coccyx. The 24 movable presacral vertebrae comprise 7 cervical, 12 thoracic, and 5 lumbar. The five vertebrae immediately below the lumbar are fused in the adult to form the sacrum. The lowermost four, fused in later life, form the coccyx 5. Vertebrae of each group can usually be identified by special characteristics. Furthermore, individual vertebrae have distinguishing characteristics of their own. The vertebral column is flexible because it is composed of many slightly movable parts-the vertebrae. Its stability however depends largely upon ligaments and muscle. Strength, however, is provided by the structure of the column and its constituent parts 5. PARTS OF A TYPICAL CERVICAL VERTEBRA A typical vertebra consists of a body, a vertebral arch and several processes for muscular and articular connections. There are two transverse processes and one spinous process. Each lever is acted upon by several muscles or muscle slips. The body of the vertebra is the part that gives strength and supports weight. It consists mostly of spongy bone that contains red marrow. The body is separated from that above and below it by the intervertebral disc 5,6.

15 15 15 FIG: 1 Parts of typical cervical vertebrae lateral and superior surfaces. Posterior to the body is the vertebral arch, which, with the posterior surface of the body, forms the walls of the vertebral foramen. These walls enclose and protect the spinal cord. The vertebral arch is composed of right and left pedicles and right and left lamina. In intact vertebral columns, the series of vertebral foramina together form the vertebral canal. A spinous

16 16 16 process (vertebral spine) projects backward from each vertebral arch at the junction of the two laminae. Transverse processes project on either side from the junction of the pedicle and the lamina superior and inferior articular processes on each side bear superior and inferior articular facets respectively. A deep notch is present on the lower edge of each pedicle, and a shallow notch on the upper edge of each pedicle. Two adjacent notches, together with the intervening body of the intervertebral disc, form an interverterbral foramen, which transmits a spinal nerve and its accompanying vessels. The seven cervical vertebrae consist of 3 atypical and 4 typical vertebrae. The first cervical vertebra is called the atlas (named after Atlas, who, according to a Greek mythology, was reputed to support the heavens). The skull rests on it and articulates through the atlantooccipital joint. The second cervical vertebra is called the axis, because it forms a pivot around which the atlas turns and carries the skull, and the seventh (C 7 ) is a transitional vertebra. The third to the sixth cervical vertebrae are regarded as typical. 5,6 Atlas:- The atlas has neither spine nor body. It consists of two lateral masses connected by a short anterior arch and by a long posterior arch. The atlas is the widest of the cervical vertebrae. On its upper surface it has kidney shaped articular surfaces that articulate with the condyles of the skull. This joint allows for nodding movements but virtually no rotation on the vertical axis can occur here. On its lower surface the flatter configuration of its articular surfaces allow for rotational movement between it and the axis this is the atlanto axial joint.

17 17 17 Axis; -The axis is characterized by the dens or odontoid peg, which projects from the upper part of the body (it is the vertebral body of the atlas developmentally). It articulates in front with the anterior arch of the atlas, posteriorly it is separated by a bursa from the transverse ligament of the atlas. The apical ligament anchors the tip of the dens to the front margins of the foramen magnum; the alar ligaments anchor it to the lateral margins. The lower part of the axis resembles that of a typical vertebra its other characteristic feature is its prominent bifid spinous process, this is the attachment of muscles and strong ligaments and shows prominently in the lateral x-ray of the cervical spine. It however has the smallest transverse processes of any belonging to a cervical vertebra. Third to sixth cervical vertebrae: -The third to sixth cervical vertebrae each has a short broad body and a large triangular vertebral foramen. Their spines are short and the ends of the spines are bifid, these are usually palpable. The transverse processes are pierced by foramen transversarium where the vertebral artery passes through.the upper borders of the bodies are raised behind, and especially at the sides. They are depressed in front.the raised margins are sometimes called uncal processes.

18 18 18 Seventh cervical vertebra:- The seventh cervical vertebra is characterized by a long spine that is not bifid but ends in a tubercle that gives attachment to ligamentum nuchae. This vertebra is known as the vertebrae prominens because its spinous process is prominent at the back of the neck being visible especially when the neck is flexed. The cervical spine can also be divided into the lower and upper cervical spine; upper cervical spine is C 1 to C 2 whilst lower cervical spine is C 3 to C 7. 2 ARTICULATIONS AND LIGAMENTS The bodies of adjacent vertebral bodies are held together by the: 1.Intervertebral discs:- The strong intervertebral disc is a secondary fibrocartilaginous joint or symphysis.the upper and lower parts are covered completely by a thin layer of hyaline cartilage these two layers are united peripherally by a strong ring of fibrous tissue called the annulus fibrosus. Inside the annulus is a bubble of semi liquid gelatinous substance known as nucleus pulposus. It is derived from the notochord and though central in the foetus differential growth makes it migrate closer to the back of the disc. Herniation is more likely to be posterior and thus to the vertebral canal compressing on the spinal cord. Liquid is not compressible so the shock absorbing property of the disc is rendered by the annulus fibrosus which is stronger that the vertebral body 5,6. 2.Longitudinal ligaments; -The bodies are further held together by longitudinal ligaments namely: - The anterior longitudinal ligament extends from the anterior tubercle of the atlas all the way to the front of the upper part of the sacrum. It

19 19 19 is firmly adherent to the periosteum of the bodies but free over the discs. The posterior longitudinal ligament extends from the back of the body of the axis to the sacral canal, it has serrated margins broadest over the intervertebral disc to which they are firmly adherent it narrows over the vertebral bodies from which it is separated by the emerging basivertebral veins. 3.Facet joints;-the other articulation between the vertebrae is through the facet joints these are synovial joints. They permit gliding movements and their configuration determines the movements at different spinal levels. At the cervical level movements possible includes extension, flexion, lateral flexion and a degree of rotation. 4.Ligaments of the neural arch and spine; -Several ligaments attach the adjacent neural arches, they are from posterior the:- Supraspinous ligament, this is a strong band of white fibrous tissue joining the adjacent spinous processes; they are lax in the extended spine and taut in the flexed spine. Interspinous ligaments, these are relatively weak sheets of fibrous tissue joining the adjacent spinous processes along their adjacent borders. They fuse with the supraspinous ligaments Ligamentum flava, is yellow in colour and joins the contiguous borders of adjacent laminae. They have a high content of elastic fibers and are stretched by flexion giving increasing anti gravity support. Intertransverse ligaments these are weak fibers joining the transverse processes along their adjacent borders.

20 20 20 BLOOD SUPPLY OF THE VERTEBRAL COLUMN The vertebra and the longitudinal muscles attached to them are supplied by segmental arteries. The ascending cervical, the intercostal and the lumbar arteries give multiple small branches to the vertebral bodies. 5,6 Venous drainage; -The richly supplied red marrow of the vertebral body drains almost wholly by a pair of large basi-vertebral veins into the internal vertebral plexus. Drainage of the neural arch and of the attached muscles is into the external vertebral plexus. The internal and external vertebral plexuses together drain into the regional segmental veins. THE MUSCLES OF THE VERTEBRAL COLUMN The movements of the vertebral column are produced by muscles. Running along the whole length of the spine, from skull to sacrum, is a posterior mass of longitudinal extensor muscles known collectively as the erector spinae. The erector spinae consists of three layers; these are the deepest, intermediate and superficial. At the front of the vertebral column are some flexor muscles derived from the innermost of the three layers of the body wall, constituting the prevertebral rectus. Longus capitis, longus colli and psoas belong to this group. The vertebral column acts as a support structure for the body (axial skeleton) and also acts as a protective structure for the spinal cord and the cauda equina.

21 21 21 THE CONCEPT OF A THREE COLUMN SPINE The cervical spine can be viewed as 3 distinct columns: anterior, middle, and posterior 7,8. The anterior column is composed of two thirds of the vertebral bodies, the annulus fibrosus, intervertebral disks, and anterior longitudinal ligament. The middle column is composed of one third of the vertebral bodies, the annulus, intervertebral disk, and posterior longitudinal ligament. The posterior column contains all of the remaining posterior elements formed by the pedicles, transverse processes, articulating facets, laminae, and spinous processes. FIG 2: -The three column spine. The anterior and posterior longitudinal ligaments maintain the structural integrity of the anterior and middle columns. The posterior column is held in alignment by a complex ligamentous system,

22 22 22 including the nuchal ligament complex, capsular ligaments, and ligamenta flava. If one column is disrupted, other columns may provide sufficient stability to prevent spinal cord injury. If two columns are disrupted, the spine may move as 2 separate units, increasing the likelihood of spinal cord injury 7,8. ANATOMY OF THE SPINAL CORD The spinal cord is a cylinder somewhat flattened antero posteriorly extending from the medulla oblongata cranially to the lower end which tapers into a cone. In the adult the spinal cord ends at the L 1 -L 2 level and in children it is found a bit lower at the level of L 2 -L 3 It has two enlargements, which occupy the regions of limb plexuses. These are the cervical (C 5 -T 1 ) and lumbar (L 2 -S 3 ) enlargements, their vertebral level however is at C 3 - T1 and T 9 -L 1 respectively; the enlargements are due to greatly increased mass of motor cells, which supply the upper and lower limbs respectively. Histologically the spinal cord consists of a central mass of grey matter surrounding the central canal, enclosed in a cylindrical mass of white matter. The white matter has specific tracts that are very important. Of the many tracts in the spinal cord, only three can be readily assessed clinically, and are of fundamental importance in clinical assessment of spinal cord injury; they are:- 1. The corticospinal tract. 2. The spinothalamjc tract. 3. The posterior columns.

23 23 23 Each is a paired tract that may be injured on one or both sides of the cord. The corticospinal tract, which lies in the posterolateral segment of the cord, controls motor power on the same side of the body and is tested by voluntary muscle contractions or involuntary response to painful stimuli. The spinothalamic tract, in the anterolateral aspect of the cord, transmits pain and temperature sensation from the opposite side of the body. Generally it is tested by pinprick and light touch. The posterior columns carry position sense (proprioception), vibration sense, and some light-touch sensation from the same side of the body, and these columns are tested by position sense in the toes and fingers or by vibration sense using a tuning fork. If there is no demonstrable sensory or motor function below a certain level, this is referred to as a complete spinal cord injury. If any motor or sensory function remains, this is an incomplete injury and the prognosis for recovery is significantly better. Sparing of sensation in the perianal region (sacral sparing) may be the only sign of residual function. Sacral sparing may be demonstrated by preservation of some sensory perception in the perianal region and / or voluntary contraction of the rectal sphincter. 1,7 BLOOD SUPPLY OF THE SPINAL CORD The spinal cord is supplied by a single anterior and two posterior spinal arteries, which descend from the level of the foramen magnum. The anterior spinal artery is the larger and supplies most of the spinal cord (Fig 3). The posterior spinal arteries consist of one or two vessels on each side which branch from the posterior inferior cerebellar or vertebral artery at the foramen magnum.they

24 24 24 supply the posterior columns, both grey and white, of the spinal cord. They receive a booster supply from spinal branches segmentally. FIG 3: -Blood supply to the spinal cord. The anterior spinal artery is a midline vessel that lies on the anterior median fissure. It is formed at the foramen magnum by union of two arteries, one from each vertebral artery, It supplies the whole cord anterior to the posterior grey columns. It also receives segmental booster supply; those at Th. 1 and Th 11 are especially large and are known as the arteries of Adamkiewicz. 6 Spinal Veins. As is usual in the body, even when arterial input is by end arteries, the emerging veins anastomose freely. The spinal veins form loose-knit plexuses anteriorly and posteriorly. On

25 25 25 each side the posterior spinal veins are double, straddling the posterior nerve roots. Both anterior and posterior spinal veins drain along the nerve roots through the intervertebral foramina and so into the segmental veins. CERVICAL SPINE INJURIES & HEAD INJURY The head is very vulnerable to injury, often with severe consequences. It is particularly susceptible to acceleration - deceleration and rotational forces because it is heavy in relation to its size (3-6 kg, average 4.5 kg or 10 lb). The cervical spine is important to consider in positioning the head in space. The dominant motion in the lower cervical spine is flexion-extension, but the cervical spine's anatomy permits a fair amount of motion in all planes.it is freely mobile in 3 dimensions and occupies a relatively unstable position, being secured only by the neck muscles and ligaments. This section of the spine connects the base of the head to the thorax and, with the help of soft tissues, supports the head. In high-speed injuries, the head can act as a significant lever arm on the cervical spine and, depending on the mechanism, can create a wide array of injury patterns. 2 The cervical spine is therefore very vulnerable and injury occurs when the forces it is subjected to exceed its ability to dissipate energy. Regardless of the cause, cervical spine fractures are serious injuries; they may involve spinal cord damage that can result in partial or complete paralysis or even death, especially in high cervical cord lesions.

26 26 26 Most Cervical spine injuries occur during motor vehicle accidents when the head is violently jerked either backwards or forwards. This type of accident may not cause a fracture but instead injure the muscles and ligaments of the neck. The resulting injury is a neck sprain, which is commonly called whiplash. Another common cause is violent collision that compresses the cervical spine against the shoulders. This force can be so great that a vertebra fractures or even bursts into small fragments e.g., striking the head against the bottom of a pool in shallow water diving or spear " tackling during contact games like rugby and American football. This mechanism is implicated is most sports injuries involving the neck. 9 Cervical spine injury can have devastating consequences. If present or if not ruled out, the patient s neck will be immobilized and this may hinder emergency measures like intubation. Krista et al 10 found that intubation with a cervical collar on can be unsuccessful in up to 46% of cases, even when multiple attempts were found to have been made, this was especially so in pre-hospital attempts. Securing an air way is important as some studies have found the incidence of hypoxia at 22% at the time of evaluation. 11 Other studies have even reported higher figures of 30% to 40% in patients with severe head injury 12. For patients with head injury hypoxia increases the mortality by 85%, with survivors having a higher rate of permanent disability. 13,14 Thus a lot of effort has been put to trying to make protocols on the handling of the cervical spine in emergency situations especially when there is head trauma. This is because the patient will usually have a decreased level of consciousness and thus not amenable to clinical clearance of cervical injury.

27 27 27 INCIDENCE OF CERVICAL SPINE INJURY IN HEAD TRAUMA Head injury can be defined as any alteration in mental or physical functioning related to a blow to the head 15. Loss of consciousness does not need to occur. Severity of head injuries most commonly is classified by the initial post resuscitation Glasgow Coma Scale (GCS) score, which generates a numerical summed score for eye, motor, and verbal abilities. A score of indicates mild injury, a score of 9-12 indicates moderate injury, and a score of 8 or less indicates severe injury. 1,15 The Advanced trauma life support (ATLS) course manual 1 gives the incidence of cervical spine injury in head injured patients at around 5-10%. It also states that any injury above the clavicle should prompt a search for cervical spine injury, which may be present in up to 15% of such patients. Several other studies done support this and the figures range from 3% to as high as 24% in fatal trauma cases. 16,17,18,19 The incidence of spinal injury increases with severity with most studies showing an incidence of between 7% to 10% in severe head injuries, 16 and around 2%-4% for moderately head injured patients. Most head injury related cervical spine injuries occur at the upper levels C 1 -C 3.Shrago 20 found 56%in upper cervical 34%mid cervical 10% lower cervical. Other studies have come up with similar results. 21,22 At least 25% to 30 % of patients with cervical spine or cord injury will have will have at least a mild head injury. 1,20

28 28 28 AETIOLOGY Most cervical spine injuries in patients with head trauma are secondary to RTA (road traffic accidents). With an average of 52% of the above injuries being secondary to RTAs associated trauma, 20,21 falls constitute around 33% with the rest being attributed to sports and other causes 20. Gun shot wounds to the head have a very low incidence of cervical spine injury 10. In general the cervical spine is the site of injury in 37 % to 55 % of all spine injuries. Causes include RTAs 50%, Falls 20%, Sports15% and 10% other causes 6. RTAs are implicated in most of the severe forms of injury. 16,21,22 In a retrospective study by Musau 23, he found that locally at the KNH and Spinal Injury unit. RTAs accounted for 54.1%, fall from a height 31.8%, assaults +gunshots 7.9%, falling objects5.3%. Peak age was found to be yrs with a male: female ratio at 4.5:1. Other figures given show the following distribution the age frequency peaks are years. The type of accidents included motor vehicle accidents (50%-70%), falls (6%-10%), diving accidents, blunt head and neck traumas, penetrating neck injuries and contact sports injuries taking the rest. 24 The majority occur at the C 1 to C 2 or C 5 to C 7 level 1.C 1 - C 2 level is more common in paediatrics 25.This is due to shifting of the fulcrum effect in the cervical spine from the upper cervical spine i.e. C 1 - C 2 in children to the C 5 C 7 level in the adult 6. At least 20% of the patients will have more than one cervical spine fractures. Twenty percent to 75% of cervical spine fractures are considered unstable and 30%-70% of these have associated neurologic injuries to the spinal cord. 24

29 29 29 Injuries of the cervical spine produce neurological damage in approximately 40% of patients. Approximately 10% of traumatic cord injuries have no obvious roentgenographic evidence of vertebral injury, this type of injury is called; Spinal Cord Injury 24, 25 Without Radiological Abnormality (SCIWORA). In traumatized patients, 3%-25% of spinal cord injuries occur during field stabilization, transit to the hospital, or early in the course of therapy. 1 This implies that, in order to prevent additional neurologic disability, care of any severely injured patient must include neck stabilization until cervical fracture is ruled out. Since the prognosis for recovery from complete cervical cord lesions is poor, emphasis must be placed first on preventing injury and second on preventing extension of neurologic injury once trauma has occurred. Some patients are more prone to cord injury especially those caused by hyperextension in older patients with spondylolitic disease or in younger patients with congenitally narrowed spinal canals. CLASSIFICATION Numerous classifications of cervical spine injuries have been formulated, but the mechanistic classification proposed by Allen, 26 appears to be the most complete. In a review of 165 lower cervical spine injuries, they identified the following six common patterns of injury, each of which is subdivided into stages based on the degree of injury to osseous and ligamentous structures. Compressive flexion (CF) five stages CF stage 1: blunting of the anterosuperior vertebral margin to a rounded contour, with no evidence of failure of the posterior ligamentous complex.

30 30 30 FIG 4:-compressive flexion injuries CF stage 2: obliquity of the anterior vertebral body with loss of some anterior height of the centrum, in addition to the changes seen in stage 1. CF stage 3: fracture line passing obliquely from the anterior surface of the vertebra through the centrum and extending through the inferior subchondral plate, and a fracture of the beak, in addition to the characteristics of a stage 2 injury. CF stage 4: deformation of the centrum and fracture of the beak with mild (less than 3 mm) displacement of the inferoposterior vertebral margin into the spinal canal. CF stage 5: bony injuries as in stage 3 but with more than 3 mm of displacement of the posterior portion of the vertebral body posteriorly into the spinal canal. The vertebral arch remains intact, the articular facets are separated, and the interspinous process space is increased at the level of injury, suggesting a posterior ligamentous disruption in a tension mode. Vertical compression (VC) three stages VC stage 1: fracture of the superior or inferior end plate with a cupping deformity. Failure of the end plate is central rather than anterior, and posterior ligamentous failure is not evident.

31 31 31 VC stage 2: fracture of both vertebral end plates with cupping deformities. Fracture lines through the centrum may be present, but displacement is minimal. FIG 5: Stages of Vertical compression VC stage 3: progression of the vertebral body damage described in stage 2. The centrum is fragmented, and the displacement is peripheral in multiple directions the ligamentous disruption is between the fractured vertebra and the one below it. Distractive flexion (DF) four stages DF stage 1: failure of the posterior ligamentous complex, as evidenced by facet subluxation in flexion, with abnormal divergence of the spinous process. FIG 6: - stages of Distractive flexion

32 32 32 DF stage 2: unilateral facet dislocation (the degree of posterior ligamentous failure ranges from partial failure sufficient only to permit the abnormal displacement to complete failure of both the anterior and posterior ligamentous complexes, which is uncommon). Subluxation of the facet on the side opposite the dislocation suggests severe ligamentous injury. In addition, a small fleck of bone may be displaced from the posterior surface of the articular process, which is displaced anteriorly. DF stage 3: bilateral facet dislocations, with approximately 50% anterior subluxation of the vertebral body. Blunting of the anterosuperior margin of the inferior vertebra to a rounded corner may or may not be present. DF stage 4: full vertebral body width displacement anteriorly or a grossly unstable motion segment, giving the appearance of a floating vertebra. Compression extension (CE) five stages CE stage 1: Unilateral vertebral arch fracture; may be through articular process (stage la), pedicle (stage lb), or lamina (stage Ic); there may be rotary spondylolisthesis of centrum. CE stage 2: Bilaminar fractures without evidence of other tissue failure. Typically the laminar fractures occur at multiple contiguous levels. CE stage 3: Bilateral vertebral arch fractures with fracture of the articular processes, pedicles, lamina, or some bilateral combination, without vertebral body displacement. CE stage 4: Bilateral vertebral arch fractures with partial vertebral body width displacement anteriorly.

33 33 33 FIG 7:- Stages of compression extension.. CE stage 5: Bilateral vertebral arch fracture with full vertebral body width displacement anteriorly.the posterior portion of the vertebral arch of the fractured vertebra does not displace, and the anterior portion of the arch remains with the centrum. Ligament failure occurs at two levels: posteriorly between the fractured vertebra and the one above it and anteriorly between the fractured vertebra and the one below it. Characteristically, the anterosuperior portion of the vertebra below is sheared off by the anteriorly displaced centrum. Distractive extension (DE) two stages DE stage 1: either failure of the anterior ligamentous complex or a transverse fracture of the centrum. The injury usually is ligamentous, and there may be a fracture of the adjacent anterior vertebral margin. The roentgenographic clue to this injury is abnormal widening of the disc space.

34 34 34 FIG 8: -Stages of distractive extension DE stage 2: evidence of failure of the posterior ligamentous complex,with displacement of the upper vertebral body posteriorly into the spinal canal, in addition to the changes seen in stage 1 injuries. Because displacement of this type tends to reduce spontaneously when the head is placed in a neutral position, roentgenographic evidence of the displacement may be minimal, rarely greater than 3 mm on initial films, with the patient supine. Lateral flexion (LF) two stages LF stage 1: asymmetrical compression fracture of the centrum and ipsilateral vertebral arch fracture, without displacement of the arch on the anteroposterior view. Compression of the articular process or comminution of the corner of the vertebral arch may be present. LF stage 2: lateral asymmetrical compression of the centrum and either ipsilateral displaced vertebral arch fracture or ligamentous failure on the contralateral side with separation of the articular processes. Both ipsilateral compressive and contralateral disruptive vertebral arch injuries may be present.

35 35 35 FIG 9: -stages of lateral flexion Injury OTHER FRACTURES UNIQUE TO THE UPPER CERVICAL SPINE Injuries at the upper cervical level are considered unstable because of their location. Nevertheless, since the diameter of the spinal canal is greatest at the level of C2, spinal cord injury from compression is the exception rather than the rule. Incompletely understood mechanisms or a combination of them usually produces injuries encountered at this level. Common injuries include fracture of the atlas, atlantoaxial subluxation, odontoid fracture, and hangman fracture. Less common injuries include occipital condyle fracture, atlanto-occipital dislocation, atlantoaxial rotary subluxation Atlas (C1) fractures Four types of atlas fractures (I, II, III, IV) result from impaction of the occipital condyles on the atlas, causing single or multiple fractures around the ring. The first 2 types of atlas fracture are stable and include isolated fractures of the anterior and posterior arch of C1, respectively. Anterior arch fractures usually are avulsion

36 36 36 fractures from the anterior portion of the ring and have a low morbidity rate and little clinical significance. The third type of atlas fracture is a fracture through the lateral mass of C1. Radiographically, asymmetric displacement of the mass from the rest of the vertebra is seen in odontoid view. This fracture also has a low morbidity rate and little clinical significance. The fourth type of atlas fracture is the burst fracture of the ring of C1 and also is known as a Jefferson fracture. This is the most significant type of atlas fracture from a clinical standpoint because it is associated with neurologic impairment. Initial management of types I, II, and III atlas fractures consists of placement of a cervical orthosis. Type IV fracture, or Jefferson fracture, is managed with cervical traction. Atlantoaxial subluxation When flexion occurs without a lateral or rotatory component at the upper cervical level, it can cause an anterior dislocation at the atlantoaxial joint if the transverse ligament is disrupted. Because this joint is near the skull, shearing forces also play a part in the mechanism causing this injury, as the skull grinds the C 1 - C 2 complex in flexion. Since the transverse ligament is the main stabilizing force of the atlantoaxial joint, this injury is unstable. Neurologic injury may occur from cord compression between the odontoid and posterior arch of C 1. Radiographically, this injury is suspected if the predental space is more than 3.5 mm (5 mm in children). Computerized tomography to confirms the diagnosis. These injuries may require fusion of C 1 and C 2 for definitive management.

37 37 37 Atlanto-occipital dislocation When severe flexion or extension exists at the upper cervical level, atlanto-occipital dislocation may occur. Atlanto-occipital dislocation involves complete disruption of all ligamentous relationships between the occiput and the atlas. Death usually occurs immediately from stretching of the brainstem, which causes respiratory arrest. Radiographically, disassociation between the base of the occiput and the arch of C1 is seen. Cervical traction is absolutely contraindicated, since further stretching of the brainstem can occur. 7 Odontoid process fractures The 3 types of odontoid process fractures are classified based on the anatomic level at which the fracture occurs. 7,25 Type I odontoid fracture is an avulsion of the tip of the dens at the insertion site of the alar ligament. Although a type I fracture is mechanically stable, it often is seen in association with atlantooccipital dislocation and this must be ruled out because it is life threatening. Type II fractures occur at the base of the dens and are the most common odontoid fractures. This type is associated with a high prevalence of nonunion because of the limited vascular supply and a small area of cancellous bone. Type III odontoid fracture occurs when the fracture line extends into the body of the axis. Nonunion is not a major problem with these injuries because of a good blood supply and the greater amount of cancellous bone. With type II and III fractures, the fractured segment may be displaced anteriorly, laterally, or posteriorly. Since posterior

38 38 38 displacement of segment is more common, the prevalence of spinal cord injury is as high as 10% with these fractures. Initial management of a type I dens fracture is use of a cervical orthosis. Types II and III fractures are managed by applying traction. Occipital condyle fracture Occipital condyle fractures are caused by a combination of vertical compression and lateral bending. Avulsion of the condylar process or a comminuted compression fracture may occur secondary to this mechanism. These fractures are associated with significant head trauma and usually are accompanied by cranial nerve deficits. Radiographically, they are difficult to delineate, and CT scan may be required to identify them. These mechanically stable injuries require only orthotic immobilization for management, and most heal uneventfully. These fractures are significant because of the injuries that usually accompany them. INSTABILITY White and Panjabi 28 defined clinical instability as the loss of the ability of the spine under physiological loads to maintain relationships between vertebrae in such a way that the spinal cord or nerve roots are not damaged or irritated and deformity or pain does not develop. Clinical instability may be caused by trauma, neoplastic or infectious disorders, and iatrogenic causes. Instability may be acute or chronic. Acute instability is caused by bone or ligament disruption that places the neural elements in danger of injury with any subsequent loading or deformity. Chronic instability is the result of progressive deformity that may cause neurological

39 39 39 deterioration, prevent recovery of injured neural tissue, or cause increasing pain or decreasing function. A motion segment is made up of two adjacent vertebrae and the intervening soft tissues. If a motion segment has two of the three columns intact, it will remain stable under physiological loads. If two or all three columns are disrupted then instability of the motion segment will result. White et al 28 proposed a scoring system for the diagnosis of clinical instability of the lower cervical spine, in which a score of 5 or more indicates instability. See check list below Checklist for diagnosis of clinical instability in lower cervical spine Elements Point value Anterior elements destroyed or unable to function 2 Posterior elements destroyed or unable to function 2 Relative sagittal plane translation >3.5 mm 2 Relative sagittal plane rotation >11 degrees 2 Positive stretch test 2 Medullary (cord) damage 2 Root damage 1 Abnormal disc narrowing 1 Dangerous loading anticipated 1 Total of 5 or more = unstable.

40 40 40 CLINICAL ASSESMENT & PHYSICAL EXAMINATION A general physical examination is performed with the patient supine. The head should be examined for lacerations and contusions and palpated for facial fractures. The ear canals should be inspected to rule out leakage of spinal fluid or blood behind the tympanic membrane, suggestive of a skull fracture. The spinous processes should be palpated from the upper cervical to the lumbosacral region. A painful spinous process may indicate a spinal injury. Palpable defects in the interspinous ligaments may indicate disruption of the supporting ligamentous complex. Careful and gentle rotation of the head may elicit pain; however, excessive flexion and extension of the neck should be avoided. Penile erection and incontinence of the bowel or bladder suggest a significant spinal injury. Quadriplegia is indicated by flaccid paralysis of the extremities. Once spinal cord injury has been identified and the appropriate precautions taken, the patient should be moved from the spine board as soon as possible to decrease the risk of decubitus ulcers. 1,29 NEUROLOGICAL EVALUATION The level of consciousness should be determined quickly, including pupillary size and reaction. Epidural or subdural hematoma, a depressed skull fracture, or other intracranial pathological conditions may cause progressive deterioration in neurological function. The Glasgow coma scale is useful in determining the level of consciousness. A detailed, initial

41 41 41 neurological examination, including sensory, motor, and reflex function, is important in determining prognosis and treatment. The presence of an incomplete or complete spinal cord injury must be determined and documented by meticulous neurological examination. Sensory examination is performed with pinpricks, beginning at the head and neck and progressing distally The skin should be marked where sensation is present before proceeding to motor examination. Evidence of sacral sensory sparing can establish the diagnosis of an incomplete spinal cord injury. The only area of sensation distal to an obvious cervical lesion in a quadriplegic patient may be in the perianal region. Motor examination should be systematic, beginning with the upper extremities. During motor examination it is important to differentiate between complete and incomplete spinal cord injuries and pure nerve root lesions. A protruded cervical disc or a unilateral dislocated facet may produce an isolated nerve root paralysis. 25,29,30 Useful grading of neurological status can be achieved using Frankels scale. 25 There are 5 categories in the scale (a to e): (a) No motor or sensory function below the level of injury. (b) Sensation but no motor function. (c) Motor function present but useless. (d) Useful motor function present. (e) Normal motor and sensory.

42 42 42 Non-Radiographic ("clinical") Spine Clearance Only when all five of the following criteria have been met can a patient's cervical spine be cleared clinically: 1. No peripheral neurologic deficit or complaint on history or examination. 2. No posterior neck pain or tenderness. 3. No recent use of intoxicants (cocaine, opiates, ethanol, benzodiazepines, etc.) 4. No closed head injury (GCS must be > 13) 5. No major distracting injuries (e.g.: open femur fracture, multiple rib fractures) If all five of the above criteria are reliably met, cervical spine precautions may be discontinued without any further testing. 31 George C. Velmahos et al 32 on 540 alert patients with negative clinical examination found no radiological abnormality. Thus patients meeting above criteria can have their cervical spine cleared clinically and do not need radiological exam. Roentgenographic Evaluation of a Suspected Cervical Spine Injury In the conscious patient the following three-step approach is followed: 1. Standard 3-view series (AP + lateral + open-mouth odontoid). 2. Swimmer's view when lower spine (C 7 to T 1 ) cannot be adequately seen on lateral view 3. If above are normal but patient complains of neck pain, obtain lateral flexion/extension views. This is best done under

43 43 43 fluoroscopic control, studies done 33 effective and devoid of complications. shows that it is easy In the unconscious patient the following steps are followed: 1. Standard 3-view series (AP + lateral + open-mouth odontoid). 2. Swimmer's view when lower spine (C 7 to T 1 ) cannot be adequately seen on lateral view. 3. CT scan with thin axial cuts through C 1 - C Any neurologically impaired patient, with the deficit attributable to cervical cord injury should remain in full spine protection and undergo immediate evaluation by the neurosurgical service. The standard 3-view films are obtained initially. CLINICAL PRINCIPLES i) Because "positive mechanism" for spine injury is, by necessity, a vague term, emphasis in field assessment has been placed on clinical criteria 31. Specific clinical criteria provide safe, accurate, and dependable assessment of possible unstable spine injury when the trauma victim is calm, cooperative, sober, and alert. These clinical criteria can also be applied to the majority of trauma patients with uncertain or non-specific mechanisms of injury. ii) The pain response is often abnormal in victims of significant trauma during the time period immediately following injury. Fear, confusion, and multiple or distracting injuries often result in an acute, autonomic type of stress reaction (Acute Stress Reaction) and a variable period of "pain-masking." For this reason, all victims of severe trauma who have a "positive mechanism" for spine injury