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脊柱骨折 FRACTURES OF SPINE AND PELVIC


FRACTURES OF SPINE AND PELVIC

Fracture of the spine

Anatomy

Three-column concept The anterior column contains the anterior longitudinal ligament, the anterior 2/3 of the vertebral body, and the anterior portion of the annulus fibrosus. The middle column consists of the posterior longitudinal ligament, the posterior 1/3 of the vertebral body, and the posterior aspect of the annulus fibrosus. The posterior column includes the neural arch, the ligamentum flavum, the facet capsules, and the interspinous ligaments

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The cervical spinal column is extremely vulnerable to injury The seven cervical vertebrae, whose specific facet joint articulations allow movement in the planes of flexion, extension, lateral bending, and rotation, have attached at the cephalic aspect the skull and its contents Injury occurs when forces applied to the head and neck result in loads that exceed the ability of the supporting structures to dissipate energy Meyer identified C2 and C5 as the two most common areas of cervical spine injury. Injuries of the cervical spine produce neurological damage in approximately 40% of patients

Important anterior and posterior supporting structures of spine

Classifications
Fractures of thoracolumbar spine

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Three-column classification of spinal instability. Illustrations of anterior, middle, and posterior columns

McAfee classification of Fractures of thoracolumbar spine
? McAfee

et al. determined the mechanisms of failure of the middle osteoligamentous complex and developed a new system based on these mechanisms

1)Wedge compression fractures:
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isolated failure of the anterior column and result from forward flexion. They are rarely associated with neurological deficit

2)Stable burst fractures: the anterior and middle columns fail because of a compressive load, with no loss of integrity of the posterior elements

3)Unstable burst fractures:
the anterior and middle columns fail in compression, and the posterior column is disrupted. The posterior column can fail in compression, lateral flexion, or rotation. There is a tendency for posttraumatic kyphosis and progressive neural symptoms because of instability

4)Chance fractures:
are horizontal avulsion injuries of the vertebral bodies caused by flexion about an axis anterior to the anterior longitudinal ligament. The entire vertebra is pulled apart by a strong tensile force

5)Flexion distraction injuries:
the flexion axis is posterior to the anterior longitudinal ligament. The anterior column fails in compression while the middle and posterior columns fail in tension. This injury is unstable because the ligamentum flavum, interspinous ligaments, and supraspinous ligaments usually are disrupted

6)Translational injuries:
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are characterized by malalignment of the neural canal, which has been totally disrupted. Usually all three columns have failed in shear. At the affected level, one part of the spinal canal has been displaced in the transverse plane

Classifications
Fractures of cervical spine

1.Flexion injury
the result of compression of anterior column and distraction of posterior column ⑴ anterior subluxation: caused by rupture of the ligament of posterior column ( complete or incomplete)

⑵ bilateral facet dislocations: extreme flexion—rupture of ligament of middle and posterior column (may with approximately 50% anterior subluxation of the vertebral body. In a more severe case, may have full vertebral body width displacement anteriorly or a grossly unstable motion segment, giving the appearance of a ‘‘floating’’ vertebra )

⑶ simple wedge compression: commonly seen in clinic, and happened more frequently in osteoporosis patient

2. Vertical compression injury
(1) Jefferson fracture: fracture of anterior and posterior arch of atlas

A, Drawing indicating axial view of stable Jefferson fracture (transverse ligament intact). B, Drawing indicating axial view of unstable Jefferson fracture (transverse ligament ruptured)

(2) Burst fracture: commonly seen in C5 and C6 The centrum is fragmented, and the displacement is peripheral in multiple directions. The centrum fails, with significant impaction and fragmentation. The posterior aspect of the vertebral body is fractured and may be displaced into the spinal canal.

3. Extension injury
(1) Distractive extension
either failure of the anterior ligamentous complex or a transverse fracture of the centrum

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 the previous injuries

(2) Hangman’s fracture: vertical fracture of the vertebral arch of dens

4. Fracture of unknown mechanisms --Dens fracture
Anderson and D’Alonzo classified odontoid fractures into three types ? Type I is oblique fracture through upper part of odontoid process ? Type II is fracture at junction of odontoid process and body of second cervical vertebra ? Type III is fracture through upper body of vertebra

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Three types of odontoid process fractures

Clinical evaluation
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Once the patient has been stabilized according to trauma care principles, patients history can be reviewed. Details of the mechanisms of injury can arouse or confirm suspicion of trauma to the spinal column The patient’s symptoms at the time of injury may provide important information in the assessment of neurologic impairment. Transient paresis or paresthesias suggest a major fracture pattern

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The physical examination should include palpation of the spine from head to sacrum. Any areas of tenderness or bruising are noted ? A careful neurological evaluation is done ? The rectal examination is important. Perianal sensation is provided by the lower sacral roots. The patient’s ability to contract the sphincter voluntarily indicates sacral root motor function ? Assessment of the bulbocavernosus reflex determines whether the patient is in spinal shock or whether a permanent complete lesion exists

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Plain roentgenograms and CT scanning provide static images ? Occult ligamentous injuries are not readily identified on plain films or CT scans, and flexion and extension views of the thoracolumbar spine are risky ? MRI is helpful in detecting occult ligamentous injuries and hemorrhage into surrounding soft tissue structures and in determining the extent of neural damage and the degree of cord edema

Acute management
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Almost 50% of patients who sustain spinal trauma have other associated injuries ? Patient management begins at the accident site. The key is to suspect spinal column injury in any patient who has multiple trauma ? The most common spine injuries occur as the result of motor vehicle accidents, falls, and sports injuries. These patients should not be moved until the spine has been temporarily immobilized. This is usually archived with a rigid spine board. A hard collar is usually carefully applied

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turning or transfer of the patient must be done with gentle inline traction and log-rolling ? Appropriate maintenance of airway, breathing, and circulation must be initiated before further attention to the spine is given

Treatment
Timing of surgery
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In the presence of a progressive neurological deficit, emergency decompression is indicated In patients with complete spinal cord injuries or static incomplete spinal cord injuries, some authors advocate delaying surgery for several days to allow resolution of cord edema. For neurologically normal patients with unstable spinal injuries and those with nonprogressive neurological injuries, open reduction and internal fixation should be carried out as soon as possible

Surgical treatment
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In most patients early open reduction and internal fixation are indicated to obtain stability and allow early functional rehabilitation Cervical spine fractures may be stabilized through an anterior, a posterior, or a combined approach Unstable injuries of the cervical spine, with or without neurological deficit, generally require operative treatment

Several basic principles
①The injury must be clearly defined before surgery by plain roentgenograms, highresolution CT scanning with sagittal and coronal reconstruction, or MRI ②Laminectomy has a limited role in the treatment of cervical fractures or dislocations and may contribute to clinical instability and neurological deficit

③Compression of the cervical cord or roots by retropulsed bone fragments or disc material usually is anterior; therefore anterior decompression and fusion, with or without internal fixation, are indicated ④For posterior ligamentous or bony instability, posterior stabilization with internal fixation and bone grafting are indicated

Burst fracture of L2 in 42-year-old woman, with incomplete paraparesis, 3 weeks after injury. A and B, Myelograms show significant extradural compression at L2 level from bone retropulsed into spinal canal. C and D, CT scans show degree of canal compromise at L2 level.

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E and F, CT scans show adequate decompression of spinal canal and proper placement of iliac strut graft from L1 to L3. Patient made excellent neurological recovery and regained ambulatory status, with return of bowel and bladder function

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A, Compressive flexion injury in 20-year-old woman with complete C5 quadriplegia. B, CT scan shows encroachment on subarachnoid space and flattening of cervical cord, with fractures of left lateral mass. C, CT scan with sagittal reconstruction shows fracture of C5 vertebral body with mild displacement of posterior vertebral margin into spinal canal

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D, CT scan after anterior decompression and iliac crest strut grafting. E,CT scan with sagittal reconstruction shows adequate decompression of spinal cord and proper position of graft from C4 to C6. F, Three years after surgery, lateral roentgenogram shows incorporation of graft and solid arthrodesis from C4 to C6.

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a complete C5 quadriplegia

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a complete C5 quadriplegia

Anteroposterior and lateral roentgenograms of C3-5 fusion with ORION anterior internal fixation device

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Lateral view of cervical spine after internal fixation of C4-5 dislocation with lateral mass plates and screws

Treatment of dens fracture:
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I fractures are uncommon, and even if nonunion occurs after inadequate immobilization, no instability results ? Type II fractures are the most common ? Type III fractures have a large cancellous base and heal without surgery in 90% of patients

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Anterior fixation of dens fracture with cannulated screws

Spinal Cord Injury

Pathophysiology of spinal cord injury
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Most spinal deficit is attributed to contusion and compression rather than to complete transection. ? The initial blunt injury leads to a sequence of molecular-level events that result in ischemia, tissue hypoxia, and secondary tissue degeneration

Spinal shock
After a severe spinal cord injury, a state of complete spinal areflexia can develop which lasts for a varying length of time, this state, conventionally termed Spinal shock, is classically evaluated by testing the bulbocavernosus reflex, a spinal reflex mediated by S3-S4 region of the conus medullaris. This reflex is frequently absent for the first 4 to 6 hours after injury but usually returns within 24 hours

Spinal cord injury
①Central cord syndrome is the most common. ? It consists of destruction of the central area of the spinal cord, including both gray and white matter. ? Generally patients have a quadriparesis involving the upper extremities to a greater degree than the lower. Sensory sparing is variable, usually sacral pinprick sensation is preserved. ? Frequently patients show immediate partial recovery after being placed in skeletal traction through skull tongs. ? Prognosis is variable, more than 50% of patients have return of bowel and bladder control

②Brown-Sé quard syndrome ? It is an injury to either half of the spinal cord and usually is the result of a unilateral laminar or pedicle fracture, penetrating injury, or a rotational injury resulting in a subluxation. ? It is characterized by motor weakness on the side of the lesion and the contralateral loss of pain and temperature sensation. ? Prognosis for recovery is good

③Anterior cord syndrome ? It usually is caused by a hyperflexion injury in which bone or disc fragments compress the anterior spinal artery and cord. ? It is characterized by complete motor loss and loss of pain and temperature discrimination below the level of injury. ? The posterior columns are spared to varying degrees resulting in preservation of deep touch, position sense, and vibratory sensation. ? Prognosis for significant recovery in this injury is poor

A and B, Central cord syndrome; spinal cord is pinched between vertebral body and buckling ligamentum flavum. C, Brown-Sé quard syndrome. D, Anterior cervical cord syndrome

Conus medullaris syndrome
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Conus medullaris syndrome, or injury of the sacral cord (conus) and lumbar nerve roots within the spinal canal, usually results in areflexic bladder, bowel, and lower extremities. ? Most of these injuries occur between T11 and L2 and result in flaccid paralysis in the perineum and loss of all bladder and perianal muscle control. ? The irreversible nature of this injury to the sacral segments is evidenced by the absence of the bulbocavernosus reflex and the perianal wink

Cauda equina syndrome
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Cauda equina syndrome, or injury between the conus and the lumbosacral nerve roots within the spinal canal, results in areflexic bladder, bowel, and lower limbs. ? With a complete cauda equina injury, all peripheral nerves to the bowel, bladder, perianal area, and lower extremities are lost, and the bulbocavernosus reflex, anal wink, and all reflex activity in the lower extremities are absent ? It is important to remember that the cauda equina functions as the peripheral nervous system, and there is a possibility of return of function of the nerve rootlets ? Most often the cauda equina syndrome presents as a neurologically incomplete lesion.

Paraplesia index
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To record the function of motor, sensory and bowel and bladder control respectively, 0=normal, 1=impaired, 2=complete loss ? all scores are added, for a total maximal and minimal score of 6 and 0

Complications
1) Respiratory failure and infections 2) Urinary tract infections are common, an intermittent catheterization program should begin immediately. 3) Skin breakdown (bedsore) in the insensate patient is commonplace and must be prevented by frequent turning and pressure relief measures. 4) Body temperature maladjustment

Treatment
1) Adequate alignment and stabilization

2) The prevention of further injury to the comprised cord and the protection of uninjured cord tissue, (to reduce spinal cord edema and secondary injury), e.g. high-dose intravenous methylprednisolone (MPS), mannitol 3) Surgical treatment

Goals of surgery
1) establishment of a balanced and stable spine with fusion of the minimal number of motion segments 2) return of the patient to optimal functional capacity as quickly and safely as possible 3) maximization of neurologic function 4) minimization of cost impact, complications, and hospital stay

Indication of operation
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Fracture –dislocation of spine with interlocking of facets Unsatisfied reduction of fracture of spine or the spine is unstable The spinal cord is compressed by cracked bone in the spinal canal which is approved by radiological examination Paralysis level increase which indicates the presence of active bleeding within the spinal canal

PELVIC FRACTURES

Anatomy
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The pelvis is composed anteriorly of the ring of the pubic and ischial rami connected with the symphysis pubis. A fibrocartilaginous disc separates the two pubic bodies.

3. Posteriorly, the sacrum and the two innominate bones are joined at the sacroiliac joint by the interosseous sacroiliac ligaments, the anterior and posterior sacroiliac ligaments, the sacrotuberous ligaments, the sacrospinous ligaments, and the associated iliolumbar ligaments. 4. This ligamentous complex provides stability to the posterior sacroiliac complex, since the sacroiliac joint itself has no inherent bony stability.

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A, Major posterior stabilizing structures of pelvic ring B, Tile compares relationship of posterior pelvic ligamentous and bony structures to suspension bridge, with sacrum suspended between two posterosuperior iliac spines

Classifications
Pennal et al. developed a mechanistic classification in which pelvic fractures are described as 1. anteroposterior compression injuries, 2. lateral compression injuries, or 3. vertical shear injuries

Tile modified the Pennal system to make it an alphanumeric system involving three groups based on the concept of pelvic stability

Type A: Stable (posterior arch intact)
A1: Avulsion injury A2: Iliac wing or anterior arch fracture caused by a transverse sacrococcygeal fracture

Type B: Partially stable (incomplete
disruption of posterior arch) B1: Open book injury (external rotation) B2: Lateral compression injury (internal rotation) B2-1:Ipsilateral anterior and posterior injuries B2-2:Contralateral (bucket handle) injuries B3: Bilateral

Tile classification of pelvic fractures based on forces acting on pelvis
Type B1: External rotation or anteroposterior compression through left femur (arrows) disrupts symphysis, pelvis, and anterior sacroiliac ligament until ilium impinges against posterior aspect of sacrum. If force stops at this level, partial stability of pelvis is maintained by interosseous sacroiliac ligaments.

Type B2-1: Lateral compression (internal rotation) force implodes hemipelvis. Rami may fracture anteriorly, and posterior impaction of sacrum may occur, with some disruption of posterior structures, but partial stability is maintained by intact pelvic floor and compression of sacrum.

Type C: Unstable (complete disruption of
posterior arch) C1: Unilateral C1-1:Iliac fracture C1-2:Sacroiliac fracture-dislocation C1-3:Sacral fracture C2: Bilateral, with one side type B, one side type C C3: Bilateral

Type C: Shearing (translational) force disrupts symphysis, pelvic floor, and posterior structures, rendering hemipelvis completely unstable.

? Young

and Burgess proposed a different modification of the original Pennal classification, adding a new category for combined mechanism injuries

Lateral compression (LC) injuries
Category LC 1 LC 2 LC 3 Common characteristic Anterior transverse fracture (pubic rami) Anterior transverse fracture (pubic rami) Anterior transverse fracture (pubic rami) Differentiating characteristic Sacral compression on side of impact Crescent (iliac wing) fracture Contralateral open book (APC) injury

Anteroposterior compression (APC)
APC 1 Symphyseal diastasis APC 2 Symphyseal diastasis or anterior vertical fracture APC 3 Symphyseal diastasis or anterior vertical fracture Slight widening of pubic symphysis and/or Sl joint; stretched but intact anterior and posterior ligaments Widened Sl joint, disrupted anterior ligaments; intact posterior ligaments
Complete hemipelvis separation but no vertical displacement; complete sacroiliac joint disruption; complete anterior and posterior ligament disruption

Vertical shear (VS) injuries
VS Symphyseal diastasis or anterior vertical fracture Vertical displacement anteriorly and posteriorly, usually through Sl joint, occasionally through iliac wing and/or sacrum

CM Anterior and/or posterior, vertical and/or transverse components

Combination of other injury patterns; LC/VS or LC/APC

In a subsequent series, lateral compression (LC) injuries were the most common injury pattern, accounting for 41% of the patients, followed by anteroposterior compression (APC) injuries (26%), acetabular fractures (18%), combined mechanism (CM) injuries (10%), and vertical shear (VS) injuries (5%). Hypovolemic shock and large blood requirements were more common in patients with vertically unstable APC type 3 injuries than in those with vertically stable anteroposterior or lateral compression injuries.

Sacral fractures have been classified separately
Denis classification of sacral fractures, in which three zones of injury are differentiated ? zone I, sacral ala ? zone II, foraminal region ? zone III, spinal canal

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type 1 fractures occur lateral to the neural foramina through the sacral ala

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type 2 fractures are transforaminal
type 3 fractures occur medial or central to the neural foramina. Transverse fractures of the sacrum are classified as type 3 injuries because they involve the spinal canal

Clinical findings
A history of high-energy injury caused by motor vehicle or motorcycle collisions or falls from heights 2. Pelvic fractures are associated with other injuries such as head, chest, abdominal and retroperitoneal vascular injuries that may be lifethreatening
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physical examinations
(1)Appropriate measurement of leg-length discrepancies and evaluation of internal and external rotational abnormalities and open wounds are important (2)The evaluation of soft tissue injuries, e.g. contusions, hemorrhage, hematomas (3)Rotational instability can be assessed by pushing on the anterosuperior iliac wings both internally and externally to determine whether the pelvis opens and closes. Pull-push evaluation of the leg can be used to determine any vertical migeration of the pelvis

Roentgenographic evaluation
The standard roentgenographic projections required for evaluation of pelvic fractures are an anteroposterior view of the pelvis and the 40-degree caudal inlet and 40-degree cephalad outlet views described by Pennal 2. Computed tomography is an essential part of the evaluation of any significant pelvic injury.
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A, Forty-degree caudad inlet view of pelvis ? B, Forty-degree cephalad outlet view of pelvis

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A, Tile type B1 pelvic injury with diastasis of symphysis and anterior widening of sacroiliac joint. ? B, CT scan shows that posterior sacroiliac joint ligaments are intact

Complications
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The potential complications of highenergy pelvic fractures include injuries to the major vessels and nerves of the pelvis and the major viscera, such as the intestines, the bladder, and the urethra. ? Reported mortality from severe pelvic fractures ranges from 10% to as high as 50% in open pelvic fractures

1) retroperitoneal vascular injuries 2) major visceral injuries: liver, kidney, or spleen and intestines 3) bladder and urethra injuries 4) rectal injuries 5) nerve injuryes: lumbosacral plexus and sciatic nerve

Treatment
1) Priority should be given to the treatment of airway, breathing, and circulation peoblems 2) For mildly displaced lateral compression injuries, bed rest usually is sufficient 3) Operative reduction and internal fixation of pelvic fractures traditionally have been delayed for a few days to allow evaluation and treatment of life-threatening injuries, preoperative planning, and assembly of necessary equipment

Posterior screw fixation of sacral fractures and sacroiliac dislocations. Patient positioning. Anteroposterior, caudad, and cephalad image intensifier projections show drill bit and screw position.

Transiliac rod fixation of sacral fractures. A, Large Steinmann pin (8 to 10 mm) is drilled from outer aspect of one ilium through opposite ilium. B, Second rod is inserted approximately 1.5 cm distal and parallel to first.

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Iliosacral screw fixation for sacroiliac or sacral fracture

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Transiliac rods for fixation of sacral fracture

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Anterior plating of sacroiliac joint


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