Abstract
Cervical traction is the placement of weighted cervical tongs commonly used to quickly reduce traumatic fracture-dislocations of the cervical spine and realign the cervical spine in awake and cooperative patients. Here, we first review the relevant anatomy and physiology, discuss indications and contraindications, and finally provide a step-by-step procedural guide with expert advice to avoid common pitfalls.
10 Cervical Traction
10.1 Introduction
Cervical traction is a technique used to restore proper cervical spine alignment and to achieve decompression of the cervical spinal cord by means of application of weight to the head. This is typically performed following a traumatic fracture or dislocation of the cervical spine. Tongs are applied to the head with metal screws that are inserted through the outer table of the skull. Weight is incrementally applied to the head to distract the cervical spine to restore cervical alignment.
Cervical traction is most commonly used as an initial adjunct treatment to restore cervical alignment prior to cervical fixation, either with internal stabilization and fusion or external fixation with a halo vest. Cervical traction can also be used intraoperatively to aid correction of alignment for degenerative cervical pathologies.
In this chapter, we describe the relevant anatomy and physiology of the cervical spine, discuss indications and contraindications for cervical traction, and review the appropriate equipment and technique of placing a patient in cervical traction.
10.2 Relevant Anatomy and Physiology
10.2.1 Cervical Spine Anatomy
The cervical spine has seven vertebral levels. C1 (atlas) and C2 (axis) have unique anatomic features that provide specialized functions. C1 is composed of a ring with lateral masses that give rise to superior facets that articulate with the occipital condyles and inferior facets that articulate with the C2 superior facets. C2 is composed of a large vertebral body, an odontoid process (dens), pedicles, a spinous process, laminae, transverse processes, and facets. A series of ligaments help stabilize the upper cervical spine and craniocervical junction during head and spine movement, including the atlanto-occipital, anterior longitudinal, transverse, apical, and alar ligaments.
The cervical spine segments below the C2 level are referred to as the subaxial cervical spine (C3–C7). Each segment in the subaxial cervical spine is composed of a vertebral body, pedicles, a spinous process, laminae, lateral masses, transverse processes, and facets. The subaxial cervical facet joints are oriented in the coronal plane (facing anterior) and angled approximately 45 degrees superiorly in the sagittal plane. The subaxial cervical ligaments can be organized into anterior and posterior groups. The anterior ligamentous complex includes the anterior longitudinal ligament (ALL) and the posterior longitudinal ligament (PLL). The posterior ligamentous complex (PLC) includes the ligamentum flavum, the interspinous ligaments, and the facet joint capsules.
10.2.2 Pathophysiology of Cervical Traction
The most common traumatic cervical injuries that would potentially require cervical traction are cervical facet dislocations, hangman’s fractures, and displaced type II odontoid fractures. The common pathophysiology of all these fractures is the unstable malalignment of the normal cervical curvature with the potential to compress the cervical spinal cord. Cervical traction is intended to distract the cervical spine to reduce angulation, subluxation, or dislocation, which will align the fracture to promote bone healing and remove any compression on the spinal cord if present.
Cervical facet dislocations are typically caused by flexion injuries which “unlock” the facets, and in the process, allow them to dislocate. Cervical traction is applied such that the vector of force flexes and distracts the neck to again unlock the facet joints until they translate back to their anatomic position, at which point the vector of force can be neutralized. Hangman’s fractures are typically caused by hyperextension injuries and cause forward angulation and distraction of C2 relative to the subaxial spine. Cervical traction is applied such that the vector of force is neutral or extend the neck slightly to reduce the angulation of C2. Similarly, anteriorly displaced or angulated type II odontoid fractures can be reduced using cervical traction with a vector of force providing gentle extension of the neck. Rotary atlantoaxial subluxation is a unilateral subluxation of the C1–C2 facet joint most often caused by severe muscle spasm in the neck. Pharmacological treatment of the muscle spasms and neutral cervical traction can usually restore normal anatomic alignment. Burst fractures of the subaxial cervical spine causing spinal cord compression can often be reduced with cervical traction provided the PLL is intact. Stretching the PLL with cervical traction can translate the fractured vertebral body ventrally away from the spinal cord.
10.3 Indications
Indications for cervical traction include: facet dislocations, displaced or angulated hangman’s fractures, displaced or angulated odontoid fractures, rotary atlantoaxial subluxation, and subaxial burst fractures. Cervical traction is also used by some spine surgeons to provide distraction during anterior and posterior cervical fusions for degenerative cervical spondylosis and cervical spondylotic myelopathy. For the purposes of this chapter, we will focus only on traumatic indications for cervical traction.
10.3.1 Facet Dislocations
Cervical facet dislocation occurs when the inferior articular process (IAP) dislocates anterior to the superior articular process (SAP) of the subjacent level. If the IAP is directly above the SAP, the dislocation is called a “perched facet,” whereas if the IAP is anterior to the SAP, the dislocation is called a “jumped facet.” Facet dislocations can be unilateral or bilateral. Facet dislocation causes anterior subluxation of the superior vertebral body, leading to spinal canal stenosis and cervical cord compression. Spinal cord injury is common in cervical facet dislocation. In general, bilateral facet dislocations have a high incidence of complete spinal cord injuries, and unilateral facet subluxations tend to cause nerve root compression and radiculopathy. Flexion injuries such as motor vehicle collisions, falls from height, and diving accidents are common causes of cervical facet dislocations (▶ Fig. 10.1).
10.3.2 Displaced or Angulated Hangman’s Fractures
Hangman’s fractures, or traumatic C2 spondylolysis, are typically caused by hyperextension of the neck combined with an axial compression or distraction force. The fractured C2 pars interarticularis creates instability between C2 and C3 and anterolisthesis of C2 on C3 is frequent. Disruption of the PLL and C2–C3 disk can lead to anterior angulation of C2 (▶ Fig. 10.2). Treatment of angulated or displaced hangman’s fractures is typically reduction followed by halo-vest immobilization for the more stable injuries and either an anterior C2–C3 anterior cervical discectomy and fusion (ACDF) or a posterior C1–C3 stabilization and fusion for the unstable injuries.
10.3.3 Displaced or Angulated Type II Odontoid Fractures
Type II odontoid fractures most commonly occur in elderly patients after simple falls from standing. However, they can also occur in younger patients after high-velocity hyperflexion or hyperextension injuries. Type II odontoid fractures occur across the base of the odontoid process, where there is a vascular watershed zone due to the embryological growth of the blood supply to the dens. As a result of this poor blood supply to the base of the dens, there is a high rate of nonunion with nonoperative management. Type II odontoid fractures are commonly displaced or angulated anteriorly from hyperflexion injuries or displaced posteriorly from hyperextension injuries. These fractures are associated with transverse atlantal ligament injuries and are more likely to be unstable. Posteriorly displaced or angulated fractures can cause spinal cord compression and should be reduced urgently.
10.3.4 Rotary Atlantoaxial Subluxations
Atlantoaxial rotary subluxation (AARS) is a rotation of C1 on C2 associated with torticollis. This injury occurs most commonly in children. Although AARS can occur after significant trauma causing a fracture at C1 or C2, it is most common after minor injuries to the neck causing muscle strain, after surgery on the neck, or after infectious or inflammatory conditions involving the neck leading to prolonged muscle spasm. If no underlying fracture is found, AARS can be treated with analgesics, muscle relaxants, and collar immobilization if the subluxation is acute. Subacute and chronic AARS often require cervical traction and occasionally halo vest immobilization to successfully reduce.
10.3.5 Subaxial Burst Fractures
Burst fractures in the subaxial spine (C3–C7) involve loss of vertebral body height and retropulsion of the vertebral body into the spinal canal. This often causes spinal cord compression and injury. These fractures typically occur after high-energy axial compression injuries. Historically, cervical traction was used to decompress the spinal cord by applying tension on the PLL, thereby reducing the amount of bone retropulsion. Several studies have shown that cervical traction often produces incomplete decompression of the spinal cord. 1 , 2 , 3 The failure of traction to achieve reduction is usually the result of the PLL being disrupted. In cases where prompt reduction is not able to be successfully achieved, surgical decompression through an anterior cervical corpectomy or a posterior decompression and instrumented fusion have become more popular in the treatment of these injuries in patients with spinal cord injury.
10.4 Contraindications
Contraindications to cervical traction include clinically relevant skull fractures or diseases involving skull bone density such as Paget’s disease of the skull or osteogenesis imperfecta, as skull pins may penetrate the skull. Young children under 3 years of age typically have skull sutures that have not yet fused and may be at increased risk during skull pin placement. As such, if traction is to be utilized in younger patients, consideration is given to utilizing a higher number of pins at a lower insertional torque through a halo ring. Atlanto-occipital dissociation (AOD) is a contraindication to cervical traction, as it is likely to widen the AOD and injure the upper cervical spinal cord and medulla. Traumatic brain injury that requires a craniotomy needs to be addressed before cervical traction is applied. Caution should be exercised when applying cervical traction in patients without a reliable neurological examination or with alterations in consciousness.
There is controversy regarding the presence of cervical disk herniation that could cause spinal cord compression while cervical traction is being applied. The incidence of disk herniation after traumatic cervical dislocation ranges from 8 to 42% in the literature. 4 , 5 , 6 , 7 While some centers rule out disk herniation with a pre-reduction magnetic resonance imaging (MRI) of the cervical spine, other centers routinely perform immediate closed reduction with cervical traction on awake patients with reliable neurological examinations prior to obtaining MRI. Those that advocate for immediate closed reduction cite the several-hour delay in spinal cord decompression associated with pre-reduction MRI, especially in patients with a potentially reversible spinal cord injury. Those that advocate for pre-reduction MRI cite the risk of iatrogenic disk protrusion during cervical traction that can lead to worsening neurologic deterioration.
Eismont et al published a series of 68 patients who underwent closed reduction with cervical traction with one neurological deterioration in their series. 4 Six patients were found to have disk herniations associated with their injuries and no awake patients in the series declined neurologically after closed reduction. Grant et al published a series of 82 patients who underwent early closed reduction with cervical traction prior to MRI. The incidence of disk herniation was 22% and one patient declined neurologically 6 hours after closed reduction. 5 Despite the presence of disk herniations, the authors found early closed reduction with cervical traction to be extremely safe when performed on awake patients who are cooperative with neurological examination. Rizzolo et al described 131 patients who underwent closed reduction with an 86% success rate and no neurologic worsening in any patient including those found to have disk herniations on MRI after reduction. 8 Vaccaro et al published a series of 11 patients, 2 with disk herniations prior to traction and 2 with new disk herniations after traction, with no neurologic deterioration in any patient after cervical traction. 9 At our institution, we have nearly immediate access to MRI and routinely attempt to obtain rapid-sequence T2 sagittal sequence to rule out disk herniation prior to closed reduction with cervical traction. However, we do not delay early closed reduction in awake patients with spinal cord injuries if there is a delay in obtaining MRI imaging.
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