What Is Chalk Stick Fracture?
Chalk stick fractures are fractures of the fused spine that are characteristically seen in ankylosing spondylitis. They are also known as carrot stick fractures. Ankylosed spine fractures of the spine are relatively common. The word ankylosis refers to abnormal stiffening and rigidity in the normal movement of the joint due to the fusion of the bones. Chalk stick fractures are also commonly seen in Paget’s disease of bone, and osteopetrosis (a bone disease where the bones become extremely fragile to fracture).
Ankylosing spondylitis (an inflammatory disorder that causes some of the bones of the spine to fuse) is commonly present in the joints of the sacrum, iliac joints of the ilium, and the spine. The spine can lose its articulation and normal structure due to ankylosing spondylitis. They become rigid and weak. A low-velocity trauma can cause spinal fractures because of this pathology. The ossified soft tissue surrounding the spine and osteoporosis make these fractures more susceptible to breakage and highly unstable. A healthy long bone typically breaks like a chalk stick as the collagen in the connective tissue matrix adds flexibility to the mineral content of the bone and the energy that is produced traverses through the bone to cause the fracture.
What Is the other Synonym of Chalk Stick Fracture?
Some authors also define the chalk stick fracture as the fracture through a Pagetoid long bone.
What Is the Pathogenesis of Chalk Stick Fracture?
Chalk stick fractures usually occur through the disco-vertebral junction (a dynamic region that contains both normal forms and modifications occurring due to numerous diseases) in the lower region of the cervical spine or the upper thoracic spine. The fused segments of the spinal column act as the lever arm that creates higher stresses on the spine. Due to a change in the biomechanics of the fused spinal cord, minimal trauma can cause fractures of the spine causing chalk stick fractures.
What Is the Etiology of Chalk Stick Fracture?
Chalk stick fractures are frequently found in
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Ankylosing spondylitis (an inflammatory disorder that causes some of the bones of the spine to fuse).
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Forestier disease (diffuse idiopathic skeletal hyperostosis).
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Surgical spinal fusion.
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Ossification (the process of bone formation) of the ligamentum flavum.
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Posterior longitudinal ligament fusion.
Why the Name Chalk Stick Fracture?
It is so named because of the appearance of the fracture which is similar to breaking a chalk stick or a carrot.
What Are the Clinical Features of Chalk Stick Fracture?
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A chalk stick fracture is a complete fracture of the ankylosed cervical spine that occurs due to trauma. Devastating results are produced in the cervical region of the spine by minor traumatic injury due to rigidity and stiffness.
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The most commonly affected area of the chalk stick fracture is C5–C6.
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Ossification of the posterior longitudinal ligament, diffuse idiopathic skeletal hyperostosis, and ossification of ligamentum flavum are most frequently observed.
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The cervical spine is more commonly involved in ankylosing spondylitis as compared to the thoracic and lumbar spinal areas.
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Ossification of the ligamentous structures of the cervical spine followed by heavy calcification usually result in chalk stick fractures after minor traumatic injuries.
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The fractures are very unstable and degenerating in nature because of the rigid and stiff fractured ligamentous structures around them.
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The fracture can become a life-threatening situation owing to the notorious involvement of degenerated structures like the muscles, ligaments, and tendons.
What Are the Radiographic Techniques Used to Diagnose Chalk Stick Fractures?
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Computed Tomography- For a quick and accurate diagnosis of bone pathology, computed tomography is the best diagnostic option. Plain radiographs can sometimes miss a minor fracture in the spine. Multislice computed tomography scan with a two-millimeter cut with three-dimensional reconstruction is very useful to identify the location, extent, and severity of the pathology.
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Magnetic Resonance Imaging- Magnetic resonance image scanning is used to identify ligament injury, perilesional edema, collection of fluid, injury of the spinal cord, and intraspinal bleeding.
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Fractures involved are usually transverse on radiographic findings.
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They often occur at cervicothoracic or thoracolumbar junctions.
What Is the Treatment and Prognosis of Chalk Stick Fracture?
Management of this pathology is very tough. In the absence of considerable deformity, and no neurological deficits, conservative management with cervical collar support immobilization is advised for the patient. However, patients that are being managed non-operatively should be followed up aggressively to ensure the fracture is sufficiently aligned till adequate union is achieved, and the patient should be compliant with the treatment. Long-term follow-up is essential to make sure they do not develop kyphotic deformities that can worsen with time.
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If malalignment syndromes are developed in such patients, surgical therapy is recommended.
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Patients suffering from any neurological disorder or unstable fracture patterns need surgical intervention for spinal cord decompression and fracture stabilization. A halo brace can also be used in the management of these patients suffering from cervical fractures.
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Soft or rigid cervical collar, techniques involving spinal traction and fixation are useful if surgical stabilization is delayed. In cervical spine injuries, the use of fiberoptic intubation (a technique for establishing airway access in patients having difficult airways)or the use of a laryngeal mask is suggested to adequately ventilate the patient.
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Intravascular blood volume with blood pressure is also maintained to prevent the spinal cord from ischemia or secondary trauma or injury.
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Various operative methods have been suggested in the past including anterior stabilization, posterior stabilization, and combined anterior and posterior stabilization. Combined anterior and posterior stabilization is the most reliable method than other techniques because of the maximum stability factor.
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Spinal decompression by laminectomy (a surgical operation to remove the back of one or more vertebrae to relieve pressure on nerves) is recommended to rectify the spinal stenosis (narrowing of spaces within the spine).
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Autologous bone graft fragments can also be used along with fixation to stabilize and enhance bone growth.
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Postoperative strict spinal stabilization requires a minimum period of 10 to 15 days. Thereafter, the cervical collar is generally suggested for four to six months.
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If the chalk stick fracture occurs at the disc space, the chance of neurological disorder or injury will be less profound and the prognosis will be good.
Conclusion
Chalk stick fracture of the cervical spine fracture poses a big challenge for healthcare providers. The medical history of ankylosing spondylitis of the cervical spine in the patient makes the situation worse. Standard international protocol for primary management of the injury of the cervical spine is required. Radiographic evaluation by experts along with an assessment of severity on an urgent basis, and quick management can change the outcome and prognosis of the pathology.
