Preoperative Evaluation of the Spine

CHAPTER PREVIEW

CHAPTER SYNOPSIS:

Careful preoperative evaluation of the spine patient is of paramount importance to the success of the treatment being initiated. This begins with careful history followed by physical examination and appropriate imaging. The physician must have a thorough knowledge of the anatomy of the pathologic area, as well as an understanding of other factors that can complicate these cases such as secondary gain issues. At the conclusion of a thorough history and physical examination, the physician should have been able to significantly narrow the differential diagnoses. Appropriate imaging with plain radiography, magnetic resonance imaging, computerized tomography, and/or myelography can then be obtained to verify the diagnosis and to guide the formation of an appropriate treatment plan.

IMPORTANT POINTS:

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90% of patients with an acute disc herniation causing a radiculopathy will improve with nonoperative management.
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The most common cervical levels that require surgical intervention are C5-6 and C6-7.
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Surgical intervention is much less common for disease in the thoracic spine than in the cervical and lumbar spine with the notable exception of thoracolumbar trauma.
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Mechanical back pain is the most common cause of lumbar spine complaints.
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History and physical examination are the most appropriate first steps in determining the presence of more severe disease such as radiculopathy, myelopathy, or myeloradiculopathy.
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The key to a successful surgical outcome lies first in a careful and thorough preoperative patient evaluation.

CLINICAL PEARLS:

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Although characteristic findings may be associated with pathology at each individual spinal level, some crossover and variability are common.
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Cervical spondylotic myelopathy is of primary concern in patients older than 55 years, and is characterized by a combination of hand “clumsiness” and gait unsteadiness.
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Cervical radiculopathy usually occurs in younger patients and is frequently caused by a disc herniation; this can also occur in patients older than 55 years with cervical spondylosis.
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Patients involved in litigation or workers’ compensation claims may have secondary gain issues that affect their pain and treatment outcome.
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Waddell described five signs to help determine the presence of nonorganic low back pain:
- a.
  
  Pain with axial loading
- b.
  
  Inconsistent performance during examination
- c.
  
  Exaggerated response to physical examination
- d.
  
  Inappropriate diffuse or superficial pain
- e.
  
  Motor or sensory findings that are not consistent with normal anatomy

CLINICAL/SURGICAL PITFALLS:

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The majority of lumbar pain is simple mechanical back pain, but careful examination must be done in every case to confirm that diagnosis.
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A high index of suspicion is necessary for conditions such as cauda equina syndrome, which, although rare, is an indication for urgent diagnosis and surgical intervention.
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Caution should be used when considering issues such as possible secondary gain so as not to miss “red flags” in the history and physical examination that might indicate more serious pathology.
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Advanced imaging should never take the place of a thorough history and physical examination to make a diagnosis of spine pain, but it should be used to confirm that diagnosis and treatment plan.

VIDEO AVAILABLE:

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Preoperative evaluation of the patient with neck or back pain begins with a careful history that is later complemented with physical examination and imaging. Without the intersection of these three areas, prognosis for recovery is sometimes difficult to predict as a physician and even more difficult to explain to the patient. This chapter attempts to elucidate the pertinent data points collected by the astute physician when determining whether an operation is indicated.

When interviewing a patient, it is helpful to remember that the most common reason to miss work is neck and low back pain. Although missing work may be a secondary gain issue for some patients, it is also useful to remember that greater than 90% of patients with symptomatic degenerative spine diseases are successfully treated with nonoperative management. So what historical complaints should prompt consideration for early imaging or laboratory studies? Historical complaints such as fever, alcohol or drug use (especially intravenous drug use), unexplained weight loss, bowel or bladder dysfunction, trauma, osteoporosis, cancer, and age older than 50 years are red flags that may indicate a more serious underlying condition. Although less common than degenerative conditions, possible diagnoses associated with the above listed “red flags” could include infection, tumor, osteoporotic fracture, or cauda equina syndrome.

SPINE ANATOMY

Basic anatomic knowledge is required for the physician to visualize the intersection of history and physical examination, and to understand the pathology demonstrated on imaging studies. This chapter is limited in length, and thus cannot cover every facet of history or physical examination; as such, we mainly focus on the most common considerations expected with cervical and lumbar pathology.

The vertebral column is made up of 33 vertebrae and 31 paired spinal nerves ( Fig. 1–1 ). Each vertebral segment from C3 to L5 consists of a vertebral body, two pedicles, a lamina, two transverse processes, and one spinous process. Each vertebral body from C2 to S1 is separated by an intervertebral disc. Notable differences to the C3 to L5 anatomy include the occipitocervical junction, C1-2 bony anatomy and unique articulation, the sacrum, and the coccyx.

The cervical spine has seven vertebra and eight pairs of spinal nerves that exit in the neural foramina above the pedicle of the named vertebral level with the exception of C8, which exits below the C7 pedicle. The remainder of the caudal spinal nerves exit below their named vertebral level through the neural foramen including the 12 thoracic, 5 lumbar, and 5 sacral paired spinal nerves. Although there are four coccygeal vertebrae, only one pair of coccygeal nerves exists.

The neural anatomy can be broken down into the different motor and sensory tracts that convey information through the spinal cord. From a physical examination standpoint, it is useful to know the difference between upper and lower motor neurons, as well as how to grade motor strength and deep tendon reflexes ( Tables 1–1 and 1–2 ). Anterior horn cells in the spinal cord and spinal nerves make up lower motor neurons, whereas the remainder of the spinal cord and the brain contains upper motor neurons. Differentiating upper from lower motor neuron disease is essential to the spine surgeon because it may direct imaging studies to other areas and may detect pathology other than the complaint that brought the patient to the office. Upper motor neuron disease is characterized on physical examination by hyperactive reflexes, increased tone or spasticity, late muscular atrophy, and no muscular fasciculations ( TABLE 1-3 ). This is in contrast with lower motor neuron disease, which has diminished or absent reflexes, decreased tone, early muscle atrophy, and fasciculations.

TABLE 1-1

Grading Motor Function

Grade	Description
0	No palpable/visible contraction
1	Muscle flicker
2	Movement with gravity eliminated
3	Movement against gravity with full range of motion
4	Movement against gravity and some resistance
5	Movement against full resistance