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Cervical Spine Anatomy and Examination

  • Anatomy:
    • The cervical spine contains 7 cervical vertebrae, from which arise 8 nerve roots.
      • The normal cervical spine has a lordotic curvature.
      • Intact functional cervical vertebrae are vital because they protect both the spinal cord and the vertebral artery.
      • Of the 8 nerve roots that arise from the cervical vertebrae, all but 1 (C8) exit above their numbered vertebral body through the vertebral foramina; C8 exits below its numbered vertebral body.
  • Vertebral anatomic structures consist of 2 lamina, 2 arches, 2 pedicles, 2 transverse processes, a spinous process, and a body.
  • C1 and C2 are unique in that C1 (atlas) lacks a vertebral body and C2 (axis) has a bony protrusion on the superior side of the body called the odontoid process.
  • Most flexion and extension occurs at the atlanto-occipital joint, whereas rotation occurs mostly at the atlantoaxial joint .
Signs and Symptoms
Physical Exam
  • The cervical spine provides support and stability to the head while allowing for a wide ROM.
  • A thorough neck examination should evaluate the soft tissues and bony structures while also testing neurologic function.
  • Motor examination:
    • Levator scapulae: Resisted elevation (C3, C4, sometimes C5)
    • Deltoids: Shoulder abduction (C5)
    • Biceps: Arm flexion (C6)
    • Wrist extension (C6)
    • Triceps: Elbow extension (C7)
    • Wrist flexion (C7)
    • Finger extension (C7)
    • Finger flexion and thumb adduction (C8)
  • Deep tendon reflexes:
    • An abnormal reflex response may be indicative of spinal stenosis or nerve root compression.
    • Reflex amplification is a symptom of spinal stenosis with myelopathy, whereas diminished reflexes indicate nerve root compression.
      • Biceps (C5)
      • Brachioradialis (C6)
      • Triceps (C7)
  • Sensation:
    • When tracing abnormal sensation, patients should be asked to be as specific as possible.
    • C2, C3, and C4 sensation should move from the posterior to the anterior neck.
    • C5-T2 has very specific dermatomes on the arm, wrist, and fingers.
      • C5: Lateral shoulder
      • C6: Radial 2 digits
      • C7: Middle finger
      • C8: Ulnar 2 digits
      • T1: Medial forearm
  • Inspection: It is important to evaluate
    • Posture of the head
    • Posture of the body, motion, gait
    • Pain
    • Scars on the anterior or posterior neck
  • Bony palpation: Anterior
    • Note any abnormalities such as tenderness, lumps, asymmetries, or misalignments.
    • May use surface landmarks to localize cervical spine level:
      • Hyoid bone: C3 vertebral body
      • Superior notch of thyroid cartilage: C4 vertebral body
      • 1st cricoid ring: C6 vertebral body (swallowing allows easier palpation.)
      • Carotid tubercle: C6 transverse process (the 2 carotid tubercles of the C6 vertebra should be palpated separately because simultaneous palpation can restrict the flow of both carotid arteries).
      • Trachea: Make sure no deviations are present from the midline and palpate for abnormalities.
  • Bony palpation: Posterior  
    • Occiput:
      • Inion: The lower, most palpable part of the occiput
    • Spinous processes:
      • C7 and T1 are the most prominent.
      • All the spinous processes should be aligned.
      • Any deviation may be secondary to a unilateral facet dislocation.
      • C3-C5 may be bifid.
    • Facet joints: Approximately 2.5 cm lateral to the spinous processes, the most common joint involved in osteoarthritis is C5-C6 .
  • Soft-tissue palpation: Anterior
    • Sternocleidomastoid
    • Parotid gland
    • Lymph nodes
    • Thyroid gland: Symmetric and smooth
    • Carotid pulse
    • Supraclavicular fossa: Palpate for bulges or cervical ribs.
  • Soft-tissue palpation: Posterior
    • Trapezius: Evaluate for lymph nodes, palpable only because of pathologic causes
    • Greater occipital nerves: If palpable, may be secondary to whiplash injury.
    • Ligamentum nuchae: Inion to C7 spinous process
  • ROM:
    • Active ROM is a crucial part of the cervical neck examination and includes flexion, extension, lateral bending, and rotation of the neck.
    • Flexion and extension:
      • 50% occurs between the occiput and C1, and the remainder is distributed from C2-C7.
      • Slightly greater motion occurs at the C5-C6 level.
      • Tests sternocleidomastoid muscle (flexor) and paravertebral extensor and trapezius (extensors).
    • Rotation:
      • 50% occurs between C1-C2, and the remainder is evenly distributed in the remainder of the cervical spine.
      • To examine, rotate the chin 60-80° to the right and left.
      • Tests sternocleidomastoid muscle (primary rotator).
    • Lateral bending:
      • Evenly distributed throughout the cervical spine and usually not a pure movement but, rather, functions in conjunction with rotation
      • To examine, touch the ear to the ipsilateral shoulder without moving the shoulder; normal lateral bending is 45°.
      • Tests scalene muscles.
  • Special maneuvers to help to identify the cause of the cervical spine symptoms:
    • Modified Spurling maneuver:
      • Extend the neck and rotate the head to 1 side as axial pressure is applied.
      • A positive test is specific for cervical root compression but with low sensitivity.
    • Distraction test:
      • Apply vertical traction to the head in slight flexion and extension.
      • Symptoms of compressed nerve roots may regress temporarily.
    • Lhermitte test :
      • Patient flexes head forward.
      • If shooting pain is noted down the arms and/or legs, an anterior compressive lesion may be present.
    • Hoffmann test:
      • Rapidly flex the nail of the middle finger.
      • If muscles of the hand and thumb flex, then a positive sign exists, indicative of an upper motor neuron lesion (myelopathy).
    • Static/dynamic Romberg test:
      • The patient stands with hands out and palms up (arms in 90° of flexion).
      • Proprioceptive deficit is present if the patient loses balance with the eyes closed or if the arms rise slowly above the parallel.
  • Radiography:
    • AP and lateral views are used to screen for most conditions.
    • Oblique views are used to detect facet dislocation and subluxation.
    • The open-mouth view is used to detect odontoid and Jefferson burst fractures (for patients with neck pain who have struck their heads).
    • When viewing radiographs of young children, ossification centers may be present and should not be mistaken for fractures.
  • MRI is used to detect and define disc herniation, facet hypertrophy, or ligamentum flavum hypertrophy that may be impinging on the spinal cord or cervical nerve root foramen.
  • CT is used to define the anatomy of the osseous cervical spinal structures.
Q: What is a commonly made mistake when reading a radiograph of a young child’s cervical spine?
A: Ossification centers may still be present in young children and should not be confused with a fracture.
Q: What does the Hoffmann sign evaluate?
A: The Hoffmann sign evaluates for an upper motor neuron lesion, such as cervical spinal stenosis with myelopathy.

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