Cervical Spine

Anatomy

There are seven cervical vertebrae and the intervertebrale discs are located between each vertebrae.

The ATLAS is the first cervical vertebrae, it supports the head. No intervertebral disc is found between C1 and C2.

AXIS is the second vertebrae, which contains the odontoid process or DENS. This small bone allows the head to rotate.

The 3rd through the 7th cervical vertebrae are similar in design to the 7th vertebrae except the 7th has a large spinous process.

Eight pairs of cervical nerves exit through the C-spine. The first seven pair exit above the vertebrae, while the 8th pair exits through the foramen below C7, above T1.

The cervical and brachial plexus emerge from the C-spine region. The C-plexus from C1 to C4 and the brachial plexus from C5 - C8/T1.

http://www.medmedia.com/o11/111.htm ( C-spine X-rays - normal and with findings)

	Normal C-Spine Lateral X-Ray

 Kinesiology

Flexors of the neck: sternocleidomastoid (SCM), hyoids, scalenus anterior. Extensors of the neck: splenius cervicis, capitis, trapezius. Rotators of the neck: splenius capitis, erector spinae, sternocleidomastoid. Lateral bending of the neck: scalenus anticus and medius.

Approximately 50% of flexion or extension occur between the occiput and C1. The remaining 50% of the ROM occurs at the remaining six vertebrae. Approximately 50% of the rotational ROM occurs between C1 and C2. Lateral bending does not occur as a pure motion.

Cervical Landmarks

Hyoid bone- located anterior to C3 Thyroid cartilage - is inferior to the hyoid in front of C4.

The cartilage is identifiable by the superior notch. "Adam's Apple"- is formed by the hyoid and the thyroid cartilage. Occiput- posterior portion of the skull. Inion - dome shaped bump at the base of the occiput, "bump of knowledge." Mastoid process - large rounded process or the posterior lateral skull. Spinous process - C1 is deep and small, C7 is the largest.

Facet joints - lie deep beneath the trapezius muscles. They feel like small rounded domes. The 4th, 5th, and 6th cervical facets are most often involved in degenerative changes or osteoarthritis.  

Soft  Tissue

Lymph node chain - is located along the medial border of the SCM. These nodes are normally only palpable when enlarged.

Thyroid gland - is located midline in the central portion of the neck anterior to C4 and C5 vertebrae. Carotid pulse - located at the carotid fossa next to C6. Parotid gland - partially covers the sharp angle of the mandible and is only palpable when enlarged.

Soft Tissue Injuries

Contusions

Anterior blow to the larynx or trachea causes immediate apprehension. The pain eases in less than 30 seconds. Persistent symptoms should be evaluated for injury to: larynx, trachea, or thyroid cartilage.

Posterior blows may effect the spinous process and related muscular and ligamentous attachments. Fractures from direct blows are uncommon.

Strains and Sprains

Differentiating between strains and sprains is difficult due to the small anatomical makeup of the cervical region. Violent hyperextension of flexion may cause stretching of the cervical muscles and ligaments. Acute spasm for 24-48 hours is the most common symptom. Beware of symptoms that indicate disk or plexus injury.

Flexion injuries force the vertebral bodies together anteriorly and apart posteriorly.

Extension injuries: The anterior longitudinal ligament holds the vertebral bodies together anteriorly. There is no evidence that the posterior edge of the head gear acts as a lever to further cause hyperextension.

Interspinous ligament is located nearer to the vertebrale body connecting each pair of spinous processes.  

Cervical Disc Disease

 

Special  Evaluation  Tests

A. Distraction test: This test demonstrates what effect neck traction may have in helping a problem. This test will relieve pain if: 1) pain is due to narrowing of the foramen. 2) facet joints are irritated. This test will likely increase ligamentous pain.

B. Compression test: Pushing the cervical vertebrae closer together will result in pain if the foramen are narrow or the facets are irritated.

C. Valsalva test: This test involves holding your breathe and bearing down. This will increase the intrathecal pressures indicating a space occupying lesion. [ DISK ]

Intervertebral Disk

D. Swallowing test: Difficulty in swallowing may be caused by cervical spine pathology. Increased pain or difficulty in swallowing (dysphagia) caused by anterior cervical spine pathology, may include but not be limited to: vertebral subluxations, osteophytes protrusion, soft tissue swelling and or tumors.

 E. Adson's test: This tests the condition of the subclavian artery. An extra cervical rib or tight scalenus muscles may compress the artery. Take the patients radial pulse. Then, abduct, extend and externally rotate the arm. Have the patient take a deep breath and rotate the head towards the affected side. If the pt. has a positive test there will be diminution of the pulse.

(Thoracic outlet syndrome) This test is positive in approx. 20% of the normal population.

F. Vertebral Artery Test: This assesses the flow of the vertebral artery.

The patient is positioned in a supine position. The practitioners’ hands support the head. The head is slowly extended, rotated and laterally flexed. The patient should be observed for dizziness, slurred speech and or loss of consciousness. Any and or all of these findings should be considered positive for partial or complete occlusion of the vertebral artery.

G. Spurling's Sign: Hyperextension with external rotation. Pain to the side of rotation is usually indicative of foraminal stenosis and nerve root irritation.

Test Position: With the patient seated, the examiner places compression on the patients head. Pressure is placed straight down and then repeated with slight lateral flexing to each side. Findings: Pain and or paresthesia into the upper extremity on the side towards the flexion is considered positive. The pain is the result of pressure on the nerve root and will thus correlate with the dermatome. Caution should be considered on patients with osteoarthritis, osteoporosis and congenital cervical stenosis.

H. Foraminal Distraction Test

Same positioning as Spurling’s Test. The practitioner places their hands under the back of the head and cups the chin while applying a distraction force. If the complaints of pain and or symptoms of paresthesia decrease or are eliminated the test would be considered positive. This test should not be performed if cervical instability is suspected.

(Special Tests for Orthopedic Examination, Slack Publishers, Konin, Wiksten, and Isear. 1997 ISBN 1-55642-351-9  

Fractures

 

Axial Compression - The normal lordotic curve that provides for some shock absorption for the c-spine is lost with minimal forward flexion. The axial load forces directly transmit the forces into the vertebral bodies creating a burst type fracture. This is frequently associated with catastrophic neurological injury. The estimated load limit of the C-spine is approx. 750 pounds.    

Forward Flexion - Posterior ligamentous disruption, facet dislocation, possible compression fracture. Facet dislocations are commonly associated with spinal cord trauma. 

Hyperextension - Cord contusion, spinous process fractures, "Clay Shoveler's Fracture", positive symptoms may include etiology that is stenotic in origin.

Cervical Burst Fracture (http://www.medmedia.com/o11/183.htm)

  Cervical Stenosis :

This is the condition, which occurs when the spinal canal is smaller when compared to the canal at other levels or in relation to the vertebral body.

Dr. Joe Torg (Philadelphia) has determined that the ratio of the canal to the body should be approx. 80 %. This is to say that the canal should be at least 80 % of the size of the vertebral body when compared on plain lateral x-ray. However, this is not a condition alone that should exclude an athlete from participation. This finding should be used in conjunction with other symptoms before any decisions are made. Recent studies by Dr. Drew Dossett (Dallas Spine and Kerlan / Jobe LA.) have showed that Torg's findings have little to no relationship to the frequency of injury to the cervical spine. CT scans are more accurate for assessment of bony canal size than plain x-ray or MRI.

http://www.hughston.com/hha/a_12_2_2.htm

                                                     Injuries to the Brachial Plexus

I. Brachial Plexus: C5-T1

A. Anatomy:

1. A nerve plexus is a result of the dividing, reuniting, and intertwining of nerves into a complex network. The plexus is commonly broken down into roots, trunks, cords, divisions and branches.

2. The brachial plexus is made up of nerves that exit the spinal column inferiorly of the vertebrae C5 - T1.  There is also a C8 that exits between the C7 and T1.         

 Reflexes - Dermatomes - Myotomes       

C5 

 1. Primary Motor: Shoulder Abduction, Elbow Flexion

2. Sensation: Lateral Arm

3. Reflex: Biceps

 C6

 1. Primary Motor: Wrist Extension

2. Sensation: Lateral Forearm, Thumb, and Index Fingers

3. Reflex: Brachioradialis

 C7

 1. Primary Motor: Elbow Extension, Wrist Flexion, Finger Extension

2. Sensation: Middle Finger  

3. Reflex: Triceps

C8

 1. Primary Motor: Finger Flexion

2. Sensation: Medial Forearm, Ring, and Small Finger.

3. Reflex: None   

T1

 1. Primary Motor: Finger Abduction, Adduction

2. Sensation: Medial Arm

3. Reflex: None

 B. Types of Injuries to Nerves:

 1. Compression: Will produce nerve injury or ischemia  (local anemia) due to interference with nerve supply. 

 2. Stretch/Traction: Stretching of nerves will produce damage to the epineural vessels.  This is the most commonly found etiology for plexus injuries. 

While nerves in general are able to withstand considerable stretching, the severity of the lesion depends upon the amount of pressure, stretch, and duration of the trauma. Severe trauma may produce nerve root avulsion which is not surgically repairable.

3. Friction: Excessive friction over a nerve bundle or ending will produce damage much like that resulting from excessive heat.   

C. Severity of Nerve Injuries:

    1. Grade 1 (Neuropraxia):

                a. Transitory cessation in function of some of the nerve fibers. 

                b. May result in some muscular weakness.

                c. Total recovery is generally gained quickly. 

   2. Grade 2 (Axonotmesis):

                a. Significant motor weakness.
       
                b. Sensory deficit in the peripheral nerves sometimes lasts 
                greater than 2 weeks.

 3. Grade 3 (Neurotmesis):      

                a. Complete loss of nerve function from the complete destruction of a 
                peripheral nerve.

                b. Characterized by complete motor and sensory deficit for 1 year or longer.  

                c. Should be categorized as a catastrophic injury.             

                http://www.hughston.com/hha/a_12_2_1.htm

 D. Mechanisms of Injury:

          1. A blow that forces the head to one side while the ipsilateral shoulder 
          is depressed. 

          2. Cervical spine hyperextension.

          3. Cervical spine extension, compression, and rotation.

          4. Stretching of the upper trunk.

E. Case Studies:

 1. A 16 year old high school football player was stuck on the anterior aspect of his shoulder with his arm externally rotated and abducted. The blow forced the arm into extension and further external rotation.  Immediate pain and weakness was noted. About ten days later, he sustained another similar incident.  The physical examination revealed atrophy over the supraspinatus muscle, and the shoulder was smaller than the good side.  Strength was 2/5 in the infraspinatus, 4/5 in biceps and deltoid, and 5/5 in other muscle groups. Electrodiagnostic studies showed slowing of the suprascapular nerve and positive currents in the deltoid, biceps, and brachioradialis.  This indicated partial axonotmesis. 

2. Although uncommon, there can be some injuries that occur to the brachial plexus during surgical procedures of the shoulder such as the Putti Platt and Bristow procedures.  Post surgically, complete paralysis of the musculocutaneous nerve was noted in several cases.  A few patients had axillary nerve palsies. There were also a few cases of partial paralysis of the radial, median, and ulnar nerves. A second surgery was necessary in 16 weeks following the initial operation to release or repair nerves that were entrapped by sutures or lacerated during the Bristow or Putti‑Platt procedures. 

 Additional Cervical Spine Case Studies

 http://www.trauma.org/resus/moulagefour/moulagefour.html

 F. Evaluation of Brachial Plexus Injuries:

            1. History of previous injury to the brachial plexus. 

            2. Range of Motion check for the neck and shoulder.  

            3. Tenderness in the supraclavicular fossa

            4. Check reflexes.

            5. Check dermatomes.

            6. Check strength bilaterally.

 G. Specific Test for Brachial Plexus Injuries:

 1. Brachial plexus Tension Test:  With the patient lying supine and fully elevating the shoulders through abduction, and the elbows extended to the point just short of the onset of pain. The patient externally rotates the shoulders to the point just short of the onset of pain.  Supinate the forearm while the examiner supports the shoulder and forearm. The patient flexes and extends the elbow.  Reproduction of symptoms implies problems of cervical origin.

 http://www.depts.washington.edu/anesth/regional/brachialplexusanatomy.html

H. Treatment and Rehabilitation:

 1. Ice, followed by heat, massage, EGS, and stretching.

 2. Ensure that the athlete doesn't return too soon. 

 3. ROM and PRE, Proprioception exercises of the neck, shoulder, elbow, wrist, and hand. 

 4. The use of a neck roll or collar is recommended when returning. 

 5. Selective Electrical Stimulation of Denervated Muscle.

     a. Peripheral nerve injuries most commonly managed by orthopedics, and sports therapists include the axillary nerve and brachial plexus at the shoulder, radial nerve in the midarm, the ulnar nerve at the elbow, and the medial nerve at the wrist. 

     b. Specifically, electrotherapy is used clinically for the following reasons:

1. To exercise and strengthen muscles that are spared following disease or injury.
2. To delay progressive muscular atrophy and fibrosis of denervated muscle until the muscle is reinnervated.

Although denervated muscles go through progressive atrophy, it is still excitable by an electrical current. (only DC current)  Selective stimulation of denervated muscle is made possible by the electrical properties of muscle.