Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Dislocation, Cervical Vertebra


Related Terms

  • Cervical Spine Dislocation
  • Jumped Facets

Differential Diagnosis

Specialists

  • Neurologist
  • Neurosurgeon
  • Occupational Therapist
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist

Factors Influencing Duration

Any complication of the injury or treatment prolongs disability. Associated injuries also delay recovery. Inability to modify the work environment during recovery adds to the disability period. There may be permanent disability with any neurologic deficit.

Medical Codes

ICD-9-CM:
839.00 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Cervical Vertebra, Unspecified
839.01 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, First Cervical Vertebra
839.02 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Second Cervical Vertebra
839.03 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Third Cervical Vertebra
839.04 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Fourth Cervical Vertebra
839.05 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Fifth Cervical Vertebra
839.06 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Sixth Cervical Vertebra
839.07 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Seventh Cervical Vertebra
839.08 - Dislocation of Cervical Vertebra, Closed; Cervical Spine; Neck, Multiple Cervical Vertebrae
839.10 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Cervical Vertebra, Unspecified
839.11 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, First Cervical Vertebra
839.12 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Second Cervical Vertebra
839.13 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Third Cervical Vertebra
839.14 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Fourth Cervical Vertebra
839.15 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Fifth Cervical Vertebra
839.16 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Sixth Cervical Vertebra
839.17 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Seventh Cervical Vertebra
839.18 - Dislocation of Cervical Vertebra, Open; Cervical Spine; Neck, Multiple Cervical Vertebrae
839.40 - Dislocations, Other, Multiple, and Ill-defined, Other Vertebra, Closed, Unspecified Site; Spine NOS
839.50 - Dislocations, Other, Multiple, and Ill-defined, Other Vertebra, Open, Unspecified Site

Overview

Cervical vertebra dislocation refers to the displacement of one of the cervical vertebra relative to another in the cervical spine. Disruption of the supporting ligaments in the cervical spine, usually from trauma or degenerative change, allows one vertebra to shift position over the vertebrae below. This results in a partial dislocation (subluxation) or a complete dislocation of the cervical spine, with possible damage to the spinal cord.

Dislocations are described according to the vertebrae involved; the most common site of cervical dislocation is between C5 and C6. Dislocations of the cervical spine may involve one or both sides of the vertebra (unilateral or bilateral facet dislocation).

Vertebral dislocation may be caused by traumatic injury or by degeneration of discs. Cervical injuries may occur as the result of trauma to the head (axial loading) or trauma to the neck such as extreme extension (head leaning back), extreme flexion (forward motion), or extreme head rotation. Traumatic dislocation of the cervical spine is often associated with fracture and may affect overall alignment of the spine.

Degeneration or herniation of the discs positioned between vertebrae may contribute to cervical instability. Degenerative instability develops over time and may be accompanied by bone spurs that also cause nerve root or spinal cord compression. Degenerative changes and osteoarthritis or rheumatoid arthritis may also lead to chronic subluxation/dislocation of the cervical spine or may complicate dislocation caused by trauma.

Dislocations may be stable or unstable, referring to the degree of mobility. The degree of stability depends on the extent of damage to the supporting ligaments and changes in bony anatomy. Dislocations that occur with trauma may also spontaneously realign (reduce), which may make diagnosis somewhat more challenging. The most devastating consequence of a traumatic dislocation of the cervical spine is injury to the spinal cord, which may include a contusion to the cord, complete breakage (transection), or nerve root injury. This may occur at the time of injury, even if the disc returns to normal alignment. It is possible to have a traumatic dislocation or fracture-dislocation without spinal cord or nerve root injury. Although not all dislocations cause permanent spinal cord damage, careful screening and handling (transportation) of any individual with a neck injury cannot be overemphasized.

Most traumatic cervical spine dislocations or fracture dislocations can be corrected, but surgery may be necessary. Degenerative subluxation or dislocation of the cervical spine may also require surgical treatment.

Incidence and Prevalence: Cervical spine injury occurs in 2% to 4.6% of individuals who have sustained a blunt trauma to the head or neck and results in neurological damage in 40% of injuries (Goodrich). Traumatic spinal injuries, including dislocation of cervical vertebrae, occur primarily to individuals between the ages of 16 and 45. Injuries among men represent 81.5% of all spinal cord injuries (Lin).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Individuals who are at risk for traumatic cervical vertebra dislocation or fracture-dislocation include those who participate in contact sports such as football, boxing, and hockey; those who participate in high-speed sports such as skiing or speed skating; and those who are involved in a motor vehicle accident, fall, or other high-velocity trauma. Degenerative disc disease and osteoarthritis or rheumatoid arthritis may increase the risk of degenerative subluxation or instability of the cervical spine.

Source: Medical Disability Advisor



Diagnosis

History: The individual may report recent acute injury or, as a result of severe trauma, may require assessment by a trauma team. Alternatively, there may be a history of a chronic neck condition. Individuals may report pain, occurring most commonly with neck motion; weakness or tingling in the shoulders and arms; and a sensation of instability in the neck. Individuals may be apprehensive about moving their heads. Temporary paralysis or general weakness, changes in sensation (paresthesia), and flushing or a feeling of warmth after the injury may be reported. Cervical zygapophyseal joint pain is common reported in patients with history of cervical dislocation or subluxation.

Physical exam: In any case of suspected neck injury, and particularly after a traumatic injury, no examination for neck range of motion should be undertaken until screening x-rays have been taken and evaluated.

If x-rays detect no pathology that would make a physical exam dangerous for the patient, the physician may examine the back of the neck with the hands (palpation). Palpation may cause pain, and active and passive range of motion may be markedly decreased. A complete neurologic examination, including testing of reflexes and sensation (light touch, pinprick, and proprioception), may be performed. Voluntary limb motion and muscle strength of the extremities may also be evaluated to detect evidence of spinal cord injury. Neurologic findings of cervical spinal cord injury (e.g., breathing alteration, hand or arm paralysis) may be immediately apparent or may be more subtle in presentation.

Tests: X-rays may include AP and lateral views, an odontoid view (open-mouth), and flexion/extension views. Diagnostic X-Ray guided facet joint blocks can be used to determine the source of facet area pain. If spinal cord injury is a concern, MRI, CT scans, or CT/myelogram may be performed emergently, for further assessment. Neurologic studies, such as EMG and nerve conduction tests, may be performed later in the course of evaluation and treatment.

Further evaluation of rheumatoid arthritis with appropriate laboratory studies (measurement of rheumatoid factor) may also be indicated, particularly in cases of upper cervical spine instability.

Source: Medical Disability Advisor



Treatment

In acute traumatic injuries, treatment aims to protect the spinal cord from further injury by regaining and maintaining stability of the cervical spine. Realignment (reduction) of the dislocation (and fracture if present) may be required and can be performed by closed reduction of the dislocation, using skull traction at 25 to 40 pounds of force (5 pounds per disc space). Closed reduction is almost always attempted before an open surgical reduction is performed (DeLee 801), but if MRI reveals a large disc herniation in addition to the dislocation, surgical reduction may be appropriate. Open reductions are used when closed reduction fails or for severe injuries, dislocations associated with fractures, and cases with worsening neurological symptoms or spinal cord involvement. To maintain stability during healing, wires, screws, and/or plates (internal fixation) are often applied during open reduction to accomplish fusion. External traction or a halo device may also be used.

In more chronic situations associated with degenerative disc disease, osteoarthritis, or rheumatoid arthritis, surgical stabilization may be indicated, with fusion and fixation (arthrodesis). In these cases, surgery may include removal of disc material or decompression of neural elements. The central part of the spinal canal and the spinal cord may be decompressed by removal of the lamina (laminectomy).

Foraminotomies are often performed to further decompress nerve roots.

Source: Medical Disability Advisor



Prognosis

The outcome is favorable for dislocations and fracture-dislocations without neurological complications that are reduced by either an open or closed method and in which stability is regained and maintained. Recurrent dislocation is possible when extensive soft tissue damage or an associated fracture is present. In most cases, however, this complication can be anticipated, and surgical stabilization will be performed. Those individuals who suffer neurologic injury will have a less predictable outcome until their neurologic condition has stabilized. Injury to the cervical spinal cord can result in paralysis and permanent disability.

Dislocation of the upper cervical vertebrae (C1-C2) has a poor prognosis, with trauma often causing brainstem compression, respiratory arrest, and death. Dislocation of the C3-C4 vertebrae is rare but is frequently associated with quadriplegia. Bilateral facet dislocation of C4 through C7 creates instability and is also frequently associated with quadriplegia.

Source: Medical Disability Advisor



Rehabilitation

Prior to initiating rehabilitation for a cervical vertebral dislocation the therapist must ascertain the stability of the cervical spine and the degree of neurological impairment. The individual should be progressed through rehabilitation under the close supervision of the treating physician. The treatment will be based on the type, location, and severity of the injury as well as the protocol of the treating physician. Other factors influencing rehabilitation include operative or nonoperative treatment and length of immobilization following the dislocation (Jackson).

The primary goal of rehabilitation is to decrease neck pain and restore functional abilities. Thermal modalities can be used to control pain. The emphasis of exercise is on stability and strength of the cervical and upper trunk muscles. If the extremities are involved, stretching and strengthening exercises should be incorporated into the rehabilitation program.

If needed, an ergonomist may be helpful in modifying the work environment to enable the individual to remain at work.

Additional information may provide greater insight into the rehabilitation needs of these individuals (Bucholz).

If the residual impairment involves the spinal cord, see Spinal Cord Injury.

FREQUENCY OF REHABILITATION VISITS
Nonsurgical
SpecialistDislocation, Cervical Vertebra
Physical TherapistUp to 12 visits within 6 weeks
Surgical
SpecialistDislocation, Cervical Vertebra
Physical or Occupational TherapistUp to 12 visits within 6 weeks
Guidelines reflect a dislocation that does not result in spinal cord injury.
The table above represents a range of the usual acceptable number of visits for uncomplicated cases. It provides a framework based on the duration of tissue healing time and standard clinical practice.

Source: Medical Disability Advisor



Complications

Neurological deficits, including paralysis and quadriplegia, are possible complications of the injury. Any underlying disease of the musculoskeletal system, especially those affecting ligamentous laxity, bone healing, and muscle strength, will complicate treatment and recovery. Associated trauma to other structures will also complicate treatment and recovery, especially concomitant vertebral fracture. Cervical disc herniations occur with 8.8% of dislocations (Canale, “Fractures,” 1629). Dislocation resulting from an invasive injury (e.g., gunshot wound) can be complicated by systemic infection carried by the blood (sepsis) or cerebrospinal fluid.

Cervical dislocations that do not fully realign are associated with a high incidence of pain, stiffness, and cervical instability. Closed reduction of cervical dislocations is only 50% successful, and the remainder will require an open surgical reduction (Goodrich). Following surgery to stabilize the cervical spine, other complications include failure to realign the spine and nerve root injury.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

To reduce the risk of complications, the individual may not be allowed to work during the early recovery period. Limited use of arms and shoulders, restrictions on work table height, and limited sitting and standing are possible restrictions. Use of a soft or rigid cervical collar, upper body traction, or halo traction devices may be required for several weeks. These traction devices may severely limit dexterity and mobility. The individual may require frequent breaks. Temporarily working reduced hours may be necessary.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Was diagnosis of dislocation of cervical vertebra confirmed?
  • Have neurological studies, MRI scans, or CT scans been conducted to rule out spinal cord injury?
  • Did individual sustain head injuries? Multiple injuries?
  • Has individual experienced neurologic deficit, including paralysis or quadriplegia, or other complications?
  • Does individual have any underlying condition that may affect recovery? Has degenerative disc disease, osteoarthritis, or osteoporosis been diagnosed?

Regarding treatment:

  • Was closed reduction unsuccessful?
  • Was open reduction performed?
  • Was individual treated with external traction weights of greater than 50 pounds?
  • Was individual treated with traction for an extended period of time?
  • If this is a chronic situation, would individual benefit from a spinal fusion and fixation?
  • Is individual wearing a cervical collar or traction device?
  • Has additional surgery been recommended to address cervical instability as a result of chronic disc degeneration associated with osteoarthritis or rheumatoid arthritis?

Regarding prognosis:

  • Did delayed diagnosis delay reduction?
  • Has malunion occurred?
  • Was there damage to the ligaments?
  • Would individual benefit from spinal fusion?
  • Did paralysis occur?
  • How has injury impacted function?
  • Has individual received comprehensive rehabilitation?

Source: Medical Disability Advisor



References

Cited

Bucholz, Robert, and James D. Heckman. Rockwood and Green's Fractures in Adults. 6th ed. Philadelphia: Lippincott, Williams & Wilkins, 2005.

Canale, S. Terry, and James H. Beaty, eds. "Fractures, Dislocations, and Fracture-Dislocations of Spine." Campbell's Operative Orthopaedics. 11th ed. Philadelphia: Mosby Elsevier, 2008. MD Consult. Elsevier, Inc. 11 Sep. 2008 <www.mdconsult.com>.

DeLee, Jesse, and David Drez, eds. "Cervical Spine." DeLee and Drez's Orthopaedic Sports Medicine. 2nd ed. 2 vols. Philadelphia: W.B. Saunders, 2003. 791-840. MD Consult. Elsevier, Inc. 11 Sep. 2008 <www.mdconsult.com>.

Goodrich, Jacob, Thad Riddle, and Samuel Hu. "Lower Cervical Spine Fractures and Dislocations." eMedicine. Eds. Daniel Riew, et al. 1 Jul. 2008. Medscape. 30 Sep. 2004 <http://emedicine.com/orthoped/topic175.htm>.

Jackson, R. S., et al. "Upper Cervical Spine Injuries." Journal of the American Academy of Orthopaedic Surgeons 10 4 (2002): 271-280. National Center for Biotechnology Information. National Library of Medicine. 11 Sep. 2008 <PMID: 15089076>.

Lin, Vernon W., ed. Spinal Cord Medicine: Principles and Practice. New York: Demos Medical Publishing, 2003. National Center for Biotechnology Information. National Library of Medicine. 17 Feb. 2009 <www.ncbi.nlm.nih.gov/books/bv.fogi?rid=spinalcord.section>.

General

Canale, S. Terry, and James H. Beaty, eds. "Rheumatoid Arthritis of the Spine." Campbell's Operative Orthopaedics. 11th ed. Philadelphia: Mosby Elsevier, 2008. 1584-1587. MD Consult. Elsevier, Inc. 11 Sep. 2008 <http://home.mdconsult.com>.

Source: Medical Disability Advisor






Feedback
Send us comments, suggestions, corrections, or anything you would like us to hear. If you are not logged in, you must include your email address, in order for us to respond. We cannot, unfortunately, respond to every comment. If you are seeking medical advice, please contact your physician. Thank you!
Send this comment to:
Sales Customer Support Content Development
 
This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is published with the understanding that the author, editors, and publisher are not engaged in rendering medical, legal, accounting or other professional service. If medical, legal, or other expert assistance is required, the service of a competent professional should be sought. We are unable to respond to requests for advice. Any Sales inquiries should include an email address or other means of communication.