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, Lumbar Vertebra


Related Terms

  • Lumbar Facet Dislocation
  • Lumbar Spine Dislocation
  • Subluxation

Differential Diagnosis

Specialists

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

Factors Influencing Duration

Any associated injuries or complications of the injury or treatment may prolong disability and delay recovery. Inability to modify the work environment during recovery may add to the disability period. Permanent disability may occur if neurologic complications are present.

Medical Codes

ICD-9-CM:
839.20 - Dislocation of Cervical Vertebra, Lumbar Vertebra, Closed
839.30 - Dislocation of Cervical Vertebra, Lumbar Vertebra, Open

Overview

Lumbar vertebra dislocation refers to displacement of one of the lumbar vertebra relative to another in the lumbar spine (low back). Lumbar vertebrae are larger than the vertebrae of the neck region (cervical spine) or upper back region (thoracic spine) and are responsible for supporting body weight along with powerful lumbar muscles.

Dislocation is traumatic, resulting from an impact that causes one vertebra to shift position over the vertebrae below it. The impact may occur because of high-speed deceleration that involves rotation, shear, hyperextension, or flexion forces. The source of the deceleration may be motor vehicle accidents, sports injuries, skiing and diving accidents, blasts, contact with falling objects, violent assault, or falls.

Dislocation, the physiological interruption of the lumbar spine, can be partial (subluxation) or complete. In severe traumatic spine injuries, dislocations may progress to cause more significant damage to the spinal cord (upper lumbar spine) or the lumbar nerve roots (lower lumbar spine). Dislocation is almost always associated with fracture of at least one lumbar vertebral body (usually a compression fracture). Fractures with dislocations (fracture-dislocations) are much more common than dislocation alone.

Dislocations are described by the vertebrae involved. In the lumbar spine, the vertebrae descend from L1 through L5. Lumbar dislocations can also occur between the last vertebra of the thoracic spine, T12, and the first lumbar vertebra, L1. Vertebral dislocations can involve one or both sides of the dislocated vertebral segments (unilateral or bilateral facet dislocation).

All traumatic dislocations are considered to be unstable, meaning nerve injury, or additional nerve injury, may occur if certain activity is permitted before the injury is treated. Immediately after injury careful screening and transportation of individuals with suspected spinal injury is critical.

Although most dislocations can be corrected (reduced) with surgical intervention, the most serious consequence of traumatic dislocation of the lumbar spine is permanent injury to the spinal cord (at the levels of thoraco-lumbar junction and upper lumbar spine) or to the lumbar nerve roots at the lower lumbar levels (cauda equina syndrome). Nerve damage occurs in 10% to 25% of all major spine injuries (Leahy).

Some chiropractic physicians may code cases of back pain as “Dislocation, ICD-9 code 839.20 or 839.21” when x-rays and CT scans do not show a dislocation, as the ICD-9 coding system does not have a code for “subluxation with normal x-rays”. Thus if the ICD-9 code for dislocation is used by a chiropractor, and yet x-rays do not show a dislocation, the case is typical non-specific back pain, and should be evaluated by criteria for ICD-9 code 724.5.

Source: Medical Disability Advisor



Causation and Known Risk Factors

The risk of lumbar vertebra dislocation is highest among individuals who play high-impact contact sports such as football, boxing, or hockey and those involved in motor vehicle accidents or other high-speed or high-impact trauma, including falls, skiing and diving accidents, and injuries from blasts or falling objects. Individuals who have degenerative disc disease or arthritis are also at increased risk for vertebral dislocation. Men are at greater risk (approximately 4 to 1) than women (Leahy), primarily because of men's greater involvement in high-impact sports and automobile accidents involving speed and alcohol (Burke).

Source: Medical Disability Advisor



Diagnosis

History: The individual may report a recent injury, fall, or other accident. Accident victims admitted to emergency settings may be intoxicated or comatose and unable to provide an accurate history. They may require assessment by a trauma team. The nature and mechanics of the accident should be understood, if possible, by questioning witnesses or emergency medical personnel present at the accident site.

Physical exam: Range of motion of the lumbar spine cannot be evaluated if an unstable fracture, fracture dislocation, or a spinal cord or neurologic injury is suspected. The emergency room patient will be examined lying down (supine) and will be evaluated for level of consciousness and presence of multiple injuries, including bleeding, lacerations, contusions, facial and head injuries, chest and abdominal injuries, pelvic fractures, and limb fractures. About 43% of individuals with spinal injuries will have multiple injuries (Leventhal).

With suspected spinal injury, extreme care is needed to avoid further injury to the spine; for this reason, imaging studies such as x-ray (radiography), contrast-enhanced magnetic resonance imaging (MRI), or computed tomography (CT) are usually performed prior to physical examination of the spine itself to determine the extent of fracture and/or dislocation and possible spinal cord injury. Since traumatic dislocations in the lumbar spine rarely realign (reduce) spontaneously, x-ray and CT scan can provide a definitive diagnosis.

Following negative imaging results, physical examination will typically include palpation of the thoraco-lumbar spine and lumbar spine and neurologic examination. Voluntary limb motion and muscle strength of the extremities should also be evaluated to detect evidence of spinal cord or cauda equina injury.

The stability of the lumbar spine is assessed radiographically, and cannot generally be evaluated based on physical examination findings. For the purposes of radiographic assessment of spinal stability, the vertebrae are divided into front (anterior), middle, and rear (posterior) portions or columns; if any two of the three columns are disrupted, the fracture is considered unstable. Dislocations and fracture-dislocations are by definition unstable. The spinal cord may be evaluated using MRI, although in the absence of compression of the cord, contusions to the cord may not be apparent.

Neurologic status may be evaluated by testing of reflexes and sensation (via light touch, pinprick, and proprioceptive response), as well as movement and muscle strength in the lower extremities. Neurologic findings consistent with lumbar spinal cord or cauda equina injury may include weakness or numbness of lower extremities or, in significant spinal injury, paralysis of the extremities, penile erection, and incontinence. Individuals capable of voluntary rectal sphincter and toe contractions show potentially good recovery of motor function.

Tests: Imaging tests such as plain x-rays, contrast-enhanced MRI, CT scans, or, less frequently, CT/myelogram, may be performed emergently to screen for possible spinal cord injury and to allow further assessment. Generally, these studies will be performed after the patient’s condition has been stabilized. Neurologic studies, such as EMG and nerve conduction tests, may be performed later in the course of evaluation and treatment.

Source: Medical Disability Advisor



Treatment

A patient in unstable clinical condition (for example, in shock) will not be treated with spine surgery until the other traumatic injuries have been treated. In acute traumatic injuries, the goals of treatment include protecting the spinal cord or cauda equina from further injury by realignment (reduction) of the dislocation and treating the associated fracture that may be present. The treating physician will decide whether operative or nonoperative treatment is appropriate. This decision will depend on the individual’s overall clinical status and presence of other traumatic injuries.

If a dislocation is associated with a fracture, surgical treatment usually achieves treatment goals most quickly and also enhances future rehabilitation. Closed reduction of a dislocation employs traction to realign the dislocated vertebra; closed reduction is nearly always attempted before open, surgical reduction is performed (DeLee). Open reduction procedures are used when closed reduction fails, for severe injuries or fracture-dislocations, and in cases with neurologic symptoms that indicate certain spinal cord involvement. To maintain stability during healing, wires, screws, rods, and/or plates (internal fixation) may be applied during open reduction, or external traction may be used exclusively. The alternative is to be nursed in the recumbent position for at least 6 weeks for soft-tissue healing, followed by bracing worn whenever the individual is sitting or standing for several additional months, or until the fractures have healed.

Source: Medical Disability Advisor



Prognosis

Dislocations without fracture frequently have a favorable outcome if there are no neurologic complications and successful reduction is achieved through open or closed procedures that regain and maintain stability. Recurrent dislocation is possible, but rare, when extensive soft tissue damage has occurred or in conjunction with fracture. Individuals who have sustained neurologic injury have less positive outcomes. Spinal cord injury can result in paralysis. The severity of neurologic injury determines the prognosis.

Source: Medical Disability Advisor



Rehabilitation

Spinal stability and possible neurologic deficit must be evaluated before a rehabilitation program can begin for dislocation of lumbar vertebrae. The treating physician should be closely involved in guiding the individual through rehabilitation (the treating physician for rehabilitation may differ from the surgeon who managed the case acutely). The type of rehabilitation will depend on the level of injury (upper or lower lumbar spine), the severity of the injury, and whether reduction of the dislocation is accomplished surgically (open reduction) or medically (closed reduction). The presence of other injuries and the period of time the spine may be immobilized following dislocation are also important factors. In spinal injury involving dislocation alone or dislocation with fracture, the primary goal of rehabilitation is to restore mobility and normal functioning and to reduce back pain. Regular use of thermal treatments and other modalities can help manage pain. Physical therapy should begin several weeks after surgery, or after mobilization of the patient. The focus is on increasing the stability and strength of upper and lower trunk muscles since all areas of the spine (cervical and thoracic spine and sacrum) are affected by injury to the lumbar spine; rehabilitation should also include stretching and strengthening exercises for the lower body and limbs, particularly if the lower extremities were affected by the injury (Browner).

Consultation with an ergonomist may help to modify the individual’s work environment to allow an earlier return to work, to provide greater comfort and safety in performing job responsibilities, and to help ensure continued employment.

For spinal cord injury resulting in permanent disability, see Spinal Cord Injury.

Source: Medical Disability Advisor



Complications

Neurologic deficits, including paraplegia, are possible complications of lumbar spine injury. Any underlying disease of the musculoskeletal system, especially those involving ligamentous laxity or affecting bone healing, and muscle strength, may complicate treatment and recovery; associated trauma to other organs or skeletal structures would also affect recovery. Dislocation resulting from an invasive injury (e.g., gunshot wound) can be complicated by systemic infection of the blood (sepsis) or cerebrospinal fluid. Renal or respiratory complications may develop associated with physiological interruption of the spine.

Lumbar vertebra dislocations that do not fully realign are associated with a high incidence of pain and stiffness. Closed reduction of dislocations is successful in about 50% of cases; the other 50% will require open surgical reduction (Leahy). Other complications following surgery to stabilize the lumbar spine include failure to realign the spine and nerve root injury.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

To reduce risk of complications, the individual may not be allowed to work during the early recovery period (first 6 weeks for "soft tissue healing"). Limited sitting, walking, or standing may be required, along with restrictions on worktable height. Wheelchairs or crutches and leg braces may be required that may limit dexterity and mobility. The individual may require frequent breaks or reduced hours of work temporarily.

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 a lumbar vertebra confirmed? Verify that this diagnosis and code is being used correctly for a true dislocation instead of by a chiropractic physician for a case of non-specific back pain.
  • Have neurologic studies and MRI or CT scans been conducted to rule out spinal cord injury?
  • Did individual sustain head injuries? Multiple injuries?
  • Has individual experienced neurologic deficits, including paraplegia, or other complications?
  • Does individual have any underlying condition that may affect recovery?

Regarding treatment:

  • Was closed reduction unsuccessful?
  • Was open reduction performed?
  • Was individual treated with hospitalization in a recumbent position for an extended period of time?
  • Do current x-rays or CT scans show the associated fractures are healed? Have internal fixation devices been placed in correct position? Is there x-ray evidence of broken or loose internal fixation devices?
  • Do current x-rays or CT scans show the dislocation component to be fully reduced?
  • If this is a chronic situation, would individual benefit from a spinal fusion?

Regarding prognosis:

  • Did delayed diagnosis delay reduction?
  • Has malunion occurred?
  • Would individual benefit from spinal fusion? If a fusion was performed, do follow-up x-rays and CT scans confirm that fusion occurred? Is there x-ray evidence of broken or loose internal fixation devices?
  • Did paralysis occur?
  • How has injury impacted function?
  • Has individual received comprehensive rehabilitation?

Source: Medical Disability Advisor



References

Cited

Browner, Bruce. D., et al., eds. Skeletal Trauma: Basic Science, Management, and Reconstruction. 3rd ed. 2 vols. Philadelphia: Elsevier, Inc., 2003.

Burke, D. A., et al. "Incidence Rates and Populations at Risk for Spinal Cord Injury: A Regional Study." Spinal Cord 39 5 (2001): 274-278. National Center for Biotechnology Information. National Library of Medicine. 2 Mar. 2009 <PMID: 11438844>.

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.

Leahy, Michael, and Mark Rahm. "Thoracic Spine Fractures and Dislocation." eMedicine. Eds. Lee H. Riley, et al. 12 Dec. 2007. Medscape. 2 Mar. 2009 <http://emedicine.medscape.com/article/1267029-overview>.

Leventhal, Martin R., and . "Fractures, Dislocations, and Fracture-Dislocations of Spine." Campbell's Operative Orthopaedics. 10th ed. St. Louis: Mosby, Inc., 2003. 1597-1714.

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.