Neck and Back

Fracture of the Thoracic and Lumbar Spine

Anatomy

The spinal column is made up of small bones (vertebrae) stacked on top of one another, creating the natural curves of the back. Between the vertebrae are flat, round, rubbery pads (intervertebral disks) that act as shock absorbers and allow the back to flex or bend. Muscles and ligaments connecting the vertebrae allow motion while providing support and stability for the spine and upper body. Each vertebra has an opening (foramen) in the center and these line up to form the spinal canal. Protected by the vertebrae, the spinal cord and other nerve roots travel through the spinal canal. Nerves branch out from the spinal column through vertebral openings, carrying messages between the brain and muscles. Facet joints align at the back of the spinal column, linking the vertebrae together and allowing for rotation and movement. Like all joints, cartilage covers the surface where facet joints meet.

The spine contains three segments: lumbar, thoracic and cervical. The lumbar spine consists of five vertebrae located in the lower back; lumbar vertebrae are larger because they carry more of the body's weight. The thoracic spine consists of 12 vertebrae and begins at the upper chest, extending to the middle back and connecting to the rib cage. The cervical spine includes the neck and consists of seven small vertebrae, beginning at the base of the skull and ending at the upper chest. Disks in the lumbar spine are composed of a thick outer ring of cartilage (annulus) and an inner gel-like substance (nucleus). In the cervical spine, disks are similar but smaller in size.

Description

The most common spinal fractures occur in the thoracic (midback) and lumbar (lower back) spine, or where the two connect (thoracolumbar junction). A spinal fracture is a serious injury, typically caused by an auto crash, fall from height, or other high-velocity accident. The energy required to severely fracture the spine may also cause spinal cord injury or other damage that requires additional treatment. Men experience fractures of the thoracic or lumbar spine four times more often than women, and seniors who have weakened bone due to osteoporosis are also at increased risk.

Causes

Fractures of the thoracic and lumbar spine are commonly caused by high-energy trauma, such as an automobile accident, fall from great height, sports accident, or a violent act, such as a gunshot wound. Osteoporosis, tumors, or other underlying conditions that weaken bone can also cause a vertebra to fracture, even during normal, daily activities.

There are several types of thoracic and lumbar spine fractures, and classification is based upon pattern of injury and whether or not the spinal cord has also been injured. Identifying the type of fracture can help your physician determine the most appropriate treatment.

Symptoms

The primary symptom of thoracic and lumbar spine fracture is moderate to severe back pain that worsens with movement. If the spinal cord is involved, numbness, tingling, weakness, or bowel/bladder dysfunction may also occur. Following a high-energy trauma (such as an auto accident), the patient may have a brain injury and experience loss of consciousness, and in some instances, the back pain may be overwhelmed by pain from other injuries (distracting injuries). In these cases, emergency responders must proceed under the assumption that a spinal fracture is present.

Emergency Stabilization

During the initial evaluation, it may be difficult to assess the extent of injuries to patients with fractures of the thoracic and lumbar spine. At the accident scene, EMS rescue workers will determine if the patient is conscious and check vital signs, including heart rate and ability to breathe. Once these are stabilized, bleeding and injuries demanding immediate attention will be addressed. The patient must be immobilized in a cervical (neck) collar and backboard before being transported to the hospital emergency room, where a complete evaluation will be performed.

Diagnosis

An emergency room physician will conduct a thorough, head-to-toe examination of the head, chest, abdomen, pelvis, limbs and spine. Neurological status will be determined by evaluating the patient's ability to move, feel and sense the position of all limbs, and testing the patient's reflexes will help determine if there has been any injury to the spinal cord or individual nerves. Following the physical examination, a radiologic evaluation is required. Depending on the extent of the injuries, this may include X-rays, computed tomography (CT), and magnetic resonance imaging (MRI) scans of multiple areas, including the thoracic and lumbar spine.

Once all other life-threatening injuries have been stabilized, the physician will identify the pattern of the fracture and determine the appropriate plan of treatment. What treatment is best and whether or not surgery is required will depend on the fracture pattern and on the treatment required for any other injuries sustained.

Flexion Fracture Pattern

• Compression fracture—While the front (anterior) of the vertebra breaks and loses height, the back (posterior) part of it does not; it is usually stable and rarely associated with neurologic problems.
• Axial burst fracture—The vertebra loses height on both the front and back sides; it is often caused by a fall from a height and landing on the feet.
• Nonsurgical treatment—Most flexion injuries can be treated with or without a brace and activity modification for 6 to 12 weeks. By gradually increasing physical activity and doing rehabilitation exercises, most patients avoid post-injury problems.
• Surgery—Surgery is typically required for unstable burst fractures that have: significant comminution (fracture fragments); severe loss of vertebral body height; excessive forward bending or angulation at the injury site; or significant nerve injury, due to parts of the vertebral body or disk pinching the spinal cord. Surgical treatment should include decompression (laminectomy) of the spinal canal to remove bone or other structures pressing on the spinal cord, and stabilization of the fracture.

Extension Fracture Pattern

• Flexion/distraction (Chance) fracture—The vertebra is literally pulled apart (distraction); this can occur in accidents such as a head-on collision, where the upper body is thrown forward while the pelvis is stabilized by a lap seat belt. Treatment will depend on where the spine fails and whether or not the bones can be fit together again (reduction) using a brace or cast.
• Nonsurgical treatment—Extension fractures that occur only through the vertebral body can typically be treated nonsurgically; these should remain in a brace or cast for 12 weeks, under close observation.
• Surgery—If there is an injury to the posterior (back) ligaments of the spine, surgery is typically necessary. If the fracture falls through the disks of the spine, surgery will be required to stabilize it.

Rotation Fracture Pattern

• Transverse process fracture—This uncommon fracture that usually does not affect stability; it results from rotation or extreme sideways (lateral) bending.
• Fracture-dislocation—This can be an extremely unstable injury involving bone and/or soft tissue in which a vertebra may move off an adjacent vertebra (displaced) as a result of very high-energy trauma. These injuries often cause serious spinal cord or nerve damage.
• Nonsurgical treatment—Transverse process fractures are predominantly treated using a gradual increase in motion, with or without bracing, based on comfort level.
• Surgery—Fracture-dislocations of the thoracic and lumbar spine require stabilization through surgery. The ideal timing of these surgeries is often complicated and may be delayed because of other serious, life-threatening injuries.

Surgical Procedure

The ultimate goal of surgical treatment for fracture of the thoracic and lumbar spine is to achieve adequate reduction (fitting the bones together), relieve pressure on the spinal cord and nerves, and allow for early movement. Stabilizing the spine may require use of devices, such as metal screws, rods and cages. During surgery, your surgeon may use an anterior (front), lateral (side), or posterior (back) approach, or a combination of all three, depending on what is most appropriate for your fracture pattern and individual situation.

Complications

There are several complications associated with fractures of the thoracic and lumbar spine, including pneumonia and pressure sores. Among the most severe complications is a blood clot that develops in the legs, due to patient immobility. These clots can travel to the lungs, resulting in death (pulmonary embolism). Complications can be reduced by early treatment, mechanical methods (lower-leg compression stockings), and medication to protect against clots, as well as proper surgical techniques and postoperative programs.

• Surgical complications—As with any surgery, there are some risks, and these vary from person to person. Many are minor treatable and unlikely to affect your final outcome. Complications specific to surgical treatment for fractures of the thoracic and lumbar spine including: bleeding, infection, spinal fluid leaks, instrument failure and nonunion of the fracture. Discuss potential complications with your surgeon prior to surgery.
  
  In general, elderly patients have higher rates of complications from surgery, as do patients who are overweight, diabetics, smokers, or suffering from multiple medical problems. General, potential risks for cervical spine surgery include: infection, bleeding, injury to nerves or spinal cord, reactions to anesthesia, tearing of the sac covering the nerves (dural tear), need for additional surgery in the future, and failure to relieve symptoms.

Rehabilitation

Regardless of whether the patient receives nonsurgical treatment or surgery, rehabilitation will be necessary after the injury has healed and both inpatient and outpatient physical therapy may be recommended. The goals of rehabilitation are to reduce pain, regain mobility and return the patient to a lifestyle and activities that are as close as possible to those experienced before the injury. Issues with the potential to complicate these goals include: inadequate reduction of the fracture, neurologic injury (paralysis), and progressive deformity. A spine conditioning program or low back exercises may also be recommended.