Fractures Of The L4 L5 Vertebrae

by Brandi Silver

Fractures of L4 and L5 vertebrae are uncommon. L4 and L5 fractures are commonly the result of a high impact trauma from falls or motor vehicle accidents.1 Treatment for L4 and L5 fractures tend to be incident specific and differ from treatments of thoracolumbar and upper lumbar fractures.2

The lumbar vertebrae are the largest and strongest in the spinal column. L4 and L5 verterbrae in addition to there discs account for 50% of lumbar lordosis. L4 and L5 lumbar vertebrae are stabilized by the pelvis, muscle, and ligament attachments. For this reason, a high displacement of force is often needed for these spinal segments to become fractured.2

Indications of L4 and L5 and lumbar fractures in general,consist of having the primary complaint of moderate to severe low back pain, which worsens with movement. If compression of the spinal column is present, then the patient could have cauda equina symptons with complaints of numbness, tingling, weakness, or problems with bowel and bladder. With high trauma impacts, patients cans also experience other assoiciated symptons due to head trauma or lost of consciousness.1

These type of fractures to the lumbar spine are not common and are caused by trauma such as motor vehicle accidents and falls. Men and the elderly populations are more likely to suffer from lumbar fractures.1 Individuals with pathologies such as osteoporosis and tumors that result in weakened bone structure are more susceptible to fractures of the vertebral column. 1 Fractures of the L4 and L5 lumbar vertebrae resulting in neurological or major biomechanical instability is extremely low and is least likey to occur. 2 Osteoporosis accounts for the majority of lumbar compression fractures.3 Osteoporotic wedge compression fractures account for fractures in 75% of women over the age of 65 with scoliosis.3

Clinical Presentation
With the presence of L4 and L5 fractures, the patient's primary complaint will be low back pain that worsens with movement. If the fracture has compressed the spinal nerve root, then the patient could have radiating symptons such as numbness and tingling, into the lower extemeties. Patients with lumbar compression fractures usually present with kyphotic posture that is unlikely to be corrected, hip flexor contractures, and moderate pain at the level of the fracture.3

Potential Etiologies
The following are types of fractures that can occur in the L4 and L5 vertebrae:

Compression Fracture - a break down in the anterior portion of the vertebral body with a loss in height, while the posterior portion of the vertebral body stays intact. This is also known as a stable fracture that in most cases does not present with neurologic deficits. 1
Burst Fractures-these fractures are the result of a high-energy axial load to the spine which are classified according to the amount of vertebral body displacement, vertebral body height, and neurological involvement that detemines if the fracture is unstable.3

Fracture Dislocations-Traumatic Spondylolisthesis-begins as a fracture in the pars interarticularis referred to as spondylolysis. This fracture then widens and the entire vertebrae shifts forward. This usually occurs at L5 which translates forward on the sacrum, resulting in a step deformity.4


Diagnostic Tests

  • Radiography (X-Ray) -This is the standard imaging required to evaluate spine fractures in anteroposterior and lateral views of the lumbar spine. The lateral view displays decrease height in the vertebral body and the anteroposterior view is useful in indicating unstable fractures by displaying increased interpedicular space.3
  • Computed Tomography (CT) scanning-These scans display spinal canal deformities such as narrowing. This is a useful tool in ruling out burst fractures in patients with compression fractures. This imaging is very helpful in displaying the posterior elements laminae of the neural arch.3
  • MRI-This type of imaging is required when a fracture with nerve root compression is suspected and the patient complains of radicular pain. This imaging has the greatest sensitivity in detecting bleeds, tumors, and infections. They also have the ability to display the best nueral images of the spine.3
  • Dual Energy Radiographic Absorptiometry (DRA) scanning-Currently this type of imaging is the most commonly used to observe an individual's amount of bone density.This imaging is most useful in determining if postmenopausal women over the age of 50 and men over the age 50 who are osteoporotic and at an increase risk for low bone density. Low bone density increases the risk of spinal fractures.3

Evaluation/Special Orthopedic Tests
Evaluation and special orthopedic tests for L4 and L5 fractures should consist of a full lumbar exam with overpressure, lower extremity neurologic exam, and a tension test in the form of a straight leg raise to differentiate from a disc injury. The physical therapist should observe the lumbar area for prespiration, warmth, and redness, as well as palpate the lumbar vertebrae to access deformity. If the patient has a fracture, he or she will complain of moderate to severe pain over the fracture site with movement and palpation. Patient may also present with kyphotic posture and radiating numbness and tingling into the lower extremities. Important Note- MOBILIZATION AND MANIPULATIONS ARE CONTRAINDICATED FOR FRACTURES. PHYSICAL THERAPISTS SHOULD REFER THE PATIENT BACK TO THERE ORTHOPEDIC PHYSICIAN FOR FURTHER TESTING AND IMAGING.5

Conservative Treatment
Bed rest and bracing of the lower lumbar spine for a period of 6-12 weeks in a TLSO (thoracic-lumbar-sacral orthosis) brace are forms of consrvative treatment for lumbar fractures.1 Patients with spondylolysis should take a break from their normal activites and wear a back brace, with a gradual return to their normal level of activity.4 Lumbar and abdominal stretching and strenthing helps to reduce pain and strengthen the lumbar spine, as well as the abdominals.4The focus of conservative treatment is to address pain relief, bracing, and rehabilitation.3

Surgery & Post-op Treatment
For individuals with neurologic impairment, open posterior reduction is beneficial in releasing pressure on the nerves.2 In cases of dislocation occurring, cage devices and structual bone grafts should be utilized from an anterior or posterior approach.2 For burst fractures with vertebral body height loss and neurological deficits, postural reduction, open posterior decompression, and pedicle screw system should be utilized for stabilization.2
Physical therapy treatment post surgery focus on mobility and strengthen of the lumbar spine. Physical therapy usually begins with the patient in a TLSO brace (thoracic-lumbar-sacral orthosis). The amount of time each patient spends in their brace depends on the type of fracture. Early mobilization and extension exercises contribute to positive outcomes for lumbar fractures. It is also important for patients to be monitored with X-Ray to track the progression of healing at the fracture site.3

Modalities are a form of non-operative treatment performed by physical therapists in addition to the use of therapeutic exercise. Some forms of modalities that can be used to treat L4 and L5 spinal fractures are superficial heat and cryotherapy.6 Superficial or moist heat assists in relaxing the muscles, increasing blood flow to the area, increases tissue extensibility, and pain relief.7 The moist heat allows the patient to perform stretching and therapeutic exercises that will strengthen their back musculature as well as their abdominals.6 Strengthening of the core muscles creates more support at the fracture site, thus making it more stable. Cryotherapy can also be utilized in the form of an ice pack to decrease blood flow to the area of injury, minimized swelling, and decrease pain. 7 This type of modality requires close monitoring of the patient because peripheral nerve injury and frostbite can occur over the localized areas due to the drop in temperature of the tissues.6 When using moist heat or an ice pack as an adjunct to physical therapy, it is important to ensure that the patient can illicit the appropriate response to hot and cold sensations. Ultrasound is another modality that shows promise in assisting in fracture healing, but more research needs to be done to justify its effectiveness in spinal fractures. Although, the overall research available on ultrasound does support its use at a very low dose to facilitate bone growth and scar tissue healing, there is still a lot of controversy around its use as a form of treatment.7 Due to this, ultrasound may not be fully applicable for use on spinal fractures. If a laminectomy is performed to alleviate the fracture site from compressing a spinal nerve, ultrasound is CONTRAINDICATED as a source of treatment.6 As always, modalities are used as an adjunctive treatment for physical therapy and not as a sole treatment alone that should be used with caution and care.

Additional Web Based Resources

1. American Academy of Orthopedic Surgeons. Fractures of the thoracic and lumbar spine. American Academy of Orthopedic Surgeons Website. Updated February 2010. Accessed November 15, 2010.
2. Robertson P. Fractures of l4 and l5. Spineuniverse Website. Updated April 22, 2010. Accessed November 15, 2010.
3. Sherman A, Razack N. Lumbar compression fracture. EMedicine Website. Updated March 25, 2010. Accessed November 15, 2010.
4. American Academy of Orthopedic Surgeons. Spondylolysis and spondylolisthesis. American Academy of Orthopedic Surgeons Website. Updated October 2007. Accessed November 22, 2010.
5. Banks K, Hengeveld E. Maitland's clinical companion: an essential guide for students. Elsevier Limited; 2010.
6. Malanga G. Physical therapy: tens, ultrasound, heat, cyotherapy. Spineuniverse Website. Updated May 3, 2010. Accessed March 8, 2011.
7. Cameron M. Physical agents in rehabilitation: from research to practice 3rd ed. St. Louis, Missouri: Saunders Elsevier.; 2009.

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