Friday, March 25, 2022

Lumbar Burst Fracture Case File

Posted By: Medical Group - 3/25/2022 Post Author : Medical Group Post Date : Friday, March 25, 2022 Post Time : 3/25/2022
Lumbar Burst Fracture Case File
Eugene C. Toy, MD, Andrew J. Rosenbaum, MD, Timothy T. Roberts, MD, Joshua S. Dines, MD

A 34-year-old male construction worker arrives in the emergency department (ED) after a 25-foot fall at a construction site 3 hours ago. The patient landed on his feet and then fell backwards and was unable to stand after the accident. He is complaining of right ankle and low back pain, as well as numbness and tingling in both legs. He has no prior medical history. On exam, the patient is hemodynamically stable with vital signs within normal limits. His right heel is swollen and tender, but the skin is intact. He has midline tenderness in the upper lumbar spine and substantially decreased sensation to light touch in his bilateral proximal thighs and extending distally. Rectal exam demonstrates decreased rectal tone, as well as decreased but intact perianal sensation. Bulbocavernosus reflex is absent, as are his bilateral patella and Achilles reflexes. Plain films and a computed tomography (CT) are acquired by the ED and are shown in Figure 27–1 .

Lateral plain radiographs
Figure 27–1. Lateral plain radiographs ( left ) of the lumbar spine and an axial CT cut ( right ) of the L1
vertebral body. (Courtesy of Timothy T. Roberts, MD)

 What type of fracture is seen in Figure 27–1?
 What is the most likely mechanism of injury for this fracture?
 What is the next diagnostic step?

Lumbar Burst Fracture                              

Summary: A 34-year-old healthy male construction worker presents to the ED with apparent injuries to his right heel and lower back after a fall from 25 feet. He landed in an upright, standing position. Furthermore, he has evidence of loss of sensation and tingling in his legs and perineal region and substantial weakness in both legs. The lack of a bulbocavernosus reflex (ie, the reflexive contraction of the anal sphincter when the glans penis is pinched or a Foley catheter is pulled) means that the patient is in spinal shock. He was unable to walk after his injury, which may be secondary to spinal cord injury and/or an additional injury to his heel.
  • Spine fracture: This patient has a lumbar spine burst fracture.
  • Common mechanism of injury: Lumbar spine burst fractures are commonly the result of high energy axial loading, most often from a fall from a height or a motor vehicle collision.
  • Next diagnostic step: Neurologic changes in the setting of spinal fracture should warrant magnetic resonance imaging (MRI) to evaluate involvement of the spinal cord and/or roots. Given the high-energy fall, this patient will also need a minimum of an anteroposterior (AP) or posteroanterior (PA) chest x-ray, an AP pelvis x-ray, C-spine imaging (x-rays and/or CT scans), and x-rays of the right ankle, given the heel tenderness and swelling on examination.

  1. Learn how to grade spinal cord injury with regard to sensation and muscle strength.
  2. Understand the definition, diagnosis, and prognosis of spinal shock, and understand its role in the management of patients with acute neurologic injuries.
  3. Know the diagnostic approach to acute injuries of the lumbar spine, and identify “red flags” for serious injuries requiring immediate surgical intervention.


This 34-year-old male sustained an injury to his lumbar spine, based on both the presence of tenderness in the lumbar region and his motor and sensory examination. Additional injuries must be excluded through imaging of the entire spinal axis. Although there are multiple types of spine injuries that could result in the neurologic deficits seen in this patient, the type of mechanism (axial load) and level of neurologic deficit suggest that he has sustained lumbar burst fracture at or around the region of L1. This is confirmed by the lateral radiograph and axial CT shown in Figure 27–1.

    The presence of a neurologic deficit suggests that fracture fragments or displaced soft tissues have compressed or directly injured the spinal cord and/or its roots. This patient’s injury is at the L1 level; the spinal cord typically ends somewhere between the top of L1 and bottom of L2, so this patient could have an injury either to the end of his spinal cord (known as the conus medullaris) or to the nerve roots
traveling to the legs from the conus medullaris (known as the cauda equina). Because the patient demonstrates evidence of spinal shock, however, we can reason that he has likely suffered injury to his conus medullaris. Spinal shock does not occur at injury levels distal to the cord.

    Several other orthopaedic injuries are characteristic of high-energy axial loading mechanisms, including calcaneus fractures, femoral shaft and neck fractures, vertical shear pelvis fractures, and lumbar spine injuries. This patient has a swollen and tender heel, likely consistent with a calcaneus fracture. Further workup and management of this extremity injury is also required.

Lumbar Spine Fracture                                


CONUS MEDULLARIS: The caudal end of the spinal cord, beneath which nerves to the lower extremities and pelvis travel in their individual roots. The conus medullaris is typically located between L1 and L2, although substantial variation in its location emphasizes the importance of locating this structure for every patient undergoing surgery on the upper lumbar spine to verify its location.

CAUDA EQUINA: The collection of nerve roots beneath the conus medullaris that transmit signals from the spinal cord to the lower extremities and pelvis. The nerve roots making up the cauda equina are independently mobile and can thus tolerate a greater degree of spinal canal compression before injury when compared with spinal levels adjacent to the spinal cord itself.

BURST FRACTURE: A type of vertebral fracture characterized by injuries to 2 or 3 “columns” of the vertebrae: the anterior column, including the anterior two thirds of the vertebral body and the anterior longitudinal ligament; the middle column, including the posterior third of the vertebral body and the posterior longitudinal ligament; and the posterior column, including the facet joints, lamina, spinous processes, and interspinous ligaments. Burst fractures may injure the neural elements if the posterior aspect of the vertebral body is pushed backward into the spinal canal. This is known as retropulsion.

COMPRESSION FRACTURE: Similar to burst fractures, these axial loading injuries involve fracture of the vertebral body; however, compression fractures only involve the anterior column or anterior portion of the vertebral body. They are inherently more stable than burst fractures and do not typically result in neurologic deficit, as the fracture does not propagate into the spinal canal.

CHANCE FRACTURE: A spinal injury in which a flexion-distraction mechanism results in injury to all 3 spinal columns. Injuries may propagate through the vertebral bony elements or result in partial or complete ligamentous disruption, with forces instead tearing through the interspinous ligaments and disc space. These injuries have a high incidence of both intra-abdominal and neurologic injuries and are associated with seatbelt restraints during violent deceleration.

SPINAL SHOCK: A temporary state of paralysis, sensory loss, and complete absence of reflexes below the level of a spinal cord injury. Spinal shock typically lasts 24 to 48 hours and ends when cord-mediated reflexes return, specifically the bulbocavernosus reflex.


History and Physical Exam

Lumbar spine trauma is often the result of high-energy mechanisms, and thus all patients should undergo a complete and thorough trauma evaluation. After the patient has been stabilized—both hemodynamically and physically—a complete history must be obtained, including the timing and mechanism of injury, symptoms immediately after the injury and on arrival to the ED, and whether the patient was moved after the initial injury. The practitioner should be wary of progressive neurologic changes, both since the initial injury and throughout the workup period in the ED. Serial examinations are essential.

    After an efficient history is obtained, physical exam should be performed. With the patient supine, motor strength, graded 0 through 5, is tested in the upper and lower extremities. A sensory exam is then performed to define sensory deficits according to nerve root dermatomes. Instructions on how to perform a complete motor, sensory, and reflex testing on patients with suspected spinal injuries are found in the first section of this text, “The Approach to the Orthopaedic Patient.”

    After neurovascular examination of the extremities, the patient is then rolled onto his or her side so that the entire spine can be palpated for regions of tenderness, crepitus, or step-off, and a rectal exam is performed. Log-roll precautions are employed to prevent further injury to a potentially unstable spine. During the rectal exam, the patient is asked whether they can sense that an exam is being performed, rectal tone is evaluated (absent, decreased, or intact), and the patient is asked to bear down as if he or she is having a bowel movement to test volitional contraction of the external sphincter. Finally, the bulbocavernosus reflex is tested by either pinching the glans penis or pulling on the Foley catheter and noting whether the anal sphincter contracts. If a patient has a spinal cord-level injury, has an absent bulbocavernosus reflex, and is less than 48 hours from injury, he or she is considered to be in spinal shock. In such situations, recognize that neurologic deficits may improve or resolve completely. Patients who have a return of this reflex or patients who are more than 48 hours from injury and have complete loss of neurologic function below the level of injury are considered to have a complete spinal cord injury. They are thus unlikely to regain any function below this level. Note that the bulbocavernosus reflex is only relevant for spinal cord-level injuries and not for injuries that affect the cauda equina.


After plain radiographs of the entire spine are obtained, areas of potential injury should undergo further imaging. CT is helpful to define bony injury and plays an essential role in surgical planning. MRI is useful for evaluating spinal cord compression or edema, individual nerve roots, and intervertebral discs and assessing for ligamentous and other soft-tissue injuries. MRI is also helpful in evaluating sequelae from direct injuries such as hematoma formation, which may result in cord compression and neurologic injury.


Initial treatment consists of stabilization, immobilization, pain and spasm control, and possibly administration of steroids. Although its true efficacy is controversial, high-dose intravenous (IV) methylprednisolone may be indicated for patients with nonpenetrating spinal cord injury who have presented within 8 hours of injury. Theoretically, steroids attenuate the deleterious inflammatory processes that lead to secondary nervous injury after primary spinal cord trauma.

    The treatment of lumbar fractures depends on the stability of the fracture. Although the exact definition is disputed, unstable fractures generally include those with marked neurologic compromise or complete 3-column disruption (whether bony or ligamentous) or those at risk of significant progression to deformity.

Nonoperative Treatment

Patients with compression fractures or burst fractures without neurologic injury and with anatomic or near anatomic alignment may be definitely treated in a well-fitted brace. Compression fractures do not generally need surgical stabilization if they have less than 30 degrees of kyphosis or less than 40% to 50% loss of height anteriorly. Stable burst fractures may be treated with the same criteria and should have no greater than 40% of spinal canal compromise by retropulsed bony fragments. Chance fractures may be treated nonoperatively if they are bony in nature and are without significant deformity (ie, result in < 15 degrees of kyphosis). Purely bony, minimally displaced Chance fractures are amenable to nonoperative treatment because the large surface area of cancellous bone involved in the fracture has a significantly greater chance of healing than their equivalent ligamentous ruptures.

Operative Treatment

Generally, patients with unstable burst fractures must undergo surgical decompression and stabilization. Patients with evidence of a neurologic injury with preservation of some function should undergo urgent decompression of compressed neural elements and stabilization of fractured vertebral levels, preferably within 12 hours of the injury to maximize chance of neurologic recovery. Patients without a neurologic injury may require surgical stabilization if imaging demonstrates unsatisfactory alignment or evidence of instability, as defined previously. Chance fractures are inherently unstable and require surgical stabilization if they are ligamentous in nature, accompanied by neurologic compromise, or result in deformity of greater than 15 degrees of kyphosis. All patients with unstable injuries must be immobilized in a brace until they are able to undergo surgery.


27.1 A 44-year-old cab driver is involved in a high-speed, head-on collision. In the ED, he is hemodynamically stable and has full neurologic function of his lower extremities. He is complaining of severe lower back pain. Radiographs and CT imaging are acquired of his lumbar spine. Which of the following findings is indicative of an unstable lumbar burst fracture that may need surgical stabilization?
A. 50% loss of vertebral height at the level of injury
B. 20 degrees of kyphosis at the level of injury
C. 30% of canal compromise
D. Injury to the anterior and middle spinal columns only
E. Injury to the posterior column only

27.2 A 43-year-old woman who fell from a third-floor balcony presents to the ED with bilateral foot numbness as well as 2/5 bilateral extensor hallucis longus (EHL) function and absent plantar flexion. Radiographs demonstrate an L5 burst fracture with 40% retropulsion and 30% loss of height. On further history, the patient states she fell 4 days ago and finally sought care because she was experiencing decreasing sensation in her groin and can no longer void. What is the next most appropriate step in management?
A. IV high-dose corticosteroids
B. Epidural steroid injection
C. Nonsteroidal anti-inflammatory drugs (NSAIDs), bedrest, and appropriate bracing
D. Surgical anterior decompression with fusion
E. Surgical posterior decompressive lumbar laminectomy without fusion

27.3 A 56-year-old male rock climber falls 8 feet from a ledge and lands on his buttocks. He arrives 6 hours later in the ED and complains of lower back pain. He is completely neurologically intact. Imaging of his lumbar spine shows an L3 burst fracture involving both anterior and middle columns with 30% loss of height anteriorly and minimal retropulsion. He has no other injuries. What is the most appropriate treatment for this patient?
A. IV steroids and appropriate bracing
B. Low-dose narcotics, NSAIDs, and appropriate bracing
C. Surgical decompression with fusion
D. Further imaging must be obtained, including an MRI to rule out spinal cord injury
E. Reassurance and activity modification


27.1 A. Lumbar burst fractures are considered unstable and indicate surgical stabilization if they involve all 3 columns, result in > 40% to 50% loss of height or > 30 degrees of kyphosis, or have > 40% canal compromise. Burst fractures by definition are not exclusive to the posterior elements.

27.2 D. Although there are details suggesting that this patient’s burst fracture may be stable (ie, only 40% retropulsion and only 30% loss of height), her progressive neurologic symptoms are indication for surgical intervention. E is incorrect because it does not address the fracture or provide stabilization, as would an anterior decompression and fusion. Local epidural steroids do not address the fracture. IV steroids are controversial; however, they are not indicated greater than 8 hours from injury.

27.3 B. This patient has a stable burst fracture involving only the anterior and middle columns without significant loss of height or angulation. The appropriate treatment is pain control (narcotics are appropriate given his acute painful injury) and brace immobilization. Because the injury is stable and because he has no neurologic disruption, he does not necessarily need surgical stabilization, nor does he need extensive, expensive imaging such as an MRI. The patient may be reassured and should certainly refrain periodically from rock climbing, but requires a minimum of brace immobilization until the fracture has healed.


 Patients with injuries secondary to axial-loading mechanisms should be evaluated for additional associated injuries, such as calcaneus fractures and lumbar burst fractures.

 A careful physical exam, including testing of the bulbocavernosus reflex, gives valuable information about whether neurologic injury has occurred and whether or not the patient is in spinal shock.

 Patients with incomplete neurologic injuries (preservation of motor or sensory function below the level of the injury) should undergo urgent decompression and stabilization of the injury to maximize the likelihood of neurologic improvement or preservation.


Egol KE, Koval KJ, Zukerman JD, eds. Thoracolumbar spine. In: Handbook of Fractures. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2010:123-140. 

Mikles MR, Stchur RP, Graziano GP. Posterior instrumentation for thoracolumbar fractures. J Am Acad Orthop Surg. 2004;12:424-435. 

Singh K, Kim D, Vaccaro AR. Thoracic and lumbar spinal injuries. In: Herkowitz HG, Garfin SR, Eismont FF, Bell GR, Balderson RA, eds. Rothman-Simeone: The Spine. Philadelphia: Saunders Elsevier; 2006:1132-1156.


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