A burst fracture is a severe spinal injury occurring when a vertebra is crushed with considerable force. This injury involves significant structural failure of the vertebral body, the large, cylindrical part of the bone that supports the spine. Burst fractures result from high-energy traumatic events, such as motor vehicle accidents or falls from a height, causing an extreme axial load onto the spine. This compromises the vertebral column, leading to spinal instability and potential neurological damage.
What Defines a Burst Fracture
The defining characteristic of a burst fracture is the shattering of the vertebral body into multiple fragments, a crushing that happens in more than one direction. This differs from a simple compression fracture, where the front of the vertebra collapses but the bone remains relatively intact. The intense force, known as an axial load, drives the intervertebral disc into the vertebral body below, causing it to break apart. Burst fractures most commonly affect the thoracolumbar junction, the area between the thoracic and lumbar spine.
A crucial feature is the displacement of bone fragments, termed retropulsion, where pieces of the shattered bone are pushed backward into the spinal canal. This bony debris directly threatens the spinal cord or nerve roots housed within the canal. The fracture involves the failure of both the anterior and middle columns of the spine, classifying it as inherently unstable.
Recognizing the Signs and Symptoms
Patients who sustain a burst fracture experience immediate, severe, localized back pain at the injury site. This pain is often debilitating and worsens with any movement. Given the extreme force involved, the injury must be assumed to be unstable until proven otherwise.
The most concerning signs relate to potential neurological compromise from bone fragments pressing on the spinal cord or nerve roots. Symptoms can include numbness, tingling, or altered sensation in the limbs below the injury level. More severe cases involve muscle weakness, difficulty with motor control, or loss of bowel or bladder function, signaling serious neural injury.
Diagnosis and Neurological Assessment
Diagnosis begins with a thorough physical and neurological examination to check for functional loss. Initial imaging includes X-rays, which assess spinal alignment and bone anatomy, showing the loss of vertebral height. However, X-rays are insufficient for detailed planning due to the fracture’s complexity.
A Computed Tomography (CT) scan is the tool of choice for detailed visualization of bone fragments and their position relative to the spinal canal. The CT scan quantifies the degree of canal compromise and characterizes the bone damage. Magnetic Resonance Imaging (MRI) is subsequently used to evaluate soft tissue structures, such as the spinal cord, surrounding ligaments, and intervertebral discs, which are not clearly seen on a CT scan. A neurological assessment determines the extent of any motor or sensory deficits, which influences the treatment strategy.
Treatment Options for Spinal Stability
The primary goal of treatment is to restore spinal stability, prevent further neurological damage, and minimize long-term deformity. Treatment is divided into non-operative and operative management, based on fracture stability and the patient’s neurological status.
Non-operative management involves immobilization with a rigid back brace. This is reserved for stable fractures with minimal bone fragment displacement and no neurological deficits. This approach allows the bone to heal naturally while restricting movement that could worsen the injury. Bracing is typically worn for 8 to 12 weeks.
Surgery is necessary for unstable fractures, those with significant spinal canal compromise, or any fracture presenting with a neurological deficit. The procedure has two main objectives: decompression and stabilization. Decompression involves removing retropulsed bone fragments or other material pressing on the spinal cord or nerve roots to relieve pressure.
Stabilization is often achieved through spinal fusion, using metal instrumentation like rods and screws to hold the affected vertebrae in a fixed position. A bone graft encourages the vertebrae to fuse into a single, solid bone, providing permanent stability. Some techniques utilize instrumentation without fusion, especially in cases without neurological injury, to stabilize the spine while preserving motion segments.
Recovery and Rehabilitation
Recovery from a burst fracture, whether treated surgically or non-surgically, is a lengthy process. Following the initial period of immobilization or surgery, physical therapy (PT) is an indispensable part of rehabilitation. PT focuses on rebuilding core muscle strength, which acts as a built-in brace to support the healing spine, and restoring flexibility and mobility.
The total recovery timeline varies significantly based on the injury’s severity and the presence of neurological damage. Simple fractures may heal within 8 to 12 weeks. However, complex cases requiring fusion surgery may take six months to a year or longer to reach near-full recovery. Patients must adhere to restrictions on bending, lifting, and prolonged sitting to avoid stressing the healing spine. Long-term outcomes for severe burst fractures can sometimes include chronic pain or persistent neurological deficits, making ongoing management and support important for the patient’s quality of life.