A T12 burst fracture is a severe, high-energy injury to the twelfth thoracic vertebra, located at the thoracolumbar junction. This injury occurs when the vertebral body shatters, or “bursts,” into multiple fragments under extreme compressive force. The primary concern is the potential for bone fragments to displace backward into the spinal canal, threatening the neurological structures housed within. Treatment focuses on stabilizing the spine, relieving any pressure on the nerves, and restoring structural integrity.
Anatomy and Mechanism of the T12 Burst Fracture
The T12 vertebra is located at the thoracolumbar junction, the transition point between the rigid, rib-cage-supported thoracic spine and the more mobile lumbar spine. This area acts as a fulcrum, making it highly vulnerable to traumatic forces, and is the most common site for burst fractures. The T12 vertebra bears a significant amount of the body’s weight and experiences substantial mechanical stress.
A burst fracture typically results from high-velocity axial loading, where a force is directed vertically along the length of the spine. Common causes include falls from a great height or severe motor vehicle accidents. This force drives the intervertebral disc into the vertebral body below, causing the bone to fail in compression.
Unlike a simple wedge or compression fracture, a burst fracture involves the collapse of the anterior and middle columns of the spine. This collapse causes the vertebral body to break into fragments in multiple directions. Crucially, fragments from the posterior wall are often retropulsed, pushed backward into the spinal canal where the spinal cord or nerve roots reside. The extent of bony retropulsion and vertebral body height loss indicates the fracture’s severity and diminishes the structural integrity of the motion segment.
Initial Assessment and Neurological Impact
Initial assessment focuses on determining the fracture pattern, spinal stability, and any neurological compromise. While the diagnostic process begins with X-rays, a Computed Tomography (CT) scan is necessary to fully characterize the fracture. The CT provides detailed visualization of bone fragments, measuring the loss of vertebral height and the extent of bone retropulsion into the spinal canal.
An Magnetic Resonance Imaging (MRI) scan is often performed to evaluate soft tissues and determine overall spinal stability. The MRI is the best tool for assessing the integrity of the Posterior Ligamentous Complex (PLC), a group of ligaments and soft tissue structures along the back of the spine. If the PLC is torn or damaged, the fracture is considered mechanically unstable, which significantly influences treatment decisions.
A detailed neurological examination is performed immediately to assess motor function, sensation, and reflexes below the injury level. Subtle deficits, such as changes in muscle strength or sensation, indicate that the neural elements are affected. Since the spinal cord ends around the T12 or L1 level, a T12 injury can cause symptoms ranging from spinal cord injury to cauda equina syndrome. However, a normal neurological examination does not rule out a severe fracture, as most thoracolumbar injuries lack neurological deficits initially.
Treatment Selection Criteria
The choice between non-operative and operative management is based on criteria derived from the initial assessment. These criteria include the fracture’s stability, the degree of kyphosis (forward angulation), the amount of spinal canal compromise, and the patient’s neurological status.
Non-operative management is reserved for stable burst fractures in neurologically intact patients. Stability requires a preserved Posterior Ligamentous Complex, minimal kyphotic deformity (less than 30 degrees), and less than 50% loss of vertebral body height. This treatment involves immediate immobilization, often with a custom-fitted Thoracolumbar Sacral Orthosis (TLSO) brace, which limits spinal movement and allows the fracture to heal.
Operative management is required for unstable fractures, progressive neurological deficits, or significant spinal canal compromise. An unstable fracture typically involves a compromised PLC or severe kyphosis or canal compromise. The primary goals of surgery are to decompress the neural elements by removing retropulsed bone fragments and to stabilize the spine.
Surgical techniques usually involve posterior instrumented fusion, placing rods and screws above and below the fractured vertebra to stabilize the segment and restore alignment. For severe canal compromise or neurological deficit, a decompression procedure removes bony fragments pressing on the spinal cord or nerves. The choice of surgical approach (posterior or anterior) depends on the specific fracture pattern and the need for optimal decompression and fixation.
Recovery and Rehabilitation
Recovery from a T12 burst fracture is a lengthy process, often taking many months to over a year, regardless of the treatment method. For non-operative patients, the TLSO brace is typically worn for eight to twelve weeks to allow for initial bone healing. After brace removal, the focus immediately shifts to regaining strength and mobility.
For surgical patients, the hospital stay is usually longer, but mobilization often begins within a few days with physical therapy assistance. Long-term recovery depends heavily on the initial neurological status. Patients who were neurologically intact generally have a near-complete recovery, while those with incomplete injuries often see substantial, gradual recovery over a year or more.
Physical therapy is a mandatory component of rehabilitation, focusing on strengthening core muscles, including deep abdominal muscles and back extensors, to provide long-term stability. Therapy also includes gentle range-of-motion exercises and posture education to ensure proper body mechanics. While most patients regain significant function, chronic back pain is a common long-term outcome managed through continued exercise and pain management strategies.