Surgical technique used to provide additional stability at the base of a spinal fusion construct. Screws are placed into the pelvis and connected to spinal instrumentation to strengthen fixation when the lower spine requires increased support.
Quick Facts:
- Provides powerful stabilization at the base of the spine
- Commonly used in long spinal fusion constructs
- Helps reduce stress on S1 screws
- Often used in deformity, revision, and complex fusion surgery
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👉 Pelvic Screw Fixation Information Packet
WHAT IS PELVIC SCREW FIXATION?
Pelvic screw fixation is a technique that anchors spinal instrumentation into the pelvis.
The procedure involves:
- Placement of screws into the pelvic bones
- Connection of pelvic screws to rods extending from the spine
- Creation of a stronger foundation for the fusion construct
Several types of pelvic fixation may be used, including:
- Iliac screws
- S2 alar-iliac (S2AI) screws – our preferred method
- Other specialized pelvic fixation techniques
These implants provide additional support when standard spinal fixation alone may not be sufficient.
👉 The goal is to create a strong, durable foundation for spinal stabilization and fusion.
WHY IS PELVIC SCREW FIXATION PERFORMED?
The lumbosacral junction experiences significant mechanical stress. In some situations, additional fixation into the pelvis improves construct strength and long-term durability.
Common Indications:
- Long-segment spinal fusion
- Adult spinal deformity
- Scoliosis
- Kyphosis
- Revision spinal surgery
- Pseudarthrosis (failure of fusion)
- Sacral fractures
- Tumors involving the lower spine
- High-grade spondylolisthesis
👉 Pelvic fixation is most commonly used when increased support is needed across the lumbosacral junction.
SYMPTOMS AND CONDITIONS THAT MAY REQUIRE PELVIC FIXATION
Common Symptoms
- Low back pain
- Leg pain
- Difficulty standing upright
- Progressive spinal deformity
- Symptoms related to spinal instability
Typical Pattern
- Patients often have complex spinal conditions requiring extensive reconstruction
- Symptoms are usually caused by the underlying spinal disorder rather than the pelvic screws themselves
🚨 Situations Where Additional Stability May Be Especially Important
- Significant spinal deformity
- Multiple prior spine surgeries
- Severe instability
- Long fusion constructs extending to the sacrum
- Poor bone quality
HOW IS THE PROCEDURE PERFORMED?
Step-by-Step Overview
Anesthesia
- Performed under general anesthesia
Exposure
- The lower spine and upper pelvis are exposed through an open or minimally invasive approach
Screw Placement
- Specialized screws are inserted into the pelvis using image guidance, navigation, fluoroscopy, or robotic assistance when appropriate
Rod Connection
- Pelvic screws are connected to the spinal rods
Construct Assembly
- Additional spinal instrumentation is placed as needed
- Alignment correction is performed when indicated
Fusion
- Bone graft is placed to encourage fusion
Closure
- The incision is closed and dressings are applied
👉 Pelvic fixation serves as a strong anchor point for complex spinal constructs.
OUR APPROACH
We consider pelvic fixation whenever long-term stability across the lumbosacral junction is critical.
Factors we evaluate include:
- Number of levels requiring fusion
- Presence of spinal deformity
- Bone quality
- Prior surgeries
- Alignment goals
- Risk of hardware failure
When appropriate, we utilize advanced technologies such as neuronavigation, intraoperative imaging, and neuromonitoring to improve implant accuracy and safety.
👉 Our goal is to create durable spinal stabilization while minimizing the risk of construct failure.
WHAT TO EXPECT
Before Surgery
- MRI and CT imaging
- Standing X-rays
- Evaluation of spinal alignment
- Bone density assessment when appropriate
- Detailed surgical planning
Day of Surgery
- Performed as part of a larger stabilization or fusion procedure
- Surgery length varies depending on the complexity of the condition
After Surgery
- Walking typically begins shortly after surgery
- Recovery depends primarily on the overall fusion procedure
- Activity restrictions may be necessary during healing
- Fusion develops gradually over several months
OUTCOMES & RISKS
Potential Benefits
- Increased construct strength
- Improved spinal stability
- Better support across the lumbosacral junction
- Reduced risk of hardware loosening
- Improved deformity correction
- Enhanced fusion support
Risks
- Infection
- Bleeding
- Nerve injury
- Hardware loosening or failure
- Pain related to instrumentation
- Failure of fusion
- Need for revision surgery
- Implant prominence in thin patients
👉 Pelvic fixation has become an important tool for improving stability in complex spinal reconstruction.
FREQUENTLY ASKED QUESTIONS
What is the difference between pelvic screws and regular spinal screws?
Regular pedicle screws are placed into the vertebrae. Pelvic screws are anchored into the pelvic bones to provide additional support.
Will I be able to feel the pelvic screws?
Most patients do not notice the implants after healing. Occasionally, thin patients may feel hardware prominence.
Are pelvic screws permanent?
In most cases, yes. They are intended to remain in place permanently.
Do pelvic screws limit movement?
Most movement at the pelvis occurs through the hips. Pelvic fixation typically does not create noticeable limitations in daily activities.
Why are pelvic screws used in long fusions?
Long spinal constructs place significant stress on the lowest fixation points. Pelvic fixation helps distribute these forces and reduce the risk of failure.
FOR REFERRING PHYSICIANS
Refer patients with:
- Adult spinal deformity
- Long-segment spinal fusion requirements
- Revision spinal fusion
- Pseudarthrosis
- High-grade spondylolisthesis
- Sacral insufficiency requiring stabilization
Imaging:
- MRI of the affected region
- CT scan when detailed bony anatomy is needed
- Standing scoliosis radiographs
- Bone density evaluation when appropriate
Consider:
- Alignment goals
- Fusion length
- Bone quality
- Risk of lumbosacral construct failure