Surreal illustration of spinal fusion with merging vertebrae in blue and gold.

Back Pain Breakthrough: Are All Spinal Fusion Procedures Created Equal?

Avery Sinclair in Health & Wellness August 2025 • 4 min read.

"New research sheds light on the initial stability of different surgical techniques for single-level transforaminal lumbar interbody fusion (TLIF)."

Lower back pain is a widespread problem, and lumbar degenerative diseases are a major cause. When conservative treatments fail, spinal fusion surgery, particularly transforaminal lumbar interbody fusion (TLIF), is a common solution to stabilize the spine and alleviate pain. TLIF involves fusing vertebrae together to eliminate motion and reduce pain.

TLIF has evolved over the years, with surgeons employing various techniques to enhance stability and fusion rates. These techniques include bilateral pedicle screw fixation (BPS), unilateral pedicle screw fixation (UPS), unilateral pedicle screw plus contralateral translaminar facet joint screw fixation (UPS+TFS), and bilateral pedicle screw fixation with bilateral facetectomies (BPS+BF).

While these methods are widely used, questions remain about whether they truly offer different levels of initial stability. A new study has investigated the biomechanical properties of these four TLIF techniques to determine if there are significant differences in their ability to stabilize the spine immediately after surgery.

Decoding Spinal Fusion: What the Research Reveals

Surreal illustration of spinal fusion with merging vertebrae in blue and gold.

Researchers conducted a biomechanical study using six fresh-frozen human cadaveric lumbar spines. They tested the stability of each spine under various loading conditions (flexion, extension, lateral bending, and axial torsion) after applying each of the four TLIF techniques sequentially.

The study measured range of motion (ROM), neutral zone (NZ), and stiffness for each technique and compared them to the intact spine. Here's a breakdown of the key findings:

Range of Motion (ROM): All four techniques significantly reduced ROM in flexion, extension, and lateral bending compared to the natural spine. However, there were no significant differences in ROM between the four surgical procedures.
Stiffness: All four techniques increased the stiffness of the spine compared to the intact spine. BPS showed the most significant increase in stiffness during flexion, extension, and lateral bending.
Axial Torsion: While all techniques reduced ROM in axial torsion, there were no significant differences between the procedures.

The researchers concluded that while all four posterior fixations improve stability in single-segmental TLIF, there isn't a significant difference in the initial biomechanical stability they provide.

The Takeaway: What This Means for Your Back Pain Journey

This research offers valuable insights for both surgeons and patients considering TLIF surgery. While different surgical techniques exist, the study suggests that their initial biomechanical stability is comparable. This means the choice of technique may depend more on the surgeon's expertise, patient-specific factors, and other considerations beyond just achieving immediate spinal stability.

It's crucial to have an open discussion with your surgeon about the potential benefits and risks of each TLIF technique. Understanding the nuances of each approach can empower you to make informed decisions about your back pain treatment.

Further research is needed to evaluate the long-term outcomes and fusion rates associated with each technique. However, this study provides a solid foundation for understanding the immediate biomechanical effects of different posterior fixations in TLIF surgery.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.clinbiomech.2017.08.011, Alternate LINK

Title: Biomechanical Evaluation Of Different Surgical Procedures In Single-Level Transforaminal Lumbar Interbody Fusion In Vitro

Subject: Orthopedics and Sports Medicine

Journal: Clinical Biomechanics

Publisher: Elsevier BV

Authors: Yuanwu Cao, Fubing Liu, Shengcheng Wan, Yun Liang, Chun Jiang, Zhenzhou Feng, Xiaoxing Jiang, Zixian Chen

Published: 2017-11-01

Everything You Need To Know

What are the different techniques of transforaminal lumbar interbody fusion (TLIF) examined in this research?

The study investigated the initial stability of four different surgical techniques used in transforaminal lumbar interbody fusion (TLIF): bilateral pedicle screw fixation (BPS), unilateral pedicle screw fixation (UPS), unilateral pedicle screw plus contralateral translaminar facet joint screw fixation (UPS+TFS), and bilateral pedicle screw fixation with bilateral facetectomies (BPS+BF). These techniques are used to stabilize the spine and alleviate pain in patients with lumbar degenerative diseases.

Why is spinal fusion surgery like TLIF performed, and what does it aim to achieve?

The primary goal of TLIF is to stabilize the spine by fusing vertebrae, which eliminates motion and reduces pain caused by lumbar degenerative diseases. The research indicates that all four techniques, including BPS, UPS, UPS+TFS, and BPS+BF, effectively reduce the range of motion and increase the stiffness of the spine immediately after surgery. This stabilization is crucial for the healing process and pain reduction.

What did the research reveal about the differences in stability among the four TLIF techniques?

The research found that while all four TLIF techniques (BPS, UPS, UPS+TFS, and BPS+BF) improved stability, there were no significant differences in initial biomechanical stability among them. All techniques reduced ROM in flexion, extension, and lateral bending compared to the natural spine. BPS showed the most significant increase in stiffness during flexion, extension, and lateral bending. In axial torsion, all techniques reduced ROM, but there were no significant differences between them.

What key metrics were used to evaluate the effectiveness of the different TLIF techniques?

The study measured Range of Motion (ROM), Neutral Zone (NZ), and stiffness to evaluate the effectiveness of the four TLIF techniques (BPS, UPS, UPS+TFS, and BPS+BF). ROM assesses the amount of movement, NZ indicates the area of minimal resistance, and stiffness measures the spine's resistance to movement under various loading conditions like flexion, extension, and torsion. By comparing these metrics across different techniques and the intact spine, researchers could determine the impact of each procedure on spinal stability.

What are the implications of these research findings for patients and surgeons considering TLIF surgery?

The research suggests that surgeons and patients should consider factors beyond initial biomechanical stability when choosing a TLIF technique. Because the study found no significant differences in initial stability among BPS, UPS, UPS+TFS, and BPS+BF, the choice may depend more on the surgeon's expertise, patient-specific factors, and other considerations that influence long-term outcomes and recovery. This means that patient outcomes are affected by a range of factors beyond just the immediate mechanical stability provided by the chosen technique.