Comparison Between Insertion of Bilateral Straight Cages Versus Unilateral Banana Cage in Lumbar Fusion Surgery

December 17, 2025 updated by: Ahmed Osman Ahmed Mahmoud, Assiut University
- To compare the clinical outcomes of bilateral straight cages and unilateral banana cage insertion in lumbar interbody fusion surgery, assess radiological outcomes, including intervertebral disc height, lumbar lordosis angle, and radiographic evidence of fusion, evaluate the rate of complications, such as cage migration, subsidence, pseudoarthrosis, and adjacent segment degeneration and analyze differences in operative time, blood loss, and length of hospital stay between the two techniques

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Lumbar fusion surgery is a widely utilized procedure for the treatment of a variety of spinal pathologies, including degenerative disc disease, lumbar spondylolisthesis, and spinal instability. Among the surgical techniques available, transforaminal lumbar interbody fusion (TLIF) has gained prominence due to its ability to access the disc space through a posterior approach, reduce neural retraction, and allow for thorough disc removal and interbody cage placement with minimal disruption to the spinal canal.(1)

A critical factor in TLIF procedures is the type and positioning of the interbody cage. Traditionally, bilateral straight cages have been inserted to promote symmetrical load sharing and increase the surface area for fusion. This technique aims to ensure even support of the anterior column and reduce the risk of cage subsidence or pseudarthrosis. On the other hand, unilateral insertion of banana-shaped cages has been introduced as a potentially less invasive alternative that simplifies the procedure while still achieving adequate segmental stability and fusion.(2,3) Despite growing adoption of both bilateral straight and unilateral banana cages, controversy remains regarding their relative biomechanical performance, clinical efficacy, and complication profiles. Factors such as asymmetrical load distribution in unilateral constructs, differences in cage surface area contact, and potential risks for adjacent segment degeneration or cage migration have yet to be definitively resolved through high-quality comparative studies.(4,5) This study protocol aims to compare the outcomes of bilateral straight cage versus unilateral banana cage insertion in lumbar spine fusion surgery. By evaluating parameters such as fusion rate, operative time, blood loss, cage subsidence, and patient-reported outcomes, the study will provide evidence-based insights to guide surgical technique selection and improve long-term outcomes for patients undergoing lumbar spine fusion surgery .(6,7)

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • • Symptomatic discogenic low back pain with Radiological evidence of disc degeneration, instability, or spondylolisthesis

    • Failed medical treatment > 6 months

Exclusion Criteria:

  • • Patients unfit for surgery .

    • Active spinal infection ,Osteoporosis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: People with bilateral straight cages
Procedure: cages in lumbar fusion surgery
A critical factor in TLIF procedures is the type and positioning of the interbody cage. Traditionally, bilateral straight cages have been inserted to promote symmetrical load sharing and increase the surface area for fusion. This technique aims to ensure even support of the anterior column and reduce the risk of cage subsidence or pseudarthrosis. On the other hand, unilateral insertion of banana-shaped cages has been introduced as a potentially less invasive alternative that simplifies the procedure while still achieving adequate segmental stability and fusion
Active Comparator: People with unilateral banana cage
Procedure: cages in lumbar fusion surgery
A critical factor in TLIF procedures is the type and positioning of the interbody cage. Traditionally, bilateral straight cages have been inserted to promote symmetrical load sharing and increase the surface area for fusion. This technique aims to ensure even support of the anterior column and reduce the risk of cage subsidence or pseudarthrosis. On the other hand, unilateral insertion of banana-shaped cages has been introduced as a potentially less invasive alternative that simplifies the procedure while still achieving adequate segmental stability and fusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
success rate of bilateral straight cages in lumbar fusion surgery
Time Frame: 6 months post operative
Percentage of success of bilateral straight cages in lumbar fusion surgery
6 months post operative
Percentage of success of unilateral banana cage in lumbar fusion surgery
Time Frame: 6 months Post operative
6 months Post operative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assiut University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

January 1, 2026

Primary Completion (Estimated)

January 1, 2028

Study Completion (Estimated)

February 1, 2028

Study Registration Dates

First Submitted

November 21, 2025

First Submitted That Met QC Criteria

December 17, 2025

First Posted (Actual)

December 31, 2025

Study Record Updates

Last Update Posted (Actual)

December 31, 2025

Last Update Submitted That Met QC Criteria

December 17, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • type of cages in lumbar fusion

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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