Comparative Effectiveness of Two Different Approaches to Radiofrequency Ablation of Lumbar Medial Branch Nerves

Not Applicable

Not yet recruiting

• Conditions: Lumbar Spondylosis
• Interventions: Procedure: Radiofrequency ablation of lumbar medial branch nerves.

• Registration Number: NCT06283628
• Lead Sponsor: Milton S. Hershey Medical Center

Brief Summary

The purpose of this voluntary research study is to determine whether the parasagittal approach to lumbar medial branch (LMB) nerve radio frequency ablation (RFA) will have greater efficacy than the traditional approach to lumbar medial branch nerve radio frequency ablation.

Detailed Description

To determine whether the parasagittal approach to lumbar medial branch (LMB) nerve radiofrequency ablation (RFA) will have greater efficacy than the traditional approach to lumbar medial branch nerve radiofrequency ablation.

This will be accomplished by comparing the results between the newly proposed parasagittal approach and the traditional approach of medial branch RFA done on the same patient (different sites) with bilateral low back pain (LBP).

Traditional approach:

The electrode is introduced at a 15-20 degrees' ipsilateral oblique angle to the sagittal plane toward the junction of the superior articular process (SAP) and transverse process (TP) of the vertebral body to target the traversing medial branch nerve. The reason for the proposed angle is to avoid the mamillo-accessory ligament (MAL) that may be ossified in up to 10% of the normal spine and, in such cases, potentially prevent proper coagulation of the medial branch nerve during the RFA procedure.

Parasagittal (new) approach:

Recently, Tran et al. showed that MAL is located more dorsally than it was thought earlier and, therefore, can't interfere with nerve coagulation during the RFA. Consequently, they proposed abandoning the 20-degree angle used for the traditional approach and placing the radiofrequency cannula parasagittally and more dorsally. It is proposed that, in order to achieve maximum nerve coagulation, the electrode should be placed as parallel to the nerve as possible, and placing it parasagittally helps achieve this goal. The remainder of the procedure does not differ from the traditional method.

Study Timeline

• Study First Submitted: 2024-02-21
• Study First Submitted QC: 2024-02-21
• Study First Posted: 2024-02-28
• Status Verified: 2025-02
• Last Update Submitted: 2025-02-25
• Last Update Posted: 2025-02-26
• Study Start: 2025-05-01
• Primary Completion: 2025-12
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 25

Inclusion Criteria

1. Bilateral equally intense axial low back pain
2. Pain duration of ≥ 6 months
3. Three-day average NRS scores of ≥ 3/10
4. Age greater than 18 years
5. Failure of conservative treatment, including nonsteroidal anti-inflammatory medications and physical therapy
6. Positive response to a series of two bilateral diagnostic lumbar medial branch nerve blocks (≥ 80% pain relief). This is the current standard of care.

Exclusion Criteria

1. Radicular pain below the knee
2. Systemic infection or localized infection at the anticipated introducer entry site
3. Pregnancy
4. Allergy to Lidocaine
5. Bleeding dyscrasias
6. Patients unable to give informed consent
7. History of lumbar spine surgery at the affected levels
8. History of previous bilateral lumbar RFA of medial branches within the past six months.
9. Significant comorbid somatization or widespread pain with central sensitization
10. Secondary gain identified due to ongoing legal proceedings or worker's compensation
11. Cognitive impairment
12. Any pre-existing condition at the discretion of the provider that may confound interpretation of results -

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Subjects with traditional approach on the left side and parasagittal approach on the right side.	Radiofrequency ablation of lumbar medial branch nerves.	Patients will undergo bilateral RFA; the left side will be done following the traditional approach, and the right side will be done following the parasagittal approach. Traditional approach is done by placing the electrode at a 20 degrees' ipsilateral oblique angle to the sagittal plane toward the junction of the superior articular process and transverse process of the vertebral body to target the traversing medial branch nerve. The reason for the proposed angle is to avoid the mamillo-accessory ligament that may be ossified in up to 10% of the normal spine and potentially prevent proper coagulation of the medial branch nerve during the RFA procedure. Parasagittal (new) approach: is performed by placing the RF cannula parasagittally and more dorsally. To achieve maximum nerve coagulation, the electrode should be placed as parallel to the nerve as possible, and placing it parasagittally helps achieve this goal. The remainder of the procedure does not differ from the traditional method.
Subjects with traditional approach on the right side and parasagittal approach on the left side.	Radiofrequency ablation of lumbar medial branch nerves.	Patients will undergo bilateral RFA; the right side will be done following the traditional approach, and the left side will be done following the parasagittal approach. Traditional approach is done by placing the electrode at a 20 degrees' ipsilateral oblique angle to the sagittal plane toward the junction of the superior articular process and transverse process of the vertebral body to target the traversing medial branch nerve. The reason for the proposed angle is to avoid the mamillo-accessory ligament that may be ossified in up to 10% of the normal spine and potentially prevent proper coagulation of the medial branch nerve during the RFA procedure. Parasagittal (new) approach: is performed by placing the RF cannula parasagittally and more dorsally. To achieve maximum nerve coagulation, the electrode should be placed as parallel to the nerve as possible, and placing it parasagittally helps achieve this goal. The remainder of the procedure does not differ from the traditional method.

Primary Outcome Measures

Name	Time	Method
The number of patients whose procedure was successful (gained 50% or more reduction in numeric rating pain (NRS) scores).	6 months post-procedure.	The patients will describe the pain intensity using NRS - 11-point numeric rating scale, with 0 means no pain, and 10 - the worst possible pain intensity.

Secondary Outcome Measures

Name	Time	Method
Oswestry Disability index (ODI)	6 months post-procedure.	10 questions assessing the functional impairment by the pain, using a 50 point scale, with 0 meaning no disability, and 50 meaning complete disability.

Trial Locations

Locations (1)

Penn State Hershey College of Medicine; 🇺🇸 Hershey, Pennsylvania, United States