Efficacy and Cost: Benefit Ratio of 0, 1, and 2 Medial Branch Blocks for Lumbar Facet Joint Radiofrequency Denervation

Prospective Randomized Study Comparing 0, 1, and 2 Diagnostic Lumbar Medial Branch (Facet Joint) Blocks Before Radiofrequency Denervation in Patients With Chronic Low Back Pain: A Cost: Benefit Analysis.

Lumbar zygapophysial (facet) joint pain is a common cause of low back pain. Radiofrequency (RF) denervation is an effective and low risk treatment of chronic low back pain of suspected facet joint etiology. Blocks of the medial branches innervating the joints are commonly used to localize the pain and make the diagnosis of facet joint pain.

There is currently no standard number of diagnostic blocks: zero, one, and two blocks have all been utilized. Considering the high false positive and false negative rates of these blocks, the cost: benefit ratio has been questioned. No study to date has examined the practice of diagnostic medial branch blocks before RF denervation.

The purpose of this study is to determine the optimal number of blocks before radiofrequency denervation. Three groups of patients will be studied. In group I, patients will undergo RF denervation based on history and physical exam alone. In group II, patients will undergo RF denervation based on a positive response to a single diagnostic block with local anesthetic. In group III, patients will undergo RF treatment only after a positive screening block and a positive confirmatory block.

Study Overview

• Status: Completed
• Conditions: Low Back Pain
• Intervention / Treatment: Procedure: Radiofrequency denervation of medial branches; Drug: 0.5% bupivacaine; Drug: 2% lidocaine; Procedure: Radiofrequency denervation; Procedure: Radiofrequency denervation; Procedure: Radiofrequency denervation; Procedure: Radiofrequency denervation

Detailed Description

Lumbar zygapophysial (facet) joints are recognized as one of the most common causes of chronic low back pain with an estimated prevalence among patients with LBP ranging from 15% to 40%. Radiofrequency (RF) denervation of facet joints has been utilized as an effective treatment of chronic pain attributed to these joints. Blocks of the medial branches innervating the joints are commonly used to localize the pain and make a diagnosis of lumbar zygapophysial (l-z) joint pain. However, considering the high false-positive rates of these blocks (25-40%), the false-negative rates (8-10%), and the number of blocks necessary to make the diagnosis before treatment, the cost-effectiveness of performing these blocks and the benefit of exposing these patients to additional risks is under question. The risks of RF denervation are so low (equivalent to performing the diagnostic block), some have questioned whether or not any diagnostic facet blocks should be performed before RF lesioning.

The purpose of the study is to determine the optimal number of diagnostic blocks that should be performed before radiofrequency denervation in patients with chronic lower back pain with suspected facet joint etiology.

In this prospective randomized study, we will recruit 150 patients with suspected chronic (l-z) joint pain without neurological symptoms to undergo one of three treatment modalities. In group I, 50 patients will undergo RF denervation based on history and physical exam alone (what we advocate in a recent review article). In group II, 50 patients will receive a single diagnostic block with 0.5% bupivacaine. Those that obtain greater than 50% pain reduction will undergo RF denervation. In group III, 50 patients will receive a block with either 2% lidocaine or 0.5% bupivacaine. Those patients that obtain greater than 50% pain relief with the first block receive a second block with the other local anesthetic. Patients that obtain greater than 50% pain relief with the second block then undergo RF. Patients in any group that obtain less than 50% pain relief with any block exit the study.

• Study Type: Interventional
• Enrollment (Actual): 151
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • District of Columbia
    • Washington, D.C., District of Columbia, United States, 20307
      • Walter Reed Army Medical Center
  • Maryland
    • Baltimore, Maryland, United States, 21287
      • Johns Hopkins Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Axial low back pain unresponsive to conservative treatment measures such as physical therapy, manual therapy and pharmacotherapy
• Duration of pain greater than 6 months

Exclusion Criteria:

• Age younger than 18 years
• Objective evidence (MRI or physical exam findings) of lumbosacral radiculopathy
• Prior radiofrequency treatment
• Significant spinal stenosis or spondylolisthesis
• Previous back surgery
• Uncorrected coagulopathy
• Unstable medical or psychiatric condition
• Pregnancy
• Allergies to local anesthetic

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 1; Radiofrequency lumbar facet joint denervation only if positive response to 2 diagnostic facet blocks.	Procedure: Radiofrequency denervation of medial branches; Radiofrequency of medial branches that innervate the lumbar facet joints; Drug: 0.5% bupivacaine; Diagnostic medial branch block with 0.5% bupivacaine. Blocking the nerves that innervate the facet joints with a long-acting local anesthetic.; Drug: 2% lidocaine; Diagnostic medial branch block with 2% lidocaine. Blocking the nerves that innervate the facet joints with a short-acting local anesthetic.; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation without a diagnostic block; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation only if positive response to 2 diagnostic blocks.; Procedure: Radiofrequency denervation; Lumbar facet radiofrequency denervation if positive response to a single diagnostic facet block; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation without a diagnostic facet block.
Experimental: 2; Radiofrequency lumbar facet joint denervation if positive response to single facet joint block.	Procedure: Radiofrequency denervation of medial branches; Radiofrequency of medial branches that innervate the lumbar facet joints; Drug: 0.5% bupivacaine; Diagnostic medial branch block with 0.5% bupivacaine. Blocking the nerves that innervate the facet joints with a long-acting local anesthetic.; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation without a diagnostic block; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation only if positive response to 2 diagnostic blocks.; Procedure: Radiofrequency denervation; Lumbar facet radiofrequency denervation if positive response to a single diagnostic facet block; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation without a diagnostic facet block.
Experimental: 3; Radiofrequency lumbar facet denervation without a diagnostic facet block.	Procedure: Radiofrequency denervation of medial branches; Radiofrequency of medial branches that innervate the lumbar facet joints; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation without a diagnostic block; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation only if positive response to 2 diagnostic blocks.; Procedure: Radiofrequency denervation; Lumbar facet radiofrequency denervation if positive response to a single diagnostic facet block; Procedure: Radiofrequency denervation; Radiofrequency lumbar facet denervation without a diagnostic facet block.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cost Per Successful Procedure	Total cost per effective treatment at 3-months. Successful procedure defined as greater or equal to 50% pain relief and satisfaction lasting at least 3 months.	3-months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Successful Treatment	Greater or equal to 50% pain relief plus procedural satisfaction lasting at least 3 months. What is being measured is the number of participants with a positive outcome.	3-months postprocedure

Collaborators and Investigators

• Sponsor: Johns Hopkins University
• Investigators: Principal Investigator: Steven P Cohen, MD, Johns Hopkins School of Medicine, Walter Reed Army Medical Center

Study record dates

Study Major Dates

• Study Start: February 1, 2007
• Primary Completion (Actual): January 1, 2009
• Study Completion (Actual): January 1, 2009

Study Registration Dates

• First Submitted: June 6, 2007
• First Submitted That Met QC Criteria: June 7, 2007
• First Posted (Estimate): June 8, 2007

Study Record Updates

• Last Update Posted (Estimate): July 26, 2011
• Last Update Submitted That Met QC Criteria: July 25, 2011
• Last Verified: January 1, 2009

More Information

Terms related to this study

• Keywords: Low back pain of suspected lumbar zygapophysial etiology
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Back Pain; Low Back Pain; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Membrane Transport Modulators; Anesthetics, Local; Voltage-Gated Sodium Channel Blockers; Sodium Channel Blockers; Lidocaine; Bupivacaine
• Other Study ID Numbers: NA_00007158