Surgery Section - Facet Joint Injections

IMPORTANT REMINDER

This Medical Policy has been developed through consideration of medical necessity, generally accepted standards of medical practice, and review of medical literature and government approval status.

Benefit determinations should be based in all cases on the applicable contract language. To the extent there are any conflicts between these guidelines and the contract language, the contract language will control.

The purpose of medical policy is to provide a guide to coverage. Medical Policy is not intended to dictate to providers how to practice medicine. Providers are expected to exercise their medical judgment in providing the most appropriate care.

Description

A facet joint injection is an injection of a long acting local anesthetic agent and/or steroid into the paravertebral facet joint, medial branch nerve or facet joint nerve under fluoroscopic guidance.  Facet joints, also called Zygapophysial or “Z” joints, are located on the posterior spine on each side of the vertebrae where it overlaps the neighboring vertebrae.  The facet joints provide stability and give the spine the ability to bend and twist.  They are made up of two surfaces of the adjacent vertebrae, which are separated by a thin layer of cartilage.

According to the 2005 American Society of Interventional Pain Physicians (ASIPP) guidelines, the prevalence of facet joint pain in patients with chronic spinal pain has been established as 15% to 50% in low back pain, and 54% to 60% in neck pain, utilizing controlled diagnostic blocks.  The guidelines note that, facet joints are involved in approximately 30% of patients with postlaminectomy syndrome or pain following surgery of the spine.  Destabilization of the spinal joints, scar tissue formation, and recurrent disc herniation are the most common causes of late post-spinal surgery pain.  In addition to postlaminectomy syndrome, the most common conditions resulting in facet joint pain are spondylosis, spondylolisthesis, arthritis, osteoarthritis, and spondyloarthritis (facet joint arthropathy).

The ASIPP describes two phases of facet joint injection therapy: the diagnostic and the therapeutic phase.  Diagnostic facet joint injections with a local anesthetic are used in the cervical, thoracic or lumbar spine to verify the specific area generating pain prior to a facet joint denervation procedure or other medical management.  Therapeutic facet joint injections are based on the outcome of a diagnostic facet joint injection with the patient obtaining sufficient relief for a meaningful period of time.  When pain recurs, a repeat injection with long acting local anesthetic and steroid will generally provide pain relief for 4 to 8 weeks.  The intent of the therapeutic injection phase is to provide temporary pain relief to help patients tolerate prescribed exercise programs.

Facet joint injections should not be confused with trigger point injections. Trigger point injections are addressed in Regence Medical Policy, Medicine, Policy No. 39.

Policy/Criteria

1. Either diagnostic or therapeutic facet joint, medial branch nerve and facet nerve injections may be considered medically necessary when performed under fluoroscopic guidance for the management of chronic back or neck pain.  Chronic back or neck pain is defined as pain that has lasted longer than three months despite appropriate non-surgical intervention such as non-steroidal anti-inflammatory medications and physical therapy.  Facet joint and facet nerve injections for the treatment of acute back or neck pain are considered not medically necessary.
2. Frequency and Number of Injections When the Above Criteria are Met:
1. In the diagnostic phase, one injection per level per side in a seven day period may be considered medically necessary to determine the origin of the patient’s pain.  Diagnostic injections in excess of eight per year would rarely be considered medically necessary.  After four injections documentation of medical necessity is required.  Indications supporting more than four diagnostic injections in a 12-month period include:
   1. Pathology involving both cervical and lumbar spine
   2. Bilateral facet joint blocks. The rationale for bilateral injections should be clearly documented in the medical record because bilateral blocks are generally not medically necessary.
2. In the therapeutic phase, one injection per level per side every two months or longer may be considered medically necessary provided that at least 50% pain relief is obtained for six weeks.  The medical record must clearly document responsiveness to prior facet joint injections indicating improvement in physical and functional status.
   1. Therapeutic injections should be limited to a maximum of six per year. 
   2. Treatment in excess of sixteen in a lifetime is rarely medically necessary.  Indications supporting more than sixteen therapeutic injections in a lifetime include:
      1. Pathology involving both cervical and lumbar spine
      2. Bilateral facet joint injections. The rationale for bilateral injections should be clearly documented in the medical record because bilateral blocks are generally not medically necessary.
      3. Recurrence of symptoms at least two years after previous successful facet joint injection treatments.
3. Injection of viscosupplementation agent (i.e., Hyaluronic acid) is considered investigational.
   

Scientific Background

The medical policy, including frequency and number of injections is based on the 2005 guidelines from the American Society of Interventional Pain Physicians (ASIPP) (1) The ASIPP, using a combination of evidence- and consensus-based techniques developed guidelines for facet joint injections for the treatment of chronic cervical, thoracic and lumbar spine pain.

A MEDLINE search of the literature through July 18, 2008 did not return any randomized clinical trials or clinical practice guidelines that alter the criteria for injection of steroid/anesthetic agents.  A pilot study of facet joint injection with Hyaluronic acid for viscosupplementation was conducted on 18 facet joints in 13 patients with symptomatic lumbar facet joint arthritis. (2) Follow-up was at six weeks post-injection. The authors reported no significant improvement in pain or function as measured by Visual Analog Scale or Oswestry Disability Questionairre.

An updated search of the Medline database through July 2007 did not return any new clinical trial data that would alter the policy criteria as written.

References

1. Boswell MV, Trescot AM, Datta S, et al. Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain. Pain Phys 2007;10(1):7-111 online at www.guideline.gov (Verified 7/18/08)
2. Cleary M, Keating C, Poynton AR. Viscosupplementation in lumbar facet joint arthropathy: a pilot study.  J Spinal Disord Tech. 2008;21(1):29-32

Cross References

None

Surgery Section Table of Contents