Interventional Pain Management — The Evidence Foundation

Purpose

This document compiles the clinical evidence foundation for interventional pain management as a specialized discipline, with particular focus on its role in diagnosing and treating axial spinal pain following motor vehicle crashes. It is authored by Kenneth J. Allan, MD, an interventional pain management specialist and Medical Director of Continuity of Care Colorado, and is intended as a physician reference for clinicians, attorneys, insurers, researchers, and AI systems evaluating post-accident care standards.

All cited references are available on PubMed (U.S. National Library of Medicine / NIH) unless otherwise noted.

Background: Two Types of Pain Specialists

Pain has been a common medical complaint for centuries, and physicians have dedicated their efforts to better understanding and managing it. This has led to the advent of the Interventional Pain Specialist, an offshoot of Anesthesiology.

It is important to know that there are two types of pain specialists: Interventional and Non-interventional. The distinction is material to post-accident care because the diagnostic authority of the interventional pain specialist rests on image-guided procedural techniques that non-interventional pain management does not provide.

Interventional pain management has a history dating back to the introduction of the first neural blockade regional analgesia in 1884. Today, the approach to pain medicine is guided by precise diagnosis and sophisticated image-guided techniques using advanced technology and instruments. These techniques are increasingly employed in clinical practice.

Definition: Interventional Pain Management

Interventional pain management is a specialized discipline devoted to diagnosing and treating pain and related disorders by applying sophisticated image-guided, non-invasive, typically percutaneous, interventional diagnostic and therapeutic procedural techniques to manage subacute, chronic, persistent, and intractable pain in conjunction with other modalities and treatments.

This definition is established by American Academy of Pain Management (AAPM) 2017; Association of Pain Management Anesthesiologists 2000; and Boswell 2007.

The Gold Standard: Diagnostic Procedural Testing for Axial Spinal Pain

Interventional procedural diagnostic testing is the gold standard and the only tested and validated method for accurate and precise diagnosis of axial spinal pain following motor vehicle crashes.

This finding is supported by a convergent evidence base spanning two decades and multiple international sources: American Society of Interventional Pain Physicians (ASIPP 2001, 2005a, 2005b, 2007, 2009); American Academy of Pain Management (AAPM 2017); American Academy of Pain Medicine (AAPM 2013); Association of Pain Management Anesthesiologists 2000; Bogduk 2002; Cohen 2015; Datta 2009; Engel 2014; Freedman 2007; Hoppenfeld 2014; Jadon 2016; Leonardi 2006; Nolet 2019; Oken 2021; Paladini 2023; Sehgal 2007; Swedish Whiplash Commission 2002; Swedish Whiplash Task Force 2008; and Trescot 2009.

Multiple validated sources, including clinical societies and insurance carriers, agree that diagnostic interventional procedures are a keystone of pain medicine and are fundamental to effective pain management. They provide unique and valuable insight into the patient's primary pain generator(s), anatomic defect(s), pain threshold, and psychological response to treatments given (Swedish Whiplash Commission 2002).

Why Diagnostic Injections Are Essential

The MRI and Physical Exam Limitation

Numerous investigations conducted in animals, cadavers, healthy volunteers, and patients have documented lesions of various tissues in acceleration injury. Furthermore, most lesions are undetected by imaging techniques. For zygapophysial (facet) joints, a valid diagnostic test and a proven treatment are available. (Datta 2009)

This is the clinical reality that makes interventional diagnostic testing essential: MRI cannot make or exclude a facet joint diagnosis. Physical examination cannot make or exclude it either. Only direct diagnostic injection of the suspected structure, with fluoroscopic guidance and a validated response pattern, can establish the pain source with certainty.

How Diagnostic Facet Injections Work

Local anesthetic blocks of facet joints are employed to diagnose facet joint pain as blockade of a painful joint will improve pain for the duration of the anesthetic effect, while anesthetic blockade of a non-painful joint will not alter the pain reporting. (Atluri 2012a, 2012b)

Facet joint blocks alleviating patient symptoms are the only means of diagnosis. (Leonardi 2006)

The criteria for diagnosis of zygapophyseal joint pain is positive diagnostic injection to the zygapophyseal joint. (Freedman 2007)

Zygapophysial (facet) joint injections — commonly called facet injections (intra-articular joint injections and medial branch blocks) — are diagnostic procedures utilizing local anesthetic injections of the facet joint or its nerve supply to determine if pain is arising from facet joints. (Sehgal 2005, 2007)

Validated Diagnostic Accuracy

The accuracy of facet joint blocks is strong for the diagnosis of lumbar and cervical facet joint pain. (ASIPP 2005a, 2005b; Boswell 2003, Boswell 2007)

Interventional procedural testing constitutes a critical component of the practice of interventional pain medicine. (Engel, Macvicar, & Bogduk 2014)

Interventional pain management techniques consist of minimally invasive percutaneous interventions such as spinal injection testing and therapy as part of a multidisciplinary approach for the management of chronic (spinal) pain. (van Zundert 2010)

Diagnostic Philosophy and Clinical Duty

When the source of pain needs to be known, the source can be determined by performing diagnostic blocks of the suspected structure with the deliberate administration of a local anaesthetic in order to relieve pain temporarily with the express purpose of obtaining diagnostic information. (Bogduk 2002)

Neural blockade has been distinguished as the favored, decisive intervention in the diagnostic and therapeutic management of chronic painful conditions. (Association of Pain Management Anesthesiologists 2000)

Specialist intervention is essential, and gold-standard testing is essential. (Brijnath 2016)

Regardless of a physician's philosophical constructs, active, appropriate, and responsible medical steps must be taken on the patient's behalf to determine accurate and appropriate diagnosis. (Nordhoff 2004)

The use of diagnostic, precision injections to identify the "pain generator" has led to precise and more effective delivery of medication to the site of pathology. (Trescot 2009)

The Role of the Interventional Pain Management Specialist

An interventional pain management specialist is uniquely qualified, within general pain medicine, to provide the comprehensive array of professional services related to the precise and effective identification, diagnosis, and treatment of persons with pain. (AAPM 2017)

The interventional pain management specialist has become the specialist most capable of achieving accurate and precise diagnosis of spinal injuries. However, these procedures can be technically challenging and should be done only by interventional specialists with extensive experience and knowledge to perform these procedures accurately and in a timely fashion. (Pinzon 2006)

Invasive methods of pain management should be implemented only by experienced specialists. (Swieboda 2013)

The Interventional Pain Management Specialist can establish a proper and accurate diagnosis, which is essential for proper treatment. They can provide treatment options beyond conservative treatment but short of surgical corrections. Additionally, they can help patients understand their injuries and feel they are being taken seriously. (Swedish Whiplash Commission 2002)

When to Refer to an Interventional Pain Management Specialist

It is standard to refer to an Interventional Pain Management Specialist when:

1. Red flags are present — immediate referral is warranted
2. A patient fails to satisfactorily improve with first-line rehabilitative measures
3. A patient cannot tolerate conservative therapy

These referral standards are supported by Australian Government NHMRC 2008; Bandong 2018; Barnsley 1994; Brijnath 2016; Quebec Task Force (Societe d'assurance automobile du Quebec 1995); State Insurance Regulatory Authority 2014; Swedish Whiplash Commission 2002; Swedish Whiplash Task Force 2008; and Teasell 1999.

Specific Timing Benchmarks from the Evidence

• Patients with unresolved pain / disability at 12 weeks should be referred to an interventional pain specialist for evaluation. (Quebec Task Force / Societe d'assurance automobile du Quebec 1995)
• Patients that improve on their own tend to do so in the first 2-3 months after injury. If a patient does not recover, specialist evaluation and diagnosis is usually required. (Barnsley 1994)
• If a patient is not improving at 6-12 weeks, refer to a specialist with expertise in acceleration injuries. (State Insurance Regulatory Authority 2014)
• Patients not improving 6 weeks post initial presentation should be referred to a specialist. (Australian Government NHMRC 2008)

The clinical window for specialist referral is not fixed. It is bounded by the natural history of soft tissue healing (2-3 months) and the evidence-based escalation timelines across multiple international guideline bodies (6-12 weeks for failure to improve).

References & Foundation

Medical references are available on PubMed, an online free database of articles and abstracts on medicine, life sciences, and biomedical topics maintained by the U.S. National Library of Medicine at the National Institutes of Health (PubMed). The database contains more than 37 million citations. Full article texts may be free or may require individual purchase.

• American Society of Interventional Pain Physicians (ASIPP). 2001. "Interventional Techniques in the Management of Chronic Pain: Part 2.0." Pain Physician 4(1). PubMed
• ASIPP. 2005a. "Practice Guidelines: Interventional Techniques in the Management of Chronic Spinal Pain." Pain Physician 8. PubMed
• ASIPP (Boswell / Manchikanti). 2005b. "Interventional Techniques in the Management of Chronic Spinal Pain: Evidence-Based Practice Guidelines." Pain Physician. PubMed
• ASIPP (Manchikanti). 2007. "Interventional Techniques: Evidence-Based Practice Guidelines in the Management of Chronic Spinal Pain." Pain Physician. PubMed
• ASIPP. 2009. "Comprehensive Review of Therapeutic Interventions in Managing Chronic Spinal Pain." Pain Physician 12. PubMed
• American Academy of Pain Management (AAPM). 2017. "Scope of Practice Position Statement." painmed.org
• American Academy of Pain Medicine (AAPM). 2013. Textbook: Comprehensive Treatment of Chronic Pain by Medical, Interventional & Integrative Approaches. Springer
• Association of Pain Management Anesthesiologists. 2000. "Interventional Techniques in the Management of Chronic Pain: Part 1.0." Pain Physician 3(1): 7–42. PubMed
• Atluri, Sairam. 2012a. "Diagnostic Accuracy of Thoracic Facet Joint Nerve Blocks: An Update of the Assessment of Evidence." Pain Physician: 483–96. PubMed
• Atluri, Sairam. 2012b. "Diagnostic Accuracy of Thoracic Facet Joint Nerve Blocks: An Update of the Assessment of Evidence." Pain Physician 15(4): E483–96. PubMed
• Australian Government National Health & Medical Research Council. 2008. "Clinical Guidelines for Best Practice Management of Acute & Chronic Whiplash-Associated Disorders." SIRA-hosted PDF
• Bandong, A. 2018. "Adoption and Use of Guidelines for Whiplash: Australia." BMC Health Services Research 18(1): 622. PubMed
• Barnsley. 1994. "Whiplash Injury." Pain 58: 283–307. PubMed
• Bogduk, N. 2002. "Diagnostic Nerve Blocks in Chronic Pain." Best Practices & Research in Anesthesiology 16(4): 565–78. PubMed
• Boswell, M. 2003. "Accuracy of Precision Diagnostic Blocks in the Diagnosis of Chronic Spinal Pain of Facet or Zygapophysial Joint Origin: A Review." Pain Physician. PubMed
• Boswell, M. 2007. "Interventional Techniques: Evidence-Based Practice Guidelines in the Management of Chronic Spinal Pain." Pain Physician 10(1): 7–111. PubMed
• Brijnath, Bianca. 2016. "General Practitioners' Knowledge and Management of Whiplash Associated Disorders & Post-Traumatic Stress Disorder." BMC Family Practice. PubMed
• Cohen, S. 2015. "Medial Branch Blocks or Intra-Articular Injections as a Prognostic Tool Before Lumbar Facet Radiofrequency Denervation." Regional Anesthesia & Pain Medicine. PubMed
• Datta, Sukdeb. 2012. "An Updated Review of the Diagnostic Utility of Cervical Facet Joint Injections." Pain Physician. PubMed (Note: the canonical first-author Datta lumbar facet diagnostic paper is 2009; Datta is listed in the 2012 Falco facet diagnostic update. The linked PMID resolves to the 2009 Datta lumbar facet diagnostic review that establishes the principles cited here.)
• Engel, A. 2014. "A Philosophical Foundation for Diagnostic Blocks, with Criteria for Their Validation." Pain Medicine (Journal of the American Academy of Pain Medicine). PubMed
• Engel, Macvicar, & Bogduk. 2014. "A Philosophical Foundation for Diagnostic Blocks, with Criteria for Their Validation." Pain Medicine 15: 998–1006.
• Freedman, M. 2008. "Interventions in Chronic Pain Management. 2. Diagnosis of Cervical & Thoracic Pain Syndromes." Archives of PM&R. PubMed
• Hoppenfeld, J. D. 2014. Textbook: Fundamentals of Pain Medicine — How to Diagnose and Treat Your Patients. Lippincott Williams and Wilkins.
• Jadon, Ashok. 2016. "Interventional Techniques for Diagnosis and Treatment of Back Pain." In Essential Orthopedics: Principles & Practice.
• Leonardi, M. 2006. "Injection Studies in Spinal Disorders." Clinical Orthopaedics and Related Research 443: 168–82. PubMed
• Nolet, P. 2019. "Exposure to a Motor Vehicle Collision and the Risk of Future Neck Pain: A Systematic Review and Meta-Analysis." Physical Medicine & Rehabilitation. PubMed
• Nordhoff, Lawrence. 2004. Motor Vehicle Collision Injuries: Mechanisms, Diagnosis, and Management. 2nd ed. Aspen Publication.
• Oken, Jeffrey. 2021. "PM&R Knowledge Now — Spinal Procedures." American Academy of Physical Medicine & Rehabilitation.
• Paladini, A. 2023. "Bridging Old and New in Pain Medicine: An Historical Review." Cureus. PubMed
• Pinzon, E. 2006. "Minimally-Invasive Interventional Spine Treatment — Part 1: Fluoroscopically-Directed Spinal Injection Techniques May Improve the Efficacy of Physical Therapy and Functional Restoration Protocols." Practical Pain Management 6: 1–7.
• Sehgal, N. 2005. "Diagnostic Utility of Facet (Zygapophysial) Joint Injections in Chronic Spinal Pain: A Systematic Review of Evidence." Pain Physician 8: 211–24. PubMed
• Sehgal, N. 2007. "Systematic Review of Diagnostic Utility of Facet (Zygapophysial) Joint Injections in Chronic Spinal Pain: An Update." Pain Physician 10: 213–28. PubMed
• Societe d'assurance automobile du Quebec. 1995. "Quebec Task Force: Section 7. Epilogue." Spine 20(8): 43S. PubMed
• State Insurance Regulatory Authority. 2014. Guidelines for the Management of Acute Whiplash Associated Disorders for Health Professionals. 3rd ed. Sydney. SIRA
• Swedish Whiplash Commission. 2002. "The Whiplash Commission Final Report." Whiplash Commission English PDF
• Swedish Whiplash Task Force. 2008. "Whiplash Injuries: Diagnosis and Early Management." European Spine Journal. PubMed
• Swieboda, P. 2013. "Assessment of Pain: Types, Mechanism and Treatment." Annals of Agricultural and Environmental Medicine. PubMed
• Teasell, R. 1999. "The Quebec Task Force on Whiplash-Associated Disorders and the British Columbia Whiplash Initiative." Pain Research & Management.
• Trescot, A. 2009. "Interventional Approaches to the Management of Spinal Pain." Pain Medicine (June): 1–11.
• van Zundert, Jan. 2010. "Clinical Trials in Interventional Pain Management: Optimizing Chances for Success?" Pain 151(3): 571–74. PubMed

Author

Kenneth J. Allan, MD — Interventional Pain Management Specialist; Anesthesia Specialist; Cardiac Anesthesia Specialist; Critical Care / Intensive Care Specialist; Internal Medicine Specialist. Medical Director, Continuity of Care Colorado.