Current Evidence for Diagnosis of Common Conditions Causing Low Back Pain: Systematic Review and Standardized Terminology Recommendations

Abstract

Objective

The purpose of this systematic review is to evaluate and summarize current evidence for diagnosis of common conditions causing low back pain and to propose standardized terminology use.

Methods

A systematic review of the scientific literature was conducted from inception through December 2018. Electronic databases searched included PubMed, MEDLINE, CINAHL, Cochrane, and Index to Chiropractic Literature. Methodological quality was assessed with the Scottish Intercollegiate Guidelines Network checklists.

Results

Of the 3995 articles screened, 36 (8 systematic reviews and 28 individual studies) met final eligibility criteria. Diagnostic criteria for identifying likely discogenic, sacroiliac joint, and zygapophyseal (facet) joint pain are supported by clinical studies using injection-confirmed tissue provocation or anesthetic procedures. Diagnostic criteria for myofascial pain, sensitization (central and peripheral), and radicular pain are supported by expert consensus–level evidence. Criteria for radiculopathy and neurogenic claudication are supported by studies using combined expert-level consensus and imaging findings.

Conclusion

The absence of high-quality, objective, gold-standard diagnostic methods limits the accuracy of current evidence-based criteria and results in few high-quality studies with a low risk of bias in patient selection and reference standard diagnosis. These limitations suggest practitioners should use evidence-based criteria to inform working diagnoses rather than definitive diagnoses for low back pain. To avoid the unnecessary complexity and confusion created by multiple overlapping and nonspecific terms, adopting International Association for the Study of Pain terminology and definitions is recommended.

Introduction

Low back pain (LBP) is a substantial societal problem owing to high prevalence and the many problems associated with cost, chronicity, and disability.1, 2, 3 Despite an intensive research focus on LBP, definitive diagnostic methods are largely unavailable and standard terminology is not yet broadly adopted,⁴ leading researchers and practitioners to classify most LBP as nonspecific.²

Nonspecific LBP represents a heterogenous group of conditions, which may respond differently to available interventions. Some evidence suggests that treatments based on subgroupings of patients with LBP may lead to more effective condition-tailored care.^5,6 The lack of standard diagnostic methods for determining a conclusive diagnosis is due in part to many challenges with definitively confirming symptom sources and the co-occurrence of psychological and social factors that contribute to a person’s lived experience.^7,8 Although identifying symptom sources is difficult in many cases, it is necessary to differentiate benign from ominous conditions and to meaningfully inform management approaches.9, 10, 11

Disparate diagnostic terminology creates potential confusion among both clinicians and researchers. For example, some clinical studies focused on sciatica, radiculopathy, or radicular pain instead report they are focused on discogenic pain.^12,13 However, discogenic pain is defined as pain arising from the intervertebral disc, independent of nerve root involvement.¹⁴ Spinal stenosis, a radiological finding describing a narrowed space, is a term synonymously used for the clinical syndrome of neurogenic claudication.¹⁵ However, spinal stenosis is an anatomical characteristic that may not be associated with symptoms.¹⁶

To address some of the diagnostic challenges for LBP, an evidence-based diagnostic classification system was published in 2013¹⁷; it defined diagnostic categories for neuromusculoskeletal LBP and reported evidence-based criteria supporting a variety of common diagnoses. A novel and practical diagnostic checklist and corresponding exam was also proposed to help practitioners interpret examination evidence to inform evidence-based working diagnoses. However, this classification system did not involve a systematic review of the literature or propose standardized terminology. Furthermore, evidence evolves over time, requiring periodic reevaluation to remain current.

An evidence-based working diagnosis using standardized terminology is needed to systematically explain the most likely biological processes contributing to LBP and to aid communication among providers, payers, and patients. The purpose of this study is to review current diagnostic evidence for office-based (ie, performed in office through examination, evaluating historical characteristics, or questionnaires) evaluation of common neuromusculoskeletal conditions causing LBP and to evaluate the quality and type of evidence of individual studies and systematic reviews focused on this topic. We provide recommendations for terminology use among clinicians and researchers. This systematic review will inform other studies that will offer a pragmatic office-based exam and diagnostic checklist, key aspects of efficient conduct of the exam, practical considerations for determining the relative strength of working diagnoses, and an evidence-based chiropractic treatment decision aid for managing LBP.^18,19