BACKGROUND CONTEXT: The North American Spine Society's (NASS) Evidence Based Clinical Guideline for the Diagnosis and Treatment of Low Back Pain features evidence-based recommendations for diagnosing and treating adult patients with nonspecific low back pain. The guideline is intended to reflect contemporary treatment concepts for nonspecific low back pain as reflected in the highest quality clinical literature available on this subject as of February 2016. PURPOSE: The purpose of the guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for adult patients with nonspecific low back pain. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition. STUDY DESIGN: This is a guideline summary review. METHODS: This guideline is the product of the Low Back Pain Work Group of NASS' Evidence-Based Clinical Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members utilized NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person rate expert opinion when necessary. The draft guideline was submitted to an internal and external peer review process and ultimately approved by the NASS Board of Directors. RESULTS: Eighty-two clinical questions were addressed, and the answers are summarized in this article. The respective recommendations were graded according to the levels of evidence of the supporting literature. CONCLUSIONS: The evidence-based clinical guideline has been created using techniques of evidence-based medicine and best available evidence to aid practitioners in the diagnosis and treatment of adult patients with nonspecific low back pain. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flowchart, suggestions for future research, and all of the references,

Local glucocorticoid injections are often used to treat joint, soft tissue, or spinal pain, but the systemic side effects associated with these injections are poorly understood and not well recognized. There are significant known risks to systemic administration of glucocorticoids. However, there are no guidelines that address issues of systemic absorption, overall systemic risks, or other side effects of locally injected glucocorticoids. For this review, a literature search was performed, and the available evidence on systemic absorption and clinical side effects of intra‐articular and epidural glucocorticoids was synthesized. The goal was to improve clinical understanding of risks associated with these injections. Existing data suggest there is significant individual variability in the amount of systemic absorption and clinical effects of locally injected glucocorticoids. However, it is clear that both intra‐articular and epidural injections can have systemic effects for weeks and that complications may be associated with their use, including Cushing syndrome, loss of bone density, infection, and hyperglycemia. The concurrent use of oral steroids, the number of injections, and the type and dose of glucocorticoids used all are important considerations in estimating risks. The total dose calculation of cumulative glucocorticoid exposure should include all local injections. Caution should be exercised when local glucocorticoid injections are used in higher risk patients, such as postmenopausal women, people with diabetes, and those considering surgery in the near term. Better provider awareness of possible systemic risks should improve decision making and informed consent with patients when considering intra‐articular and epidural steroid injections for painful conditions. Level of Evidence IV

Piriformis syndrome is a form of sciatica caused by compression of the sciatic nerve by the piriformis muscle. It is a relatively uncommon, but not insignificant, cause of sciatica. The diagnosis of piriformis syndrome is complicated by the large differential diagnosis of low back and buttock pain with many diagnoses having overlapping symptoms. This narrative review highlights the relevant anatomy, history, physical exam maneuvers, electrodiagnostic findings, and imaging findings that are used to diagnose piriformis syndrome. Also discussed are posterior gluteal myofascial pain syndromes that mimic piriformis syndrome. The review then outlines the different treatment options for piriformis syndrome including conservative treatment, injections, and surgical treatment. In addition, it provides the reader with a clinical framework to better understand and treat the complex, and often misunderstood, diagnosis of piriformis syndrome.

Objective To determine if commonly used knee radiofrequency ablation (RFA) techniques would be able to completely denervate the knee joint. Methods A comprehensive search of the literature on knee joint innervation was conducted using the databases Medline, Embase, and PubMed from inception through February 1, 2019. Google Scholar was also searched. Data on the origin, number of articular branches, course, distribution, and frequency of each nerve innervating the knee joint were extracted from the included studies and compared in order to identify variations. Results Twelve studies of anterior knee joint innervation and six studies of posterior knee joint innervation were included. The anterior knee joint was innervated by 10 nerves and further subdivided into two parts (anteromedial and anterolateral) or four quadrants (superomedial, inferomedial, superolateral, and inferolateral) based on innervation patterns; the posterior knee joint was innervated by two or three nerves, most commonly via the popliteal plexus. There is a lack of precise, validated anatomic targets identifiable with fluoroscopy and ultrasound for knee diagnostic blocks and RFA. Only three of the 12 or potentially 13 nerves innervating the knee joint are targeted by commonly used knee RFA techniques. Conclusions Commonly used knee RFA techniques would not be able to completely denervate the knee joint. It may not be necessary to capture all of the nerves, but only the nerves mediating a patient’s pain. Further clinical studies are required to validate specific diagnostic blocks and evaluate clinical outcomes using rigorous diagnostic blocks and anatomically specific knee RFA techniques.

This preliminary study provides evidence that successful medial branch RFN for lumbar zygapophysial-mediated pain does cause initial denervation but no discernable segmental atrophy of the multifidus at long-term follow-up. Previous denervation and diffuse atrophy in these subjects was not associated with pain.