Richard Derby

The prevalence and clinical features of internal disc disruption in patients with chronic low back pain.

Study Design This was a cross-sectional analytic study of patients with chronic low back pain. Objective To investigate whether the criteria for internal disc disruption, as adopted by the International Association for the Study of Pain, could be satisfied in patients with chronic low back pain and to test whether there were any conventional clinical features that could identify this condition. Summary of Background Data Internal disc disruption has been postulated as an important cause of low back pain. To diagnose this condition, the International Association for the Study of Pain taxonomy requires that pain be reproduced on provocation discography and that computed tomography discography reveal internal disc disruption, provided that as a control, stimulation of at least one other disc fails to reproduce pain. Methods Ninety-two consecutive patients with chronic low back pain and no history of previous lumbar surgery were studied. Each patient underwent a standard physical examination. Computed tomography discography was performed at a minimum of two levels. Results The diagnostic criteria for internal disc disruption were fully satisfied in 39% of patients, most commonly at L5-S1 and L4-L5. None of the clinical tests used could differentiate between those patients with internal disc disruption and other patients. Conclusions A diagnosis of internal disc disruption can be made in a significant proportion of patients with chronic low back pain, but no conventional clinical test can discriminate patients with internal disc disruption from patients with other conditions.

Clinical features of patients with pain stemming from the lumbar zygapophysial joints. Is the lumbar facet syndrome a clinical entity

Study Design This study is a prospective cross-sectional analytic study. Objectives The authors determined the prevalence and clinical features of patients with pain stemming from the lumbar zygapophysial joints. Summary of Background Data Previous studies have demonstrated a wide range of prevalence for zygapophysial joint pain and conflicting results with regard to clinical signs. Methods One hundred and seventy-six consecutive patients with chronic low back pain were investigated with a series of screening zygapophysial joint blocks using lignocaine and confirmatory blocks using bupivacaine. Results Forty-seven percent of patients had a definite or greater response to the screening injection at one or more levels but only 15% had a 50% or greater response to a confirmatory block. Response to zygapophysial joint injection was not associated with any single clinical feature or set of clinical features. Conclusions The zygapophysial joint is an important source of pain but the existence of a “facet syndrome” must be questioned.

The relative contributions of the disc and zygapophyseal joint in chronic low back pain.

Study Design. A prospective cross-sectional analytic approach was taken. Objectives. This study sought to determine the relative contribution of the disc and the zygapophyseal Joint as a pain source in patients with chronic low back pain. Summary of Background Data. Previous studies have employed either zygapophyseal joint blocks or discography, but in no studies have both procedures been performed. Methods. Ninety-two consecutive patients with chronic low back pain were studied using both discography and blocks of the zygapophyseal joints. Results. Thirty-six patients (39%) had at least one positive discogram as defined by exact pain reproduction, an abnormal image, and a negative control. Eight patients responded to both a screening zygapophyseal joint block using lignocaine and confimatory block using bupivacaine. Only three patients had both a positive discogram and a symptomatic zygapophyseal joint. Conclusions. In patients with chronic low back pain, the combination of discogenic pain and zygapophyseal joint pain is uncommon.

Epidural injections for the diagnosis and treatment of low-back pain.

Three hundred four consecutive patients with low-back pain were given epidural anesthetic and steroid injections. A prospective study demonstrated that selected patients had 87% short-term success and 34% relief of pain for as long as 6 months. No patient was cured by these injections. Needle placement during epidural injections was incorrect 25% of the time in experienced hands.

Contemporary concepts in spine care. Epidural steroid injections.

Epidural steroid injections are commonly used for the management of lumbosacral radicular syndromes. The literature is replete with case reports and noncontrolled studies, but relatively few controlled studies exist. The well-designed studies that are available, however, do show a significantly positive pain reducing benefit from lumbar epidural steroid injections. This Contemporary Concepts review summarizes theoretic concepts, clinical applications, and data from the literature regarding the use of lumbar epidural steroid injections and provides current recommendations and suggestions for future research.

Response to steroid and duration of radicular pain as predictors of surgical outcome.

Prolonged structural compromise of spinal nerve roots can lead to chronic changes that surgical decompression might not be able to reverse. In this study, it was hypothesized that if there were a reversible structural pain component, a steroid injected into the patients symptomatic nerve root should provide temporary pain relief and that these patients should have a favorable surgical outcome. It also was hypothesized that duration of radicular symptoms would correlate inversely with surgical outcome. For postoperative relief of radicular pain, the results showed that patients with pain lasting less than 1 year had a positive surgical result (89%), regardless of response to steroid. Patients with pain lasting more than 1 year and who have had a positive response to steroid injected into the symptomatic nerve root (roots) had a positive surgical outcome of 85%. Patients who did not respond to the steroid and had pain for more than 1 year (95%) generally had a poor surgical outcome. Although the poor outcome in the last group might be explained in some cases by an inadequate structural correction, inadequate stabilization, or functional reasons, the majority of these failures represented irreversible changes in the neural structures.

Size and Aggregation of Corticosteroids Used for Epidural Injections

OBJECTIVE The purpose of this study was to document particulate size in commonly used corticosteroid preparations. Inadvertent injection of particulate corticosteroids into a vertebral or foraminal artery can cause brain and spinal cord embolic infarcts and the size of the particles could be directly related to the chance that a clinically significant infarct would occur. One might assume that corticosteroids with particles significantly smaller than red blood cells might be safer. DESIGN The following four types of corticosteroid preparations were used in various solutions and evaluated under light microscopy: dexamethasone sodium phosphate injection, triamcinolone acetonide injectable suspension, betamethasone sodium phosphate and betamethasone acetate injectable suspension, and methylprednisolone acetate injectable suspension. RESULTS Dexamethasone sodium phosphate particle size was approximately 10 times smaller than red blood cells and the particles did not appear to aggregate; even mixed with 1% lidocaine HCl solution and with contrast dye, the size of the particles were unchanged. Triamcinolone acetonide and betamethasone sodium phosphate showed variable sizes; some particles were larger than red blood cells, and aggregation of particles was evident. Methylprednisolone acetate showed uniformity in size and the majority were smaller than red blood cells which were not aggregated, but the particles were densely packed. CONCLUSIONS Compared with the particulate steroid solutions, dexamethasone sodium phosphate had particles that were significantly smaller than red blood cells, had the least tendency to aggregation, and had the lowest density. These characteristics should significantly reduce the risk of embolic infarcts or prevent them from occurring after intra-arterial injection. Until shown otherwise in clinical studies, interventionalists might consider using dexamethasone or another corticosteroid preparation with similar high solubility and negligible particle size when performing epidural injections.

Intradiscal Electrothermal Annuloplasty (IDET): A Novel Approach for Treating Chronic Discogenic Back Pain

Objective. This one‐year pilot outcome study was designed to investigate prospectively a series of patients with chronic discogenic back pain who underwent intradiscal electrothermal annuloplasty (IDET). Patients with chronic discogenic low back pain usually respond poorly to conservative medical care. Spinal fusion procedures have yielded mixed results. IDET is a new procedure to heat the intervertebral disc for the purpose of relieving discogenic pain. This study presents the one‐year results for the first 32 patients undergoing the IDET procedure. The objective of this article is to determine the safety and efficacy of the IDET procedure in patients with chronic discogenic back pain.

Comparison of growth factor and cytokine expression in patients with degenerated disc disease and herniated nucleus pulposus

OBJECTIVES This study was conducted to investigate the expression of cytokines and growth factors in disc specimens obtained from patients with herniated nucleus pulposus (HNP) and degenerated disc disease (DDD). DESIGN AND METHODS MRI and Western blot analyses were performed to evaluate the levels of disc degeneration and the expression levels of cytokines and growth factors. RESULTS The levels of TNF-alpha and IL-8 were significantly greater in the DDD group than in the HNP group, but no statistical differences were observed in the expression of IL-1beta, IL-6 and IL-12 between the HNP and DDD groups. In addition, the expression of TGF beta, VEGF and NGF was significantly higher in the DDD group than in the HNP group. CONCLUSION The greater levels of cytokine and growth factor expression in the DDD group than in the HNP explain why discogenic patients usually have more severe back pain than patients with herniated discs.

15. Discogenic Low Back Pain

An estimated 40% of chronic lumbosacral spinal pain is attributed to the discus intervertebralis. Degenerative changes following loss of hydration of the nucleus pulposus lead to circumferential or radial tears within the annulus fibrosus. Annular tears within the outer annulus stimulate the ingrowth of blood vessels and accompanying nociceptors into the outer and occasionally inner annulus. Sensitization of these nociceptors by various inflammatory repair mechanisms may lead to chronic discogenic pain.