Axial Low Back Pain Research Articles

Analysis of efficacy differences between caudal and lumbar interlaminar epidural injections in chronic lumbar axial discogenic pain: local anesthetic alone vs. local combined with steroids.

Study Design: Comparative assessment of randomized controlled trials of caudal and lumbar interlaminar epidural injections in chronic lumbar discogenic pain.Objective: To assess the comparative efficacy of caudal and lumbar interlaminar approaches of epidural injections in managing axial or discogenic low back pain.Summary of Background Data: Epidural injections are commonly performed utilizing either a caudal or lumbar interlaminar approach to treat chronic lumbar axial or discogenic pain, which is pain exclusive of that associated with a herniated intervertebral disc, or that is due to degeneration of the zygapophyseal joints, or due to dysfunction of the sacroiliac joints, respectively. The literature on the efficacy of epidural injections in managing chronic axial lumbar pain of presumed discogenic origin is limited.Methods: The present analysis is based on 2 randomized controlled trials of chronic axial low back pain not caused by disc herniation, radiculitis, or facet joint pain, utilizing either a caudal or lumbar interlaminar approach, with a total of 240 patients studied, and a 24-month follow-up. Patients were assigned to receive either local anesthetic only or local anesthetic with a steroid in each 60 patient group.Results: The primary outcome measure was significant improvement, defined as pain relief and functional status improvement of at least 50% from baseline, which was reported at 24-month follow-ups in 72% who received local anesthetic only with a lumbar interlaminar approach and 54% who received local anesthetic only with a caudal approach. In patients receiving local anesthetic with a steroid, the response rate was 67% for those who had a lumbar interlaminar approach and 68% for those who had a caudal approach at 12 months. The response was significantly better in the lumbar interlaminar group who received local anesthetic only, 77% versus 56% at 12 months and 72% versus 54% at 24 months.Conclusion: This assessment shows that in patients with axial or discogenic pain in the lumbar spine after excluding facet joint and SI Joint pain, epidural injections of local anesthetic by the caudal or lumbar interlaminar approach may be effective in managing chronic low back pain with a potential superiority for a lumbar interlaminar approach over a caudal approach.

Associations between serum biomarkers and pain and pain-related function in older adults with low back pain: a pilot study.

To examine the relationship between serum biomarkers and self-reported pain intensity and pain-related function, in addition to the contribution of magnetic resonance imaging (MRI) findings of lumbar spine degenerative changes, in older adults with chronic low back pain. Single-center cross-sectional cohort study. Academic medical center. Individuals aged 60 and older with axial low back pain without radiculopathy or previously diagnosed osteoarthritis of the knee or hip or pain outside the low back that is more severe than the back pain (n = 43). To examine pain-related impairment, pain was measured on a pain thermometer and the McGill Pain Questionnaire Short Form was administered. To examine pain-related function or activity limitation, the Roland Morris Disability Questionnaire, Short Physical Performance Battery (SPPB), and repetitive trunk rotation were used. Single plasma samples were obtained before and after physical performance tests and analyzed for inflammatory markers (E-selectin and regulated on activation, normal T cell expressed and secreted (RANTES)), inhibitors of catabolic enzymes (tissue inhibitor of metalloproteinases-1 (TIMP-1)), markers of matrix turnover (C- telopeptide of type II collagen (CTX-II) and aggrecan chondroitin sulfate 846 (CS846)), and stress biomarkers (neuropeptide Y (NPY)). Conventional nongadolinium lumbar MRI was performed and analyzed quantitatively and clinically. Composite MRI measurements did not show significant correlation with pain or pain-related function. Basal levels and changes in serum biomarkers in response to activity, particularly NPY and RANTES, demonstrated associations with pain and pain-related function in addition to the explanatory power of MRI-based results. Serum biomarkers may be a metric for assessment of active disease in older adults, in whom imaging changes are ubiquitous. In addition, changing levels of biomarkers in response to activity suggests that they may be useful as metrics to measure treatment responses in future studies and may reflect potential targets for use in designing personalized treatment for older adults with low back pain.

SO-01 * PRIMARY INTRADURAL MALIGNANT PERIPHERAL NERVE SHEATH TUMOR: CASE REPORT AND REVIEW

Malignant peripheral nerve sheath tumor (MPNST) is a rare sarcoma which is most commonly encountered in the extremities, and is often associated with neurofibromatosis type 1 (NF-1). Primary intradural lesions are rarely reported, particularly in the pediatric population. A 15 year old girl was referred to neurosurgery with 18 months of axial low back pain radiating into her hips and thighs, and 3 months of a House-Brackmann 3 right facial droop associated with left sided impaired pupillary constriction and anisocoria. Neurologic exam was otherwise normal. Genetic testing for NF-1 was negative. Brain imaging was normal. Spine imaging revealed an intradural mass associated with the left L3 nerve root. The patient was taken to surgery for resection of the mass. A lesion intrinsic to that nerve was identified and subtotally resected due to concern for iatrogenic injury. Postoperatively, the patient did not develop any new neurologic deficit. Pathologic diagnosis was grade 3 (FNCLCC score 6 of 8) malignant peripheral nerve sheath tumor. Staging CT/PET revealed 2 additional sites of disease in the nerve roots at C6/7 and C7/T1. Lumbar puncture was negative for malignant cells. The patient has subsequently initiated craniospinal proton beam radiotherapy. MPNSTs constitute 5-10% of all soft tissue sarcomas, with a peak incidence in the 7th decade of life. Up to half of these lesions are found in patients with neurofibromatosis type 1, in whom the peak incidence is in the 3rd or 4th decade. 19 cases of pediatric primary intradural MPNST have been previously reported. Surgical treatment is limited due to inability to achieve en bloc resection with wide margins within the intradural compartment. Outcomes have been poor, with 50% or less survival at 2 years despite aggressive multimodal therapies. Further optimization of adjuvant therapies is necessary to improve outcomes.

Neurostimulation for the treatment of axial back pain: a review of mechanisms, techniques, outcomes, and future advances.

The use of spinal cord stimulation (SCS) is well established in the treatment of neuropathic pain. This procedure has been approved in the United States for neuropathic pain of the trunk and limbs from various conditions. International use is variable based on governmental policy. Most studies showing efficacy have focused on pain primarily in the limbs for such conditions as complex regional pain syndrome (CRPS), sciatica, radiculitis, ischemic limb pain, and peripheral neuropathy. Data on success in neuropathic pain of the trunk and particularly of the axial back are limited. New understanding about the targets of neuromodulation and their treatment with novel neurostimulation approaches has led to a new dawn of enthusiasm for spinal cord stimulation for axial low back pain. The authors review mechanisms, current and future targets, techniques, and their outcomes for treating axial back pain with neurostimulation. The paper discusses many newer methods and targets that may substantially improve results for the treatment of this patient group. The continuing evolution of technology and new data may well change these recommendations over time and regular updates of this manuscript will be critical moving forward. Improved technology and a better understanding of the goals of stimulation have led to a new ability to stimulate the axial low back and increase the effectiveness of these therapies to reduce pain. New paddle lead constructs, percutaneous paddle lead introduction, and other new technologies have led to an increased number of potential candidates for spinal cord stimulation. Optimizing the application of neurostimulation for chronic axial back pain will depend upon answering questions relating to patient selection, implantation technique, and stimulation parameters.

Tactile allodynia in patients with lumbar radicular pain (sciatica)

We report a novel symptom in many patients with low back pain (LBP) that sheds new light on the underlying pain mechanism. By means of quantitative sensory testing, we compared patients with radicular LBP (sciatica), axial LBP (LBP without radiation into the leg), and healthy controls, searching for cutaneous allodynia in response to weak tactile and cooling stimuli on the leg and low back. Most patients with radicular pain (~60%) reported static and dynamic tactile allodynia, as well as cooling allodynia, on the leg, often extending into the foot. Some also reported allodynia on the low back. In axial LBP, allodynia was almost exclusively on the back. The degree of dynamic tactile allodynia correlated with the degree of background pain. The presence of allodynia suggests that the peripheral nerve generators of background leg and back pain have also induced central sensitization. The distal (foot) location of the allodynia in patients who have it indicates that the nociceptive drive that maintains the central sensitization arises paraspinally (ectopically) in injured ventral ramus afferents; this is not an instance of somatic referred pain. The presence of central sensitization also provides the first cogent account of shooting pain in sciatica as a wave of activity sweeping vectorially across the width of the sensitized dorsal horn. Finally, the results endorse leg allodynia as a pain biomarker in animal research on LBP, which is commonly used but has not been previously validated. In addition to informing the underlying mechanism of LBP, bedside mapping of allodynia might have practical implications for prognosis and treatment. Social media questionHow can you tell whether pain radiating into the leg in a patient with sciatica is neuropathic, ie, due to nerve injury?

Multidimensional pain profiles in four cases of chronic non-specific axial low back pain: An examination of the limitations of contemporary classification systems

Classifying patients with chronic low back pain (CLBP) may facilitate targeted treatment, and optimise outcomes. Most classification systems (CS) do not consider multiple, interacting dimensions (for example, psychological or movement dimensions) involved in the lived experience of people with CLBP. A framework incorporating these multiple dimensions, and acknowledging individual variability, could provide a pathway to better assess and treat people with CLBP. Here we explored this proposition, presenting four cases (P1–4), profiling their clinical presentations within a multidimensional framework.P1's profile was characterised by localised lumbar sensitisation consistent with dominant peripheral nociception. P2 presented a ‘mixed’ profile characterised by localised lumbar hypersensitivity, combined with factors suggestive of centrally-mediated facilitation of nociception. P3's profile suggested widespread hypersensitivity possibly reflective of dominant centrally-mediated pain mechanisms. P4's profile was characterised by dominant psychosocial factors and comorbidities.These cases are discussed in relation to contemporary CLBP CS, highlighting the complexity of these disorders and limitations of CS for people with CLBP and their treating health professionals. This paper reinforces the need for a consensus CS for people with CLBP that is flexible, has clinical utility and considers all relevant dimensions.

Spinal cord stimulation with implanted epidural paddle lead relieves chronic axial low back pain.

IntroductionSpinal cord stimulation (SCS) provides significant relief for lumbosacral radiculopathy refractory to both medical and surgical treatment, but historically only offers limited relief for axial low back pain (LBP). We aim to evaluate the response of chronic axial LBP treated with SCS using a surgically implanted epidural paddle lead.Materials and methodsThis is a retrospective review of a consecutive series of patients with exclusive LBP or predominant LBP associated with lower extremity (LE) pain evaluated and treated with SCS using an implanted paddle lead within the dorsal thoracic epidural space. Baseline LBP, and if present LE pain, were recorded using the visual analogue scale (VAS) at an initial evaluation. At a follow-up visit (a minimum of 12 months later), LBP and LE pain after a spinal cord stimulator implantation were again recorded using the VAS. Patients were also asked to estimate total LBP pain relief achieved.ResultsPatients with either exclusive (n=7) or predominant (n=2) axial LBP were treated with SCS by implantation of a paddle lead at an average spine level of T9. The baseline VAS score for LBP was 7.2; after a follow-up of 20 months, the score decreased to 2.3 (P=0.003). The LE pain VAS score decreased from 7.5 to 0.0 (P=0.103). Patients also reported a subjective 66.4% decrease of their LBP at follow-up. There were no surgical complications.ConclusionsAxial LBP is refractory to many treatments, including SCS. SCS using a surgically implanted paddle electrode provides significant pain relief for chronic axial LPB, and is a safe treatment modality.

ISSLS Prize Winner

Immunohistochemical and behavioral study using the SPARC (secreted protein, acidic, rich in cysteine)-null mouse model of low back pain (LBP) associated with accelerated intervertebral disc (IVD) degeneration. To determine if behavioral signs of LBP in SPARC-null mice are accompanied by sensory nervous system plasticity. IVD pathology is a significant contributor to chronic LBP. In humans and rodents, decreased expression of SPARC is associated with IVD degeneration. We previously reported that SPARC-null mice exhibit age-dependent behavioral signs of chronic axial LBP and radiating leg pain. SPARC-null and age-matched control young, middle-aged, and old mice (1.5, 6, and 24 mo of age, respectively) were evaluated. Cutaneous hind paw sensitivity to cold, heat, and mechanical stimuli were evaluated as measures of radiating pain. The grip force and tail suspension assays were performed to evaluate axial LBP. Motor impairment was assessed using an accelerating rotarod. IVD innervation was identified by immunohistochemistry targeting the nerve fiber marker PGP9.5 and the sensory neuropeptide calcitonin gene-related peptide (CGRP). Sensory nervous system plasticity was evaluated by quantification of CGRP- and neuropeptide-Y-immunoreactivity (-ir) in dorsal root ganglia neurons and CGRP-ir, GFAP-ir (astrocyte marker), and Iba-1-ir (microglia marker) in the spinal cord. SPARC-null mice developed hypersensitivity to cold, axial discomfort, age-dependent motor impairment, age-dependent increases in sensory innervation in and around the IVDs, age-dependent upregulation of CGRP and neuropeptide-Y in dorsal root ganglia, and age-dependent upregulation of CGRP, microglia, and astrocytes in the spinal cord dorsal horn. Increased innervation of degenerating IVDs by sensory nerve fibers and the neuroplasticity in sensory neurons and spinal cord could contribute to the underlying pathobiology of chronic discogenic LBP. N/A.

Present and Potential Use of Spinal Cord Stimulation to Control Chronic Pain

Background: Spinal cord stimulation is an intervention that has become increasingly popular due to the growing body of literature showing its effectiveness in treating pain and the reversible nature of the treatment with implant removal. It is currently approved by the FDA for chronic pain of the trunk and limbs, intractable low back pain, leg pain, and pain from failed back surgery syndrome. In Europe, it has additional approval for refractory angina pectoris and peripheral limb ischemia. Objective: This narrative review presents the current evidence supporting the use of spinal cord stimulation for the approved indications and also discusses some emerging neuromodulation technologies that may potentially address pain conditions that traditional spinal cord stimulation has difficulty addressing. Study Design: Narrative review. Results: Spinal cord stimulation has been reported to be superior to conservative medical management and reoperation when dealing with pain from failed back surgery syndrome. It has also demonstrated clinical benefit in complex regional pain syndrome, critical limb ischemia, and refractory angina pectoris. Furthermore, several cost analysis studies have demonstrated that spinal cord stimulation is cost effective for these approved conditions. Despite the lack of a comprehensive mechanism, the technology and the complexity in which spinal cord stimulation is being utilized is growing. Newer devices are targeting axial low back pain and foot pain, areas that have been reported to be more difficult to treat with traditional spinal cord stimulation. Percutaneous hybrid paddle leads, peripheral nerve field stimulation, nerve root stimulation, dorsal root ganglion, and high frequency stimulation are actively being refined to address axial low back pain and foot pain. High frequency stimulation is unique in that it provides paresthesia free analgesia by stimulating beyond the physiologic frequency range. The preliminary results have been mixed and a large randomized control trial is underway to evaluate the future of this technology. Other emerging technologies, including dorsal root ganglion stimulation and hybrid leads, also show some promising preliminary results in non-randomized observational trials. Limitation: This review is a primer and not an exhaustive review for the current evidence supporting the use of spinal cord stimulation and precursory discussion of emerging neuromodulation technologies. This review does not address peripheral nerve stimulation and focuses mainly on spinal cord stimulation and touches on peripheral nerve field stimulation. Conclusions: Spinal cord stimulation has demonstrated clinical efficacy in randomized control trials for the approved indications. In addition, several open label observational studies on peripheral nerve field stimulation, hybrid leads, dorsal root ganglion stimulation, and high frequency stimulation show some promising results. However, large randomized control trials demonstrating clear clinical benefit are needed to gain evidence based support for their use. Key words: Spinal cord stimulation, chronic pain; low back pain, high frequency stimulation, peripheral nerve field stimulation, dorsal root ganglion stimulation, failed back surgery syndrome, complex regional pain syndrome, critical limb ischemia, refractory angina pectoris

A Practice Audit of CT-Guided Injections of Pars Interarticularis Defects in Patients with Axial Low Back Pain: A Primer for Further Investigation

To assess whether computed tomography (CT)-guided injections of local anesthetic and corticosteroid into chronic lumbar pars interarticularis defects may identify and provide benefit to a cohort of patients where the pars defects act as a primary axial pain generator. Retrospective practice audit. Single academic radiology pain management practice. 59 consecutive patients undergoing CT-guided injections of lumbar pars defects. Patients were assessed with a pain numerical rating scale (NRS, 0-10) and Roland-Morris disability questionnaire (R-M) prior to injection and at 2 weeks and 2 months follow-up. For categorical outcomes, successful pain relief response was defined as either ≥50% reduction in NRS or pain 0/10; functional response was defined as ≥40% reduction in R-M score. Continuous outcomes (mean NRS, R-M scores) were assessed for significant change following injection. For categorical outcomes, 37.9% of patients were responders at 2 months' follow-up; 20.7 % had complete relief of index pain. For functional recovery, 34.5% were responders at 2 months. Using continuous outcomes, mean NRS was 5.4 ± 2.1 prior to injection and 3.6 ± 2.6 at 2 months (P < 0.0001). Mean R-M score was 11.7 ± 6.0 prior to injection and 9.0 ± 5.4 at 2 months (P = 0.001). There were no complications. This practice audit suggests that in patients with axial low back pain and chronic pars defects, the pars defects may be implicated as the primary axial pain generator in a small subgroup of patients. Local deposition of corticosteroids into the pars defect may provide significant pain relief in one out of three patients, and complete relief in one out of five patients. This data suggest there may be benefit to pursuing randomized controlled trials of pars injections comparing steroid injection with placebo.

DIAM Implantation for Degenerative Disc Disease

Introduction Lumbar disc degeneration (LDD) is among the most common causes of low back pain. Typical symptoms include axial low back pain, buttock pain, with or without radiation to posterior thighs or legs, and intolerance to upright positions. Several surgical treatment options are available, including intradiscal injections, intradiscal electrothermal therapy, discectomy, total disc arthroplasty, and fusion. Recently, implantation of interspinous process devices has been shown to decrease low back pain, and provide morphological alterations of the degenerative discs, resulting in satisfactory clinical outcomes. This study was conducted to review our results of using stand-alone DIAM implantation as the treatment for symptomatic LDD. Materials and Methods A total of 24 selected cases of LDD were treated surgically with stand-alone DIAM implantation. In 20 patients, the presenting symptoms were predominantly axial low back/buttock pain with little leg pain, while in 4 patients there was only axial pain. Motor weakness and sensory disturbance involving the corresponding nerve roots were present in eight cases. Three patients had undergone previous lumbar discectomy of the afflicted discs. Typical MRI findings included loss of height, signal changes, and/or annular tear of the discs. On the basis of Pfirrmann grading scale for disc degeneration, three cases were categorized as Grade II, and 21 cases as Grade III. Our exclusion criteria included intermittent claudication due to lumbar spinal stenosis, severe disc space collapse with Modic changes, greater than Grade II spondylolisthesis, facet ankylosis, and L5-S1 pathology. Provocative test with intradiscal injection of normal saline-induced concordant pain in all cases. Results All patients reported significant symptom relief after surgery, as reflected by VAS and ODI improvements. The final outcomes were excellent in 19, good in 2, fair in 2, and poor in 1 cases. Segmental flexion/extension mobility was maintained in 20, and restricted or lost in 2, of 22 cases with preoperative mobility. In the other two cases with no preoperative mobility, DIAM implantation did not change the status. MRI was repeated in the two cases showing fair, and the one case showing poor outcomes. In all of them, enlargement of neuroforamens at the implanted levels were found. In one fair case, disappearance of annular tear was observed. In the other fair case (L4-5 implantation), L5-S1 disc herniation was disclosed, and removed in a second operation. The case with poor outcome was diagnosed with depression, having concomitant multiple joint pain, dysmenorrhea, sleep disorder, despite normal findings on different exams ordered by different specialists. Conclusion In highly selected cases with symptomatic LDD, stand-alone interspinous DIAM implantation is effective for alleviation of symptoms, and stabilization of disc status. Disclosure of Interest None declared References Sandu N, Schaller B, Arasho B, Orabi M. Wallis interspinous implantation to treat degenerative spinal disease: description of the method and case series. Expert Rev Neurother 2011;11(6):799–807 Buric J, Pulidori M, Sinan T, Mehraj S. DIAM device for low back pain in degenerative disc disease : 24 months follow-up. Acta Neurochir Suppl (Wien) 2011;108:177–182 Pfirrmann CW, Metzdorf A, Zanetti M, Hodler J, Boos N. Magnetic resonance classification of lumbar intervertebral disc degeneration. Spine 2001;26(17):1873–1878

(496) Percutaneous rupture and aspiration of lumbar intra-facet cysts: a case report

Synovial cysts arising from the lumbar spine facet joints are most commonly seen in the setting of degenerative spondylosis. These cysts are often termed juxta-facet cysts since they are located beside the facet joint and only exhibit a communicating pathway with the joint itself. There may be a small amount of fluid within the facet joint but the majority of the fluid lies within the cyst. Treatment options include surgical resection and percutaneous rupture. Percutaneous rupture of lumbar facet cysts is most commonly performed indirectly through the facet joint by use of CT guidance or fluoroscopy. We present a unique case that describes the percutaneous rupture and aspiration of lumbar facet cysts located entirely in the joint itself (intra-facet cysts) using fluoroscopy. A 52-year-old female presented with a one-year history of axial low back pain worse when lying down. The pain radiated to her bilateral buttocks but she denied parasthesias. She had already tried oral anti-inflammatory medications, physical therapy, and opioid medications with no improvement in her pain. Lumbar spine MRI revealed large bilateral intra-facet cysts at L4-L5 with a grade 2 spondylolisthesis at L4-L5. The patient was seen by a spine surgeon who recommended conservative treatment with no surgical intervention at that time. After surgical consultation, the decisionwasmade to perform percutaneous rupture and aspiration of the bilateral intra-facet cysts at L4-L5 followed by intra-articular facet steroid injections under fluoroscopy. One milliliter of synovial fluid was aspirated from each of her facet joints using a 22-guage needle with no complications. Following the procedure, the patient reported an 80% decrease in her pain score. Although juxta-facet cysts are the most common presentation of lumbar spine synovial cysts, intra-facet cysts may also occur and can be successfully treated with percutaenous rupture and aspiration under fluoroscopy.

Sacroiliac joint arthropathy and low back pain

DOI: http://dx.doi.org/10.3329/jbsa.v22i2.18147Journal of BSA, 2009; 22(2): 78-83

Correlation of Pain With Objective Quantification of Magnetic Resonance Images in Older Adults With Chronic Low Back Pain

Cross sectional study. The goal of this study is to identify relationships between objectively measured and subjectively scored parameters and reported pain. Studies have demonstrated the unreliability of magnetic resonance imaging (MRI)-based parameters to identify pathological pain generators of chronic low back pain, but they were based on visual inspection and subjective assessment of lumbar disc features. Advancements in computer image analysis provide objective measurements of lumbar disc features. Two radiologists evaluated 39 axial and sagittal T1- and T2-weighted MR images of patients with chronic axial low back pain (age, >65 yr) and graded 4 subjective lumbar disc parameters (T2 signal intensity, nucleus shape, Modic changes, and osteophyte formation) whose sum is the cumulative MRI score. Objective parameter, MRI index, was calculated as the product of the measured lumbar disc area and total disc MRI signal intensity. Discs were sorted from least to the most degenerated relative to each parameter. Pearson correlation coefficient and multiple linear regression analysis were performed between the reported pain score and each parameter. The most and least degenerated discs in each patient, as assessed by MRI index, had the highest negative and positive correlation coefficient and regression weight contribution, respectively. All subjective parameters had low correlation coefficients and regression goodness of fit. Although limited by small sample size, the objective parameter, MRI index, can be a potential imaging biomarker used to identify possible pain generators. This study presents a potential new application of MR imaging in identifying pain generators of patients with chronic low back pain.

Mid- to long-term results of total lumbar disc replacement: a prospective analysis with 5- to 10-year follow-up

Background contextThe role of fusion of lumbar motion segments for the treatment of intractable low back pain (LBP) from degenerative disc disease (DDD) without deformities or instabilities remains controversially debated. Total lumbar disc replacement (TDR) has been used as an alternative in a highly selected patient cohort. However, the amount of long-term follow-up (FU) data on TDR is limited. In the United States, insurers have refused to reimburse surgeons for TDRs for fear of delayed complications, revisions, and unknown secondary costs, leading to a drastic decline in TDR numbers. PurposeTo assess the mid- and long-term clinical efficacy as well as patient safety of TDR in terms of perioperative complication and reoperation rates. Study design/settingProspective, single-center clinical investigation of TDR with ProDisc II (Synthes, Paoli, PA, USA) for the treatment of LBP from lumbar DDD that has proven unresponsive to conservative therapy. Patient samplePatients with a minimum of 5-year FU after TDR, performed for the treatment of intractable and predominant (≥80%) axial LBP resulting from DDD without any deformities or instabilities. Outcome measuresVisual analog scale (VAS), Oswestry Disability Index (ODI), and patient satisfaction rates (three-scale outcome rating); complication and reoperation rates as well as elapsed time until revision surgery; patient's professional activity/employment status. MethodsClinical outcome scores were acquired within the framework of an ongoing prospective clinical trial. Patients were examined preoperatively, 3, 6, and 12 months postoperatively, annually from then onward. The data acquisition was performed by members of the clinic's spine unit including medical staff, research assistants, and research nurses who were not involved in the process of pre- or postoperative decision-making. ResultsThe initial cohort consisted of 201 patients; 181 patients were available for final FU, resembling a 90.0% FU rate after a mean FU of 7.4 years (range 5.0–10.8 years). The overall results revealed a highly significant improvement from baseline VAS and ODI levels at all postoperative FU stages (p<.0001). VAS scores demonstrated a slight (from VAS 2.6 to 3.3) but statistically significant deterioration from 48 months onward (p<.05). Patient satisfaction rates remained stable throughout the entire postoperative course, with 63.6% of patients reporting a highly satisfactory or a satisfactory (22.7%) outcome, whereas 13.7% of patients were not satisfied. The overall complication rate was 14.4% (N=26/181). The incidence of revision surgeries for general and/or device-related complications was 7.2% (N=13/181). Two-level TDRs demonstrated a significant improvement of VAS and ODI scores in comparison to baseline levels (p<.05). Nevertheless, the results were significantly inferior in comparison to one-level cases and were associated with higher complication (11.9% vs. 27.6%; p=.03) and inferior satisfaction rates (p<.003). ConclusionsDespite the fact that the current data comprises the early experiences and learning curve associated with a new surgical technique, the results demonstrate satisfactory and maintained mid- to long-term clinical results after a mean FU of 7.4 years. Patient safety was proven with acceptable complication and reoperation rates. Fear of excessive late complications or reoperations following the primary TDR procedure cannot be substantiated with the present data. In carefully selected cases, TDR can be considered a viable treatment alternative to lumbar fusion for which spine communities around the world seem to have accepted mediocre clinical results as well as obvious and significant drawbacks.

A Randomized, Double-Blind, Active-Controlled Trial of Fluoroscopic Lumbar Interlaminar Epidural Injections in Chronic Axial or Discogenic Low Back Pain: Results of 2-Year Follow-Up

Background: Chronic low back with or without lower extremity pain is extremely common, expensive, and disabling. Although it is responsible for a very small proportion of patients, disc herniation is the primary focus of modalities of treatments. In fact, chronic low back pain without disc herniation is common. Multiple modalities of treatments are utilized in managing axial or discogenic pain without disc herniation including surgery, intradiscal therapies, and epidural injections. There is, however, continued debate on the effectiveness, indications, and medical necessity of all modalities of treatments in managing axial or discogenic pain in the lumbar spine. Objectives: To assess the effectiveness of lumbar interlaminar epidural injections in managing chronic axial or discogenic low back pain with epidural injections of local anesthetic with or without steroids. Study Design: A randomized, double-blind, active-controlled trial. Setting: A private practice, specialty referral, interventional pain management practice in the United States. Methods: In this study, a total of 120 patients were randomly allocated to one of 2 groups of 60 patients receiving either local anesthetic alone or local anesthetic with steroids. The primary outcome measure was at least a 50% improvement in the numeric rating scale (NRS) and Oswestry Disability Index (ODI). Outcomes were assessed at 3, 6, 12, 18, and 24 months post treatment. Results: Significant pain relief and functional status improvement, defined as a reduction in scores from baseline of at least 50% or more, were observed in 72% of patients receiving local anesthetic alone and 67% of patients receiving local anesthetic with steroids. Opioid intake was reduced from the baseline in each group for 2 years. Limitations: The results of the study are limited by the lack of a placebo group. Conclusion: Lumbar interlaminar epidural injections of local anesthetic with or without steroids are effective in patients with chronic axial low back pain of discogenic origin without facet joint pain, disc herniation, and/or radiculitis. Key words: Lumbar disc herniation, axial or discogenic pain, lumbar interlaminar epidural injections, local anesthetic, steroids, controlled comparative local anesthetic blocks

The Identification of Biomarkers That Are Predictive of Response to Interventional Spinal Procedures for Axial Low Back Pain: A Pilot Study

The Identification of Biomarkers That Are Predictive of Response to Interventional Spinal Procedures for Axial Low Back Pain: A Pilot Study

Lumbar artificial intervertebral disc replacement: a systematic review

Low back pain represents a significant disease burden in Australia. Lumbar artificial intervertebral disc replacement (AIDR) has emerged as an alternative surgical option to lumbar fusion for patients suffering from axial low back pain as a result of degenerative disc disease. The aim of this review was to assess the safety and effectiveness of lumbar AIDR for patients suffering from significant axial back pain and/or radicular (nerve root) pain, secondary to disc degeneration or prolapse, who have failed non-operative treatment. A systematic search of several electronic databases was conducted between January 2005 and April 2012 to identify relevant randomized controlled trials and non-randomized comparative studies. Inclusion of studies was established through the application of a predetermined protocol by two independent reviewers. Six randomized controlled trials (comprising nine studies) and one non-randomized comparative study comparing lumbar AIDR with lumbar fusion were included in this review. For the majority of adverse events reported, there were no obvious differences in incidence rates between the two treatment groups, and serious adverse events were rare in both groups. Following lumbar AIDR, effectiveness outcomes including Oswestry Disability Index scores, procedural success rates, pain scores, narcotic medication use and patient satisfaction were generally significantly better than, or equivalent to, outcomes achieved following lumbar fusion. In the short to medium term, the safety and effectiveness of lumbar AIDR appears to be comparable to that of lumbar fusion.

Axial Low Back Pain: One Painful Area – Many Perceptions and Mechanisms

Axial low back pain can be considered as a syndrome with both nociceptive and neuropathic pain components (mixed-pain). Especially neuropathic pain comprises a therapeutic challenge in practical experience and may explain why pharmacotherapy in back pain is often disappointing for both the patient and the therapist. This survey uses epidemiological and clinical data on the symptomatology of 1083 patients with axial low back pain from a cross sectional survey (painDETECT). Objectives were (1) to estimate whether neuropathic pain contributes to axial low back pain and if so to what extent. (2) To detect subgroups of patients with typical sensory symptom profiles and to analyse their demographic data and co-morbidities. (3) To compare patients with and without prior intervertebral disc surgery (IVD). Neuropathic pain components could be detected in 12% of the entire cohort. Cluster analyses of these patients revealed five distinct subgroups of patients showing a characteristic sensory profile, i.e. a typical constellation and combination of symptoms. All subgroups occurred in relevant numbers and some showed distinct neuropathic characteristics while others showed nociceptive features. Post-IVD-surgery patients showed a tendency to score more “neuropathic” than patients without surgery (not statistically significant). Axial low back pain has a high prevalence of co-morbidities with implication on therapeutic aspects. From these data it can be concluded that sensory profiles based on descriptor severity may serve as a better predictor for therapy assessment than pain intensity or sole diagnosis alone. Standardized phenotyping of pain symptoms with easy tools may help to develop an individualized therapy leading to a higher success rate in pharmacotherapy of axial low back pain.

Cost Utility Analysis of Caudal Epidural Injections in the Treatment of Lumbar Disc Herniation, Axial or Discogenic Low Back Pain, Central Spinal Stenosis, and Post Lumbar Surgery Syndrome

Background: In this era of escalating health care costs and the questionable effectiveness of multiple interventions, cost effectiveness or cost utility analysis has become the cornerstone of evidence-based medicine, and has an influence coverage decisions. Even though multiple cost effectiveness analysis studies have been performed over the years, extensive literature is lacking for interventional techniques. Cost utility analysis studies of epidural injections for managing chronic low back pain demonstrated highly variable results including a lack of cost utility in randomized trials and contrasting results in observational studies. There has not been any cost utility analysis studies of epidural injections in large randomized trials performed in interventional pain management settings. Objectives: To assess the cost utility of caudal epidural injections in managing chronic low back pain secondary to lumbar disc herniation, axial or discogenic low back pain, lumbar central spinal stenosis, and lumbar post surgery syndrome. Study Design: This analysis is based on 4 previously published randomized trials. Setting: A private, specialty referral interventional pain management center in the United States. Methods: Four randomized trials were conducted assessing the clinical effectiveness of caudal epidural injections with or without steroids for lumbar disc herniation, lumbar discogenic or axial low back pain, lumbar central spinal stenosis, and post surgery syndrome. A cost utility analysis was performed with direct payment data for a total of 480 patients over a period of 2 years from these 4 trials. Outcome included various measures with significant improvement defined as at least a 50% improvement in pain reduction and disability status. Results: The results of 4 randomized controlled trials of low back pain with 480 patients with a 2 year follow-up with the actual reimbursement data showed cost utility for one year of quality-adjusted life year (QALY) of $2,206 for disc herniation, $2,136 for axial or discogenic pain without disc herniation, $2,155 for central spinal stenosis, and $2,191 for post surgery syndrome. All patients showed significant improvement clinically and showed positive results in the cost utility analysis with an average cost per one year QALY of $2,172.50 for all patients and $1,966.03 for patients judged to be successful. The results of this assessment show a better cost utility or lower cost of managing chronic, intractable low back pain with caudal epidural injections at a QALY that is similar or lower in price than medical therapy only, physical therapy, manipulation, and surgery in most cases. Limitations: The limitations of this cost utility analysis include that it is a single center evaluation, even though 480 patients were included in the analysis. Further, only the costs of interventional procedures and physician visits were included. The benefits of returning to work were not assessed. Conclusion: This cost utility analysis of caudal epidural injections in the treatment of disc herniation, axial or discogenic low back pain, central spinal stenosis, and post surgery syndrome in the lumbar spine shows the clinical effectiveness and cost utility of these injections at less than $2,200 per one year of QALY. Key words: Caudal epidural injections, chronic low back pain, lumbar disc herniation, lumbar discogenic pain, lumbar spinal stenosis, lumbar post surgery syndrome, cost utility analysis, cost effectiveness analysis, quality-adjusted life years