A comparison of three different surgery approaches and methods for neurologically intact thoracolumbar fractures: a retrospective study.

OBJECTIVES: The purpose of this study was to evaluate and compare the feasibility, safety, and efficacy of conventional open pedicle screw fixation (COPSF), percutaneous pedicle screw fixation (PPSF), and paraspinal posterior open approach pedicle screw fixation (POPSF) for treating neurologically intact thoracolumbar fractures. METHODS: We retrospectively reviewed 108 patients who were posteriorly stabilized without graft fusion. Among them, 36 patients underwent COPSF, 38 patients underwent PPSF, and 34 patients underwent POPSF. The clinical outcomes, relative operation indexes, and radiological findings were assessed and compared among the 3 groups. RESULTS: All of the patients were followed up for a mean time of 20 months. The PPSF group and POPSF group had shorter operation times, lower amounts of intraoperative blood loss, and shorter postoperative hospital stays than the COPSF group (P < 0.05). The radiation times and hospitalization costs were highest in the PPSF group (P < 0.05). Every group exhibited significant improvements in the Cobb angle (CA) and the vertebral body angle (VBA) correction (all P < 0.05). The COPSF group and the POPSF group had better improvements than the PPSF group at 3 days postoperation and the POPSF group had the best improvements in the last follow-up (P < 0.05). CONCLUSION: Both PPSF and POPSF achieved similar effects as COPSF while also resulting in lower incidences of injury. PPSF is more advantageous in the early rehabilitation time period, compared with COPSF, but POPSF is a better option when considering the long-term effects, the costs of treatment, and the radiation times.

Cost-Effectiveness of Radiofrequency Denervation for Patients With Chronic Low Back Pain: The MINT Randomized Clinical Trials.

OBJECTIVES: To evaluate the cost-effectiveness of radiofrequency denervation when added to a standardized exercise program for patients with chronic low back pain. METHODS: An economic evaluation was conducted alongside 3 pragmatic multicenter, nonblinded randomized clinical trials (RCTs) in The Netherlands with a follow up of 52 weeks. Eligible participants were included between January 1, 2013, and October 24, 2014, and had chronic low back pain; a positive diagnostic block at the facet joints (n = 251), sacroiliac (SI) joints (n = 228), or a combination of facet joints, SI joints, and intervertebral discs (n = 202); and were unresponsive to initial conservative care. Quality-adjusted life-years (QALYs) and societal costs were measured using self-reported questionnaires. Missing data were imputed using multiple imputation. Bootstrapping was used to estimate statistical uncertainty. RESULTS: After 52 weeks, no difference in costs between groups was found in the facet joint or combination RCT. The total costs were significantly higher for the intervention group in the SI joint RCT. The maximum probability of radiofrequency denervation being cost-effective when added to a standardized exercise program ranged from 0.10 in the facet joint RCT to 0.17 in the SI joint RCT irrespective of the ceiling ratio, and 0.65 at a ceiling ratio of €30 000 per QALY in the combination RCT. CONCLUSIONS: Although equivocal among patients with symptoms in a combination of the facet joints, SI joints, and intervertebral discs, evidence suggests that radiofrequency denervation combined with a standardized exercise program cannot be considered cost-effective from a societal perspective for patients with chronic low back pain originating from either facet or SI joints in a Dutch healthcare setting.

In vivo assessment of nervous fiber distribution in the intervertebral disc.

This present study aims to assess in vivo the nervous fibers distribution in the intervertebral disc using diffusion tensor imaging technique. Five healthy subjects participated into the data acquisition. Fiber extraction and tracking algorithms were used. The number of fibers in L4/5 disc ranges from 314 to 679 and the mean fiber length L4/5 in disc ranges from 8.22 ± 2.36 mm to 11.24 ± 5.17 mm. This study showed the feasibility of using diffusion tensor imaging technique to detect and assess the nervous fibers in the intervertebral discs. This could be of great clinical interest for the study of the correlations between these useful characteristics with pain levels on the low back pain patients.

The diagnostic utility and cost-effectiveness of selective nerve root blocks in patients considered for lumbar decompression surgery: a systematic review and economic model.

BACKGROUND: Diagnostic selective nerve root block (SNRB) involves injection of local anaesthetic, sometimes in conjunction with corticosteroids, around spinal nerves. It is used to identify symptomatic nerve roots in patients with probable radicular pain that is not fully concordant with imaging findings. OBJECTIVES: (1) Determine the diagnostic accuracy of SNRB in patients with low back and radiating pain in a lower limb; (2) evaluate whether or not accuracy varies by patient subgroups; (3) review injection-related adverse events; and (4) evaluate the cost-effectiveness of SNRB. DATA SOURCES: MEDLINE, EMBASE, Science Citation Index, Bioscience Information Service (BIOSIS), Latin American and Caribbean Health Sciences Literature (LILACS) and grey literature databases were searched from inception to August 2011. Reference lists of included studies were screened. METHODS: A systematic review (SR) of studies that assessed the accuracy of SNRB or adverse events in patients with low back pain and symptoms in a lower limb for the diagnosis of lumbar radiculopathy. Study quality was assessed using the quality assessment of diagnostic accuracy studies (QUADAS)-2 checklist. We used random-effects meta-analysis to pool diagnostic accuracy data. Decision tree and Markov models were developed, combining SR results with information on the costs and outcomes of surgical and non-surgical care. Uncertainty was assessed using probabilistic and deterministic sensitivity analyses. RESULTS: Five studies assessed diagnostic accuracy: three diagnostic cohort and two within-patient case-control studies. All were judged to be at high risk of bias and had high concerns regarding applicability. In individual studies, sensitivity ranged from 57% [95% confidence interval (CI) 43% to 70%] to 100% (95% CI 76% to 100%) and specificity from 9.5% (95% CI 1% to 30%) to 86% (95% CI 76% to 93%). The most reliable estimate was judged to come from two cohort studies that used post-surgery outcome as the reference standard; summary sensitivity and specificity were 93% (95% CI 86% to 97%) and 26% (95% CI 5% to 68%), respectively. No study provided sufficient detail to judge whether or not accuracy varied by patient subgroup. Seven studies assessed adverse events. There were no major or permanent complications; minor complications were reported in 0-6% of patients. The addition of SNRB to the diagnostic work-up was not cost-effective with an incremental cost per quality-adjusted life-year of £1,576,007. Sensitivity analyses confirmed that SNRB was unlikely to be a cost-effective method for diagnosis and planning surgical therapy. LIMITATIONS: We identified very few studies; all were at high risk of bias. The conduct and interpretation of SNRBs varied and there was no gold standard for diagnosis. Limited information about the impact of SNRB on subsequent care and the long-term costs and benefits of surgery increased uncertainty about cost-effectiveness. CONCLUSIONS: There were few studies that estimated the diagnostic accuracy of SNRB in patients with radiculopathy and all were limited by the difficulty of making a reference standard diagnosis. Summary estimates suggest that specificity is low, but results are based on a small number of studies at a high risk of bias. Based on current weak evidence, it is unlikely that SNRB is a cost-effective method for identifying the symptomatic nerve root prior to lumbar spine surgery. Future research should focus on randomised controlled trials to evaluate whether or not SNRB improves patient outcomes at acceptable cost. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Comparison of CatWalk analysis and von Frey testing for pain assessment in a rat model of nerve crush plus inflammation.

STUDY DESIGN: Assessment of pain-related behavior and immunohistology of the dorsal root ganglion in a rat model. OBJECTIVE: To investigate pain-related behavior in a rat model of nerve crush plus inflammation using the CatWalk system. SUMMARY OF BACKGROUND DATA: A definitive method for evaluating animal models of lumbar disease has not been established. Von Frey testing has often been used in this type of study, but the reliability remains in question. The CatWalk system is a computer-assisted apparatus for analyzing gait that provides an automated way to assess gait function during pain. However, there have been few reports using this system for models of lumbar disease. METHODS: Fourteen rats were divided into 2 groups: a treatment group and a sham group. For the treatment group, nucleus pulposus was applied to the sciatic nerve and the sciatic nerve was pinched. Two different methods for assessment of pain-related behavior, von Frey testing and CatWalk analysis, were used before surgery and at 4 and 7 days after surgery. Immunohistochemistry was used to examine calcitonin gene-related peptide expression in L4 to L6 dorsal root ganglia. RESULTS: No significant differences were found between the treatment and sham control groups using von Frey testing. However, significant differences in 4 parameters were found between the 2 groups using the CatWalk system (P < 0.05). The proportion of calcitonin gene-related peptide-immunoreactive neurons was higher in the treatment group than in the control group (P < 0.05). CONCLUSION: Our results demonstrate that the CatWalk system is useful for the measurement of pain-related behavioral change in our rat model in which nociception was indicated at a cellular level. Although further studies are needed, we think that this system is a valid alternative method for the evaluation of models of lumbar disease in rodents.

Multicenter, randomized, comparative cost-effectiveness study comparing 0, 1, and 2 diagnostic medial branch (facet joint nerve) block treatment paradigms before lumbar facet radiofrequency denervation.

BACKGROUND: Among patients presenting with axial low back pain, facet arthropathy accounts for approximately 10-15% of cases. Facet interventions are the second most frequently performed procedures in pain clinics across the United States. Currently, there are no uniformly accepted criteria regarding how best to select patients for radiofrequency denervation. METHODS: A randomized, multicenter study was performed in 151 subjects with suspected lumbar facetogenic pain comparing three treatment paradigms. Group 0 received radiofrequency denervation based solely on clinical findings; group 1 underwent denervation contingent on a positive response to a single diagnostic block; and group 2 proceeded to denervation only if they obtained a positive response to comparative blocks done with lidocaine and bupivacaine. A positive outcome was predesignated as > or =50% pain relief coupled with a positive global perceived effect persisting for 3 months. RESULTS: In group 0, 17 patients (33%) obtained a successful outcome at 3 months versus eight patients (16%) in group 1 and 11 (22%) patients in group 2. Denervation success rates in groups 0, 1, and 2 were 33, 39, and 64%, respectively. Pain scores and functional capacity were significantly lower at 3 months but not at 1 month in group 2 subjects who proceeded to denervation compared with patients in groups 0 and 1. The costs per successful treatment in groups 0, 1, and 2 were $6,286, $17,142, and $15,241, respectively. CONCLUSIONS: Using current reimbursement scales, these findings suggest that proceeding to radiofrequency denervation without a diagnostic block is the most cost-effective treatment paradigm.

Radiofrequency neurotomy for lumbar pain.

(1) Chronic lumbar (lower back) pain, which affects many Canadians, imposes a large economic burden. (2) Symptoms may occur in the vertebral facet joints of 15% to 40% of patients with lower back pain. (3) Medial branch radiofrequency neurotomy is a minimally invasive outpatient procedure that reduces pain by interrupting the nerve supply to painful facet joints. (4) Four systematic reviews of this procedure offer disparate conclusions. (5) One small well designed observational study has shown positive results, but no equally rigorous randomized controlled trial has been conducted.

Regional assessment of joint position sense in the spine.

STUDY DESIGN: A test-retest design was used to assess the reproducibility of position sense measurements of the spine recorded at T1, T7, L1, and S2. OBJECTIVES: To measure position sense at four spinal levels in healthy volunteers and to determine if this varies on a day-to-day basis. The overall purpose is to provide baseline data for studying position sense of the spine in patients with spinal lesions. SUMMARY OF BACKGROUND DATA: Position sense, which is one component of proprioception, is assessed by the ability to reposition the body after displacement. In peripheral joints, position sense is accurate to within a few degrees. Studies on the spine suggest similar accuracy, but most have used indirect methods of measurement that often incorporate unusual extraneous cues. METHODS: Spinal position sense was assessed in 20 healthy volunteers using an electromagnetic movement sensor system, the 3-Space Fastrak (Polhemus, Colchester, VT), to measure absolute error in actively reproducing upright and flexed positions during movements in both coronal and sagittal planes. Three randomized measurements were taken for each position in one testing session, and measurements were repeated in all participants 2 weeks later. RESULTS: Same-day measurements indicate that spinal position sense is reproducible in upright postures to within a mean of 3.79 +/- 2.56 for movements in the sagittal plane and 2.26 +/- 1.59 degrees for movements in the coronal plane. Corresponding measurements for flexed postures are 5.27 degrees +/- 3.47 degrees and 3.70 +/- 2.62 degrees, respectively. Intraclass correlation coefficients between repeated measurements are generally good in the sagittal plane but are affected by side dominance in the coronal plane. Also, repositioning errors tend to increase on ascending the spine. Repeat measurements taken 2 weeks later show similar values. CONCLUSIONS: 1) Healthy volunteers were able to reposition their spine with considerable accuracy as measured with the 3-Space Fastrak; 2) this ability does not change significantly on a day-to-day basis; and 3) the 3-Space Fastrak offers a noninvasive and accurate method for the measurement of spinal position sense.

A critical assessment of clinical diagnosis of disc herniation in patients with monoradicular sciatica.

The diagnostic power or clinical parameters in the diagnosis of lumbar disc herniation in patients with monoradicular pain was evaluated in a prospective study with a 100% verification of the diagnosis. Eighty patients with monoradicular pain corresponding to the fifth lumbar or the first sacral nerve root were included. Pre-operatively a number of clinical parameters were recorded and compared to the intra-operative finding of a disc herniation. The parameters were analysed by receiver operating characteristic (ROC) curves. Results from the available literature were analysed by ROC curves for comparison. In 76% of the cases a disc herniation was discovered. The level of the disc herniation was correctly predicted in 93% of these cases by the location of the pain alone or supplemented by neurological signs. Apart from radicularly distributed pain, all parameters in the present study and in the literature had no or low diagnostic accuracy. Thus, in patients with monoradicular sciatica further clinical parameters do not add to the diagnosis of lumbar disc herniation.

Lumbar percutaneous facet rhizotomy.

The author reports on 223 patients who underwent lumbar percutaneous facet rhizotomy for chronic low-back or chronic back and leg pain. The overall success rate was 69%. The procedure is very safe and can offer relief for many patients in whom organic pathology, most commonly a herniated lumbar disc, has been eliminated. The procedure, screening and results are discussed.

An anatomical assessment of the "percutaneous rhizolysis" procedure.

The procedure known as rhizolysis has been claimed to denervate the lumbar zygapophyseal joints. Analysis of the surgical anatomy of the incisions used in the procedure reveals that theoretically they do not interrupt the nerve supply to the zygapophyseal joints. The procedure was performed at six levels in each of three cadavers. Subsequent dissection revealed that at no level was the nerve supply to the zygapophyseal joints interrupted. The writers conclude that denervation of the Zygapophyseal joints cannot be held to be the mechanism of any pain relief that rhizolysis may achieve.