Twelve-month follow-up of a controlled trial of intradiscal thermal anuloplasty for back pain due to internal disc disruption

Clinical Practice in Spine Surgery: An International Survey

BACKGROUND

 The availability of diverse and sophisticated surgical options to treat spine conditions is compounded by the scarcity of high-level evidence to guide decision-making. Although studies on discrete treatments are frequently published, little information is available regarding real-world surgical practice. We intended to survey spine surgeons to assess clinical management of common spine diagnosis in day-to-day settings.

METHODS

 An online survey was distributed among neurosurgeons and orthopaedic surgeons worldwide. The obtained assessment of common surgical practice is contextualized in a review of the best available evidence.

RESULTS

 The survey was answered by more than 310 members of several European, Australasian, and South African professional societies. The submitted responses translate a surgical practice generally grounded on evidence, favoring well-tried techniques, providing comprehensive treatment for the most severe diagnoses. Such practice comes mostly from neurosurgeons focused on spine surgery, practicing in teaching hospitals.

CONCLUSION

 We believe that the pragmatic, day-to-day approach to spine conditions captured in the present survey offers an informative insight to involved surgeons.

Percutaneous plasma laser disc coagulation and navigable ablation decompression in the treatment of cervical disc herniation: a single center experience

Background/aim

We aimed to compare the effectivity of percutaneous disc coagulation therapy (PDCT) and navigable ablation decompression treatment (L-DISQ) in patients who were diagnosed with cervical disc herniation.

Materials and methods

Visual analog scale (VAS) and Neck Pain Index (NPI) scores were recorded initially and at the 1st, 3rd, 6th, and 12th months after the procedures. Patient Satisfaction Scale (PSS) scores were recorded 12 months after the procedures

Results

Mean VAS scores were 7.55 and 3.1 points in the PDCT group and 7.6 and 3.00 points in the L-DISQ group; mean NPI scores were 34.2 and 20.75 points in the PDCT group and and 34.1 and 20.4 points in the L-DISQ group initially and at the 12th month. When compared between months, there was a significant decrease in time-dependent VAS and NPI scores in both PDCT and L-DISQ groups (P = 0.001). Some complications included esophageal, vascular, and neural injuries; hoarseness; Horner syndrome; infections; dural puncture; and muscle spasm. The only difference between groups was the rate of cervical spasm within 1 month after the procedure: 75% in the PDCT group and 15% in the L-DISQ group.

Conclusion

The diameter of the canal of the cervical vertebrae is narrower than of the lumbar and thoracic regions; therefore, the smaller part of the disc may be sufficient to create clinical signs. The response to decompression therapies is faster in the case of cervical percutaneous procedures that are performed correctly. Proper patient selection and practitioner’s experience are important in the treatment success

Discogenic low back pain: interventional treatment

Low back pain (LBP) is one of the most common causes of disability in the adult population. A significant place in its genesis is occupied by a degenerative-dystrophic diseases of intervertebral discs. The article highlights the classification and mechanism of discogenic pain origin. Various types of interventions aredescribed for this pathology: indications, specificities of carrying out manipulations and therapeutic effects, efficiency and possible complications of procedures.

Bioinformatics analysis reveals different gene expression patterns in the annulus fibrosis and nucleus pulpous during intervertebral disc degeneration

Degeneration of the intervertebral disc (IVD), which consists of the annulus fibrosus (AF) and nucleus pulposus (NP), is a multifactorial physiological process associated with lower back pain. Despite decades of research, the knowledge of the underlying molecular mechanisms of IVD degeneration (IDD) has remained limited. The present study aimed to reveal the differential gene expression patterns in AF and NP during the process of IDD and to identify key biomarkers contributing to these differences. The microarray dataset GSE70362 containing 24 AF and 24 NP samples was retrieved from the Gene Expression Omnibus database. Of these, 8 healthy samples were discarded. GeneSpring11.5 software was employed to identify differentially expressed genes (DEGs). Metascape online tools were used to perform enrichment analyses. Finally, the DEGs were mapped with the Search Tool for the Retrieval of Interacting Genes, and a protein-protein interaction (PPI) network was constructed in Cytoscape software. A total of 87 DEGs were identified. Gene ontology enrichment revealed that these DEGs were mainly involved in the inflammatory response, the extracellular matrix and RNA polymerase II transcription factor activity. Pathway enrichment revealed that the DEGs were mainly involved in the transforming growth factor (TGF-β) and estrogen signaling pathways. Matrix metalloproteinase (MMP)1 and interleukin (IL)6 were included in the genes enriched in rheumatoid arthritis, whereas bone morphogenetic protein (BMP)2 and thrombospondin 1 (THBS1) were among the genes enriched in the TGF-β signaling pathway. In the PPI network, IL6 was identified as the central gene. In conclusion, as MMP1 has been demonstrated degrade collagen III at higher rates compared with other types of collagen (which is at a higher quantity in AF than NP), collagen types may be in different distribution patterns, which may contribute to the upregulation of MMP1 in AF. Differences in the expression of BMP2, ESR1 and THBS1 may explain for the pathological differences between AF and NP. IL6 may have a key role in different degeneration processes in AF and NP.

Comparison the Postoperation Results of Discectomy with Nucleoplasty in Single Cervical Disc Herniation

BACKGROUND

The standard treatment for cervical disc herniation is open discectomy surgery but some of techniques, such as nucleoplasty were applied by neurosurgeons in recent decade. The aim of this study was to compare the postoperation results of open discectomy and nucleoplasty methods in people suffering from single cervical disc herniation.

MATERIALS AND METHODS

In a clinical trial study that performed during 2012-2013, 70 patients who candidate for neck surgery were selected and randomly divided into two groups. The first group was operated with standard discectomia and the second group was operated with nucleoplasty method. All patients were followed neck pain, upper limb pain and common complications included discitis, infection and hematoma in 2 weak, 1, 2, 3, and 6 months after operation. All data were analyzed using SPSS software.

RESULTS

Cervical pain mean from before the operation to 6 months after operation had no significant difference between two groups, but radicular pain had significant difference in 2 and 3 months after operation (P < 0.05). It is notable that after operation it is not observed any discitis, infection and hematoma of operated place.

CONCLUSION

Doing nucleoplasty surgery in patients suffering from single cervical disc herniation causes decrease in cervical and radicular pain, at least as the same as discectomy method. Since now it is possible in our country to apply this method and on the other hand, in this method, time of surgery, postoperation complications, hospital costs, and period of convalescence is low, it is preferred in patients suffering from cervical disc and its application is advised.

Clinical Efficacy of Selective Focal Ablation by Navigable Percutaneous Disc Decompression Device in Patients With Cervical Herniated Nucleus Pulposus

Objective

To evaluate the clinical efficacy and safety following percutaneous disc decompression, using navigable disc decompression device for cervical herniated nucleus pulposus (HNP).

Methods

Twenty subjects diagnosed with cervical HNP and refractory to conservative management were enrolled for the study. The herniated discs were decompressed under fluoroscopic guidance, using radiofrequency ablation device with navigable wand. The sagittal and axial plain magnetic resonance images of the clinically significant herniated disc, decided the space between the herniated base and outline as the target area for ablation. Clinical outcome was determined by Numeric Rating Scale (NRS), Neck Disability Index (NDI), and Bodily Pain scale of Short Form-36 (SF-36 BP), assessed after 48 weeks. After the procedure, we structurally matched the magnetic resonance imaging (MRI) and C-arm images through bony markers. The wand position was defined as being ‘correct’ if the tip was placed within the target area of both AP and lateral views; if not, the position was stated as ‘incorrect’.

Results

The average NRS fell from 7 to 1 at 48 weeks post procedure (p<0.05). In addition, statistically significant improvement was noted in the NDI and SF-36BP (p<0.05). The location of the wand tip resulted in 16 correct and 4 incorrect placements. Post-48 weeks, 3 of the incorrect tip cases and 1 correct tip case showed unsuccessful outcomes.

Conclusion

The study demonstrated the promising results and safety of the procedure. Thus, focal plasma ablation of cervical HNP with navigable wand can be another effective treatment option.

Comparison of open surgical discectomy versus plasma-laser nucleoplasty in patients with single lumbar disc herniation

Background:

Intervertebral disc herniation is a major cause of low back pain. Several treatment methods are available for lumbar disc herniation including Chemonucleolysis, open surgery, nucleoplasty, laser disc decompression, and intradiscal electrothermal therapy. The high prevalence of lumbar disc herniation necessitates a minimally invasive yet effective treatment method. In this study, we compared the outcomes of open surgery and nucleoplasty method in patients with single lumbar disc herniation.

Materials and Methods:

This study was a noninferiority randomized clinical trial conducted in one of the University Hospitals of Isfahan Medical University; The Alzahra Hospital. About 200 patients with the diagnosis of lumbar disc herniation were recruited and were assigned to either the treatment or control groups using block randomization. One group received open surgery and the other group received nucleoplasty as the method of treatment. Patients were revisited at 14 days, 1, 2, 3 months, and 1-year after surgery and were assessed for the following variables: Lower back pain, lower limb pain, common complications of surgery (e.g., discitis, infection and hematoma) and recurrence of herniation.

Results:

The mean (standard deviation) severity of low back pain was reduced from 6.92 (2.5) to 3.43 (2.3) in the nucleoplasty group (P = 0.04) and from 7.5 (2.2) to 3.04 (1.61) in the discectomy group (P = 0.73). Between group difference was not statistically significant (P = 0.44), however, time and treatment interaction was significant (P = 0.001). The level of radicular pain evaluated 1 year after treatment was reduced from 8.1 (1.2) to 2.9 (1.2) (P = 0.004) and from 7.89 (2.1) to 3.6 (2.5) (P =0.04) in the discectomy and the nucleoplasty groups respectively, significant interaction between time and treatment options was observed (P < 0.001) while there was no significant difference between two treatment groups (P = 0.82).

Conclusion:

Our results show that while nucleoplasty is as effective as open discectomy in the treatment of lumbar disc herniation, it is also less invasive with higher patient compliance. Taking factor such as decreased cost and duration of the surgery, as well as faster recovery in patients into account; we suggest considering nucleoplasty as an effective method of treatment in patients with single-level disc herniation.

Identification of the potential molecular targets for human intervertebral disc degeneration based on bioinformatic methods

The present study aimed to explore potential molecular targets and gain further insights into the mechanism of intervertebral disc degeneration (IDD) progression. Microarray datasets of GSE19943, GSE15227 and GSE34095 were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) in 3 IDD specimens compared with 3 controls in GSE34095, DEGs in 7 grade III and 3 grade IV samples compared with 5 grade II samples in GSE19943, and differentially expressed miRNAs in 3 degenerated samples compared with 3 controls in GSE15227 were screened. Grade III‑ and IV‑specific networks were constructed and grade‑specific genes were extracted. The network features were analyzed, followed by Gene Ontology (GO) enrichment analysis and pathway enrichment analysis of grade‑specific genes and DEGs identified in GSE34095. Furthermore, miRNA‑pathway interactions were analyzed using Fisher's exact test. Tumor protein p53 (TP53) was a hub gene in the grade III‑specific network and ubiquitin C (UBC) was identified to be a hub gene in the grade IV‑specific network. Six significant features were identified by grade‑specific network topology analysis. Grade‑specific genes and DEGs were involved in different GO terms and pathways. Differentially expressed miRNAs were identified to participate in 35 pathways, among which 6 pathways were significantly enriched by DEGs, including apoptosis. The present study identified that key genes (TP53 and UBC) and miR‑129‑5p may participate in the mechanism of IDD progression. Thus, they may be potential therapeutic targets for IDD.

Minimally invasive discectomy versus microdiscectomy/open discectomy for symptomatic lumbar disc herniation

BACKGROUND

Microdiscectomy or open discectomy (MD/OD) are the standard procedures for symptomatic lumbar disc herniation and they involve removal of the portion of the intervertebral disc compressing the nerve root or spinal cord (or both) with or without the aid of a headlight loupe or microscope magnification. Potential advantages of newer minimally invasive discectomy (MID) procedures over standard MD/OD include less blood loss, less postoperative pain, shorter hospitalisation and earlier return to work.

OBJECTIVES

To compare the benefits and harms of MID versus MD/OD for management of lumbar intervertebral discopathy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (November 2013), MEDLINE (1946 to November 2013) and EMBASE (1974 to November 2013) and applied no language restrictions. We also contacted experts in the field for additional studies and reviewed reference lists of relevant studies.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) and quasi-randomised controlled trials (QRCTs) that compared MD/OD with a MID (percutaneous endoscopic interlaminar or transforaminal lumbar discectomy, transmuscular tubular microdiscectomy and automated percutaneous lumbar discectomy) for treatment of adults with lumbar radiculopathy secondary to discopathy. We evaluated the following primary outcomes: pain related to sciatica or low back pain (LBP) as measured by a visual analogue scale, sciatic specific outcomes such as neurological deficit of lower extremity or bowel/urinary incontinence and functional outcomes (including daily activity or return to work). We also evaluated the following secondary outcomes: complications of surgery, duration of hospital stay, postoperative opioid use, quality of life and overall participant satisfaction. Two authors checked data abstractions and articles for inclusion. We resolved discrepancies by consensus.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We used pre-developed forms to extract data and two authors independently assessed risk of bias. For statistical analysis, we used risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes with 95% confidence intervals (CI) for each outcome.

MAIN RESULTS

We identified 11 studies (1172 participants). We assessed seven out of 11 studies as having high overall risk of bias. There was low-quality evidence that MID was associated with worse leg pain than MD/OD at follow-up ranging from six months to two years (e.g. at one year: MD 0.13, 95% CI 0.09 to 0.16), but differences were small (less than 0.5 points on a 0 to 10 scale) and did not meet standard thresholds for clinically meaningful differences. There was low-quality evidence that MID was associated with worse LBP than MD/OD at six-month follow-up (MD 0.35, 95% CI 0.19 to 0.51) and at two years (MD 0.54, 95% CI 0.29 to 0.79). There was no significant difference at one year (0 to 10 scale: MD 0.19, 95% CI -0.22 to 0.59). Statistical heterogeneity was small to high (I(2) statistic = 35% at six months, 90% at one year and 65% at two years). There were no clear differences between MID techniques and MD/OD on other primary outcomes related to functional disability (Oswestry Disability Index greater than six months postoperatively) and persistence of motor and sensory neurological deficits, though evidence on neurological deficits was limited by the small numbers of participants in the trials with neurological deficits at baseline. There was just one study for each of the sciatica-specific outcomes including the Sciatica Bothersomeness Index and the Sciatica Frequency Index, which did not need further analysis. For secondary outcomes, MID was associated with lower risk of surgical site and other infections, but higher risk of re-hospitalisation due to recurrent disc herniation. In addition, MID was associated with slightly lower quality of life (less than 5 points on a 100-point scale) on some measures of quality of life, such as some physical subclasses of the 36-item Short Form. Some trials found MID to be associated with shorter duration of hospitalisation than MD/OD, but results were inconsistent.

AUTHORS' CONCLUSIONS

MID may be inferior in terms of relief of leg pain, LBP and re-hospitalisation; however, differences in pain relief appeared to be small and may not be clinically important. Potential advantages of MID are lower risk of surgical site and other infections. MID may be associated with shorter hospital stay but the evidence was inconsistent. Given these potential advantages, more research is needed to define appropriate indications for MID as an alternative to standard MD/OD.

Application of percutaneous cervical nucleoplasty using the navigable disc decompression device in patient of cervical herniated intervertebral disc: a case report

Recent years, various percutaneous procedures including cervical nucleoplasty have been developed for disc decompressions to relieve radicular pains caused by disc herniations. We report the application of percutaneous cervical nucleoplasty (PCN) by using the navigable disc decompression device in two patients of cervical herniated intervertebral discs (HIVD). A 38-year-old female diagnosed with C4-C5 disc extrusion with bilateral C5 roots impingement received nucleoplasty twice at C4-C5 disc level. After second procedure, her pain was improved from 6-7/10 to 1-2/10 by visual analog scale (VAS). The second case, a 51-year-male was diagnosed with C6-C7 disc extrusion with right C7 roots impingement and received the procedure at C6-C7 disc level. The pain improved from 8/10 to 3-4/10 by VAS. Successfully, we decompressed cervical herniated discs in 2 HIVD patients without major complications. The PCN with the navigable device will be recommended as an alternative treatment method for cervical HIVD.

Diagnostic criteria and treatment of discogenic pain: a systematic review of recent clinical literature

BACKGROUND CONTEXT

Pain innate to intervertebral disc, often referred to as discogenic pain, is suspected by some authors to be the major source of chronic low back and neck pain. Current management of suspected discogenic pain lacks standardized diagnosis, treatment, and terminology.

PURPOSE

In an attempt to determine whether patterns existed that may facilitate standardization of care, we sought to analyze the terminologies used and the various modes of diagnosis and treatment of suspected discogenic pain.

STUDY DESIGN

A systematic review of the recent literature.

METHODS

A Medline search was performed using the terms degenerative disc disease, discogenic pain, internal disc disruption while using the limits of human studies, English language, and clinical trials, for the last 10 years. The search led to a total of 149 distinct citations, of which 53 articles, where the intervertebral disc itself was considered the principal source of patient's pain and was the main target of the treatment, were retained for further analysis.

RESULTS

The results of this review confirm and help quantify the significant differences that existed in the terminology and all the areas of diagnosis and treatment of presumed discogenic pain.

CONCLUSIONS

Our findings show that suspected discogenic pain, despite its extensive affirmation in the literature and enormous resources regularly devoted to it, currently lacks clear diagnostic criteria and uniform treatment or terminology.

Gene therapy for intervertebral disk degeneration

Intervertebral disk degeneration is a common and potentially debilitating disease process affecting millions of Americans and other populations each year. Current treatments address resultant symptoms and not the underlying pathophysiology of disease. This has spawned the development of biologic treatments, such as gene therapy, which attempt to correct the imbalance between catabolism and anabolism within degenerating disk cells. The identification of therapeutic genes and development of successful delivery systems have resulted in significant advances in this novel treatment. Continued investigation of the pathophysiology of disk degeneration, however, and safety mechanisms for the application of gene therapy are required for clinical translation.

Mesenchymal stem cells injection in degenerated intervertebral disc: cell leakage may induce osteophyte formation

Recent studies have shown that mesenchymal stem cell (MSC)-based therapy might be an effective approach for the treatment of intervertebral disc degeneration (IDD). However, many unanswered questions remain before clinical translation, such as the most effective stem cell type, a reliable transplantation method, including the carrier choice, and the fate of stem cells after misdirected delivery, among others. The objective of the study was to evaluate the fate and effect of allogenic bone marrow MSCs after transplantation into an IDD model. The L2-3, L3-4 and L4-5 intervertebral discs (IVDs) of four rabbits were stabbed to create IDD. Rabbit MSCs were expanded in vitro and in part transduced with retrovirus/eGFP. After 3 weeks, 1 × 10(5) MSCs were injected into the IVDs. The rabbits were followed by X-ray and MRI 3 and 9 weeks after injection. Then the animals were sacrificed and the spines analysed histologically. MRI showed no signs of regeneration. X-ray and gross anatomy inspection demonstrated large anterolateral osteophytes. Histological analysis showed that the osteophytes were composed of mineralized tissue surrounded by chondrocytes, with the labelled MSCs among the osteophyte-forming cells. The labelled MSCs were not found in the nucleus. Inflammatory cells were not observed in any injected IVDs. These results raise concern that MSCs can migrate out of the nucleus and undesirable bone formation may occur. While cause cannot be inferred from this study, the presence of MSCs in the osteophytes suggests a potential side-effect with this approach. IVD regeneration strategies need to focus on cell carrier systems and annulus-sealing technologies to avoid pitfalls.

Heparanase isoform expression and extracellular matrix remodeling in intervertebral disc degenerative disease

OBJECTIVE

To determine the molecules involved in extracellular matrix remodeling and to identify and quantify heparanase isoforms present in herniated and degenerative discs.

INTRODUCTION

Heparanase is an endo-beta-glucuronidase that specifically acts upon the heparan sulfate chains of proteoglycans. However, heparanase expression in degenerative intervertebral discs has not yet been evaluated. Notably, previous studies demonstrated a correlation between changes in the heparan sulfate proteoglycan pattern and the degenerative process associated with intervertebral discs.

METHODS

Twenty-nine samples of intervertebral degenerative discs, 23 samples of herniated discs and 12 samples of non-degenerative discs were analyzed. The expression of both heparanase isoforms (heparanase-1 and heparanase-2) was evaluated using immunohistochemistry and real-time RT-PCR analysis.

RESULTS

Heparanase-1 and heparanase-2 expression levels were significantly higher in the herniated and degenerative discs in comparison to the control tissues, suggesting a possible role of these proteins in the intervertebral degenerative process.

CONCLUSION

The overexpression of heparanase isoforms in the degenerative intervertebral discs and the herniated discs suggests a potential role of both proteins in the mediation of inflammatory processes and in extracellular matrix remodeling. The heparanase-2 isoform may be involved in normal metabolic processes, as evidenced by its higher expression in the control intervertebral discs relative to the expression of heparanase-1.

6-month results of TransDiscal Biacuplasty on patients with discogenic low back pain: preliminary findings

STUDY DESIGN

Prospective observational study.

OBJECTIVE

Our aim is to investigate the efficacy and safety of TransDiscal Biacuplasty.

SUMMARY OF BACKGROUND DATA

Chronic discogenic pain is one of the leading causes of low back pain; however, the condition is not helped by most non-invasive methods. The results of major surgical operations for these patients are unsatisfactory. Recently, attention has shifted to disk heating methods for treatment. TransDiscal Biacuplasty is one of the minimally invasive treatment methods. The method was developed as an alternative to spinal surgical practices and Intradiscal Electrothermal Therapy for treatment of patients with chronic discogenic pain.

METHODS

The candidates for this study were patients with chronic discogenic pain that did not respond to conservative treatment. The main criteria for inclusion were: the existence of axial low back pain present for 6 months; disc degeneration or internal disc disruption at a minimum of one level, and maximum of two levels, in MR imaging; and positive discography. Physical function was assessed using the Oswestry Disability Index when measuring the pain with VAS. Patient satisfaction was evaluated using a 4-grade scale. Follow-ups were made 1, 3, and 6 months after treatment.

RESULTS

15 patients were treated at one or two levels. The mean patient age was 43.1 ± 9.2 years. We found the mean symptom duration to be 40.5 ± 45.7 months. At the sixth month, 57.1% of patients reported a 50% or more reduction in pain, while 78.6% of patients reported a reduction of at least two points in their VAS values. In the final check, 78.6% of patients reported a 10-point improvement in their Oswestry Disability scores compared to the initial values. No complications were observed in any of the patients.

CONCLUSIONS

TransDiscal Biacuplasty is an effective and safe method.

A randomized placebo-controlled trial of intradiscal methylene blue injection for the treatment of chronic discogenic low back pain

A preliminary report of clinical study revealed that chronic discogenic low back pain could be treated by intradiscal methylene blue (MB) injection. We investigated the effect of intradiscal MB injection for the treatment of chronic discogenic low back pain in a randomized placebo-controlled trial. We recruited 136 patients who were found potentially eligible after clinical examination and 72 became eligible after discography. All the patients had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-six were allocated to intradiscal MB injection and 36 to placebo treatment. The principal criteria to judge the effectiveness included alleviation of pain, assessed by a 101-point numerical rating scale (NRS-101), and improvement in disability, as assessed with the Oswestry Disability Index (ODI) for functional recovery. At the 24-month follow-up, both the groups differed substantially with respect to the primary outcomes. The patients in MB injection group showed a mean reduction in pain measured by NRS of 52.50, a mean reduction in Oswestry disability scores of 35.58, and satisfaction rates of 91.6%, compared with 0.70%, 1.68%, and 14.3%, respectively, in placebo treatment group (p<0.001, p<0.001, and p<0.001, respectively). No adverse effects or complications were found in the group of patients treated with intradiscal MB injection. The current clinical trial indicates that the injection of methylene blue into the painful disc is a safe, effective and minimally invasive method for the treatment of intractable and incapacitating discogenic low back pain.

Complete percutaneous treatment of vertebral body tumors causing spinal canal compromise using a transpedicular cavitation, cement augmentation, and radiosurgical technique

Object

Patients with symptomatic pathological compression fractures require spinal stabilization surgery for mechanical back pain control and radiation therapy for the underlying malignant process. Spinal radiosurgery provides excellent long-term radiographic control for vertebral metastases. Percutaneous cement augmentation using polymethylmethacrylate (PMMA) may be contraindicated in lesions with spinal canal compromise due to the risk of displacement of tumor resulting in spinal cord or cauda equina injury. However, there is also significant morbidity associated with open corpectomy procedures in patients with metastatic cancer, especially in those who subsequently require adjuvant radiotherapy. This study evaluated a treatment paradigm for malignant vertebral compression fractures consisting of transpedicular coblation corpectomy combined with closed fracture reduction and fixation, followed by spinal radiosurgery.

Methods

Eleven patients (6 men and 5 women, mean age 58 years) with symptomatic vertebral body metastatic tumors associated with moderate spinal canal compromise were included in this study (8 thoracic levels, 3 lumbar levels). Primary histologies included 4 lung, 2 breast, 2 renal, and 1 each of thyroid, bladder, and hepatocellular carcinomas. All patients underwent percutaneous transpedicular coblation corpectomy immediately followed by balloon kyphoplasty through the same 8-gauge cannula under fluoroscopic guidance. Patients subsequently underwent radiosurgery to the affected vertebral body (mean time to treatment 14 days). Postoperatively, patients were assessed for pain reduction and neurological morbidity.

Results

There were no complications associated with any part of the procedure. Adequate cement augmentation within the vertebral body was achieved in all cases. The mean radiosurgical tumor dose was 19 Gy covering the entire vertebral body. The procedure provided long-term pain improvement and radiographic tumor control in all patients (follow-up range 7–44 months). No patient later required open surgery. No radiation-induced toxicity or new neurological deficit occurred during the follow-up period.

Conclusions

This treatment paradigm for pathological fractures of percutaneous transpedicular corpectomy combined with cement augmentation followed by radiosurgery was found to be safe and clinically effective. This technique combines minimally invasive procedures that avoid the morbidity associated with open surgery while providing spinal canal decompression and immediate fracture stabilization, and then administering a single-fraction tumoricidal radiation dose.

A randomized double-blind controlled trial of intra-annular radiofrequency thermal disc therapy--a 12-month follow-up

The discTRODE probe applies radiofrequency (RF) current, heating the annulus to treat chronic discogenic low back pain. Randomized controlled studies have not been published. We assessed the long-term effect and safety aspects of percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) with the discTRODE probe in a prospective parallel, randomized and gender stratified, double-blind placebo-controlled study. Twenty selected patients with chronic low back pain and a positive one-level pressure-controlled provocation discography were randomized to either intra-annular PIRFT or intra-annular sham treatment. A blinded interim analysis was performed when 20 patients had been followed for six months. The 6-month analysis did not reveal any trend towards overall effect or difference between active and sham treatment for the primary endpoint: change in pain intensity (0-10). The inclusion of patients was therefore discontinued. After 12 months the overall reduction from baseline pain had reached statistical significance, but there was no significant difference between the groups. The functional outcome measures (Oswestry Disability Index, and SF 36 subscales and the relative change in pain) appeared more promising, but did not reach statistical significance when compared with sham treatment. Two actively treated and two sham-treated patients reported increased pain levels, and in both groups a higher number was unemployed after 12 months. The study did not find evidence for a benefit of PIRFT, although it cannot rule out a moderate effect. Considering the high number, reporting increased pain in our study, we would not recommend intra-annular thermal therapy with the discTRODE probe.

Radiofrequência na dor crônica

Radiofrequência (RF) é uma técnica minimamente invasiva alvo-seletiva e tem sido usada durante muitos anos para o tratamento de diferentes doenças, como dor lombar crônica, neuralgia trigeminal e outros. Trata-se de uma corrente elétrica alternada com frequência oscilatória de 500.000 hz, que flui através de um eletrodo introduzido percutaneamente. O calor é formado ao redor do eletrodo porque o tecido age como um resistor. Essa técnica pode, portanto, ser usada para causar lesões em tecidos nervosos no tratamento de dor crônica. O objetivo desta revisão é abordar alguns aspectos importantes do mecanismo e evolução da radiofrequência na dor crônica. Serão abordados os aspectos básicos da Física e o mecanismo de ação da radiofrequência, método que tem sido usado para tratar dores crônicas de diferentes etiologias, além da evolução com o advento da radiofrequência pulsátil. O uso da radiofrequência no manejo da dor crônica é uma ferramenta útil em diferentes condições dolorosas e tem sido usada com sucesso por mais de 25 anos. Seu mecanismo de ação ainda não foi totalmente elucidado. A radiofrequência pulsátil é, em particular, uma técnica minimamente destrutiva e poderá ser uma alternativa à forma convencional de tratamento para a dor por radiofrequência.

Burned-out discs stop hurting: fact or fiction?

STUDY DESIGN

Cross-sectional study of a general-population sample.

OBJECTIVE

The aim was to test the hypothesis that moderate disc degeneration (DD) is stronger associated with low back pain (LBP) than severe degeneration, and also to identify a possible dose-response relationship between numbers of degenerated discs and LBP.

SUMMARY OF BACKGROUND DATA

Among many clinicians there has been a belief that DD initially causes pain because of the penetration of fluid nuclear material through annular fissures, and that pain eventually resolves as the nucleus becomes fibrotic and can no longer penetrate the fissures.

METHODS

From a population-based cohort of 412 individuals, all aged 40, three groups were created for a primary analysis: those with exclusively normal discs (white nuclei on a T2-weighted MRI), those with moderate DD (grey) + normal, and those with severely degenerated (black) + normal discs. The number of individuals reporting LBP during the past year (the most relevant for chronic/intermittent pain) and the past month were separately related to DD. Second, a possible dose-response in terms of numbers of abnormal discs was analyzed.

RESULTS

The percentage of people with LBP was virtually not influenced by grey discs, where the fraction with pain during the past year was close to 69% irrespective of the presence or number of grey discs. Black discs, however, increased the corresponding fraction from 60%, if no black discs, to 86% for those with 2 (odds ratio of 2 per number of black disc). The risk for LBP during the past year attributed to black discs was 11%.

CONCLUSION

The data could not support the hypothesis that severely degenerated discs are "burned out" and become less painful. People with black discs had a higher prevalence of LBP compared to those with grey or normal discs, the latter 2 being equally often painful.

Lumbar spinal arthroplasty: analysis of one center's twenty best and twenty worst clinical outcomes

STUDY DESIGN

This is a retrospective analysis of data that were collected prospectively from 2 concurrent FDA IDE lumbar arthroplasty clinical trials performed at a single center.

OBJECTIVES

The purpose of this study was to determine if factors differentiating those patients with the best and worst clinical outcomes from total disc arthroplasty (TDR) could be identified.

SUMMARY OF BACKGROUND DATA

Overall the results of TDR have been favorable, including recent results from 2 FDA IDE trials conducted in the United States. However, as with any surgical procedure, there were some patients with extremely good outcomes, and some with poor outcomes. If factors differentiating these groups could be identified, this may help refine patient selection criteria and improve future results.

METHODS

The databases of Charite and ProDisc patients at a single site were reviewed to identify patients who reached the 24-month follow-up period. A total of 203 patients, 63 who were implanted with the Charite prosthesis, and 140 who were implanted with the ProDisc prosthesis, were identified. The percentage change in the preoperative to postoperative VAS and Oswestry scores were used to identify the 10 best and 10 worst outcomes for each of the device types. Logistic regression analysis was conducted to determine which of a battery of demographic and clinical assessments were related to the best/worst group classification.

RESULTS

Results of the regression analysis found that the only factor significantly related to clinical outcome was the length of time off work before surgery. None of the demographic variables, preoperative VAS or Oswestry scores or radiographic assessment of device placement, were significantly related to clinical outcome. Patients who were off work for shorter durations, or not at all, were more likely to be in the best-outcome group compared with patients who were off work for an extended period of time before surgery.

CONCLUSION

This study suggests that among patients undergoing TDR, the length of time off work before surgery was related to outcome. No additional factors related to the best/worst classification were identified in the current study.

Intradiscal electrothermal therapy (IDET) for low back pain in worker's compensation patients: can it provide a potential answer? Long-term results

OBJECTIVE

This prospective study was conducted to evaluate improvements in pain and disability in a series of 53 consecutive worker's compensation patients with low back pain (LBP) after treatment with the intradiscal electrothermal therapy (IDET) procedure.

MATERIALS AND METHODS

All patients seen in the out-patient clinic of the Spine Institute of Louisiana for LBP of discogenic origin were screened for eligibility to receive IDET procedure. A total of 134 patients were treated using IDET for their discogenic LBP during the study period. Fifty-three patients presented to us via the worker's compensation claim program. The outcomes of these 53 patients were analyzed statistically for the current study by physical examination and self-assessment questionnaires of pain and disability at baseline and at 12-months postprocedure. Pain and disability outcomes were assessed by visual analog scale (VAS) pain score and Oswestry disability index, respectively.

RESULTS

The mean patient age was 41.83 years (range 20 to 61 y). Whites (52.8%), African-Americans (30.2%), and Hispanics (17%) formed the majority of population. Forty-nine percent were using narcotics. The first definitive end point was considered at 12 months after the procedure. Median follow-up period was 56 months (range 29 to 72 mo). A mean reduction (P<0.001) of 62.6% in the VAS score and 69.3% in the Oswestry scores was noted after IDET. The patient's initial VAS and Oswestry scores (P<0.05) significantly affected the final outcomes. About 47.2% of the patients had some degree of economic productivity and only 7 (initial 26) consumed narcotic analgesics.

CONCLUSIONS

IDET procedure can be a useful, safe, and cost-effective option in the management of carefully selected workers compensation claimants with chronic LBP of discogenic etiology.

Coculture of bone marrow mesenchymal stem cells and nucleus pulposus cells modulate gene expression profile without cell fusion

STUDY DESIGN

Changes in gene expression profile and cell fusion of mesenchymal stem cells (MSC) and nucleus pulposus cells (NPC) after coculture were analyzed.

OBJECTIVE

To investigate the mechanisms of the interaction between NPC and MSC such us differentiation, stimulatory effect, and cell fusion.

SUMMARY OF BACKGROUND DATA

Introduction of exogenous cells to supplement and replenish intervertebral disc cell population offers a potential approach to treat intervertebral disc degeneration (IDD). Recent evidences showed that intradiscal injection of MSC effectively alter the course of IDD in vivo, and the regenerative potential may result from up-regulated extracellular matrix protein synthesis mediated by MSC and NPC interaction.

METHODS

Using a double labeling cell system and flow activated cell sorting, we quantitatively analyzed changes in the gene expression profile of human male MSC and female NPC after coculture in a 3-dimensional system that allows short distance paracrine interactions typical of the nucleus pulposus. Furthermore, we analyzed for cell fusion in the cell interaction by fluorescence in situ hybridization (FISH) for X and Y chromosomes, using a 3-dimensional culture system to allow cell-to-cell interactions conducive to cell fusion.

RESULTS

Two weeks of coculture cell interaction in a 3-dimensional environment induces a change in MSCs towards a more chondrogenic gene expression profile indicating MSC differentiation, and NPC gene expression changes in matrix and chondrogenic genes demonstrating only a modest trophic effect of MSC on NPC. Moreover, FISH analysis demonstrated that cell fusion is not responsible for MSC plasticity in the interaction with NPCs.

CONCLUSION

This study clarifies the mechanism of MSCs and NPCs interaction in a 3-dimensional environment, excluding cell fusion. These data support the use of undifferentiated MSC for stem cell therapy for IDD treatment.

Intervertebral disc biacuplasty for the treatment of lumbar discogenic pain: results of a six-month follow-up

OBJECTIVE

Intradiscal biacuplasty (IDB) is a novel bipolar cooled radiofrequency system for the treatment of degenerative disk disease. We present the results of a pilot trial with 6-month follow-up. DESIGN, SETTING, PATIENTS, AND INTERVENTIONS: Fifteen patients, 22-55 years old, underwent one- or two-level IDB treatment of their painful lumbar discs. All had chronic low back pain >6 months, back pain exceeding leg pain, concordant pain on provocative discography, disc height >50% of control, and evidence of single- or two-level degenerative disc disease without evidence of additional changes on magnetic resonance imaging. IDB was performed under fluoroscopy using two radiofrequency probes positioned bilaterally in the intervertebral disc. Thirteen patients completed follow-up questionnaires at 1, 3, and 6 months. Pain disability was evaluated with Oswestry and Short Form (SF)-36 questionnaires.

RESULTS

Median visual analog scale pain scores were reduced from 7 (95% confidence interval [CI] 6, 8) to 4 (2, 5) cm at 1 month, and remained at 3 (2, 5) cm at 6 months. The Oswestry improved from 23.3 (SD 7.0) to 16.5 (6.8) points at 1 month and remained similar after 6 months. The SF-36 Physical Functioning scores improved from 51 (18) to 70 (16) points after 6 months, while the SF-36 Bodily Pain score improved from 38 (15) to 54 (23) points. Daily opioid use did not change significantly from baseline: from 40 (95% CI 40, 120) before IDB to 5 (0, 40) mg of morphine sulfate equivalent 6 months after IDB. No procedure-related complications were detected.

CONCLUSIONS

Patients showed improvements in several pain assessment measures after undergoing IDB for discogenic pain. A randomized controlled study is warranted and needed to address the efficacy of the procedure.

Intervertebral disc: anatomy-physiology-pathophysiology-treatment

This review article describes anatomy, physiology, pathophysiology and treatment of intervertebral disc. The intervertebral discs lie between the vertebral bodies, linking them together. The components of the disc are nucleus pulposus, annulus fibrosus and cartilagenous end-plates. The blood supply to the disc is only to the cartilagenous end-plates. The nerve supply is basically through the sinovertebral nerve. Biochemically, the important constituents of the disc are collagen fibers, elastin fibers and aggrecan. As the disc ages, degeneration occurs, osmotic pressure is lost in the nucleus, dehydration occurs, and the disc loses its height. During these changes, nociceptive nuclear material tracks and leaks through the outer rim of the annulus. This is the main source of discogenic pain. While this is occurring, the degenerative disc, having lost its height, effects the structures close by, such as ligamentum flavum, facet joints, and the shape of the neural foramina. This is the main cause of spinal stenosis and radicular pain due to the disc degeneration in the aged populations. Diagnosis is done by a strict protocol and treatment options are described in this review. The rationale for new therapies are to substitute the biochemical constituents, or augment nucleus pulposus or regenerate cartilaginous end-plate or finally artificial disc implantation..

Evidence-informed management of chronic low back pain with intradiscal electrothermal therapy

The management of chronic low back pain (CLBP) has proven very challenging in North America, as evidenced by its mounting socioeconomic burden. Choosing among available nonsurgical therapies can be overwhelming for many stakeholders, including patients, health providers, policy makers, and third-party payers. Although all parties share a common goal and wish to use limited health-care resources to support interventions most likely to result in clinically meaningful improvements, there is often uncertainty about the most appropriate intervention for a particular patient. To help understand and evaluate the various commonly used nonsurgical approaches to CLBP, the North American Spine Society has sponsored this special focus issue of The Spine Journal, titled Evidence-Informed Management of Chronic Low Back Pain Without Surgery. Articles in this special focus issue were contributed by leading spine practitioners and researchers, who were invited to summarize the best available evidence for a particular intervention and encouraged to make this information accessible to nonexperts. Each of the articles contains five sections (description, theory, evidence of efficacy, harms, and summary) with common subheadings to facilitate comparison across the 24 different interventions profiled in this special focus issue, blending narrative and systematic review methodology as deemed appropriate by the authors. It is hoped that articles in this special focus issue will be informative and aid in decision making for the many stakeholders evaluating nonsurgical interventions for CLBP.

The Evolution and Advancement of Endoscopic Foraminal Surgery: One Surgeon's Experience Incorporating Adjunctive Techologies

Background

Endoscopic spine surgery has evolved gradually through improvements in endoscope design, instrumentation, and surgical techniques. The ability to visualize and treat painful pathology endoscopically through the foramen has opened the door for the diagnosis and treatment of degenerative conditions of the lumbar spine (from T10 to S1). Other endoscopic techniques for treating a painful disc have been focused on a posterior approach and has been compared with micro–lumbar discectomy. These procedures have not been more effective than open microdiscectomy but are less invasive, have less surgical morbidity, and allow for more rapid surgical recovery. Spinal decompression and fusion was the fallback procedure when nonsurgical treatment or discectomy failed to relieve sciatica and back pain. Foraminal endoscopic surgery, however, provides a truly minimally invasive alternative approach to the pathoanatomy of the lumbar spine because it preserves the multifidus muscle, maintains motion, and eliminates or, at worst, delays the need for fusion.

Methods

The following developments helped facilitate the evolution of a transforaminal endoscopic surgery procedure for disc herniations from a foraminal disc decompression, also known as percutaneous endoscopic lumbar discectomy, to a more complete foraminal surgical technique that can address spinal stenosis and spinal instability. This expanded capability gives foraminal endoscopic surgery distinct advantages and flexibility for certain painful degenerative conditions compared with open surgery. Advancement of the technique occurred when needle trajectory and placement was refined to better target each type of herniation with precise needle and cannula positioning directed at the herniation. New instrumentation and inclusion of a biportal technique also facilitated removal of extruded, migrated, and sequestered disc herniations. The further development of foraminoscopes with larger working channels and high speed burrs to remove bone more efficiently, along with recognition of foraminal pathoanatomy in the foramen, led to the identification and treatment of other painful degenerative conditions of the lumbar spine such as failed back surgery syndrome, recurrent disc herniations, lateral foraminal stenosis, degenerative spondylolisthesis, and isthmic spondylolisthesis.

A summary of the endoscopic techniques currently used and trademarked by the author as the YESS technique include: (1) a published protocol for optimal needle and instrument placement calculated by lines drawn on the skin from the C-arm image; (2) evocative chromodiscography by the operating surgeon with nonionic radiologic contrast and indigo carmine dye to confirm concordant pain production and to stain tissue in contact with the injectate; (3) selective endoscopic discectomy, which targets the removal of loose degenerative nucleus stained differentially by indigo carmine dye; (4) thermal annuloplasty, a visualized radiofrequency thermal modulation of disc and annular defects guided by vital tissue staining; (5) endoscopic foraminoplasty, a decompression of the lateral and subarticular recess, including disc and foraminal degenerative and isthmic spondylolisthesis; (6) visually and radiologically guided exploration of the epidural space; (7) probing the hidden zone of MacNab for normal nerves (and branches of spinal nerves known as furcal nerves) versus anomalous autonomic nerves in the foramen; and (8) a uniportal and biportal technique for inside-out removal of extruded and sequestered nucleus pulposus.

Results

Endoscopic foraminal surgical procedures are not limited to disc decompression. The approaches and techniques allow access to the lumbar spine for treatment of conditions ranging from discogenic pain to failed back surgery syndrome (most commonly caused by residual or recurrent disc herniation and lateral recess stenosis). More than 3000 patients have undergone endoscopic posterolateral surgical exploration and decompression by the author since 1991. The first 80 patients reported formed the basis for expansion of techniques as new instruments and adjunctive therapy methods were added to selective endoscopic discectomy and thermal annuloplasty. New anatomic and pathoanatomic conditions were reported as they were encountered.

Conclusions

New skills will become desirable and necessary for the spine surgeon to keep up with endoscopic technology in spine care. The emphasis is on visualization of painful pathoanatomy and preservation of mobility. A new focus is on nucleus replacement, annular repair, annular reinforcement, biologics, and even transforaminal interbody fusion as the procedure of last resort. The transforaminal surgical approach to the lumbar spine can allow for minimally invasive access without negatively affecting and destabilizing the multifidus muscle.

Efficacy of IDET for relief of leg pain associated with discogenic low back pain

Intradiscal electrothermal annuloplasty (IDET) is an effective treatment for chronic discogenic low back pain (LBP). However, efficacy of IDET for the treatment of referred leg pain has not been examined. This study was performed to assess the long-term efficacy of IDET for the treatment of referred leg pain in chronic discogenic LBP patients. Data were retrospectively analyzed as an IDET case series from January 1999 to December 2000. The IDET procedure was performed at 1-3 symptomatic levels confirmed by pressure-controlled discography. General pain outcome was evaluated by Visual Analog Scale (VAS). LBP and leg pain were assessed separately using five-point pain scales (subsets of the North American Spine Society [NASS] LBP outcome assessment instrument: 0 = no pain, 4 = worst pain) at the 18-month follow-up. Among 129 patients who underwent IDET, 30 patients underwent subsequent back surgery and were excluded from the study, giving a total of 99 patients. Eighty-three patients (83.8%) had leg pain without sciatica. Fifty-two (52.5%), 21 (21.2%), and 8 (8.0%) patients showed LBP > leg pain, LBP = leg pain and LBP < leg pain, respectively. Fifty-three out of 83 patients (63.9%) showed post-IDET improvement in pain, with a mean VAS score of 3.28 +/- 2.31. Thirty patients (36.1%) showed no improvement. A statistically significant (P < 0.05) improvement in subjective back and referred leg pain was observed. Improvements in back and referred leg pain were well-correlated (r = 0.721, P < 0.01). A relatively large number of LBP patients who underwent IDET (84%) presented with referred leg pain without sciatica. The IDET procedure afforded improvements in leg pain that correlated well with improvements in back pain (0.75/4 and 0.88/4, respectively). These data suggest that IDET may relieve associated limb pain in chronic discogenic LBP patients.

The role of minimally invasive techniques in the management of spine tumors: percutaneous bone cement augmentation, radiosurgery, and microendoscopic approaches

In a similar manner to which patients with degenerative spinal disorders have benefited from advances in minimally invasive spine surgery techniques, patients with spine tumors may benefit from the option of less invasive techniques for tumor ablation, resection, reconstruction, and stabilization. Percutaneous bone cement augmentation, radiosurgery, and microendoscopic approaches for the treatment of spine tumors have allowed for improved clinical outcomes while limiting procedure-related morbidity in this unique patient population.

MR imaging and osseous spinal intervention and intervertebral disk intervention

Percutaneous spine intervention, a wide range of invasive spine procedures performed through a puncture hole or through a small incision not requiring soft tissue closure and with few or no skin sutures or staples, is rapidly emerging as an effective alternative to open surgery. This article describes many of the minimally invasive osseous, intervertebral disk, and spinal nerve interventions currently being performed, including both well-established procedures and procedures developed recently. A general introduction to these types of procedures is provided, along with the characteristic pre- and postprocedural MR imaging appearance related to these techniques. The article also discusses reported and theoretical complications that may arise and their respective MR imaging appearances.

Intradiscal thermal annuloplasty for discogenic pain: an outcome study

OBJECTIVES

Published studies of intradiscal thermal annuloplasty (IDTA) have shown at most 50% pain relief as an improved outcome with little focus on functional improvement in the treatment of discogenic pain. Previous studies have used a number of criteria for patient selection including low back pain unresponsive to conservative care, no compressive radiculopathy, positive provocative discography and absence of previous surgery at the same symptomatic level. The purpose of present study is to examine the hypothesis that additional inclusion criteria for patient selection such as disc height, absence of degenerative disc disease (DDD) in untreated discs, absence of herniated nucleus pulposus or lumbar canal stenosis may improve the outcome of treatment.

METHODS

In this prospective case-series study additional criteria of patient selection were introduced, namely disc height of at least 50%, no lumbar canal stenosis, one or two levels of DDD, no evidence of nucleus pulposus herniation on magnetic resonance image. Thirty-four patients were enrolled in the study and 32 of them were followed over a period of 12 months. The visual analog scale (VAS) pain score and seven activities of daily living (ADLs) were followed and reported on a scale from 0 to 10.

RESULTS

Sustained decrease of the VAS pain scores was observed from 3 to 12 months following IDTA. ADLs improved in all patients between 3 and 12 months post-treatment. Patients in the Bureau of Workers Compensation (BWC) group had a higher VAS score but showed the same level of improvement in ADLs as compared to commercial insurance or self-pay patients. In the non-BWC patient group an average VAS pain score decrease of more than 6 points on a 10-point scale was reported at 6 to 12 months following IDTA.

CONCLUSIONS

We found dramatic improvement of pain scores and ADLs following IDTA when strict patient selection was applied. We believe that IDTA is an effective, minimally invasive treatment for discogenic pain in properly selected patients.

Novel Intradiscal Biacuplasty (IDB) for the Treatment of Lumbar Discogenic Pain

Reported here is the treatment of severe axial discogenic pain in a young man utilizing the new minimally invasive transdiscal radiofrequency technique called intradiscal biacuplasty (Baylis Medical Inc., Montreal, Canada). The new procedure is detailed and step-by-step fluoroscopic imaging presented. There were no intra- and postoperative complications, and significant improvements in patient functional capacity, and pain scores were noted. Visual analog scale pain score decreased from 5 to 1 cm at 6-month follow-up, Oswestry disability scores improved from 14 (28% or moderate disability) to 6 points (12% or minimal disability) and SF-36-PF (physical function) score changed from 67 to 82. Potential advantages of cooled, bipolar radiofrequency to heat the posterior annulus are discussed.

Percutaneous thermocoagulation intradiscal techniques for discogenic low back pain

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically review the evidence on the efficacy, effectiveness, and safety of percutaneous thermocoagulation intradiscal techniques for discogenic low back pain.

SUMMARY OF BACKGROUND DATA

The intervertebral disc is thought to be the source of pain in a relevant proportion of cases of low back pain (LBP). Two percutaneous thermocoagulation intradiscal techniques have been described to treat discogenic LBP: percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) and intradiscal electrothermal therapy (IDET).

METHODS

An electronic search was performed in MEDLINE, EMBASE, and the Cochrane Library databases up to 2005, to identify nonrandomized controlled trials and randomized controlled trials (RCTs) on those techniques. All relevant studies were methodologically assessed independently by 3 reviewers. RCTs were assessed following the criteria recommended by the Cochrane Back Review Group. A qualitative synthesis of results was performed.

RESULTS

Six studies were included with a total of 283 patients. Two open, nonrandomized trials (95 patients) showed positive results for IDET compared with rehabilitation and PIRFT. Results from 2 RCTs showed no differences between PIRFT and placebo, and between different PIRFT techniques. Two RCTs compared IDET with placebo. One suggested differences only in pain and in disability, while the best quality RCT showed no differences.

CONCLUSIONS

The available evidence does not support the efficacy or effectiveness of percutaneous thermocoagulation intradiscal techniques for the treatment of discogenic low back pain.

Effects of monopolar radiofrequency heating on intradiscal pressure in sheep

BACKGROUND CONTEXT

No previous study has assessed the effect of monopolar radiofrequency (RF) heating on intradiscal pressure.

PURPOSE

To determine the decrease in lumbar intradiscal pressure after monopolar RF heating.

STUDY DESIGN/SETTING

Intradiscal pressure was measured in sheep lumbar discs treated with monopolar RF heating.

METHODS

Two monopolar RF heat treatments at 90 degrees C were applied for 2 minutes each to lumbar intervertebral discs of sheep. Intradiscal pressure was measured in live sheep at 0, 7, 14, 21, and 28 days posttreatment. Pressure measurements were taken with a microtip pressure transducer. Electrodes were inserted but not activated in separate discs as a sham control. In vitro sheep spine of different age groups, loading conditions, and electrode orientations were similarly heat treated and intradiscal pressures were measured.

RESULTS

Intradiscal pressure was significantly reduced 1 week after monopolar RF heating and remained stable through the 4-week observation period. The RF electrode orientation, the age, and the type of disc loading have significant effects on the amount of initial intradiscal pressure reduction.

CONCLUSIONS

Monopolar RF heating can reduce intradiscal pressure in the lumbar spine of sheep.

Intradiscal thermal therapy using interstitial ultrasound: an in vivo investigation in ovine cervical spine

STUDY DESIGN

In vivo investigation of intradiscal ultrasound thermal therapy in ovine cervical spine model.

OBJECTIVE

To evaluate the potential of interstitial ultrasound for selective heating of intradiscal tissue in vivo.

SUMMARY OF BACKGROUND DATA

Application of heat in the spine using resistive wire and radiofrequency current heating devices is currently being used clinically for minimally invasive treatment of discogenic low back pain. Treatment temperatures are representative of those required for thermal necrosis of ingrowing nociceptor nerve fibers and disc cellularity alone, or with coagulation and restructuring of anular collagen in the high temperature case.

METHODS

Two interstitial ultrasound applicator design configurations with directional heating patterns were evaluated in vivo in ovine cervical intervertebral discs (n = 62), with up to 45-day survival periods. Two heating protocols were employed in which the temperature measured 5 mm away from the applicator was controlled to either <54 C (capable of nerve and cellular necrosis) or >70 C (for coagulation of collagen) for a 10-minute treatment period. Transient and steady state temperature maps, calculated thermal doses (t43), and histology were used to assess the thermal treatments.

RESULTS

These studies demonstrated the capability to control spatial temperature distributions within selected regions of the in vivo intervertebral disc and anular wall using interstitial ultrasound.

CONCLUSIONS

Ultrasound energy is capable of penetrating within the highly attenuating disc tissue to produce more extensive radial thermal penetration, lower maximum intradiscal temperature, and shorter treatment times than can be achieved with current clinical intradiscal heating technology. Thus, interstitial ultrasound offers potential as a more precise and faster heating modality for the clinical management of low back pain and studies of thermal effects on disc tissue in animal models.

Interventions for low back pain: what does the evidence tell us

Although interventional therapy for chronic spinal pain continues to be popular among patients and providers, the scientific evidence supporting these techniques has lagged behind their presence in the market. This article collates both classic and more recent experimental results involved in the interventional assessment and treatment of chronic spinal pain, and presents key findings for physicians. Although much of the body of evidence is either unsupportive or inconclusive, there are some definitive findings involving each technique that can help shape rational practice. As interventional pain medicine seeks to become a more validated specialty, introspection and advancing science will be key to this development.