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Richard Derby

Publications and source records attributed to Richard Derby.

At least 19 recordsLinked to original sources
PubMed2006

Percutaneous lumbar disc decompression.

Chronic low back pain is a major social, economic, and healthcare issue in the United States. Various techniques are utilized in managing discogenic pain, with or without disc herniation. Percutaneous techniques are rapidly replacing traditional open surgery in operations requiring discectomy, decompression, and fusion. The percutaneous access to the disc was first used in the 1950s to biopsy the disc with needles. Percutaneous access to the disc using endoscopic techniques was developed in the 1970s. Technical advances in the use of intradiscal therapies led to the development of intradiscal electrothermal annuloplasty (IDET), DISC Nucleoplasty, and DeKompressor, along with laser-assisted, endoscopic, and Nucleotome disc decompressions. The indications for percutaneous lumbar disc decompression include low back and lower extremity pain caused by a symptomatic disc. Internal disc disruptions and disc herniations are common causes of low back and/or lower extremity pain which may become chronic, if not diagnosed and treated. Annular tears lead to migration of the nuclear material and deranged internal architecture. In the chronically damaged intervertebral disc, leakage of nuclear material from annular tears can initiate, promote, and continue the inflammatory process and delay or stop recovery of vital remaining intradiscal tissue. The most often stated goal of central nuclear decompression is to lower the pressure in the nucleus and to allow room for the herniated fragment to implode inward. Provocative discography prior to percutaneous lumbar disc decompression is recommended. Percutaneous disc decompression may result in a small number of complications but occasionally, these could be serious.

Decompression, Surgical↗
PubMed2006

The efficacy of a two needle electrode technique in percutaneous radiofrequency rhizotomy:An investigational laboratory study in an animal model.

BACKGROUND: Radiofrequency neurotomies are used to help reduce pain caused by structures innervated by the medial branch of the dorsal spinal nerve. The duration of effect may vary proportionally to the length of nerve coagulated. Techniques used to maximize the length of nerve within the radius of maximal heat include making multiple lesions, using larger needles, positioning the exposed needle parallel to the target nerve, and attempting more precise placement using 50 hertz test stimulation. A variation of the technique uses two needles that are simultaneously placed to lie parallel to one another and parallel to the probable area the target nerve is known to traverse. Heating both needles at the same time would be a faster method that theoretically might also include more tissue within the heating radius of the needle lengths. OBJECTIVE: The purpose of this study was to confirm that two parallel radiofrequency lesions increased the volume of tissue included within the heating radius of the exposed needle tips, to determine optimal heating parameters, and to establish how far apart the needles can be placed and still achieve temperatures between the needles that will coagulate nerves. STUDY DESIGN: Investigational laboratory study in an animal model. METHODS: Ex-vivo porcine spinal tissue samples were prepared following a standardized protocol and two needle electrodes were connected to the Stryker rhizotomy device. A series of tissue samples were prepared with the needles placed 1, 1.5, 2, 3, 4, 5, 6, 7, 8, or 9 mm apart in respective samples. The needles were positioned parallel to the surface, and perpendicular to the tissue. In one series of samples, two needle electrodes were heated sequentially for each needle placement. Temperature parameters ranged from 60 to 100 degrees C and the time duration ranged from 60 to 90 seconds for each electrode. After each heating, all tissue was dissected and the size of the coagulated area measured. Temperatures at the midpoint between the two needle electrodes were monitored and measured with a Radionics needle sensor. Using the same study protocol and evaluation, a second set of samples was studied but both needle electrodes were heated simultaneously. RESULTS: Maximal lesion size was observed when the temperature of the electrode was higher than 70-80 degrees C and maintained for longer than 70 seconds. When the needles were heated sequentially, the needles could be placed no further than 1.5 to 2 mm apart before areas of incomplete coagulation were visualized at the midpoint between the needles. When both needles were simultaneously heated the needles could be placed 4 mm apart before incomplete coagulation was visualized. With simultaneous heating, the highest peak temperature of the midpoint between two needles (6 mm apart) exceeded 66 degrees C, compared to a temperature of 40 degrees C achieved with sequential heating. CONCLUSIONS: This research confirms the efficacy of utilizing two needle electrodes during lumbar facet rhizotomy in an experimental model. Heating the two electrodes sequentially appears to coagulate a wider area and thus would be more likely to include a longer length of the target nerve and thus potentially could achieve better results in less time.

Animals↗
PubMed2005

Does the number of levels affect lumbar fusion outcome?

STUDY DESIGN: Retrospective outcome measurement after circumferential reconstructive surgery with lumbar fusion in patients with chronic discogenic low back pain. OBJECTIVE: To examine the effect of the number of fusion levels on surgical outcomes in patients with chronic discogenic low back pain using provocative pressure-controlled diskography as a primary diagnostic tool. SUMMARY OF BACKGROUND DATA: Although there is general agreement that construct length adversely affects arthrodesis success rates, the effect of the number of levels on lumbar fusion surgery outcome has not been reported. Previous fusion outcome studies have generally relied on magnetic resonance imaging or conventional diskography for diagnosis. METHODS: From 1994 through 2000, prospectively collected medical records of patients who underwent reconstructive lumbar spine surgery with confirmation of the pain generator by pressure-controlled diskography were retrospectively analyzed. Data were subdivided into 2 groups of patients. The first group, designated the short segment group, contained patients who underwent fusion at 1 or 2 levels. The second group, designated the long segment group, contained patients who underwent fusion at 3-5 levels. Surgical methods included circumferential reconstruction of the lumbar spine by either posterior or combined anterior and posterior approach. Surgeries included posterior decompression necessary to relieve documented regions of neural compression, combined with interbody arthrodesis at selective levels, augmented by posterior segmental spinal instrumentation and posterolateral arthrodesis. All patients completed a preoperative aquatic-conditioning program. Whenever possible, coexisting medical conditions were corrected or stabilized before surgery. A preoperative Short Form RAND 36-Item Health Survey (SF-36) was completed, and repeated at 1 and 2 years after surgery. The short and long segment groups contained 142 and 82 patients, respectively, who completed the preoperative SF-36 questionnaire completely. RESULTS: One hundred patients in the short segment group (vide infra) were available for 1-year follow-up, and68 were available for 2-year follow-up. In the long segment group, 81 patients were available for 1-year follow-up, and 49 were available for 2-year follow-up. Mean ages were 41.0 and 47.6 years in the short and the long segment groups, respectively. The 2 groups did not differ significantly in gender, smoking habits, workers' compensation, or litigation (P > 0.05). In the short segment group, postoperative 1-year mean Physical Component Summary (PCS) and Mental Component Summary scores significantly improved (P < 0.001 and P = 0.002, respectively). Domains other than general health perceptions showed significantly improved 1-year follow-up scores (P 0.05), although the PF score showed differences in 1 and 2-year follow-up scores (P = 0.048 and P = 0.068, respectively). CONCLUSIONS: When using strict patient selection criteria that include independent determination of pain generators via pressure-controlled diskography and completion of a preoperative conditioning program for improving general health status, the number of levels in reconstructive lumbar surgery may not significantly impact overall clinical outcome.

Activities of Daily Living↗
PubMed2005

Electromyographic technique for lumbar multifidus examination: comparison of previous techniques used to localize the multifidus.

OBJECTIVES: To verify and compare established techniques for needle localization in the multifidus muscle and to explore more practical techniques. DESIGN: Human cadaver study. SETTING: Anatomy laboratory in a university setting. CADAVERS: Six fresh human cadavers. INTERVENTION: A 22-gauge needle was inserted into the multifidus muscle fascicle of 6 cadavers using 2 different techniques described previously in the electrodiagnostic literature by Haig and Stein and colleagues. A mixture of colored latex and contrast dyes (0.1 mL) was injected bilaterally into each fascicle at levels L1 to L5. Two electromyographers performed injections into 60 targeted muscles, affording 120 total insertions. Separate investigators dissected the muscles to determine dye position. MAIN OUTCOME MEASURES: Not applicable. RESULTS: A total of 88 (73%) and 79 (66%) injections were successfully delivered to the targeted multifidus muscles using the Haig and the Stein techniques, respectively. With the Haig method, 22 injections (18%) were delivered to different superficial muscles. With the Stein method, 24 injections were delivered to a common tendon and 3 injections were delivered to the spinal canal. CONCLUSIONS: This study highlights the nonoptimizing accuracy of previous techniques for multifidus needle electromyography. A modified Haig method involving less acute needle angulation relative to the skin surface and closer insertion from the midline may increase accuracy and safety.

Aged↗
PubMed2005

The relation between annular disruption on computed tomography scan and pressure-controlled diskography.

OBJECTIVE: To analyze the relation between annular disruption determined by computed tomography (CT) scan and diskographic findings using pressure-controlled manometric diskography. DESIGN: Cross-sectional using prospectively gathered data. SETTING: Ambulatory spine intervention unit. SPECIMENS: Two hundred seventy-nine disks from 86 patients (55 men, 31 women) who were referred for diskography of suspected chronic diskogenic low back pain. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The grade of annular disruption was rated using CT diskography and fluoroscopic imaging as follows: 0 (no disruption); 1 (extension into the inner third of the annulus); 2 (extension into the middle third of the annulus); 3 (extension into the outer third of the annulus); 4 (circumferential extension with a >30 degrees arc at the disk center); and 5 (contrast media leakage into the outer space). Diskography was performed via a pressure-controlled manometric technique using an injection rate of .05 mL/s and a restricted total volume of 3.5 mL. Pain was rated on a 0 to 10 numeric rating scale (NRS). Criteria for symptomatic disks included provocation of patient concordant pain (NRS score, > or =6/10) at 50psi or less above opening pressure, with 3.5 mL or less of total volume. Symptomatic disks were classified as "low pressure sensitive" or "high pressure sensitive" based on the pressure level that evoked pain. Disks classified as low pressure sensitive required an NRS score of 6 out of 10 or higher at 15 psi or less above opening pressure. Disks classified as high pressure sensitive required an NRS score of 6 out of 10 or higher at pressures within a range of 15 to 50 psi. RESULTS: The numbers of disks at each annular disruption grade were 19 (6.8%) at grade 0, 29 (10.4%) at grade 1, 35 (12.5%) at grade 2, 42 (15.1%) at grade 3, 69 (24.7%) at grade 4, and 85 (30.5%) at grade 5. A total of 93 disks met the criteria for a symptomatic disk. The extent of annular disruption and the rate of symptomatic disks correlated significantly (P<.001). The highest symptomatic disk rate was observed in grade 4 disks. Of 93 symptomatic disks, 88 (94.6%) showed annular disruption of grade 3 or greater. Disks with grades 0 to 2 and grades 3 to 5 annular disruption differed significantly when the mean NRS relative to intradiskal pressure was compared (P<.001). Comparing the disk type of symptomatic disks at each annular disruption grade, there was a decreasing trend of low pressure sensitive disks relative to the extent of annular disruption (62.5% at grade 3, 39.4% at grade 4, 34.2% at grade 5). CONCLUSIONS: Annular disruption reaching the outer annulus fibrosus is a key factor in pain generation. Disk morphology, including annular disruptions extending beyond the outer annulus, may permit increased diskography specificity.

Adult↗
PubMed2005

Single-level lumbar fusion in chronic discogenic low-back pain: psychological and emotional status as a predictor of outcome measured using the 36-item Short Form.

OBJECT: The authors examined the effect of psychological and emotional status on the outcome in patients with suspected chronic discogenic low-back pain (LBP) who have undergone lumbar fusion. METHODS: The authors retrospectively analyzed the medical records, including the results of the 36-item Short Form (SF-36), of 57 consecutive patients (mean age 42.7 years) who underwent single-level lumbar reconstructive surgery between 1994 and 2000. The SF-36 physical component summary (PCS) and mental component summary (MCS) domains were evaluated. Data were sorted into the following categories: excellent, good, fair, same, and worse. Scores greater than 40 for MCS and PCS were defined as "normal" according to US general population data provided by the Medical Outcomes Trust. Of 57 patients, 47 completed postoperative SF-36 surveys at 1 year and 36 completed the 2-year follow-up surveys. Analysis showed that preoperative MCS scores exhibited a significant, direct correlation with PCS score improvements at 1 (r = 0.584, p = 0.000) and 2 (r = 0.623, p = 0.000) years after surgery. In patients in whom preoperative MCS scores reflected normal status, outcomes were excellent or good in 60% at 1-year (18 of 30 cases) and 2-year (15 of 25 cases) follow-up intervals. Patients in whom MCS scores represented abnormal status had less satisfactory outcomes, with excellent or good outcome in only two (18.2%) of all patients at the 2-year follow-up study. CONCLUSIONS: Analysis of the data suggests that psychological and emotional distress may negatively affect postoperative outcome in patients with chronic discogenic LBP. The SF-36 may be easily and effectively used to measure both preoperative psychosocial distress and postoperative outcome.

Adult↗
PubMed2004

Percutaneous disc decompression in the management of chronic low back pain.

Although there has not yet been a percutaneous intradiscal procedure developed with the superior therapeutic efficacy of open surgery, these procedures are less invasive and avoid the complications of open surgery. All of these procedures have limitations, but their therapeutic effect increases substantially given careful patient selection and proper technique. New appliances and techniques to treat LBP or sciatica continue to evolve, and numerous controlled studies are underway. With tremendous technologic advances, use of minimally invasive techniques to treat chronic back pain continues to expand.

Animals↗
PubMed2004

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.

Journal Article↗
PubMed2004

Non-surgical interventional treatment of cervical and thoracic radiculopathies.

Cervical and thoracic radiculopathies are among the most common causes of neck pain. Outcome studies of conservative treatments have shown varying results and have not been well controlled or systematic. Although there has not yet been a non-surgical interventional procedure developed with the therapeutic efficacy of open surgery, conservative procedures can offer substantial benefits, are less invasive, and avoid surgical complications. While more invasive procedures may be appropriate when conservative treatment fails, prospective studies evaluating cervical and thoracic radiculopathy treatment options would help guide practitioners toward optimally cost-effective patient evaluation and care.

Journal Article↗
PubMed2004

Complications following cervical epidural steroid injections by expert interventionalists in 2003.

BACKGROUND: Two major portals are available for delivery of medication into the cervical epidural space: interlaminar and transforaminal. The choice of which approach to use is commonly made by assessing the patient's structural pathology, one's skill in performing each procedure, and then weighing the advantages versus the risk associated with the particular technique. Over the past several years, a growing number of cases involving serious complications following cervical transforaminal epidural steroid injections have led some to question the safety of the procedure and to preferentially perform interlaminar epidural injections. OBJECTIVE: To explore the prevalence of complications caused by transforaminal versus interlaminar injections. DESIGN: Retrospective survey. METHODS: We selected the list of course instructors of the International Spine Intervention Society (ISIS) as our source for expert spine injection specialists. All data were collected by survey during a period from April 2004 through June 2004. Questions were asked about the type of cervical epidural injections performed and any complications during the preceding 12 months, January through December 2003. RESULTS: All 29 ISIS course instructors were surveyed. Seventeen instructors replied. In 2003, an estimated total of 5968 cervical epidural injections were performed by 17 instructors for neck and/or arm pain. The interlaminar approach was performed in 4389 cases by 14 instructors and the transforaminal approach was used in 1579 cases by 16 of the instructors. Of the 4389 interlaminar injections there were 23 cases (0.52%) of various minor complications including headaches caused by dural puncture, transient vagal episodes, and prolonged complaints of new or increased numbness and paresthesias. In the 1579 transforaminal there were five cases (0.32%) of minor complications including aggravated radicular pain, prolonged paresthesias, and skin rashes. In addition, 2 cases of radicular artery injection were confirmed by digital subtraction angiography during 354 transforaminal approaches performed by one physician. The rates of complication were not different between interlaminar and transforaminal approaches. CONCLUSION: When performed by experienced interventionalists, major complications are probably rare and it could take years for a significant complication to occur. We must however all be aware that these complications can occur.

Journal Article↗
PubMed2004

Comparison of intradiscal restorative injections and intradiscal electrothermal treatment (IDET) in the treatment of low back pain.

This was a pilot study to test the potential effectiveness of intradiscal restorative injection therapy and compare with intradiscal electrothermal therapy (IDET). Thirty-five patients for intradiscal injection and seventy-four for IDET took part in the study. All patients had intractable chronic discogenic low back pain, confirmed by discogram study. Injection solution consisted of glucosamine and chondroitin sulfate combined with hypertonic dextrose and dimethylsulfoxide. Outcome was rated as 0-10 on visual analog scale (VAS), satisfaction rate, and flare up before and after the procedures. Post-procedure, patients were followed from 6 months to 18 months. Pain relief was statistically significant for both procedures, but slightly better for injections (2.2 VAS) than for IDET (1.27 VAS). 47.8% of IDET patients reported that they felt better, whereas 65.6% of injection patients reported this outcome. Among IDET patients, 35.8% reported they were worse, while no restorative injection patient reported worsening of pain. Post-procedure flare-up occurred more frequently after restorative injection (81%) than after IDET (68.9%) and was more severe (7.9 versus 6.1 VAS, respectively). However, the duration of pain flare-up was notably shorter for restorative injections (8.6 days) than for IDET (33.1 days). Biochemical intradiscal restorative injections may be useful to reduce pain and disability in patients with chronic discogenic low back pain, and have clinically similar efficacy to IDET, but with improved cost-benefit ratio. The results of this study indicate that controlled random prospective comparative studies need to be performed to establish the efficacy of this treatment.

Journal Article↗
PubMed2002

Disc stimulation and patterns of referred pain.

STUDY DESIGN: Prospective, within-subjects, observational experimental design. OBJECTIVES: To determine the pattern of pain response to noxious stimulation of the intervertebral disc. SUMMARY OF BACKGROUND DATA: Experimental studies have demonstrated that noxious stimulation of interspinous ligaments, facet joints, and paravertebral muscles causes referred pain into the extremity, with the distal extent of radiation dependent on the intensity of stimulation. Analogous studies have not been performed on the lumbar intervertebral disc. METHODS: A total of 25 consecutive patients meeting inclusion criteria completed a pain diagram before undergoing the intradiscal electrothermal annuloplasty procedure. The location, intensity, and familiarity of any pain provoked during disc heating were correlated with presenting symptoms and duration of heating. RESULTS: During disc heating, 68% of patients reported exact reproduction of their presenting pain, in both pain quality and location. None of the patients experienced unfamiliar pain during the procedure. The pattern of pain reproduction was consistent; pain originated proximally and progressed distally as stimulus intensity increased. CONCLUSION: Noxious stimulation of the intervertebral disc may result in low back and referred extremity in patients presenting with these symptoms. The distal extent of pain produced depends on the intensity of stimulation. Disc stimulation may reproduce pain that extends to below the knee.

Catheterization↗
PubMedDate not supplied

In vitro measurement of pressure in intervertebral discs and annulus fibrosus with and without annular tears during discography.

BACKGROUND CONTEXT: Discogram studies have shown that pain reproduction correlates with the extent of annular disruption. However, it has not been assessed if pressure changes in the annulus fibrosus vary incrementally with intradiscal pressure. PURPOSE: To determine the relationship between intradiscal pressure and outer annular pressure during discography in intervertebral discs with and without annular tears. STUDY DESIGN: Intradiscal and periannular pressures were measured simultaneously in vitro during intradiscal injection in porcine cadaver spines. METHODS: Twenty fresh porcine cadaver lumbar spines with intervening discs were tested. Intradiscal and periannular pressures were measured simultaneously using two pressure sensors during intradiscal contrast injection. The tip of a 25-gauge needle connected with a pressure manometer was placed in the center of the nucleus pulposus. A second pressure transducer was located at the outer third of the annulus fibrosus. Needle and transducer locations were confirmed by fluoroscopy. To compare the intact and torn annulus fibrosus, annular disruptions were created with a 20-gauge needle and confirmed by fluoroscopy. RESULTS: During intradiscal injections of discs with an intact annulus, annulus fibrosus pressure remained low and a sharp increase in intradiscal pressure was observed. Significantly higher pressures were noted in the outer annulus in discs with annular tears (p<.01). Mean pressures at the central nucleus pulposus, the outer third of intact annuli and torn annuli were 93.4+/-40.9 psi, 14.8+/-1.9 psi and 85.7+/-24.8 psi, respectively. CONCLUSIONS: Volumetric injection of intervertebral discs with a torn annulus fibrosis during discography may increase intra-annular pressure similar to the increase in pressure that may occur during spinal loading activities. This effect may not occur in discs with an intact annulus fibrosus.

Animals↗
PubMedDate not supplied

A factor analysis of lumbar intradiscal electrothermal annuloplasty outcomes.

BACKGROUND CONTEXT: Intradiscal electrothermal annuloplasty (IDET) is a minimally invasive procedure for managing chronic discogenic low back pain (LBP). Although there have been numerous reports of IDET outcome rates, few have dissected the detailed factors affecting those outcomes. PURPOSE: To evaluate how heating variables and the number of catheters used affect the outcomes and pain flare-up in LBP patients treated with IDET. STUDY DESIGN/SETTING: Retrospective analysis. PATIENT SAMPLE: Data were gathered on the basis of chart records from January 6, 1999 to January 6, 2000. Twenty-five cases treated at a single level with disc protrusion < or = 2 mm, nonfocal neurological abnormalities, and positive discogram with annular tear were studied. Six patients were unavailable for follow-up at 16 months. OUTCOME MEASURES: All assessments were incorporated into our own evaluation sheet, completed before the procedure and at follow-up. Assessments included the following: 1) Visual Analog Scale (VAS) and 2) Back Pain Improvement Scales (BPI) preoperatively and at 8 and 16 months post-procedure. Post-procedure flare-up of the pain was defined as the pain aggravation after the IDET procedure from the pre-procedure baseline pain. It was evaluated by a 10-point numeric rating scale, ranging from no aggravated pain "0" to the worst aggravated pain "10". METHODS: Patients were partitioned into a single-catheter group and a double-catheter group. In these two groups, statistical analyses were done to compare the outcomes and flare-up duration and intensity. In each catheter group, the correlation coefficients were analyzed between heating variables such as heating duration/temperature and two outcome scales. Then, two outcome scales relative to intensity and duration of post-IDET flare-up were analyzed with Pearson's correlation. Also the combined effect of the heating duration and temperature was evaluated as a thermal dosage, which is the total amount of heat developed during the procedure. It was calculated by multiplying the temperature and its heating duration above a starting temperature of 65 degrees C. RESULTS: Comparing the single- and double-catheter groups, patients placed in the single-catheter group showed significantly shorter flare-up duration (11.00+/-19.17 vs. 24.89+/-20.84 days, p < .05). In the single-catheter group, the flare-up duration manifested moderate linear correlation with heating variables (0.580 with temperature, 0.519 with thermal dosage, p < .05). Also, the improvements of pain with VAS displayed moderate reverse correlation with heating variables at 8 months (-.436 with temperature, -0.439 with thermal dosage, p < .1). In the double-catheter group, the Back Pain Improvement% had strong reverse correlations with temperature and thermal dosage at 8 months (-.735 and -.729, p < .05). The correlation between the improvement of VAS and temperature yielded a moderate reverse relationship (-.619, p < 0.1). These correlations were not, however, observed at 16 months in either the single- or double-catheter groups. CONCLUSIONS: Higher temperatures and larger total heating doses during IDET procedures with catheters placed in the outer annulus may increase the duration of post-procedure pain flare-ups and lead to less favorable outcomes at 8 months follow-up. The long-term outcomes at 16 months may, however, not be affected by these heating variables.

Electric Stimulation Therapy↗
PubMedDate not supplied

Comparison of discographic findings in asymptomatic subject discs and the negative discs of chronic LBP patients: can discography distinguish asymptomatic discs among morphologically abnormal discs?

BACKGROUND CONTEXT: Lumbar discography has been widely used for evaluating discogenic low back pain (LBP). Comparison of pain responses from suspected symptomatic discs with pain responses from asymptomatic negative discs is routine. However, the ability of discography to distinguish asymptomatic morphologically abnormal discs from those that are symptomatic has been understudied. In addition, the discographic characteristics of negative discs in patients with chronic discogenic LBP have not been reported. Criteria for negative morphologically abnormal discs may be valuable for excluding discs from further treatment and examination. PURPOSE: To determine if discography can distinguish asymptomatic discs among morphologically abnormal discs in patients with suspected chronic discogenic LBP and establish the standard characteristics of negative discs. STUDY DESIGN/SETTING: Prospective, experimental with control group. PATIENT SAMPLE: Fifty-five discs from a control group of 16 healthy volunteers without current back pain (11 men, 5 women, 32-61 years of age, mean age: 47 years) and 282 discs from a patient group of 90 LBP patients (59 men, 31 women, 20-70 years of age, mean age: 44.7 years) were recruited. METHODS: Discography was performed using a pressure-controlled manometric technique with an injection rate of 0.05 mL/s and a 3.5 mL restricted total volume. Concordance was rated as none/unfamiliar, or familiar. Pain was rated via a 0-10 numerical rating scale (NRS). The pressure and volume at which pain was evoked and NRS pain responses at 15, 30, and 50 psi were recorded. Annular disruption grade was rated during the procedure by computed tomography discography and fluoroscopic imaging. Negative discogram required no pain described by the participant as "familiar," with no pain responses >or=6/10 NRS at pressures <or=50 psi above opening pressure and <or=3.5 mL total injected volume. Patient discs were partitioned into two subgroups based on discographic findings: Neg-D (negative discs) and Pos-D (positive discs). Only discs with Grade 3 annular tears (Dallas Discogram Scale) were included in the study. RESULTS: Among 55 asymptomatic control group discs, 32 (58.2%) exhibited Grade 3 annular tear. All discs in the asymptomatic control group satisfied negative response criteria. Among 282 patient group discs, 199 (70.6%) exhibited Grade 3 annular tear. Of 199 discs with Grade 3 annular tears, 104 (52.3%) satisfied negative response criteria and were categorized as the Neg-D group. The other 95 discs were categorized as a Pos-D group. Patients showed significantly lower pain tolerance relative to control subjects (p<.05). The control and Neg-D groups showed similar pressures and volumes at which pain was initially evoked. Mean control group pain scores were 0.47 NRS at 15 psi and 1.58 NRS at 50 psi. Mean Neg-D group pain scores were 0.11 NRS at 15 psi and 1.1 NRS at 50 psi. Discographic findings for the Pos-D group were significantly different from those of the control and Neg-D groups (p<.001). CONCLUSIONS: Pain tolerance was significantly lower in patients relative to asymptomatic subjects. Negative patient discs and asymptomatic subject discs showed similar characteristics. Pressure-controlled manometric discography using strict criteria may distinguish asymptomatic discs among morphologically abnormal discs with Grade 3 annular tears in patients with suspected chronic discogenic LBP.

Adult↗