Thermal-Induced Osteonecrosis of Adjacent Vertebra after Intradiscal Electrothermal Therapy

A 42-year-old man was admitted to our hospital with complaints of low back pain and intermittent right thigh pain. Twelve weeks before admission, the patient received intradiscal electrothermal therapy (IDET) at a local hospital. The patient still reported low back pain after the procedure that was managed with narcotic analgesics. Follow-up magnetic resonance imaging (MRI) was performed, and his referring physician thought the likely diagnosis was spondylodiscitis at the L4–5 spinal segment with a small epidural abscess. At admission to our department, the patient reported aggravated low back pain. Blood test results, including the erythrocyte sedimentation rate and C-reactive protein levels, were slightly elevated. Biopsy samples of the L4, L5 vertebral bodies and disk were obtained. The material underwent aerobic, anaerobic, fungal, mycobacterial cultures and histologic examination. Results of all cultures were negative. Histologically, necrosis of the bone was evident from the number of empty osteocyte lacunae. In addition, there was no evidence of infection based on biopsy results. No antibiotic treatment was administered on discharge. Repeat computed tomography and MRI performed 12 months after IDET showed a bony defect in the L4 and L5 vertebral bodies, and a decrease in the size of the L4–5 intervertebral disc lesion. We report a case of lumbar vertebral osteonecrosis induced by IDET and discuss etiology and radiologic features.

Analysis of Inadvertent Intradiscal Injections during Lumbar Transforaminal Epidural Injection

BACKGROUND: Recently, there have been several case reports and retrospective studies about the incidence of intradiscal (ID) injection during transforaminal epidural steroid injection (TFESI). Inadvertent ID injection is not a rare complication, and it carries the risk of developing diskitis, although there has been no report of diskitis after TFESI. We prospectively evaluated the incidence of inadvertent ID injection during lumbar TFESI and analyzed the contributing factors. METHODS: Ten patients received 2-level TFESI, and the remaining 229 patients received 1-level TFESI. When successful TFESI was performed, 2 ml of contrast dye was injected under real-time fluoroscopy to check for any inadvertent ID spread. A musculoskeletal radiologist analyzed all magnetic resonance images (MRIs) of patients who demonstrated inadvertent ID injection. When reviewing MRIs, the intervertebral foramen level where ID injection occurred was carefully examined, and any anatomical structure which narrowing the foramen was identified. RESULTS: Among the 249 TFESI, we identified 6 ID injections; thus, there was an incidence of 2.4%. Four patients had isthmic spondylolisthesis, and the level of spondylolisthesis coincided with the level of ID injection. We further examined the right or left foramen of the spondylolisthesis level and identified the upward migrated disc material that was narrowing the foramen. CONCLUSIONS: Inadvertent ID injection during TFESI is not infrequent, and pain physicians must pay close attention to the type and location of disc herniation.

Effect of Intradiscal Monopolar Pulsed Radiofrequency on Chronic Discogenic Back Pain Diagnosed by Pressure-Controlled Provocative Discography: A One Year Prospective Study

OBJECTIVE: To investigate the efficacy and safety of percutaneous intradiscal monopolar pulsed radiofrequency (PRF) in patients with chronic disabling discogenic back pain. METHOD: Twenty-six subjects (7 males; mean age 43.2 years) with chronic back pain refractory to active rehabilitative management were recruited. All subjects underwent MRI for evaluation of Modic changes, and monopolar PRF (20 min at 60 V) at the center of target lumbar intervertebral disc confirmed by pressure-controlled provocative discography. Clinical outcomes were measured by the visual analogue scale (VAS), Oswestry disability index (ODI), and sitting tolerance time (ST) for 12 months after treatment. Successful clinical outcome was described as a minimum of 2 point reduction in VAS compared with the baseline at each follow-up period. RESULTS: The mean VAS for low back pain reduced significantly from 6.4+/-1.1 at pre-treatment to 4.4+/-1.9 at 12 months (p<0.05). The mean ODI score was 47.3+/-15.4 points at pre-treatment and 36.7+/-19.5 at 12 months (p<0.001). The ST was 27.8+/-20.4 minutes at pre-treatment and 71.5+/-42.2 at 12 months (p<0.001). However, successful clinical outcome was achieved at 58%, 50%, and 42%, measured at 3, 6, and 12 months post-treatment. There were no significant relationship between the clinical outcome and Modic changes; no adverse events were recorded. CONCLUSION: The results demonstrated that the application of intradiscal monopolar PRF might be relatively effective but limited; successful intervention for chronic refractory discogenic back pain is needed. To achieve the optimal outcome through intradiscal PRF, we suggested further studies about stimulation duration, mode, and intensity of PRF.

Effect of Intradiscal Methylene Blue Injection for the Chronic Discogenic Low Back Pain: One Year Prospective Follow-up Study

OBJECTIVE: To evaluate the efficacy of intradiscal methylene blue (MB) injection in patients with chronic discogenic low back pain. METHOD: Twenty patients with discogenic low back pain (4 males, 16 females; mean age 45.6 years) refractory to conservative management were recruited. All subjects underwent MB injection in target lumbar intervertebral discs confirmed by provocative discography. The clinical outcome was assessed by visual analog scale (VAS) and Oswestry disability index (ODI) at baseline and 1, 3, 6 and 12 months after treatment. Successful outcome was described as minimum of 2 points reduction in pain intensity compared with the baseline. RESULTS: VAS and ODI significantly decreased after one injection. The average VAS and ODI were reduced significantly from 5.1 and 38.0 at baseline to 3.2 and 27.4 at 3 months after injection (p<0.05). However, the mean score of VAS at 12 month follow-up was 4.5 and we could not observe any difference between 12 months after injection and pretreatment. Eleven of twenty patients (55%) reported successful outcomes after intradiscal MB injection at 3 month follow up and the average VAS was reduced by 3.3+/-1.1 (p<0.05). At the time of 12 month follow up, pain had relapsed in 6 patients who have had satisfactory effect at 3 month follow up. Successful outcome was maintained in only 5 patients (20%) for 1 year. CONCLUSION: The intradiscal MB injection is a short-term effective minimally invasive treatment indicated for discogenic back pain but it may lose its effectiveness long-term.

Clinical Outcomes of Percutaneous Plasma Disc Coagulation Therapy for Lumbar Herniated Disc Diseases

OBJECTIVE: This is prospective study of clinical outcomes of percutaneous plasma disc coagulation Therapy (PDCT) in patients with herniated lumbar disc disease (HLD) to evaluate the safety and efficacy in its clinical application and usefulness as a reliable alternative to microscopic discectomy. METHODS: Forty-six patients were enrolled in this study from April 2006 to June 2010. All patients had one-level HLD. Disc degeneration was graded on routine T2-weighted magnetic resonance Image (MRI) using the Pfirrmann's grading system and all index levels were grade 3 and grade 4. Indications for surgery were radiculopathy caused by disc protrusion with soft consistency. MRI was done at one month after the procedure in all patients to check post-PDCT change. The clinical outcomes were evaluated using Visual Analog Scales (VAS) score and MacNab's criteria. RESULTS: This study was approved by the Institutional Review Board of our institution. The age of the study population ranged from 16 to 59 years with a mean age of 37.2 years. There were 29 males and 17 females in this study. The mean period of clinical follow-up was 21 months. The average preoperative VAS score for radiculopathy was 7.4+/-1.4, while the final follow-up VAS score was 1.4+/-0.7 (p<0.001). In MacNab's criteria, 41 patients (89.1%) had achieved favorable improvement (excellent and good) until later follow-up. There were one patient from infection and two patients who needed to convert to open discectomy. CONCLUSION: PDCT is a safe and efficient treatment modality in a selective patient with HLD.

Results of Intradiscal Pulsed Radiofrequency for Lumbar Discogenic Pain: Comparison with Intradiscal Electrothermal Therapy

BACKGROUND: We have developed an intradiscal pulsed radiofrequency (Disc PRF) technique, using Diskit II(R) needles (NeuroTherm, Wilmington, MA, USA), as a minimally invasive treatment option for chronic discogenic low back pain (LBP). The purpose of this study was to compare the representative outcomes of Disc PRF and Intradiscal Electrothermal Therapy (IDET) in terms of pain relief and reduction of disability. METHODS: Thirty-one patients with chronic discogenic LBP who underwent either Disc PRF (n = 15) or IDET (n = 16) were enrolled in the study. A Diskit II(R) needle (15-cm length, 20-gauge needle with a 20-mm active tip) was placed centrally in the disc. PRF was applied for 15 min at a setting of 5 x 50 ms/s and 60 V. The pain intensity score on a 0-10 numeric rating scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ) were assessed pretreatment and at 1, 3, and 6 months post-treatment. RESULTS: The mean NRS was significantly improved from 7.2 +/- 0.6 pretreatment to 2.5 +/- 0.9 in the Disc PRF group, and from 7.5 +/- 1.0 to 1.7 +/- 1.5 in the IDET group, at the 6-month follow-up. The mean RMDQ also showed significant improvement in both the Disc PRF group and the IDET group at the 6-month follow-up. There were no significant differences in the pretreatment NRS and RMDQ scores between the groups. CONCLUSIONS: Disc PRF appears to be an alternative to IDET as a safe, minimally invasive treatment option for patients with chronic discogenic LBP.

Effect of new nucleus pulposus replacement on the flexibility motion and intradiscal pressure at the adjacent level / 医用生物力学

Objective To evaluate the biomechanical stability of pectin/polyvinyl alcohol composite （CoPP）hydrogel and to assess the range of motion(ROM) and intradiscal pressure (IDP) changes at the above adjacent segment after the anterior implantation of CoPP hydrogel and cage. Method Six fresh cadaveric lumbar spine specimens（L3～L5）were biomechanically tested on the robotic testing machine. ROM at L3/4 and L4/5 and intradiscal pressure at L3/4 were measured. All measurements were made with initially intact and followed by both CoPP and cage implantations. Results At the implanted level (L4/5), the CoPP spine showed no significant change in the other five motion directions except left lateral bending motion compared with the intact spine (P>0.05), whereas the cage spine decreased significantly in all motion directions when compared with the intact spine or CoPP spine (P0.05), whereas the ROM of cage spine significantly increased in all motion directions compared with the intact spine (P0.05). While the IDP of cage spine significantly increased in flexion/extension and left/right lateral bending compared with the intact spine or CoPP spine (P0.05). Conclusions The implantation of CoPP prosthetic nucleus can preserve the motion function at the operated level and maintain the lumbar stability. Compared with the lumbar fusion, the nucleus replacement has no significant effect on the ROM and IDP at adjacent level, which may decrease or avoid the adjacent segment degeneration.

A Biomechanical Analysis on Disc Pressure Distribution Changes with Interspinous Spinal Spacer Insertion for Lumbar Spinal Stenosis / 대한정형외과학회잡지

PURPOSE: To assess the biomechanical effects and effectiveness of an interspinous spinal spacer (ISS) on the intradiscal pressure using in vitro biomechanical tests. MATERIALS AND METHODS: Six calf spine specimens (less than 2 weeks of age, L1-L5) were divided to two groups the intact and the surgery groups (n=3 each). For the surgery group, an ISS made from PMMA (Greek pi=12-mm) were inserted into the space between the spinous processes of L3-L4. The intradiscal pressures at the various regions of the annulus (anterior, posterior, and posterolateral locations) and the nucleus pulposus were measured using the four pressure transducers under pure compression (700 N) and extension loads (700 N+7.5 Nm). RESULTS: An increase in pressure was observed from neutral to extension at the posterior and posterolateral annulus. After inserting the ISS, the changes in pressure at the adjacent disc levels (L2-L3, L4-L5) were negligible regardless of the loading conditions (p>0.05). However, at the implanted level (L3-L4) statistically significant changes in the pressure were found under extension loading at the nucleus pulposus, posterior and posterolateral regions of the annulus with a pressure drop from 1.48 MPa, 1.42 MPa, 1.71 MPa to 1.11 MPa, 0.961 MPa, 1.08 MPa, at the respective locations (p<0.05). The relative percentage decrease were 25%, 31.7%, and 36.8%. CONCLUSION: On the implanted level, these results showed that the insertion of the ISS with PMMA can effectively reduce the intradiscal pressures by at least 25% quite uniformly over the intravertebral disc during extension. More effective reduction was observed at the posterolateral location. The pressure changes at the adjacent levels were negligible in contrast to the abnormal pressure changes that are frequently reported after conventional rigid fusion. This suggests that the likelihood of adjacent level degeneration after surgery can be minimized using the ISS insertion.

Nursing care for patients receiving percutaneous lumbar discectomy and intradiscal electrothermal treatment for lumbar disc herniation / 介入放射学杂志

Objective To summarize the nursing experience in caring patients with lumbar intervertebral disc herniation who received percutaneous lumbar discectomy(PLD) together with intradiscal electrothermal treatment(IDET) under DSA guidance.Methods The perioperative nursing care measures carried out in 126 patients with lumbar intervertebral disc herniation who underwent PLD and IDET were retrospectively analyzed.Results Successful treatment of PLD and IDET was accomplished in 112 cases.Under comprehensive and scientific nursing care and observation,no serious complications occurred.Conclusion Scientific and proper nursing care is a strong guarantee for a successful surgery and a better recovery in treating lumbar intervertebral disc herniation with PLD and IDET under DSA guidance.

Histological Changes after Intradiscal Steroid Injection to the Intervertebral Disc in Disc Injury Rabbit Model

OBJECTIVE: To evaluate the degeneration changes of disc injury rabbit model produced by needle puncture to intervertebral disc and to observe the histological changes of the degenerated disc treated with intradiscal steroid. METHOD: The subjects were composed of 10 L4-5 intervertebral discs (study group) and 10 L3-4 intervertebral discs (control group) of Newzealand white rabbits. The rabbits' discs were exposed by anterior approach and degeneration was elicited by 21 G needle puncture. After 4 weeks, the study group was injected with 0.2 ml triamcinolone acetonide (Tamcetone 40 mg/ml) and the control group was injected with 0.2 ml normal saline, intradiscally. The discs were extracted on 4 weeks after degeneration and stained with Hematoxylin-Eosin and investigated by light microscopy. RESULTS: Degenerative changes, including fissuring and focal fibrosis, were elicited in the all groups, but there were no significant histological differences between the two groups. CONCLUSION: We concluded that the degenerative changes are well observed in disc injury rabbit model. The mollification of discogenic pain following intradiscal steroid injection in practice may not be explained from light microscopic histological changes of the disc. Further biochemical or electromicroscopic study will be necessary to clarify the mechanism of alleviation of discogenic pain by intradiscal steroid.

Anterior Cervical Instrumentation Using Intradiscal Cage with Integrated Plate

OBJECTIVE: The retrospective study is undertaken to report clinical results of anterior cervical interbody fusion with an intradiscal cage with an integrated plate (PCB cervical plating system). METHODS: 38 patients underwent anterior cervical interbody fusion with PCB cervical plating system and followed 6~24 months. The authors investigated overall surgical results; clinical outcome, fusion rate, change of interspace height & lordotic angle, and complications. RESULTS: No complication was observed during the operation. Clinical improvement was identified in 34 cases (89.5%). Bone fusion observed in 44 out of 49 sites (90.7%). After operation, the interspace height increased from 5.4+/-1.3 mm to 7.8+/-1.5 mm and maintained 7.4+/-1.1 mm and, interspace angle went up from 4.2+/-0.7 degrees to 4.8+/-1.1 degrees and maintained 4.6+/-0.9 degrees. The loosening of screw was observed in 6 cases, one of which had reoperation because of the expulsion of the device accompanied. CONCLUSION: PCB cervical plating system could restore interbody height and lordosis in anterior cervical interbody fusion. But, if the insertion of the spacer is not precise, the frequencies of hardware failure are relatively high. It is considered necessary for the operator to be careful in the procedure.

Intradiscal Electrothermal Treatment for Chronic Lower Back Pain Patients with Internal Disc Disruption

Chronic lower back pain is one of the most common musculoskeletal problems; it is also the most expensive industrial injury. Not surprisingly, many treatments have been developed to combat this expensive and debilitating condition. One of these, intradiscal electrothermal treatment (IDET), was developed for patients with chronic discogenic lower back pain who failed to improve with any of the wide variety of non- surgical treatments. The present study sought to evaluate the efficacy of IDET for patients with chronic lower back pain. Twenty-five patients were enrolled in this prospective study; the patients received IDET between June 2001 and June 2003. MRI was used to confirm the diagnosis of internal disc disruption in all patients. The patients then underwent a pre-operative provocative test and discography. The follow-up duration was at least 1 year in all cases, and the visual analogue scale, recovery rate, and satisfaction of each patient were evaluated. The average age of the patients was 32 years (age range 18 to 49 years), and the patient group was 33% male and 67% female. Of the 25 patients, 5 underwent lumbar fusion surgery within 1 year of IDET. After IDET, 8 patients (32%) reported more pain than before, 14 patients (56%) reported less pain, and 3 patients (12%) experienced no change. Twelve patients (48%) were satisfied with IDET, 11 (44%) were dissatisfied, and 2 (8%) were undecided about the treatment. At least 1 year after IDET, nearly half the study patients were dissatisfied with their medical outcome. Consequently, 5 patients (20%) underwent fusion surgery at 1 year after IDET. Although other studies have shown good results with IDET for at least 2 years, this investigation suggests the IDET may be somewhat less effective. In order to firmly establish the efficacy of IDET for treating chronic discogenic lower back pain, additional studies with larger numbers of patients evaluated over longer time periods are recommended.

Availability of Intradiscal Injection of Marcaine as a Pain Relief Test for Diagnosis of Internal Disc Disruption / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To investigate the availability of an intradiscal injection of marcaine as a pain relief test to enhance specificity in the diagnosis of IDD. SUMMARY OF LITERATURE REVIEW: The diagnosis and treatment of IDD have been controversial. A discography, which has been widely used for the diagnosis of IDD, has many problems that might result in a faulty diagnosis. MATERIALS AND METHODS: Twenty nine patients, with an average age and duration of symptom of 36.9 years (22 to 46 years) and 5 years 1 month (6 months to 10 years), respectively, were reviewed. After the discography, the marcaine was injected. Based on the responses after the injection, the group was sub-divided into a further two groups. Group A (n=19): transient pain relief and surgical treatment was performed. Group B (n=10): no pain relief and conservative treatment was performed. An analysis to examine the correlation between the response to marcaine and age, duration of symptom, subjective pain level, number of disc degeneration and high intensity zone was also performed, and the clinical results quantified. RESULTS: The agreement rate between the discography and response to marcaine was 55.2%. The longer the symptom duration, the more meaningful were the responses to the marcaine injection (p<0.05). The result of surgical treatment was important statistically, as the pain was relieved from 8.6 +/- 0.97 to 1.8 +/- 0.42 points, and the ODI decreased from 68 +/- 16.92 to 30 +/- 9.97% (p<0.05). CONCLUSIONS: An intradiscal injection of marcaine, as the pain relief test, can enhance the specificity for the diagnosis of IDD.

Effect of Pulling and Rotating Manipulation in Different Postures on Intradiscal Pressure of the Cervical Spinal Cord / 广州中医药大学学报

Objective To compare the effect of pulling and rotating manipulation in different cervical postures on intradiscal pressure of the cervical spinal cord.Methods Quantitative simulation of pulling and rotating manipulation was performed on 6 fresh corpse cervical samples by Mechanical Testing & Simulation(MTS) system in different cervical postures of 20 degrees of anteflexion,neutral position,and 20 degrees of posterior extension,and the changes of intramedullary pressure of intervertebral C3/4,C4/5 and C6/7 were measured.Results The intradiscal pressure of intervertebral C3/4 and C4/5 in the posture of 20 degrees of posterior extension at the end of pulling manipulation by 200N and when the posture returned to the primary after pulling and rotating manipulation was less than that in the posture of 20 degrees of anteflexion(P

Effects of Intradiscal Steroid Injection in Patients with Lumbar Discogenic Pain

OBJECTIVE: To determine the therapeutic effects of intradiscal steroid injection in patients with lumbar discogenic pain. METHOD: Seventeen patients with lumbar discogenic pain who have not received other interventional procedures were studied. After confirmation of needle placement into the discs by C-arm fluoroscopy, discogram was done. And 40 mg of triamcinolone and 0.5 cc of 2% lidocaine were injected into the nucleus. Correlation between degeneration and Visual Analogue Scale (VAS) was analyzed. The effects of steroid injection were evaluated using VAS and limitation of lumbar flexion at pre-injection, 1 week post-injection, 1 month post-injection, and 3 months post-injection. Changes over time were assessed statistically using ANOVA and chi-square. RESULT: Correlation between degeneration and VAS was high (r=0.7). The averages of VAS reduced significantly from 6.1+/-1.6 at pre-injection, to 2.4+/-1.8 at 1 week post- injection, to 1.8+/-1.2 at 3 months post-injection, respectively (p<0.05). The number of group of highly or moderately limited lumbar flexion was decreased from 10 at pre- injection to 4 at 1 day post-injection. Fourteen of 17 patients (82.4%) had a successful outcome reporting at least 50% reduction between pre and 3 months post-injection in VAS. CONCLUSION: Intradiscal steroid injection was an effective treatment for patients with lumbar discogenic pain.

The Biomechanical Responses of Intervertebral Disc due to Degenerative Change in Porcine Lumbar Spine / 대한정형외과연구학회지

PURPOSE: The biomechanical responses of degenerative porcine intervertebral disc were compared with those MATERIALS AND METHODS: Two groups were set; Group A (44.0+/-2.8 months old, female) and Group B (6.2 +/-1.3 months old, female). Histological (H&E stain) observations were carried out to see the degeneration for both groups. Then biomechanical responses were investigated by measuring height changes in disc, intradiscal pressure values and relaxation time for each specimen under axial compressive loads. RESULTS: Degenerative changes were confirmed through H&E staining in Group A. The ratios of the nucleus pulposus area to total area were 14.7+/-4.5% and 29.2+/-6.0% in Group A and B, respectively (p=0.000). The decrease rates in disc height were 12.1+/-3.3% and 21.6+/-7.6%, in Group A and B, respectively under the axial compression of 740 N (p=0.000). No significant difference in intradiscal pressure measured in anterior zone between-groups except at axial load of 740N (p> 0.05). However, significant difference in pressure was found in posterolateral zone when the load was 542 N and higher (542 N: p=0.015, 740 N: p=0.010). The average relaxation time for Group A was significantly longer than that for Group B at 740N, i.e., at maximum load (anterior: p=0.010, posterolateral: p=0.014). CONCLUSION: Different biomechanical responses in degenerative disc were confirmed. They are 1) less flexible, 2) slower in energy relaxation under axial loading, and 3) larger portion of the external load were taken up at posterior part of annulus fibrous, especially in degenerative disc.

Nucleoplasty as an Alternative Intradiscal Therapy in Patients with Lumbar Disc Herniation

OBJECTIVE: The nucleoplasty ablates, coagulates and decompresses the nucleus pulposus by way of high-density plasma field rather than by way of high thermal energy. The authors intended to describe the effects, indications and technical details of nucleoplasty. METHODS: From August 2001 to January 2002, the authors performed nucleoplasty for 40 consecutive patients (45 levels) and evaluated the short-term(mean 3 months) result after the procedure according to Macnab criteria. Exclusion criteria were same for the other percutaneous procedures, significant or ruptured, sequestered disc material, spinal stenosis, spinal instability, etc. Intraoperative discogram was prerequisite for determination of the precise causative level. Average operation time was 40 minutes, and patients discharged on the next day after the procedure. RESULTS: Male was outnumbered female by 21 to 19 and age was ranged from 20 to 67 years old(mean: 42.9). Procedures were performed at single level in 35 cases and at two levels in 5 cases. The L4-5 level was the most commonly involved. According to Macnab's outcome criteria, excellent and good outcome was achieved in 35 patients(87.5%), and fair and poor outcome was in 3(7.5%) and 2(5%) patients, respectively. CONCLUSION: Nucleoplasty by using coblation method in patients with lumbar disc herniation shows immediate relief of leg and back pain in 87.5% of the patients during the short span of follow-up. However, data collection with respect to the lengthening of population number and follow-up span, and refinement of strict inclusion/exclusion criteria are prerequisite in near future.

Host Immune Responses to Intradiscal Gene Transfer / 대한척추외과학회지

PURPOSE: To elucidate host immune responses to intradiscal gene transfer. MATERIALS AND METHODS: Twenty rabbits were utilized. Ad/luciferase (adenovirus construct) were injected into nucleus pulposus of lumbar vertebrae. Group 1 received intradiscal injection of Ad/luciferase only, Group 2 received subcutaneous and intradiscal injection simultaneously, Group 3 received subcutaneous injection then intradiscal injection with 2 weeks interval. Blood samples were obtained serially after injection. Animals were sacrificed at 7 weeks. Antibody to adenovirus in peripheral blood was measured with ELISA and transgene expression was measured with standard luciferase kits. RESULTS: All rabbits in the Group 2 and 3 exhibited increased production of neutralizing antibody. There were clearly two subgroups in Group 1, three rabbits exhibited production of antibody but remaining three rabbits showed little or no production of antibody. All rabbits showed robust increase in transgene expression regardless of titer of neutralizing antibody. CONCLUSION: The intervertebral disc is favorable site for adenovirus-mediated gene transfer escaping from systemic immunity.

Intradiscal Electrothermal Annuloplasty in Chronic Discogenic Low Back Pain / 대한마취과학회지

Chronic discogenic low back pain remains a difficult treatment challenge. Also, Internal disc derangement in the lumbar spine is a common yet difficult clinical condition to treat. The reported prevalence of chronic low back pain due to intrinsic disc mediated pain is at least 40%. Internal disc derangement has characteristics such as degeneration of the collagen of the disc annulus, fissures, global disc degeneration, and herniation with or without root compression. The common treatment for chronic discogenic low back pain has been conservative, including physical therapy and pharmacological management but the effectiveness remians controversial. Surgical fusion offers modest results at best, but often fails, and is associated with complications and postoperative continued pain. The intradiscal electrothermal annuloplasty has become known as a safe and effective treatment for patients suffering from discogenic pain and offers the advantage of potentially repairing the damaged disc while maintaining normal disc function. We applied a navigable catheter with a temperature controlled thermal resistive coil, deployed intradiscally through a percutaneous extrapedicular approach under two plane fluoroscopic guidance in chronic low back patients. The authors experienced two cases of chronic discogenic pain that had failed to respond to any kind of conservative treatment but which was successfully relieved by the intradiscal electrothermal annuloplasty.

Histological Changes of the Intervertebral Disc with Intradiscal Steroid Injection

OBJECTIVE: To observe histological changes of the intervertebral disc injected with intradiscal steroid and mollification of discogenic pain. METHOD: A study group of 25 Sprague-Dawely rats was divided into five subgroups. A control group of 10 Sprague-Dawely rats was divided into five subgroups. The rats' intervertebral discs were exposed by an anterior surgical approach. For study group, the rats were injected intradiscally methylprednisolone acetate 4 mg (Depomedrol, 40 mg/ml) to the L4-L5 intervertebral disc, methylprednisolone sodium succinate 4 mg (Solumedrol, 40 mg/ml) to the L5-L6 intervertebral disc, and triamcinolone acetonide 4 mg (Triamcinolone, 40 mg/ml) to the L6-S1 intervertebral disc. For control group, the rats were injected intradiscally 0.1 ml of saline to the L5-L6 intervertebral disc and a needle was inserted in the L6-S1 intervertebral disc. The intervertebral discs were extracted after 1 week, 2 weeks, 3 weeks, 4 weeks, and 16 weeks. The extracted intervertebral discs were stained with Hematoxylin-Eosin and examined histomorphometrically. RESULTS: There is no significant histological change in either group until 4 weeks after the different types of steroid were injected. Focal fibrotic change was present in the Solumedrol and Triamcinolone injection subgroups after 16 weeks. CONCLUSION: We concluded that rapid mollification of discogenic pain following intradiscal steroid injection may not result from histological change of the disc. Further biochemical study will be neccessary to clarify mollification mechanism of discogenic pain by intradiscal steroid injection.