STUDY DESIGN: Experimental animal study. PURPOSE: To evaluate pain-related behavior and changes in nuclear factor-kappa B (NF-kB), receptor activator of NF-kB (RANK), and ligand (RANKL) in dorsal root ganglia (DRG) after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. OVERVIEW OF LITERATURE: The pathological mechanisms underlying pain from lumbar-disc herniation have not been fully elucidated. RANKL are transcriptional regulators of inflammatory cytokines. Our aim was to evaluate pain-related behavior and RANKL expression in DRG after sciatic-nerve compression and application of NP in rats. METHODS: Mechanical hyperalgesia and RANKL expression were assessed in three groups of rats: NP+sciatic nerve compression (2 seconds), sham-operated, and controls (n=20 each). Mechanical hyperalgesia was measured every other day for 3 weeks using von Frey filaments. RANKL expression in L5 DRGs was examined at five and ten days after surgery using immunohistochemistry. RESULTS: Mechanical hyperalgesia was observed over the 12-day observation period in the NP+nerve compression group, but not in the control and sham-operated animal groups (p<0.05). RANKL immunoreactivity was seen in the nuclei of L5 DRG neurons, and its expression was significantly upregulated in NP+nerve compression rats compared with control and sham-operated rats (p<0.01). CONCLUSIONS: The exposure of sciatic nerves to mechanical compression and NP produces pain-related behavior and up-regulation of RANKL in DRG neurons. RANKL may play an important role in mediating pain after sciatic nerve injury with exposure to NP.
Animals ; Cytokines ; Diagnosis-Related Groups ; Ganglia, Spinal* ; Hyperalgesia ; Immunohistochemistry ; Negotiating ; Neurons ; NF-kappa B ; RANK Ligand* ; Rats* ; Sciatic Nerve* ; Up-Regulation

STUDY DESIGN: Experimental animal study. PURPOSE: To evaluate pain-related behavior and changes in glial activity in the spinal dorsal horn after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. OVERVIEW OF LITERATURE: Mechanical compression and inflammation caused by prostaglandins and cytokines at disc herniation sites induce pain. Structural changes and pain-associated cytokines in the dorsal root ganglia and spinal dorsal horn contribute to prolonged pain. Glial cells in the spinal dorsal horn may also function in pain transmission. METHODS: The sciatic nerve was compressed with NP for 2 seconds using forceps in the NP+nerve compression group; the sham-operated group received neither compression nor NP; and the control group received no operation. Mechanical hyperalgesia was measured for 3 weeks using von Frey filaments. Glial activity in the spinal dorsal horn was examined 7 days and 14 days postsurgery using anti-glial fibrillary acidic protein and anti-Ionized calcium binding adaptor molecule-1 antibodies to detect astrocytes and microglia, respectively. RESULTS: Mechanical hyperalgesia was detected throughout the 14-day observation in the NP+nerve compression group, but not in control or sham-operated groups (p<0.05). Both astrocytes and microglia were significantly increased in the spinal dorsal horn of the NP+nerve compression group compared to control and sham groups on days 7 and 14 (p<0.05). CONCLUSIONS: Nerve compression with NP application produces pain-related behavior, and up-regulates astrocytes and microglia in the spinal dorsal horn, suggesting that these glia may be related to pain transmission.
Animals ; Antibodies ; Astrocytes ; Calcium ; Cytokines ; Ganglia, Spinal ; Horns ; Hyperalgesia ; Inflammation ; Microglia ; Neuroglia ; Prostaglandins ; Rats* ; Sciatic Nerve* ; Spinal Cord* ; Surgical Instruments ; Up-Regulation*

PURPOSE: Surgery for lumbar spinal degeneration disease is widely performed. While posterior decompression and fusion are popular, anterior lumbar interbody fusion (ALIF) is also used for treatment. Extreme lateral interbody fusion (XLIF) is commonly used for noninvasive ALIF; however, several complications, such as spinal nerve and psoas muscle injury, have been reported. In the current study, we examined the clinical efficacy and complications of oblique lateral interbody fusion (OLIF) for lumbar spinal degeneration disease. MATERIALS AND METHODS: Thirty-five patients with degenerated spondylolisthesis, discogenic pain, and kyphoscoliosis were examined. All patients underwent OLIF surgery (using a cage and bone graft from the iliac crest) with or without posterior decompression, without real-time electromyography monitoring. Posterior screws were used in all patients. Visual analog scale (VAS) score and Oswestry Disability Index (ODI) were evaluated before and 6 months after surgery. Surgical complications were also evaluated. RESULTS: Pain scores significantly improved after surgery, compared to those before surgery (p<0.05). There was no patient who underwent revision surgery. There was no spinal nerve, major vessel, peritoneal, or urinary injury. Few patients showed symptoms from psoas invasion. CONCLUSION: OLIF surgery produced good surgical results without any major complication.
Adult ; Aged ; Decompression, Surgical/*methods ; Electromyography ; Female ; Humans ; Lumbar Vertebrae/surgery ; Male ; Middle Aged ; Pain ; Pain Measurement ; Scoliosis/*surgery ; Spinal Diseases/surgery ; Spinal Fusion/*methods ; Spondylolisthesis/*surgery ; Treatment Outcome ; Young Adult

STUDY DESIGN: Prospective study of changes in intervertebral disc degeneration after injection of bupivacaine. PURPOSE: To examine whether injection of bupivacaine into human intervertebral discs accelerates their degeneration. OVERVIEW OF LITERATURE: Bupivacaine is commonly used for therapy and diagnosis of discogenic low back pain. However, several in vitro studies have reported toxic effects of bupivacaine to disc cells. We sought to evaluate whether this finding is clinically relevant. METHODS: We selected 46 patients with low back pain who showed disc degeneration at only one level (L4-L5 or L5-S1) on magnetic resonance imaging (MRI) (discography group, n=18), discoblock group (injection of bupivacaine, n=18), and a control group, n=10). There were no significant differences in baseline characteristics across the 3 groups. The two experimental groups underwent either discography or anesthetic discoblock, respectively. All three groups were followed up 5 years after the examination. RESULTS: At 5 years follow-up, there was no significant difference in the rate of disc degeneration among the 3 groups (p>0.1). Moreover, X-ray images showed that there was no significant difference in disc height, range of motion, or translation between flex and extension position (p>0.1). CONCLUSIONS: In conclusion, radiologic and MRI findings did not show acceleration of intervertebral disc degeneration at 5 years after a single injection of bupivacaine into human discs.
Bupivacaine ; Follow-Up Studies ; Humans ; Intervertebral Disc ; Intervertebral Disc Degeneration ; Low Back Pain ; Lumbar Vertebrae ; Magnetic Resonance Imaging ; Prospective Studies ; Range of Motion, Articular

PURPOSE: Bupivacaine is commonly used for the treatment of back pain and the diagnosis of its origin. Nonunion is sometimes observed after spinal fusion surgery; however, whether the nonunion causes pain is controversial. In the current study, we aimed to detect painful nonunion by injecting bupivacaine into the disc space of patients with nonunion after anterior lumbar interbody fusion (ALIF) surgery for discogenic low back pain. MATERIALS AND METHODS: From 52 patients with low back pain, we selected 42 who showed disc degeneration at only one level (L4-L5 or L5-S1) on magnetic resonance imaging and were diagnosed by pain provocation on discography and pain relief by discoblock (the injection of bupivacaine). They underwent ALIF surgery. If the patients showed low back pain and nonunion 2 years after surgery, we injected bupivacaine into the nonunion disc space. Patients showing pain relief after injection of bupivacaine underwent additional posterior fixation using pedicle screws. These patients were followed up 2 years after the revision surgery. RESULTS: Of the 42 patient subjects, 7 showed nonunion. Four of them did not show low back pain; whereas 3 showed moderate or severe low back pain. These 3 patients showed pain reduction after injection of bupivacaine into their nonunion disc space and underwent additional posterior fixation. They showed bony union and pain relief 2 years after the revision surgery. CONCLUSION: Injection of bupivacaine into the nonunion disc space after ALIF surgery for discogenic low back pain is useful for diagnosis of the origin of pain.
Back Pain ; Bupivacaine* ; Diagnosis ; Humans ; Intervertebral Disc ; Intervertebral Disc Degeneration ; Low Back Pain* ; Magnetic Resonance Imaging ; Methods ; Spinal Fusion ; Spine

PURPOSE: To introduce a new simple technique using suture anchors and ceramic spacers to stabilize the elevated laminae in open-door cervical laminoplasty. Although ceramic spacers were placed in the opened laminae and fixed with nylon threads in this series, it was occasionally difficult to fix the nylon threads to the lateral mass. MATERIALS AND METHODS: Study 1: A preliminary study was conducted using a suture anchor system. Sixteen consecutive patients who underwent surgery for cervical myelopathy were prospectively examined. Study 2: The second study was performed prospectively to evaluate the feasibility of this new technique based on the result of the preliminary study. Clinical outcomes were examined in 45 consecutive patients [cervical spondylotic myelopathy (CSM)] and 43 consecutive patients (OPLL). The Japanese Orthopedic Association scoring system (JOA score), axial neck pain, and radiological findings were analyzed. RESULTS: 1) In one case, re-operation was necessary due to dislodgement of the ceramic spacer following rupture of the thread. 2) In all patients, postoperative CT scans showed that the anchors were securely inserted into the bone. In the CSM group, the average JOA score improved from 9.5 points preoperatively to 13.3 at follow-up (recovery 51%). In the OPLL group, the average JOA score improved from 10.1 (5-14) points preoperatively to 14.4 (11-16) at follow-up (recovery 62%). There were no serious complications. CONCLUSION: The use of the suture anchor system made it unnecessary to create a hole in the lateral mass and enabled reliable and faster fixation of the HA spacers in open-door laminoplasty.
Adult ; Aged ; *Ceramics ; Cervical Vertebrae/radiography ; Feasibility Studies ; Female ; Follow-Up Studies ; Humans ; Laminoplasty/*methods ; Male ; Middle Aged ; Postoperative Period ; Prospective Studies ; Spinal Cord Diseases/*surgery ; Suture Anchors ; *Sutures ; Tomography, X-Ray Computed ; Treatment Outcome

PURPOSE: Osteoarthritic pain is largely considered to be inflammatory pain. Sensory nerve fibers innervating the knee have been shown to be significantly damaged in rat models of knee osteoarthritis (OA) in which the subchondral bone junction is destroyed, and this induces neuropathic pain (NP). Pregabalin was developed as a pain killer for NP; however, there are no reports on pregabalin use in OA patients. The purpose of this study was to investigate the efficacy of pregabalin for pain in OA patients. MATERIALS AND METHODS: Eighty-nine knee OA patients were evaluated in this randomized prospective study. Patients were divided into meloxicam, pregabalin, and meloxicam+pregabalin groups. Pain scores were evaluated before and 4 weeks after drug application using a visual analogue scale (VAS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Pain scales among groups were compared using a Kruskal-Wallis test. RESULTS: Before drug application, there was no significant difference in VAS and WOMAC scores among the three groups (p>0.05). Significant pain relief was seen in the meloxicam+pregabalin group in VAS at 1, 2, and 4 weeks, and WOMAC score at 4 weeks, compared with the other groups (p<0.05). No significant pain relief was seen in the meloxicam only group in VAS during 4 weeks and WOMAC score at 4 weeks compared with the pregabalin only group (p>0.05). CONCLUSION: Meloxicam+pregabalin was effective for pain in OA patients. This finding suggests that OA pain is a combination of inflammatory and NP.
Aged ; Aged, 80 and over ; Drug Therapy, Combination/adverse effects ; Female ; Humans ; Male ; Middle Aged ; Osteoarthritis, Knee/*drug therapy ; Pain Measurement ; Thiazines/administration & dosage/adverse effects/*therapeutic use ; Thiazoles/administration & dosage/adverse effects/*therapeutic use ; gamma-Aminobutyric Acid/administration & dosage/adverse effects/*analogs & derivatives/therapeutic use

PURPOSE: Pain from vertebral or femoral neck fractures is a particularly important problem in clinical orthopaedics. Transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated nonselective cation channel, and there are recent reports on an association between bone pain and TRPV1. However, an increase in TRPV1 activity has not been reported following femoral fracture. MATERIALS AND METHODS: We applied a neurotracer [Fluoro-gold (FG)] onto femur to detect dorsal root ganglia (DRGs) innervating the cortex of the femur in 30 Sprague Dawley rats. Seven days after application, a closed mid-diaphyseal fracture of the femur was performed. FG labeled TRPV1-immunoreactive (ir) DRGs innervating the femur were examined in nonfractured controls, and 3 days, 1 week, 2 weeks, and 4 weeks after fracture. We evaluated bone healing of the femur and compared the ratio of TRPV1-ir DRG neurons innervating the femur at the time points. RESULTS: Four weeks after fracture, complete bone union was observed. There was no significant difference in the ratio of FG labeled DRG neurons to total DRG neurons at each time point. The percentages of TRPV1-ir neurons in DRGs innervating the femur at 3 days and 1 week after fracture were significantly higher than those in control, 2 weeks, and 4 weeks after fracture (p<0.05). CONCLUSION: Fracture induced an increase of TRPV1-ir neurons in DRGs innervating the fractured femur within 3 days, and decreased during bone healing over 4 weeks. These findings show that TRPV1 may play a role in sensory sensation of bone fracture pain.
Animals ; Female ; Femur/*innervation/*metabolism ; Immunohistochemistry ; Rats ; Rats, Sprague-Dawley ; TRPV Cation Channels/*metabolism

PURPOSE: Sacroiliac fixation using iliac screws for highly unstable lumbar spine has been reported with an improved fusion rate and clinical results. On the other hand, there is a potential for clinical problems related to iliac fixation, including late sacroiliac joint arthritis and pain. MATERIALS AND METHODS: Twenty patients were evaluated. Degenerative scoliosis was diagnosed in 7 patients, failed back syndrome in 6 patients, destructive spondyloarthropathy in 4 patients, and Charcot spine in 3 patients. All patients underwent posterolateral fusion surgery incorporating lumbar, S1 and iliac screws. We evaluated the pain scores, bone union, and degeneration of sacroiliac joints by X-ray imaging and computed tomography before and 3 years after surgery. For evaluation of low back and buttock pain from sacroiliac joints 3 years after surgery, lidocaine was administered in order to examine pain relief thereafter. RESULTS: Pain scores significantly improved after surgery. All patients showed bone union at final follow-up. Degeneration of sacroiliac joints was not seen in the 20 patients 3 years after surgery. Patients showed slight low back and buttock pain 3 years after surgery. However, not all patients showed relief of the low back and buttock pain after injection of lidocaine into the sacroiliac joint, indicating that their pain did not originate from sacroiliac joints. CONCLUSION: The fusion rate and clinical results were excellent. Also, degeneration and pain from sacroiliac joints were not seen within 3 years after surgery. We recommend sacroiliac fixation using iliac screws for highly unstable lumbar spine.
Aged ; Arthritis/*surgery ; Bone Screws ; Female ; Humans ; Low Back Pain/diagnosis/epidemiology ; Lumbar Vertebrae/*surgery ; Male ; Middle Aged ; Pain/diagnosis/*epidemiology ; Sacroiliac Joint/*immunology/*pathology

PURPOSE: Chronic low back pain is a common clinical problem. As medication, non-steroidal anti-inflammatory drugs are generally used; however, they are sometimes non-effective. Recently, opioids have been used for the treatment of chronic low back pain, and since 2010, transdermal fentanyl has been used to treat chronic non-cancer pain in Japan. The purpose of the current study was to examine the efficacy of transdermal fentanyl in the treatment of chronic low back pain. MATERIALS AND METHODS: This study included patients (n=62) that suffered from chronic low back pain and were non-responsive to non-steroidal anti-inflammatory drugs. Their conditions consisted of non-specific low back pain, multiple back operations, and specific low back pain awaiting surgery. Patients were given transdermal fentanyl for chronic low back pain. Scores of the visual analogue scale and the Oswestry Disability Index, as well as adverse events were evaluated before and after therapy. RESULTS: Overall, visual analogue scale scores and Oswestry Disability Index scores improved significantly after treatment. Transdermal fentanyl (12.5 to 50 microg/h) was effective in reducing low back pain in 45 of 62 patients; however, it was not effective in 17 patients. Patients who experienced the most improvement were those with specific low back pain awaiting surgery. Adverse events were seen in 40% of patients (constipation, 29%; nausea, 24%; itching, 24%). CONCLUSION: Disability Index scores in 73% of patients, especially those with specific low back pain awaiting surgery; however, it did not decrease pain in 27% of patients, including patients with non-specific low back pain or multiple back operations.
Administration, Cutaneous ; Adult ; Aged ; Aged, 80 and over ; Chronic Disease ; Female ; Fentanyl/*administration & dosage/*therapeutic use ; Humans ; Low Back Pain/*drug therapy ; Male ; Middle Aged ; Young Adult