Shin-ichi Konno

Incision of the anulus fibrosus induces nerve root morphologic, vascular, and functional changes : An experimental study

Study Design The effects on nerve root structure, vasculature, and function after incision of the adjacent disc was studied in a dog model. Objectives To see if only incision of the disc per se is sufficient for inducing similar changes. Summary of Background Data It is well known that nucleus pulposus will induce nerve root structural and functional changes in experimental situations. In these previous studies, relatively large amounts of nucleus pulposus were applied. Methods The left L7 nerve root was exposed and mobilized in 10 dogs. In five dogs, the adjacent L6‐L7 disc was incised, and in five other dogs, the disc was not incised. After 7 days, nerve conduction velocity was recorded, and specimens were obtained for histologic evaluation. Results The nerve conduction velocity was significantly lower in the incision group (13 ± 14 m/sec) compared with the nonincision group (73 ± 5 m/sec). Structural changes of the axons were more pronounced in the incision group, however, the degree and distribution was too limited to fully account for the neurophysiologic reactions observed. There also were obvious signs of capillary stasis with an increased number and diameter of the intraneural capillaries in the incision group. Conclusions The present study indicated that incision of the anulus fibrosus is sufficient to induce significant morphologic and functional changes and that vascular mechanisms may be of importance for the observed changes. These experimental data suggest that leakage of nucleus pulposus material from anular tears, with injury to adjacent nerve roots, might be one pathophysiologic mechanism in patients with low back pain and sciatica but with no radiologic or surgical evidence of disc herniation.

Inflammatory cytokines released from the facet joint tissue in degenerative lumbar spinal disorders.

Study Design. A prospective study of surgical cases of degenerative lumbar spinal disorders demonstrated inflammatory cytokines in the facet joint tissue. Objective. To quantify various inflammatory cytokines released from the facet joint tissue in surgical cases of degenerative lumbar spinal disorders. Summary of Background Data. In degenerative lumbar spinal disorders, pain is often caused by osteoarthritis of a facet joint. There are inflammatory mediators such as prostaglandins and leukotrienes in facet joint tissue in lumbar spinal degeneration. However, no reports have studied if there are also inflammatory cytokines in the facet joint, which generated arthropathic changes in degenerative lumbar spinal disorder and if pain is caused by chemical factors associated with inflammation such as inflammatory cytokines. Methods. Forty patients with degenerative lumbar disorders who had undergone operative treatment were included in this study. Fifty-five joint cartilages and 67 synovia were harvested from the lumbar facet joints in responsible intervertebral levels of patients. There were 24 male and 16 female subjects with average ages of 50 and 67 years, respectively, in 11 cases of lumbar disc herniation and 29 cases of lumbar spinal canal stenosis. Using ELISA and CLEIA methods, joint cartilage and synovial tissues were harvested during surgery from the facet joint at the responsible upper levels to measure IL-1β, TNF-α, and IL-6 in individual tissues. Results. IL-1β was detected in joint cartilage and synovium in both groups and its positive reaction rate was higher in LSCS than in LDH. There was no difference in IL-1β concentration in cartilage tissue between the two groups. There was TNF-α in the synovium of LSCS. IL-6 was high in joint cartilage and synovium in both groups. The concentration was significantly higher in LSCS than in LDH. Conclusions. There are inflammatory cytokines in facet joint tissue at high levels in degenerative lumbar spinal disorders. Inflammatory cytokines have a higher concentration rate in lumbar spinal canal stenosis than in lumbar disc herniation. This finding suggests that inflammatory cytokines in degenerated facet joints may have some relation to the cause of pain in degenerative lumbar disorders.

An anatomic study of the lumbar plexus with respect to retroperitoneal endoscopic surgery.

Study Design. The distribution of the lumbar plexus was analyzed using cadavers. Objective. To clarify the safety zone to prevent nerve injuries with respect to retroperitoneal endoscopic surgery. Summary of Background Data. Surgical approaches to the retroperitoneal space vary among surgeons. Recently, retroperitoneal endoscopic surgery has been applied to various spinal disorders. When the psoas major muscle is separated during retroperitoneal endoscopic surgery, there is a potential risk of injury to the lumbar plexus or nerve roots. However, there is sparse knowledge regarding the relationship between the greater psoas muscle and the lumbar plexus. Methods. A total of 30 cadavers were analyzed. Six lumbar spines of the cadavers were cut in parallel with the lumbar disc space. Each axial section was photographed and captured into a computer. The distribution of the lumbar plexus was analyzed using computer images. The positions where the genitofemoral nerve emerged on the abdominal surface of the psoas major muscle were analyzed using 24 cadavers. Results. L2/3 and above, all parts of the lumbar plexus, and nerve roots were located from the dorsal fourth of the vertebral body and dorsally. The genitofemoral nerve descends obliquely forward through the psoas major muscle, emerging on the abdominal surface between the cranial third of the L3 vertebra and the caudal third of the L4 vertebra. The safety zone of the psoas major muscle to prevent nerve injuries, excluding the genitofemoral nerve, is at L4/L5 and above. Conclusions. The safety zone, excluding the genitofemoral nerve, is at L4-L5 and above.

Do Corticosteroids Produce Additional Benefit in Nerve Root Infiltration for Lumbar Disc Herniation

Study Design. Experimental animal study. Objective. To determine whether corticosteroids produce additional benefit to nerve root infiltration (NRI) for experimental lumbar disc herniation. Summary of Background Data. NRI is used for nonsurgical treatment of radicular symptoms caused by lumbar disc herniation or lumbar spinal canal stenosis. Various studies have shown that NRI using local anesthetic or combinations of local anesthetic and corticosteroid can provide both short- and long-term pain relief. However, whether corticosteroids produce additional benefit to NRI remains controversial. Methods. A total of 174 adult female Sprague-Dawley rats were used in this study. The left L5 nerve root and dorsal root ganglion (DRG) were exposed. For the nontreatment group, autologous nucleus pulposus was harvested from the tail and applied to the DRG. For treatment groups, 1% lidocaine (Lido group), 0.4% dexamethasone (Dexa group), 1% lidocaine + 0.4% dexamethasone (Lido + Dexa group), or saline (Saline group) was injected into the underlayer of epineurium just distal to the nucleus pulposus. At 2, 7, 14, and 21 days after surgery, withdrawal threshold was determined using the von Frey test for mechanical allodynia. Expression of tumor necrosis factor (TNF)-&agr; in the DRG was examined by immunohistochemical analyses and immunoblotting. Results. Withdrawal threshold decreased in the nontreatment group from day 2 to day 14. Conversely, Lido, Dexa, and Lido + Dexa groups showed no decreases in withdrawal thresholds, and no significant differences were observed among these 3 groups. Immunohistochemical analyses showed that TNF-&agr; was localized in DRG neurons in all groups. Immunoblotting showed that expression of TNF-&agr; in the DRG was lower in Lido, Dexa, and Lido + Dexa groups than in the nontreatment group. No significant differences were observed among these 3 groups. Conclusion. NRI prevented mechanical allodynia. However, no additional benefit from using corticosteroid was identified, suggesting that corticosteroid may be unnecessary for NRI.

The relationship between intramuscular pressure of the paraspinal muscles and low back pain.

Study Design The relationship between lumbar intramuscular pressure and backache with degenerative lumbar spine diseases was examined. Lumbar intramuscular pressure in 102 patients with low back pain and in 20 normal adults was compared in different positions using Millers microtip catheter transducer. Objectives. This study sought to study the relationship between intramuscular pressure of the lumbar back muscles and degenerative lumbar diseases. Summary of Background Data Measurement of intramuscular pressure is an objective technique for diagnosing lumbar compartment syndrome. The diagnosis of chronic compartment syndrome of the lumbar back muscles is confirmed when an association between an increase in intramuscular pressure and the onset of back pain is established. As spinal alignment changes from lordosis to kyphosis, the intramuscular pressure increases and blood flow decreases. Methods Intramuscular pressure measurements of the lumbar back muscles were performed in various positions and loading. Results in patients with low back pain and in normal adults were compared. Results The intramuscular pressure levels were found to be closely related to position and loading. The pattern of changes in pressure depended on the type of disease. The changes in intramuscular pressure in the patients with backache were classified into four distinct patterns. Chronic compartment syndrome of the lumbar back muscles showed two patterns: waxing and plateau. Conclusions Measurement of intramuscular pressure of the lumbar back muscles might be an important method of obtaining a greater knowledge about backache.

JOA Back Pain Evaluation Questionnaire (JOABPEQ)/JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) The report on the development of revised versions April 16, 2007

1 Laboratory of Statistics, Osaka City University Faculty of Medicine, Osaka, Japan 2 Department of Orthopaedic Surgery, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan 3 Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan 4 Department of Orthopaedic Surgery, School of Medicine, Fukushima Medical University, Fukushima, Japan 5 Department of Orthopedic Surgery, Nippon Medical School, Tokyo, Japan 6 Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan 7 Department of Orthopaedic Surgery, Iwate Medical University School of Medicine, Morioka, Japan 8 Department of Orthopaedic Surgery, Saitama Medical School. Saitama, Japan 9 Department of Orthopedic Surgery, Yamaguchi University School of Medicine, Yamaguchi, Japan 10 Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan 11 Department of Orthopaedics, Kochi Medical School, Kochi, Japan 12 Department of Orthopaedic Surgery, Hoshigaoka Koseinenkin Hospital, Osaka, Japan 13 National Hospital Organization, Osaka-Minami Medical Center, Osaka, Japan 14 Department of Internal Medicine, Houai Hospital, Osaka, Japan 15 Department of Public Health, Osaka City University Faculty of Medicine, Osaka, Japan

Lumbosacral transitional vertebrae and nerve-root symptoms

Transitional vertebrae (TV) may be one of the risk factors for lumbar disc herniation. It is not clear, however, whether the presence of TV can affect the development of nerve-root symptoms. Our aim was to clarify this relationship. A total of 501 patients with lumbar degenerative disease and nerve-root symptoms was studied in respect of their level and the presence of TV. As a control group, 508 patients without low back pain or nerve-root symptoms were studied to establish the incidence of TV. In patients with disc herniation, the incidence was statistically higher and the mean age lower in patients with TV than in those without. In most patients, the symptomatic disc level was just above the TV. Similarly, in those with stenosis of the spinal canal without spondylolisthesis, the symptomatic disc level was most commonly just above the TV.

Epidural application of nucleus pulposus enhances nociresponses of rat dorsal horn neurons.

Study Design. An electrophysiologic study to examine responses of dorsal horn neurons in the rat L5 spinal cord to noxious stimuli after disc herniation or application of the nucleus pulposus to the L5 nerve root. Objectives. To investigate the pathogenic role of nucleus pulposus in the neural mechanism underlying sciatica and low back pain. Summary of Background Data. Application of the nucleus pulposus to the lumbar nerve root induced morphologic, vascular, and functional changes in the nerve root, suggesting that some factors in the nucleus pulposus may be implicated in the pathogenesis of chronic changes. However, it has not been studied whether the epidural application of nucleus pulposus enhances nociresponses of pain-processing neurons in the superficial dorsal horn of the spinal cord. Methods. Extracellular recordings were made from the L5 dorsal horn neurons in 20 Wistar rats. The wide-dynamic-range (WDR) neurons activated by electric stimulation of the ipsilateral footpad of hindpaw were selected, and their responses to noxious and innocuous stimulation were examined after L5–L6 disc herniation onto the L5 nerve root (Group A) and application of the autologous nucleus pulposus (Group B) or fat tissues (Groups C and D). Results. The herniation of the nucleus pulposus (Group A) and application of the autologous nucleus pulposus (Group B) to the nerve root remarkably enhanced responses of WDR neurons to noxious stimuli for hours, whereas application of fat tissue scarcely enhanced nociresponses (Groups C and D). Conclusions. Results suggest that somewhat pathogenic factors in the nucleus pulposus may have a crucial role in the induction of hyperalgesia. This may help to elucidate the reason why a severe pain is sometimes induced without a visually identified protrusion.

Presence and Distribution of Antigen-antibody Complexes in the Herniated Nucleus Pulposus

STUDY DESIGN Herniated tissue was studied by immunohistochemistry in eight patients with lumbar disc herniation. The results were compared with those of control subjects. OBJECTIVE To assess the presence and distribution of possible antigen-antibody complexes in herniated disc tissue. SUMMARY OF BACKGROUND DATA It has been suggested that the nucleus pulposus may be recognized as a foreign-body by the immune system and that this will lead to secondary nerve root disturbance. Such immunologic events should be initiated by binding of antibodies to a specific antigen in the disc tissue. However, the presence of antigen-antibody complexes in the herniated disc tissue has not been assessed. METHODS Amplification of the peroxidase reaction produced in avidin-biotin-peroxidase complex immunostaining by diaminobenzidine was used to visualize antigen-antibody complexes in the herniated tissue. The authors used herniated tissue from eight patients with lumbar disc herniation and nucleus pulposus from five control subjects with nonlumbar disc herniation. Thin paraffin sections, prefixed in 4% paraformaldehyde, were incubated with anti-human IgG antibody to allow visualization of antigen-antibody complexes in the specimens. RESULTS A brown deposit, indicating antigen-antibody complexes, could be observed in the pericellular capsule in herniated disc tissue but not in control discs or in the residual discs of the herniation patients. CONCLUSION Antigen-antibody complexes seem to be commonly present in herniated disc tissue, but not in healthy discs. However, the pathophysiologic and clinical significance of this observation has to be elucidated further.

Prospective study of surgical treatment of degenerative spondylolisthesis: comparison between decompression alone and decompression with graf system stabilization.

Study Design. A prospective study of patients with degenerative spondylolisthesis who underwent decompression of the spine, with and without stabilization using the Graf system. Objectives. To assess the clinical result of decompression alone and decompression using the Graf system. Summary of Background Data. The clinical outcome of lumbar stabilization for degenerative spondylolisthesis remains uncertain. There is no prospective study of differences in clinical outcome between patients who undergo decompression alone and those who undergo decompression and stabilization using the Graf system. Methods. Eighty-eight patients with degenerative spondylolisthesis were included in this study. All patients reported leg symptoms. Decompression alone (Group D) was performed in 42 patients during a 5-year period from 1988 through 1992. Decompression and stabilization with the Graf system (Group G) was performed in 46 patients during a 4-year period from 1993 through 1996. There was no statistical difference regarding sex, the age at operation, compensable cases, and preoperative duration between two groups. The two groups were evaluated at follow-up examinations 1 and 3 years after surgery. The clinical results were evaluated for all patients by means of a 4-grade scale, visual analog scale, recurrence of leg symptoms, and persistent low back pain. The radiographic and clinical findings were examined by an independent investigator. Results. The results according to the 4-grade scale deteriorated with time in both groups. There was no statistical difference between the two groups in the 4-grade scale, visual analog scale, or recurrence of leg symptoms at each follow-up time. Persistent low back pain in Group G was significantly lower than that in Group D at both the 1- and 3-year follow-ups. Conclusions. Although lumbar Graf stabilization had no effect in preventing the recurrence of leg symptoms, there was a significant effect on reduction of low back pain at the 1- and 3-year follow-ups.