The source of low back pain and sciatica

Does paravertebral ozone injection have efficacy as an additional treatment for acute lumbar disc herniation? A randomized, double-blind, placebo-controlled study

OBJECTIVE

In this study we investigate the effects of paravertebral ozone injections (POI), which have been used as a new treatment approach for lower back pain in recent years, on pain and physical activity in patients with acute lumbar disc herniation (LDH) as an additional treatment.

METHODS

Thirty-eight patients were assigned into the ozone therapy (OT) group (n= 20) and placebo control (PC) group (n= 18). Both groups received two sessions per week, a total of 8 sessions of lumbar POI. The ozone concentrations of 20-25 μg/ml (30 ml) and 0.1 μg/ml (30 ml) were administered to the OT and PC groups, respectively. The patients were assessed with the visual analog scale (VAS) and Oswestry Disability Index (ODI) before the treatment (V1), 15 (V2) and 30 (V3) days after the treatment started, and one month (V4) after the treatment ended.

RESULTS

A significant improvement was seen in the VAS and ODI scores in the final follow-up (V4) as compared with the baselines scores (V1) in both groups (P< 0.05). The patients in the OT group had lower mean VAS and ODI scores in V2, V3, and V4 follow-ups compared with the patients in the PC group. This significant difference reached its peak in the final follow-up (V4) (P< 0.05).

CONCLUSION

As an additional treatment combined with conservative treatment, lumbar POI can lessen pain and disability in patients with acute LDH.

Capability of nondegenerated and degenerated discs in producing inflammatory agents with or without macrophage interaction

STUDY DESIGN

Molecular biological and immunohistological examinations.

OBJECTIVE

To clarify whether nondegenerated and degenerated discs produce inflammatory agents such as prostaglandin (PG)E2, interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)α, which have been reported to play pivotal roles in lumbar disc diseases, in the presence or absence of macrophages.

SUMMARY OF BACKGROUND DATA

A recent study reported discogenic low back pain might be caused by annular disruption followed by vascularized granulation formation extending from the outer layer of the annulus fibrosus into the nucleus pulposus along the torn fissure. Moreover, abundant macrophages have been shown to be present in symptomatic discs but not in normal and aged discs. However, there has been no in vitro report investigating the interaction between macrophages and several degrees of degenerated discs.

METHODS

Degenerated intervertebral discs were obtained from Sprague-Dawley rats with different lengths of rat tail compression (2, 4, and 8 weeks). These degenerated disc and nondegenerated disc tissues were respectively cultured in the presence or absence of macrophages. The culture supernatants were analyzed for PGE2, IL-6, IL-1β, and TNF-α. Immunohistochemical staining for cyclooxygenase-2 and IL-6 was also carried out on 4-week compression discs.

RESULTS

Nondegenerated discs alone, several degrees of degenerated discs alone, and macrophages alone produced small amounts of PGE2 and IL-6. However, they were able to produce significantly higher amounts of PGE2 and IL-6 when cocultured with macrophages. In contrast, we detected small amounts of IL-1β and TNF-α at every stage of degeneration regardless of the presence or absence of macrophages. The immunohistological examination showed anticyclooxygenase-2 and anti-IL-6 reactivities in the chondrocytes embedded in the disc matrix obtained from the degenerated disc.

CONCLUSION

These results suggest PGE2 and IL-6 play a pivotal role in the interaction between degenerated discs and macrophages.

Intramuscular oxygen-ozone therapy in the treatment of acute back pain with lumbar disc herniation: a multicenter, randomized, double-blind, clinical trial of active and simulated lumbar paravertebral injection

STUDY DESIGN

Multicenter randomized, double-blind, simulated therapy-controlled trial in a cohort of patients with acute low back pain (LBP) due to lumbar disc herniation (LDH).

OBJECTIVE

To assess the benefit of intramuscular-paravertebral injections of an oxygen-ozone (O2O3) mixture.

SUMMARY OF BACKGROUND DATA

Recent findings have shown that O2O3 therapy can be used to treat LDH that fails to respond to conservative management. However, these findings are based on intradiscal/intraforaminal O2O3 injection, whereas intramuscular-paravertebral injection is the technique used most in clinical practice in Italy and other Western countries.

METHODS

Sixty patients suffering from acute LBP caused by LDH was randomized to an intramuscular O2O3 or control group. Patients were observed up to assess pain intensity, LBP-related disability, and drug intake (15 [V2] and 30 [V3] days after treatment started, and 2 weeks [V4], and 3 [V5] and 6 [V6] months after treatment ended).

RESULTS

A significant difference between the 2 groups in the percentage of cases who had become pain-free (61% vs. 33%, P < 0.05) was observed at V6. Patients who received O2O3 had a lower mean pain score than patients who received simulated therapy throughout the observation period. A significant improvement was observed in LBP-related disability in the study group patients when compared with the control group patients. Active O2O3 therapy was followed by a significantly lower number of days on nonsteroidal anti-inflammatory drugs at V2 and V3 and by a lower number of days at V4. No adverse events were reported.

CONCLUSION

Treatment of LBP and sciatica is a major concern. Although the natural history of acute LBP is often self-limiting, conservative therapies are not always effective; in such cases, O2O3 intramuscular lumbar paravertebral injections, which are minimally invasive, seem to safely and effectively relieve pain, as well as reduce both disability and the intake of analgesic drugs.

Interleukin-6 production is upregulated by interaction between disc tissue and macrophages

STUDY DESIGN

Interleukin (IL)-6 production was investigated using a coculture system of disc tissue and macrophages.

OBJECTIVES

The purpose of this study was to investigate the interaction between intervertebral disc tissue and macrophages in terms of IL-6 production.

SUMMARY OF BACKGROUND DATA

IL-6 production is observed in human herniated disc specimens, and there is a correlation between IL-6 production and neurologic symptoms. However, the mechanism of IL-6 production in the herniated disc is not clear.

MATERIALS AND METHODS

Coccygeal intervertebral discs and exudated peritoneal macrophages were obtained from male Sprague-Dawley rats. Macrophages and intervertebral disc without endplates were cocultured in a serum-free medium. Fat tissue culture with or without macrophages, intervertebral disc alone, and macrophages alone were used for controls. The supernatant fluid of the culture was utilized for the enzyme-linked immunosorbent assay. The precipitations of macrophages and disc coculture were used for semiquantitative RT-PCR for IL-6. Immunohistochemical staining for IL-6 and the macrophages marker (ED2) were also carried out using disc tissue cultured with macrophages.

RESULTS

IL-6 production level was significantly increased in the coculture of intervertebral disc and macrophages (P < 0.01). However, there was no significant production of IL-6 in the control groups. The precipitations from coculture of macrophages and disc expressed IL-6 mRNA in semiquantitative RT-PCR. Immunohistochemical staining revealed most IL-6 producing cells were also positive for ED2, which adheres to or infiltrates the peripheral area of the nucleus pulposus.

CONCLUSIONS

Our results demonstrated that interaction between disc tissue and macrophage is necessary for upregulation of IL-6 production. Immunohistochemical staining also indicated that infiltrated macrophages played a major role in production of IL-6, suggesting that infiltration of macrophages into herniated disc material may be a trigger for IL-6 production and associated neurologic symptoms.

Pain resolution after lumbar disc surgery is influenced by macrophage tissue infiltration. A prospective consecutive study on 177 patients

The aim of this study was to assess the influence of inflammatory reactions in herniated lumbar disc specimens on pain resolution after lumbar disc surgery. Disc specimens of 200 patients who underwent surgery for lumbar disc herniation were studied immunohistologically. Preoperatively each patient received a verbal rating scale (VRS) for classification of the pain level and general clinical data were recorded prospectively. Varying amounts of macrophages could be demonstrated. Eighty-nine percent of patients could be followed up for a mean period of 7 months. A statistically significant correlation between the histologically observed macrophage infiltration and postoperative pain grading according to the VRS was found. Patients with evidence of inflammatory reactions rated their postoperative complaints lower than patients with no evidence of inflammatory reactions on the VRS (P = 0.04). In our study, a statistically significant correlation between inflammatory changes in the herniated lumbar disc specimen and outcome after lumbar disc surgery could be demonstrated.

Comparison of the prevalence of inflammatory cells in subtypes of disc herniations and associations with straight leg raising

STUDY DESIGN

The prevalence of inflammatory cells in 205 disc herniations (DHs) and nine macroscopically normal discs for comparison was studied immunohistochemically. Inflammatory cells were separately analyzed in subtypes of DH. Immunohistochemical data were related to clinical parameters, the straight leg raising test (SLR) in particular.

OBJECTIVES

The objectives of the study were to compare the occurrence of inflammatory cells in various subtypes of DH and to determine the association between clinical data and inflammatory cell occurrence in a more extensive sample of DH, with separate analysis of DH subtypes.

SUMMARY OF BACKGROUND DATA

Previous studies have suggested a common occurrence of inflammation and inflammatory cells, particularly macrophages, in DHs. No studies on any larger material comprising different subtypes of DH have been done.

METHODS

For immunohistochemistry the alkaline phosphatase antialkaline phosphatase method was used. Monoclonal antibodies to T cells in general (CD2), activated T cells (CD25), B cells (CD22), and macrophages (CD68) were used. Obtained immunostaining results were then compared with clinical data, e.g., duration of pain, SLR, and type of DH (sequesters 86, extrusions 103, protrusions 16). Associations were studied by the chi2 test or Fisher's exact test, as applicable (level of significance P < 0.05).

RESULTS

Abundant T cells were seen in 17% of the 205 DHs, activated T cells in 17%, B cells in 16%, and macrophages in 37%. All cell types were 2-3 times more prevalent in sequestrated discs than in extrusions. In protrusions macrophages were abundantly seen in 25% (4 of 16) and no other inflammatory cells. In patients with positive SLR and a sequestrated disc abundant lymphocytes were seen three times more often than in extrusions. When patients with bilaterally negative SLR were compared with those with tight SLR (< or =30 degrees ) with respect to inflammatory cell occurrence, some significant differences were noted (CD68, P < 0.025; CD25, P = 0.04). A comparison between SLR bilaterally positive and bilaterally negative also showed associations for all four inflammatory cell types (P = 0.016 to P = 0.029). There was no correlation between inflammatory cells and duration of pain. Abundant inflammatory cells were never seen in control discs.

CONCLUSIONS

When SLR was positive and the DH type was sequestered, inflammatory cells were most commonly seen. Our results showed some statistically significant associations between inflammatory cells and SLR, most clearly when comparing bilaterally positive and negative SLR. Interestingly, a bilaterally positive SLR showed an association with all four inflammatory cell types analyzed. Tight SLR also showed an association, particularly with macrophages. In addition to tissue resorption, they may participate in sciatic pain. Even though lymphocytes were less prevalent, they may have some role in sequestered discs and bilaterally positive SLR.

In vivo macrophage recruitment by murine intervertebral disc cells

SUMMARY

An in vivo murine experiment was conducted to measure the capacities of viable intervertebral disc cells to recruit inflammatory cells. The objective was to determine whether compounds secreted from viable cells induce inflammation or whether inflammation in disc herniation simply requires exposure to structural cell or matrix components. Three tissue preparations were inserted into the right lower peritoneal cavity of male mice: tissue with viable annulus fibrosus and nucleus pulposus cells, tissue with viable annulus fibrosus cells, or devitalized annulus fibrosus and nucleus pulposus tissue. Controls included sham-operated and nonoperated groups. Mice were killed 1, 2, or 7 days after surgery. Macrophage recruitment occurred after exposure to viable disc tissue but not after exposure to devitalized disc components; recruitment increased over time. Viable disc cells play a role in the etiology of inflammation in disc herniation.

Influence of macrophage infiltration of herniated lumbar disc tissue on outcome after lumbar disc surgery

STUDY DESIGN

An immunohistochemical examination of the presence of inflammatory cells in routinely processed resection specimens of the lumbar disc, and a comparison of the histologic results with clinical data collected prospectively before and after surgery.

OBJECTIVES

To assess the influence of inflammatory reactions in herniated lumbar disc specimens on the outcome after lumbar disc surgery.

SUMMARY OF BACKGROUND DATA

Histologic and biochemical studies on herniated lumbar disc tissue led to the notion of inflammation-induced sciatic pain. At this writing, no investigations have sought to discover how outcome after lumbar disc surgery is influenced by histologically described inflammation.

METHODS

Disc specimens from 79 patients who underwent surgery for lumbar disc herniation were studied immunohistologically with regard to the presence of inflammatory reactions. Of these, 92% were followed up approximately 7 months after surgery. The histologic results were compared with the outcome at follow-up evaluation.

RESULTS

A statistically significant correlation was found between the histologically proven inflammation and the outcome, as shown by the pain grading scale.

CONCLUSIONS

The results from this study seem to support the theory of a foreign body reaction to the herniated material. This reaction may result in inflammation-induced sciatic pain.

Is there a clinical correlate to the histologic evidence of inflammation in herniated lumbar disc tissue?

STUDY DESIGN

The presence of inflammatory cells was examined immunohistochemically in routinely processed resection specimens of the lumbar disc. The histologic results were compared with prospectively obtained clinical data.

OBJECTIVES

To assess the clinical relevance of inflammatory cells in herniated lumbar disc specimens.

SUMMARY OF BACKGROUND DATA

It is postulated that in addition to nerve root compression, an inflammatory stimulus of the herniated lumbar disc is responsible for sciatic pain and radiculopathy. However, the clinical relevance of the histologically described inflammatory infiltrates is not defined clearly.

METHODS

Disc specimens from 44 patients who underwent surgery for lumbar disc herniation were studied immunohistologically. Before surgery, severity of pain was classified in each patient according to a visual analog scale, and general clinical data were recorded prospectively.

RESULTS

Varying amounts of inflammatory cells could be demonstrated in the resected disc tissue. In the statistical analysis, no statistically significant correlation between the histologic evidence of macrophage infiltrates and the pain grading scale or the clinical data was noted.

CONCLUSIONS

There is no statistically significant correlation between macrophage infiltrates in herniated lumbar disc specimens and the obtained clinical data.

Murine nucleus pulposus-derived cells secrete interleukins-1-beta, -6, and -10 and granulocyte-macrophage colony-stimulating factor in cell culture

STUDY DESIGN

Cultures established from murine disc-derived cells were stimulated by lipopolysaccharide. The cells' capacity to secrete proinflammatory cytokines and interleukin-10 with and without lipopolysaccharide stimulation was determined using enzyme-linked immunosorbent assays.

OBJECTIVES

To determine the capacity of disc-derived cells to secrete proinflammatory cytokines, and the effect of lipopolysaccharide stimulation on such secretion.

SUMMARY OF BACKGROUND DATA

The pathophysiology of compressive radiculopathy is unclear. Inflammation is a possible explanation. Proinflammatory cytokine secretion was demonstrated in herniated nucleus pulposus. It is unknown whether these cytokines are secreted from disc-derived cells or from infiltrating inflammatory cells in the herniated nucleus pulposus.

METHODS

Discs were microsurgically harvested from inbred mice and cut to allow the nucleus pulposus to establish cell culture. A study group was exposed to lipopolysaccharide stimulation. Media were harvested from the study and control groups 24 hours later. Secretion of interleukins-1-, -6, and -10, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-alpha were determined using enzyme-linked immunosorbent assays.

RESULTS

Basal secretion of interleukins-6 and -10, but no basal secretion of interleukin-1-, granulocyte-macrophage colony-stimulating factor, or tumor necrosis factor-alpha was detected. Secretion of interleukin-1- rose from zero to 27.69 pg/10(5) cells, and granulocyte-macrophage colony-stimulating factor secretion rose from zero to 9.77 pg/10(5) cells after lipopolysaccharide stimulation. A 75-fold increase in interleukin-6 secretion and a 150-fold increase in interleukin-10 secretion were detected after stimulation with lipopolysaccharide. No tumor necrosis factor-alpha secretion was detectable. All result had high statistical significance (all P < 0.001).

CONCLUSIONS

Cultured murine disc-derived cells have the capacity to secrete proinflammatory cytokines and interleukin-10 in the absence of inflammatory cells. This finding supports the hypothesis that disc-derived cells are capable of initiating or amplifying an inflammatory process.

Inflammatory cytokines in the herniated disc of the lumbar spine

STUDY DESIGN

Tissues in the area of herniated lumbar discs were examined for inflammatory cytokines to elucidate the causes of sciatic pain in lumbar disc herniation.

OBJECTIVES

To determine the role of inflammatory cytokines in the stimulation of sciatic pain in lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

It is postulated that in addition to mechanical compression of lumbar nerve roots and sensory root ganglia by herniated discs, there is a chemical stimulus to the production of sciatic leg pain. The exact mechanisms of chemical stimulation are not clearly defined.

METHODS

During surgery, cases of lumbar disc herniation in 77 patients were classified macroscopically into protrusion, extrusion, and sequestration types. Tissues adjacent to nerve roots at the herniation were excised and analyzed biochemically and immunohistochemically for the presence of inflammatory cytokines and for the production of these cytokines and prostaglandin E2 in vitro.

RESULTS

The homogenates of samples were analyzed for interleukin-1 alpha, interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, and granulocyte-macrophage colony stimulating factor, which were detectable. Most of the cytokine-producing cells were histiocytes, fibroblasts, or endothelial cells in extrusion and sequestration types, and chondrocytes in protrusion type. The secretion of these cytokines and prostaglandin E2 was decreased by the addition of betamethasone. The prostaglandin E2 production was dramatically enhanced by additional interleukin-1 alpha, but decreased by the addition of tumor necrosis factor-alpha.

CONCLUSION

The results demonstrate that at the site of lumbar disc herniation, inflammatory cytokines such as interleukin-1 alpha are produced, which increases prostaglandin E2 production. Further studies are required to elucidate the role of inflammatory cytokines in causing sciatic pain.

A scanning electron microscopic and immunohistochemical study of spinal ligaments innervation

Neural elements in the interspinous and longitudinal ligaments of the human lumbar spine were investigated by means of scanning electron microscopy (SEM) and immunohistochemistry for neurofilament protein (NFP). The SEM results agree with our previous findings of nerve fibers and localized them in the superficial layers of the ligaments as well as in the deeper ligamentous substance. The immunohistochemical staining for NFP has clearly confirmed the presence of sensory nerve endings. Most of the nerve fibers terminated as simple free endings which are thought to be nociceptors.

Innervation of spinal ligaments of patients with disc herniation. An immunohistochemical study

The purpose of this work was to demonstrate whether neural elements are present in the spinal ligaments removed from patients with disc herniation. The tissue samples were stained by an immunohistochemical technique using antibodies to neurofilament protein (NFP) subunits as specific markers. Numerous NFP-immunoreactive nerve fibers and free nerve endings were demonstrated within the ligamentous structures. These findings were discussed relative to the low-back pain of disc herniated patients.