The effect of age on inflammatory responses and nerve root injuries after lumbar disc herniation: an experimental study in a canine model

Effect of cartilaginous endplates on extruded disc resorption in lumbar disc herniation

Objective

The aim of this study was to investigate the clinicopathologic features of lumbar disc herniation (LDH) with endplate degeneration and the association between cartilaginous fragments and inflammatory response to the herniated disc.

Summary of background data

LDH often involves hyaline cartilage fragments pulled from the vertebral endplates. Modic changes are closely associated with LDH that contains hyaline cartilage, and cartilaginous endplates seem to affect resorption of the herniated disc.

Methods

A total of 78 patients who underwent microscopic discectomy between 9 and 16 weeks after an occurrence of LDH were reviewed. Modic changes, disc degeneration, high-intensity zone, and vertebral corner defect were evaluated using magnetic resonance imaging (MRI). Histopathological observations of cartilaginous endplates and inflamed granulation tissue in the herniated disc were made. In cases with inflamed granulation tissue, neovascularization and macrophage infiltration were also evaluated using immunohistochemical analysis.

Results

Modic changes were observed in approximately one-third of the patients (26 cases: type 1, 7; type 2, 17; and type 3, 2). Cartilaginous endplates were observed in 32 cases (41%) and in the majority of cases with Modic changes compared with cases without Modic changes (65%, p = 0.001). Although inflamed granulation tissue was observed in 60 cases (77%), no significant differences were detected in patient age and the composition of the herniated material. Immunohistochemical analysis showed that fewer CD34-positive capillaries and CD68-positive cells were found in cases with cartilaginous fragments compared with those without cartilaginous fragments (p < 0.001). In addition, a higher immunoreactivity to CD34 and CD68 was found in herniated discs <25% of whose area was occupied by cartilaginous endplates compared with discs whose area was occupied at 25% or more (p < 0.001).

Conclusion

There is an association between LDH with endplate degeneration and cartilaginous herniation, with Modic type 2 predominating. Furthermore, neovascularization and macrophage infiltration, especially if the amount of cartilage is high, are likely to be less frequent in cartilaginous herniation, leading to failure in the spontaneous remission of clinical symptoms.

Surgical treatment of lumbar disc herniation in different ages-evaluation of 11,237 patients

BACKGROUND CONTEXT

Surgical treatment of lumbar disc herniation (LDH) may lead to different outcomes in young, middle-aged, and elderly patients. However, no study has, by the same data ascertainment, evaluated referral pattern, improvement, and outcome in different age strata.

PURPOSE

This study aimed to evaluate referral pattern and outcome in patients of different ages surgically treated because of LDH.

STUDY DESIGN

This is a register study of prospectively collected data.

PATIENT SAMPLE

In SweSpine, the national Swedish register for spinal surgery, we identified 11,237 patients who between 2000 and 2010 had their outcome of LDH surgery registered in pre-, per-, and 1-year postoperative evaluations.

OUTCOME MEASURES

The data collected included age, gender, smoking habits, walking distance, preoperative duration and degree of back and leg pain, consumption of analgesics, quality of life in the patient-reported outcome measure (PROM) Short-Form 36 (SF-36) and EuroQol 5 dimensions (EQ5D), disability in the Oswestry Disability Index, operated level, type of surgery, and complications.

METHODS

We compared the outcome in patients within different 10-year age strata. IBM SPSS Statistics 22 was used in the statistical calculations. No funding was obtained for this study. The authors have no conflicts of interest to declare.

RESULTS

Patients in all ages referred to surgery had inferior PROM data compared with published normative age-matched PROM data. Referral to LDH surgery demanded of each 10-year strata statistically significantly more pain, lower quality of life, and more disability (all p<.001). Surgery markedly improved quality of life and reduced disability in all age groups (all p<.001), but with statistically significantly less PROM improvement with each older 10-year strata (all p<.001). This resulted in statistically significantly inferior PROM values for pain, quality of life, and disability postoperatively for each 10-year strata (all p<.001). There were also more complications (p<.001) with each 10-year older strata.

CONCLUSIONS

In general, older patients referred to LDH surgery have statistically significantly inferior PROM scores, improve less, and reach inferior PROM scores postoperatively. The clinical relevance must however be questioned because most patients reach, independent of age group, the defined level for a successful outcome, and the patient satisfaction rate is high.

Value of a new pathological classification of lumbar intervertebral disc herniation based on transforaminal endoscopic observations

Removal of herniated disc materials based on an imaging only method may not relieve symptoms in many patients. Therefore, the aim of the present study was to develop a transforaminal endoscopic method of classifying the pathological type of lumber intervertebral disc herniation and to compare the outcomes of surgery based on the pathological type with those of conventional endoscopic disc removal. The records of patients who received endoscopic transforaminal nucleotomy with foraminoplasty for symptomatic lumbar disc herniation between 2009 and 2013 were retrospectively reviewed. Patients were then divided into two groups: Group A, which consisted of 275 patients who received conventional endoscopic transforaminal nucleotomy with foraminoplasty between 2009 and 2011 and group B, which consisted of 316 patients who received ‘targeted’ endoscopic transforaminal nucleotomy with foraminoplasty between 2011 and 2013 (based on the pathological type of disc herniation identified at surgery, including fresh, calcified and scar type based on intraoperative observations). The results showed that there were no significant differences in age, gender, body mass index, symptom duration, operated segments or previous invasive therapies between the two groups. Moreover, evaluation of visual analogue scale pain scores and Oswestry disability index scores revealed that the patients in group B had a greater improvement in symptoms than those in group A (P<0.05). In addition, an age >40 years and a longer symptom duration were associated with the calcified type, and previous invasive therapy was associated with the scar type. Therefore, specific surgical treatment based on the transforaminal endoscopic pathological type can result in better outcomes for patients with lumbar disc herniation.

The outcome of lumbar disc herniation surgery is worse in old adults than in young adults

Background and purpose - The outcome of surgical treatment of lumbar disc herniation (LDH) has been thoroughly evaluated in middle-aged patients, but less so in elderly patients. Patients and methods - With validated patient-reported outcome measures (PROMs) and using SweSpine (the national Swedish Spine Surgery Register), we analyzed the preoperative clinical status of LDH patients and the 1-year postoperative outcome of LDH surgery performed over the period 2000-2012. We included 1,250 elderly patients (≥ 65 years of age) and 12,840 young and middle-aged patients (aged 20-64). Results - Generally speaking, elderly patients were referred for LDH surgery with worse PROM scores than young and middle-aged patients, they improved less by surgery, they experienced more complications, they had inferior 1-year postoperative PROM scores, and they were less satisfied with the outcome (with all differences being statistically significant). Interpretation - Elderly patients appear to have a worse postoperative outcome after LDH surgery than young and middle-aged patients, they are referred to surgery with inferior clinical status, and they improve less after the surgery.

Gender differences in the surgical treatment of lumbar disc herniation in elderly

PURPOSE

Outcome after lumbar disc herniation (LDH) surgery in middle-aged patient is usually reported to fulfill the criteria for successful outcome. It is also known that women in these years have an inferior outcome compared to men. This study evaluates whether the same gender differences exist in elderly.

METHOD

In the national Swedish register for spine surgery (SweSpine) we identified 1668 patients ≥65 years. 1250 of these patients had both pre- and 1-year postoperative data registered, 53 % males with mean age 70.6 ± 5.0 (mean ± SD) and 47 % females with mean age 71.3 ± 5.2. All were surgically treated due to LDH between 2000 and 2012.

RESULTS

Before surgery both men and women had severe impairment, compared to normative data, in all patient-reported outcome measures (PROMs), with women having inferior status to men. Improvement by surgery was similar in both genders but neither of them reached normative values in quality of life as compared to normative age-matched individuals. As a consequence of this women 1 year after surgery had more back and leg pain, higher consumption of analgesics, greater impairment in walking distance and inferior scoring in virtually all registered PROMs compared to men (all p < 0.005). In spite of this women were as satisfied with the surgical outcome as the men.

CONCLUSION

Elderly women with LDH surgery report inferior outcome compared to males, mainly as a result of being referred to surgery with an inferior status but are despite this as satisfied with outcome as the men.

Spontaneous regression of herniated lumbar discs: Report of one illustrative case and review of the literature

Lumbar disc herniation (LDH) is a common disease that induces back pain and radicular pain. The most efficient method for the treatment of lumbar disc herniation is still controversial. Spontaneous regression of LDH has been recognized with the advancement of radiological diagnostic tools and can explain the reason of spontaneous relief of symptoms without treatment. The proposed hypotheses are; dehydration, retraction of the disc to the hernia in the annulus fibrosis, enzymatic catabolism and phagocytosis. In this study, the case of a patient with huge lumbar disc hernia regressing by itself has been presented and the potential mechanisms of disc regression have been discussed.

Three-dimensional analysis of volumetric changes in herniated discs of the lumbar spine: does spontaneous resorption of herniated discs always occur?

PURPOSE

To investigate volumetric changes in lumbar disc herniation (LDH) using three-dimensional measurements obtained by magnetic resonance imaging (MRI) and to identify possible factors affecting such changes.

METHODS

Between January 2004 and December 2011, 43 patients who underwent conservative treatment for LDH were enrolled. In all, 56 disc levels were investigated. MRI was performed on two or more occasions (minimally, at the initial visit and 6 months later). The volume of each herniated disc was determined. For each patient, disc migration, morphology, initial LDH size, and clinical outcome were evaluated.

RESULTS

The mean volumes of herniated discs at the initial and follow-up visits were 1,304.57 ± 837.99 and 993.84 ± 610.04 mm(3), respectively. The mean change in volume from the initial to the follow-up visit was 310.73 ± 743.60 mm(3). Volumes decreased at 35 disc levels and increased at 21 levels. The disc containment, the extent of LDH, the initial size of the herniated disc, and the degree of intactness of the posterior longitudinal ligament were significantly correlated with disc resorption and an increase in disc volume (p = 0.01, p = 0.018, p = 0.001, and p < 0.001, respectively). No significant association was evident between disc volumetric change and clinical outcome.

CONCLUSIONS

We observed that LDH is a dynamic disease and that a herniated disc is not always spontaneously resorbed, in contrast to what has been reported previously. Alleviation of clinical symptoms can be achieved via conservative treatment even if the volume of the herniated disc changes. Spinal surgeons should not only present an option of initial non-surgical treatment to LDH patients but should also inform them that the LDH may change in size during daily activity or exercise.

Clinical and pathological analysis of epidural inflammation in intervertebral disk extrusion in dogs

BACKGROUND

Little is known about the pathologic changes in the epidural space after intervertebral disk (IVD) extrusion in the dog.

OBJECTIVES

To analyze the pathology of the epidural inflammatory response, and to search for correlations between this process and clinical findings.

METHODS

Clinical data from 105 chondrodystrophic (CD) and nonchondrodystrophic (NCD) dogs with IVD extrusion were recorded. Epidural material from these dogs was examined histopathologically and immunohistochemically. Using statistical analysis, we searched for correlations between severity of epidural inflammation and various clinical and pathologic variables.

RESULTS

Most dogs exhibited an epidural inflammatory response, ranging from acute invasion of neutrophils to formation of chronic granulation tissue. The mononuclear inflammatory infiltrates consisted mostly of monocytes and macrophages and only few T and B cells. Surprisingly, chronic inflammatory patterns also were found in animals with an acute clinical history. Severity of the epidural inflammation correlated with degree of the epidural hemorrhage and nucleus pulposus calcification (P = .003 and .040), but not with age, chondrodystrophic phenotype, neurologic grade, back pain, pretreatment, or duration. The degree of inflammation was statistically (P = .021) inversely correlated with the ability to regain ambulation.

CONCLUSION AND CLINICAL IMPORTANCE

Epidural inflammation occurs in the majority of dogs with IVD extrusion and may develop long before the onset of clinical signs. Presence of calcified IVD material and hemorrhage in the epidural space may be the triggers of this lesion rather than an adaptive immune response to the nucleus pulposus as suggested in previous studies. Because epidural inflammation may affect outcome, further research is warranted.

Nonsurgical treatment of lumbar disk herniation: are outcomes different in older adults?

OBJECTIVES

To determine whether older adults (aged ≥ 60) experience less improvement in disability and pain with nonsurgical treatment of lumbar disk herniation (LDH) than younger adults (< 60).

DESIGN

Prospective longitudinal comparative cohort study.

SETTING

Outpatient specialty spine clinic.

PARTICIPANTS

One hundred thirty-three consecutive patients with radicular pain and magnetic resonance-confirmed acute LDH (89 younger, 44 older).

INTERVENTION

Nonsurgical treatment customized for the individual patient.

MEASUREMENTS

Patient-reported disability on the Oswestry Disability Index (ODI), leg pain intensity, and back pain intensity were recorded at baseline and 1, 3, and 6 months. The primary outcome was the ODI change score at 6 months. Secondary longitudinal analyses examined rates of change over the follow-up period.

RESULTS

Older adults demonstrated improvements in ODI (range 0-100) and pain intensity (range 0-10) with nonsurgical treatment that were not significantly different from those seen in younger adults at 6 month follow-up, with or without adjustment for potential confounders. Adjusted mean improvement in older and younger adults were 31 versus 33 (P = .63) for ODI, 4.5 versus 4.5 (P = .99) for leg pain, and 2.4 versus 2.7 for back pain (P = .69). A greater amount of the total improvement in leg pain and back pain in older adults was noted in the first month of follow-up than in younger adults.

CONCLUSION

These preliminary findings suggest that the outcomes of LDH with nonsurgical treatment were not worse in older adults (≥ 60) than in younger adults (< 60). Future research is warranted to examine nonsurgical treatment for LDH in older adults.

Effect of multi-planar CT image reformatting on surgeon diagnostic performance for localizing thoracolumbar disc extrusions in dogs

Accurate pre-operative localization and removal of disc material are important for minimizing morbidity in dogs with thoracolumbar disc extrusions. Computed tomography (CT) is an established technique for localizing disc extrusions in dogs, however the effect of multi-planar reformatting (MPR) on surgeon diagnostic performance has not been previously described. The purpose of this study was to test the effect of MPR CT on surgeon diagnostic accuracy, certainty and agreement for localizing thoracolumbar disc extrusions in dogs. Two veterinary surgeons and one veterinary neurologist who were unaware of surgical findings independently reviewed randomized sets of two-dimensional (2D) and MPR CT images from 111 dogs with confirmed thoracolumbar disc extrusions. For each set of images, readers recorded their localizations for extruded disc material and their diagnostic certainty. For MPR images, readers also recorded views they considered most helpful. Diagnostic accuracy estimates, mean diagnostic certainty scores and inter-observer agreement were compared using surgery as the gold standard. Frequencies were compared for MPR views rated most helpful. Diagnostic accuracy estimates were significantly greater for MPR vs. 2D CT images in one reader. Mean diagnostic certainty scores were significantly greater for MPR images in two readers. The change in agreement between 2D and MPR images differed from zero for all analyses (site, side, number affected) among all three readers. Multi-planar views rated most helpful with the highest frequency were oblique transverse and curved dorsal planar MPR views. Findings from this study indicate that multi-planar CT can improve surgeon diagnostic performance for localizing canine thoracolumbar disc extrusions.

Age-related effects of cocultured rat nucleus pulposus cells and macrophages on nitric oxide production and cytokine imbalance

STUDY DESIGN

A study of age-related effects on nitric oxide (NO) and cytokine production in cocultured rat nucleus pulposus (NP) cells and macrophages.

OBJECTIVE

To evaluate the effects of age on NO and cytokine production in an in vitro model of cocultured NP cells and macrophages.

SUMMARY OF BACKGROUND DATA

It is well known that the clinical characteristics of lumbar disc herniation differ with age. The relationship between age-related differences in clinical features and immuno-chemical factors, such as NO and inflammatory cytokines, has not been established.

METHODS

Male Sprague Dawley rats (n = 45), including 15 animals from 3 groups (3-, 12-, and 32-weeks old), were used. NP cells and exudated peritoneal macrophages were cocultured in serum-free media. NO levels were measured at 2-, 24-, 48-, and 72 hours using the Griess method. After 7 days of culture, the production of cytokines, including tissue inhibitor metalloproteinase-1, interferon-gamma (IFN-gamma), and interleukin-10 (IL-10) were evaluated.

RESULTS

NO levels of coculture increased with age. In the coculture groups, tissue inhibitor metalloproteinase-1 and IFN-gamma level of 3 weeks old were statistically higher than 12 and 32 weeks old. IL-10 level of 3 weeks old was statistically lower than 12 and 32 weeks old.

CONCLUSION

NO levels of cocultures increased with age that suggests inflammatory reactions increase with age. This study showed an age-related cytokine imbalance, as represented by levels of IFN-gamma and IL-10. Stress and aging are thought to affect the extracellular matrix and change the immunologic response. Younger rat NP cells had higher cell-mediated immunity activity, while the older rat had higher humoral immunity activity. These results demonstrate that age affects the immunologic response attributable to NP cells. Further studies are needed to elucidate the mechanism of this newly observed occurrence and to apply these findings clinically.

Late results of surgery for herniated lumbar disk as related to duration of preoperative symptoms and type of herniation

BACKGROUND

Ten to 40% of patients who have undergone state-of-the-art surgery for HLD do not obtain relief of pain. The relationship among timing of surgery for HLD, type of herniation, and clinical outcome, questioned in the present study, has rarely been referred to as an individual medical factor.

METHODS

Sixty-three patients belonging to a single ethnic group were called in 2 to 5 years after surgery and scored for change in severity of HLD-related pain (VAS) and current disability as scored by a functional rating system (Spangfort).

RESULTS

Patients with noncontained herniation (group 1), as compared with those with contained herniation (group 2), had had more intense radicular pain preoperatively (mean VAS, 8.3 vs 6.5), had a shorter history of pain (mean, 7.4 vs 15.8 weeks), and enjoyed a better functional outcome (good or fair in 96.4% vs 74.3%). Those in group 1 with a preoperative pain history of 6 weeks or less showed a greater decrease in pain intensity than those with a pain history of 6 to 12 weeks. Group 2 patients had had a longer preoperative history of symptoms than any in group 1 (>12 weeks in all) and showed an intermediate decrease in pain intensity.

CONCLUSIONS

Patients with noncontained herniation who do not show signs of improvement should be offered elective surgery after 6 to 8 weeks of observation; those having contained herniation should be advised that a certain degree of benefit can be expected from surgery, however late.

A Review of Spinal Injuries in the Invasive Cardiologist II: Prevention and Treatment

This review provides a perspective of spinal injuries related to invasive cardiology, an understanding of the anatomy and physiology of the spine, the etiology and pathophysiology of spinal injuries, and options for prevention and treatment. In this part of our review, conventional surgical and minimally invasive options are discussed as well as emerging techniques for the treatment of back pain. We also discuss methods of preventing back injuries by modifications to the work environment as well as preventive measures that may be practiced by the invasive cardiologist. Our final objective is to describe and illustrate proven techniques for strengthening the supportive musculature to avoid spinal injury as well as to reduce painful exacerbations.

Determinants of spontaneous resorption of intervertebral disc herniations

STUDY DESIGN

A follow-up of disc herniation (herniated nucleus pulposus [HNP]) resorption on magnetic resonance imaging (MRI).

OBJECTIVE

To assess the determinants of resorption of HNP.

SUMMARY OF BACKGROUND DATA

Neovascularization in the outermost areas of HNP, presenting as an enhancing rim in gadolinium diethylenetriamine pentaacetic acid MR images, is thought to be a major determinant of spontaneous resorption of HNP.

METHODS

Patients with HNP-induced sciatica at baseline were rescanned at 2 months (N = 74) and after 12 months (N = 53). The volume of HNP (mm), thickness (mm) and extent (%) of enhancement, and the degree of HNP migration (Komori classification) were analyzed. Repeated measures analysis of covariance was used in statistical analysis.

RESULTS

Significant resorption of HNP occurred from baseline to 2 months, although the resorption rate was more pronounced over the whole 1-year follow-up. Higher baseline scores of rim enhancement thickness, higher degree of HNP displacement in the Komori classification, and age category 41-50 years were associated with a higher resorption rate. Thickness of rim enhancement was a stronger determinant of spontaneous resorption than extent of rim enhancement. Clinical symptom alleviation occurs concordantly with a faster resorption rate.

CONCLUSIONS

MRI is a useful prognostic tool for identifying patients with HNP-induced sciatica with a benign natural course.

Effect of periradicular methylprednisolone on spontaneous resorption of intervertebral disc herniations

STUDY DESIGN

Prospective comparison of periradicular infiltration with steroid versus saline on the spontaneous resorption of herniated nucleus pulposus in a randomized controlled trial.

OBJECTIVES

To evaluate whether periradicular steroid retards the resorption of herniated nucleus pulposus.

SUMMARY OF BACKGROUND DATA

Rim enhancement around herniated nucleus pulposus is associated with spontaneous resorption of disc herniations. As rim enhancement consists of a macrophage infiltrate, periradicular steroid could theoretically interfere with the resorption process. METHODS.: Patients with disc herniation-induced sciatica were randomized to receive either periradicular methylprednisolone (in combination with bupivacaine) or saline. Lumbar magnetic resonance imaging (MRI) was performed at baseline, at 2 months, and at 12 months. Disc herniation volume (mm3), coverage of rim enhancement (%), and rim enhancement thickness (mm) were evaluated by a radiologist blinded to the allocation. Operated patients were excluded from the 1-year imaging. Changes in the parameters from baseline to 2 months, and from 2 to 12 months, were evaluated with the Mann-Whitney U test.

RESULTS

Change in herniation volume from baseline to 2 months was measurable in 34 patients of both groups, and from 2 to 12 months in 26 patients of the steroid group and 24 patients of the saline group. Significant spontaneous resorption of disc herniations occurred in both groups during the 1-year follow-up. In the subgroup analysis, there tended to be even faster resorption in the steroid group from baseline to 2 months for extrusions, and from 2 months to 12 months for contained herniations. No significant differences were observed in the enhancement parameters (coverage and thickness) between the two treatments.

CONCLUSIONS

Periradicular corticosteroid does not have a negative effect on the spontaneous resorption of the herniated nucleus pulposus.

Pathophysiology of lumbar disc degeneration: a review of the literature

Lumbar disc degeneration occurs because of a variety of factors and results in a multitude of conditions. Alterations in the vertebral endplate cause loss of disc nutrition and disc degeneration. Aging, apoptosis, abnormalities in collagen, vascular ingrowth, loads placed on the disc, and abnormal proteoglycan all contribute to disc degeneration. Some forms of disc degeneration lead to loss of height of the motion segment with concomitant changes in biomechanics of the segment. Disc herniation with radiculopathy and chronic discogenic pain are the result of this degenerative process.