Trauma induces apoptosis in human thoracolumbar intervertebral discs

The mTOR pathway is involved in the process of platelet-rich plasma improving intervertebral disc degeneration

Objectives

Platelet-rich plasma (PRP) contains multiple growth hormones that may stimulate tissue repair. We aimed to assess PRP's efficacy and explore possible mechanisms using the intervertebral disc degeneration (IDD) model.

Materials and Methods

A total of 48 male Sprague-Dawley (SD) rats were randomly divided into three groups: sham, IDD+PBS, and IDD+PRP (n=16, respectively). IL-1β (10 ng/ml) was used to establish a humanized IDD model in human lumbar nucleus pulposus (NP) tissues from 36 patients with degenerative disc disease. These NP cells were randomly divided into three groups: sham, IDD+PBS, and IDD+PRP (n=12, respectively). RT-PCR and western blot were used to detect the expression of aggrecan, collagen II, IL-1β, IL-6, TNF-α, Bcl-2, cleaved-Caspase 3, Bax and Akt/mTOR/p70S6K signaling pathway. A related assay kit was used to detect MDA, SOD, and GSH.

Results

PRP affected the expression of aggrecan, collagen II, IL-1β, IL-6, TNF-α, MDA, SOD, GSH, Bcl-2, cleaved-Caspase 3, and Bax in IDD rats. Compared with the IDD+PBS group, the expression of p-mTOR, p-p70/S6K, and p-Akt was much lower in the rat IDD+PRP group (P<0.05). Similarly, with PRP treatment in the humanized IDD model, the expression of p-mTOR, p-p70/S6K, and p-Akt was also inhibited.

Conclusion

PRP may be a potential therapy for IDD via the mTOR signaling pathway in regulating and affecting extracellular matrix degradation, inflammatory factors, oxidative stress, and apoptosis.

Progress in the study of molecular mechanisms of intervertebral disc degeneration

Degenerative intervertebral disc disease (IVDD) is one of the main spinal surgery, conditions, which markedly increases the incidence of low back pain and deteriorates the patient's quality of life, and it imposes significant social and economic burdens. The molecular pathology of IVDD is highly complex and multilateral however still not ompletely understood. New findings indicate that IVDD is closely associated with inflammation, oxidative stress, cell injury and extracellular matrix metabolismdysregulation. Symptomatic management is the main therapeutic approach adopted for IVDD, but it fails to address the basic pathological changes and the causes of the disease. However, research is still focusing on molecular aspects in terms of gene expression, growth factors and cell signaling pathways in an attempt to identify specific molecular targets for IVDD treatment. The paper summarizes the most recent achievements in molecularunderstanding of the pathogenesis of IVDD and gives evidence-based recommendations for clinical practice.

Role of signal transduction pathways in IL-1β-induced apoptosis: Pathological and therapeutic aspects

BACKGROUND

Interleukin-1β (IL-1β) is a pro-inflammatory cytokine mainly produced by monocytes and macrophages with a wide range of biological effects. Evidence has shown that IL-1β plays a vital role in the process of apoptosis; however, the specific mechanisms, by which IL-1β induces apoptosis, vary due to different cellular and experimental conditions. Therefore, this present reviewstudy aimed to systematically review the association between the molecular mechanisms of IL-1β-induced apoptosis in pathological processes and the role of signaling pathways. This article also sought to briefly investigate the potential of signaling pathway-targeted therapy in the prevention and treatment of disease.

METHODS

This is a literature review article. The present discourse aim is first to scrutinize and assess the available literature on IL-1β and apoptosis. The relevant studies using the keywords of "IL-1β-induced apoptosis" and "signaling pathways" were searched in the databases of PubMed, Scopus, Google Scholar, and Web of Science. Gathered relevant material, and extracted information was then assessed.

RESULTS

IL-1β can induce apoptosis in various types of cells under different external stimuli via the mitochondrial pathway, death receptor pathway and endoplasmic reticulum pathway, and that the different pathways are often interconnected. The NF-kB signaling pathway, p38MAPK, and JNK signaling pathways mainly play a proapoptotic part, and the ERK1/2 pathway has a bidirectional role in regulating apoptosis, while activation of the PI3K-Akt signaling pathway can inhibit apoptosis.

CONCLUSION

This review indicates that IL-1β-induced apoptosis plays an important role in pathogenesis and development of pathology of many inflammatory diseases. Elucidating the role of the signaling pathways will aid the development of targeted therapeutic treatments.

Comparison of the Outcomes between AO Type B2 Thoracolumbar Fracture with and without Disc Injury after Posterior Surgery

Objective

The type AO B2 thoracolumbar fracture is a kind of flexion‐distraction injury and the effect of disc injury on treatment results of patients with B2 fracture remains unclear. The objective of the current study was to compare and analyze the outcomes in AO Type B2 thoracolumbar fracture patients with and without disc injuries in terms of the Cobb angle of kyphosis, the incidence of complication, and the rate of implant failure.

Methods

This is a retrospective study. Of the 486 patients with thoracolumbar fractures who underwent posterior fixation, 38 patients with AO type B2 injuries were included. All the patients were divided into two groups according to changes in the adjoining discs. Disc injury group A included 17 patients and no disc injury group included 21 patients. Clinical and radiologic parameters were evaluated before surgery, after surgery, and at follow‐up. Clinical outcomes included visual analogue scale (VAS) scores, incidence of complications, and incidence of implant failure. Radiologic assessment was accomplished with the Cobb angle (CA), local kyphosis (LK), percentage of anterior vertebral height (AVBH%), intervertebral disc height, and intervertebral disc angle. Fisher's precision probability tests were employed and chi square test were used to compare categorical variables. Paired sample t tests and independent‐sample t tests were used to compare continuous data.

Results

Disc injury mainly involved the cranial disc (15/19, 78.9%). The mean follow‐up period for the patients was 30.2 ± 20.1 months. No neurologic deterioration was reported in the patients at the last follow‐up. Radiological outcomes at the last follow‐up showed significant differences in the CA (18.59° ± 13.74° vs 8.16° ± 9.99°, P = 0.008), LK (12.74° ± 8.00° vs 6.55° ± 4.89°, P = 0.006), and %AVBH (77.16% vs 90.83%, P = 0.01) between the two groups.Implant failure occurred after posterior fixation in five patients with disc injury who did not undergo interbody fusion during the initial surgery. Additionally, in the subgroup analysis, interbody fusion in the implant failure group were significantly different than in the no implant failure group (0% vs 75%, P = 0.009).

Conclusions

AO B2 fracture patients with disc injury have higher risk of complications, especially implant failure after posterior surgery. Interbody fusion should be considered in AO type B2 fracture patients with disc injury.

Intervertebral disc cell chondroptosis elicits neutrophil response in Staphylococcus aureus spondylodiscitis

To understand the pathophysiology of spondylodiscitis due to Staphylococcus aureus, an emerging infectious disease of the intervertebral disc (IVD) and vertebral body with a high complication rate, we combined clinical insights and experimental approaches. Clinical data and histological material of nine patients suffering from S. aureus spondylodiscitis were retrospectively collected at a single center. To mirror the clinical findings experimentally, we developed a novel porcine ex vivo model mimicking acute S. aureus spondylodiscitis and assessed the interaction between S. aureus and IVD cells within their native environment. In addition, the inflammatory features underlying this interaction were assessed in primary human IVD cells. Finally, mirroring the clinical findings, we assessed primary human neutrophils for their ability to respond to secreted inflammatory modulators of IVD cells upon the S. aureus challenge. Acute S. aureus spondylodiscitis in patients was characterized by tissue necrosis and neutrophil infiltration. Additionally, the presence of empty IVD cells’ lacunae was observed. This was mirrored in the ex vivo porcine model, where S. aureus induced extensive IVD cell death, leading to empty lacunae. Concomitant engagement of the apoptotic and pyroptotic cell death pathways was observed in primary human IVD cells, resulting in cytokine release. Among the released cytokines, functionally intact neutrophil-priming as well as broad pro- and anti-inflammatory cytokines which are known for their involvement in IVD degeneration were found. In patients as well as ex vivo in a novel porcine model, S. aureus IVD infection caused IVD cell death, resulting in empty lacunae, which was accompanied by the release of inflammatory markers and recruitment of neutrophils. These findings offer valuable insights into the important role of inflammatory IVD cell death during spondylodiscitis and potential future therapeutic approaches.

Raloxifene retards the progression of adjacent segmental intervertebral disc degeneration by inhibiting apoptosis of nucleus pulposus in ovariectomized rats

BACKGROUND

Adjacent segmental intervertebral disk degeneration (ASDD) is a major complication secondary to lumbar fusion. Although ASSD pathogenesis remains unclear, the primary cause of intervertebral disk degeneration (IVDD) development is apoptosis of nucleus pulposus (NP). Raloxifene (RAL) could delay ASDD by inhibiting NP apoptosis.

METHODS

An ASDD rat model was established by ovariectomy (OVX) and posterolateral spinal fusion (PLF) on levels 4-5 of the lumbar vertebrae. Rats in the treatment groups were administered 1 mg/kg/d RAL by gavage for 12 weeks, following which, all animals were euthanized. Lumbar fusion, apoptosis, ASDD, and vertebrae micro-architecture were evaluated.

RESULTS

RAL maintained intervertebral disk height (DHI), delayed vertebral osteoporosis, reduced histological score, and inhibited apoptosis. The OVX+PLF+RAL group revealed upregulated expression of aggrecan and B-cell lymphoma-2 (bcl2), as well as significantly downregulated expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), metalloproteinase-13 (MMP-13), caspase-3, BCL2-associated X (bax), and transferase dUTP nick end labeling (TUNEL) staining. Micro-computed tomography (Micro-CT) analysis revealed higher bone volume fraction (BV/TV), bone mineral density (BMD), and trabecular number (Tb.N), and lower trabecular separation (Tb.Sp) in OVX+PLF+RAL group than in the OVX+PLF group.

CONCLUSIONS

RAL can postpone ASDD development in OVX rats through inhibiting extracellular matrix metabolic imbalance, NP cell apoptosis, and vertebral osteoporosis. These findings showed RAL as a potential therapeutic target for ASDD.

Lentivirus-mediated transfer of gene encoding fibroblast growth factor-18 inhibits intervertebral disc degeneration

Fibroblast growth factor 18 (FGF-18) is a well-characterized anabolic growth factor involved in cartilage homeostasis. However, the effect of FGF-18 on intervertebral disc (IVD) degeneration has not been investigated. The present study aimed to investigate the role of FGF-18 in the process of rabbit IVD degeneration. In vitro, primary nucleus pulposus cells (NPs) were cultured and transfected with a lentivirus. Tert-butyl hydroperoxide (TBHP) was used to induce apoptosis in NPs on the second passage, while overexpression of FGF-18 in NPs attenuated TBHP-induced apoptosis. A rabbit annular puncture model was generated to induce IVD degeneration in vivo. The discs were injected with an FGF-18-overexpression lentivirus or a negative control lentivirus. In the sham group, the discs were exposed and not punctured. Disc degeneration was evaluated using H&E staining and a histological grading system. Reverse transcription-quantitative PCR was used to detect the expression of the extracellular matrix-degrading enzymes matrix metalloproteinase-3 (MMP-3) and A disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5). Nucleus pulposus apoptosis was detected via western blotting, immunohistochemical methods and TUNEL staining. Histologic examination showed that disc degeneration was attenuated after FGF-18 overexpression treatment. At 8 weeks after surgery, the expression of MMP-3 and ADAMTS-5 in the annular puncture groups was higher compared with in the sham group. FGF-18 treatment inhibited the expression of MMP-3 and ADAMTS-5 at the mRNA level. Western blot assays indicated that the expression level of Bax was significantly reduced in the FGF-18 groups, and that the expression level of Bcl-2 was significantly increased compared with those in the control group. Moreover, immunohistochemical analysis indicated that the FGF-18 group exhibited a lower percentage of cleaved caspase 3-positive NPs. Quantification of the TUNEL staining demonstrated that the FGF-18 group had fewer apoptotic NPs than the control group. These findings indicated that FGF-18 could delay IVD degeneration by inhibiting the apoptosis of NPs and the expression of matrix-degrading enzymes.

Targeted therapy for intervertebral disc degeneration: inhibiting apoptosis is a promising treatment strategy

Intervertebral disc (IVD) degeneration (IDD) is a multifactorial pathological process associated with low back pain (LBP). The pathogenesis is complicated, and the main pathological changes are IVD cell apoptosis and extracellular matrix (ECM) degradation. Apoptotic cell loss leads to ECM degradation, which plays an essential role in IDD pathogenesis. Apoptosis regulation may be a potential attractive therapeutic strategy for IDD. Previous studies have shown that IVD cell apoptosis is mainly induced by the death receptor pathway, mitochondrial pathway, and endoplasmic reticulum stress (ERS) pathway. This article mainly summarizes the factors that induce IDD and apoptosis, the relationship between the three apoptotic pathways and IDD, and potential therapeutic strategies. Preliminary animal and cell experiments show that targeting apoptotic pathway genes or drug inhibition can effectively inhibit IVD cell apoptosis and slow IDD progression. Targeted apoptotic pathway inhibition may be an effective strategy to alleviate IDD at the gene level. This manuscript provides new insights and ideas for IDD therapy.

[Diagnostics and treatment of cervical spine trauma in pediatric patients : Recommendations from the Pediatric Spinal Trauma Group]

BACKGROUND

Severe cervical spine injuries in children under the age of 17 years are rare. Recommendations or even guidelines for the diagnostics and treatment of such injuries in children are currently not available.

OBJECTIVE

The aim of the study was to formulate recommendations for diagnostics and treatment of injuries of the cervical spine in pediatric patients.

MATERIAL AND METHODS

First, a search of primary and secondary literature on the topic complex of diagnostics and treatment of cervical spine injuries in children was carried out. An appropriate internal literature database was defined and maintained. Second, within the framework of 9 meetings from April 2017 to December 2019 the members of the Pediatric Spinal Trauma Group of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU) systematically formulated recommendations for the diagnostics and treatment of injuries of the cervical spine in pediatric patients by a consensus process.

RESULTS

Recommendation for the diagnostics and treatment for injuries of the cervical spine could be formulated for three age groups (age group I: 0-6 years; age group II: 7-9 years; age group III: 10-16 years). The diagnostic and therapeutic principles known from adult patients suffering from injuries to the cervical spine cannot be easily transferred to pediatric patients.

CONCLUSION

Injuries to the pediatric spine are rare and should be treated in specialized spine centers. Pediatric patients with a stable cardiopulmonary status should undergo magnetic resonance imaging (MRI) if a spinal trauma is suspected. Classification systems and therapeutic recommendations for injuries to the cervical spine known from adult patients could also be used for adolescent patients. This is not possible for children under the age of 10 years. Only few classification systems exist for this age group. Basic principles of the treatment of spinal trauma in children is the restoration of spinal stability and correct anatomical relationships as well as the protection of all neural structures.

[Diagnostics and treatment of thoracic and lumbar spine trauma in pediatric patients : Recommendations from the Pediatric Spinal Trauma Group]

BACKGROUND

Spinal injuries in pediatric patients are overall very rare. Current reference studies including large patient numbers that enable the formulation of evidence-based recommendations on diagnostics and treatment of these injuries do not exist.

OBJECTIVE

The aim of the current study was to formulate recommendations on the diagnostics and treatment for injuries of the thoracic and lumbar spine in pediatric patients.

MATERIAL AND METHODS

Firstly, a search for primary and secondary literature on the topic of diagnostics and treatment of spinal injuries in children was carried out. From this, a literature database was established and maintained. Secondly, within the framework of 9 meetings in the time period from April 2017 to December 2019 the members of the Pediatric Spinal Trauma Group of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU) documented recommendations on diagnostics and treatment of injuries of the thoracic and lumbar spine in pediatric patients by a consensus process.

RESULTS

Recommendations on the diagnostics and treatment of injuries of the thoracic and lumbar spine could be given for 3 age groups (age group I: 0-6 years; age group II: 7-9 years; age group III: 10-16 years). Diagnostic and therapeutic principles known from adult patients suffering from injuries to the thoracic or lumbar spine cannot easily be transferred to pediatric patients.

CONCLUSION

Spinal injuries in childhood are rare and should be treated in specialized spine centers. Pediatric patients with a stable cardiopulmonary status should undergo magnetic resonance imaging (MRI) if a spinal trauma is suspected. The basic principles of the treatment of spinal trauma in children is the restoration of spinal stability and correct anatomical parameters as well as the protection of all neural structures. The potential for correction and regeneration of the individual spinal sections depending on the age of the patient must be considered for deciding between operative vs. conservative treatment. Whenever operative treatment is needed, it should be performed by minimally invasive techniques as a sole instrumentation without spondylodesis. An early removal of the screw-rod-system should be performed.

Melatonin Protects Intervertebral Disc from Degeneration by Improving Cell Survival and Function via Activation of the ERK1/2 Signaling Pathway

Melatonin, a neuroendocrine hormone secreted by the pineal body, has a positive effect on intervertebral disc degeneration. The present study is aimed at investigating the biological role of melatonin in intervertebral disc degeneration and its underlying mechanism. A human nucleus pulposus cell (NPC) line was exposed to melatonin at different concentrations. Cell proliferation was measured by CCK-8 assay. Cell cycle and apoptosis were analyzed by flow cytometry. Western blot was performed to measure the protein expression of indicated genes. A rabbit model of intervertebral disc degeneration was established to detect the role and mechanism of melatonin on intervertebral disc degeneration. Our study showed that melatonin promoted NPC viability and inhibited cell arrest. Furthermore, melatonin treatment led to the upregulation of collagen II and aggrecan and downregulation of collagen X. Moreover, melatonin significantly elevated the activity of the ERK signaling pathway. Inhibition of the ERK1/2 signals reversed the role of melatonin in the regulation of NPCs both in vitro and in vivo. Melatonin increased NPC viability through inhibition of cell cycle arrest and apoptosis. Moreover, melatonin promoted the secretion of functional factors influencing the nucleus pulposus cell physiology and retarded cell degeneration. Our results suggest that melatonin activated the ERK1/2 signaling pathway, thereby affecting the biological properties of the intervertebral disc degeneration.

Interleukin-1β induces apoptosis in annulus fibrosus cells through the extracellular signal-regulated kinase pathway

PURPOSE

The loss of intervertebral disc (IVD) cells due to excessive apoptosis induced by inflammatory cytokines is a major cause of IVD degeneration. This study aims to explore the mechanism of interleukin-1β (IL-1β)-induced apoptosis of annulus fibrosus cells (AFCs). It's hypothesized that IL-1β induces apoptosis through the extracellular signal-regulated kinase (ERK) pathway in AFCs.

METHODS

The mRNA and protein expression levels of apoptosis-associated genes were analyzed by quantitative real-time PCR and Western blotting. The apoptotic rate was measured by flow cytometry. Three experimental groups were established, including Control, IL-1β, and IL-1β+U0126 groups, respectively.

RESULTS

Increase in the expression of apoptosis-associated genes including B-cell lymphoma-2 associated X (Bax), caspase-3, and caspase-9, and meanwhile, decrease in the expression of B-cell lymphoma-2 (Bcl-2) gene were found in patients with degenerative IVDs. In in vitro tests, both apoptosis and phosphorylated ERK expression in rat AFCs decreased in the IL-1β+U0126 group compared with the IL-1β group. The expression levels of Bax, caspase-3, and caspase-9 in AFCs decreased significantly in the IL-1β+U0126 group compared with those in the IL-1β group. The expression level of Bcl-2, on the other hand, significantly increased.

CONCLUSIONS

Findings from this study suggest that IL-1β induces apoptosis in AFCs through the ERK pathway, and therefore, ERK inhibition may provide certain protection against the adverse effects of IL-1β.

The Role of Minimally Invasive Vertebral Body Stent on Reduction of the Deflation Effect After Kyphoplasty: A Biomechanical Study

STUDY DESIGN

Biomechanical investigation using cadaver spines.

OBJECTIVE

The aim of the present study was to assess the magnitude of the deflation effect after balloon kyphoplasty (BKP) or use of minimally invasive vertebral body stent (MIVBS) in in vitro biomechanical condition.

SUMMARY OF BACKGROUND DATA

BKP is a well-established minimally invasive treatment option for osteoporotic vertebral compression fractures. However, this technique can lead to a secondary height loss-known as the "deflation effect"-causing intrasegmental kyphosis and an overall alignment failure.

METHODS

The study was conducted on 24 human cadaveric vertebral bodies (T12-L5). After creating a compression fracture model, the fractured vertebral bodies were reduced by BKP (n = 12) or by MIVBS (n = 12) and then augmented with polymethyl methacrylate bone cement. Each step of the procedure was performed under fluoroscopic guidance and the results were analyzed quantitatively. Finally, the strength and stiffness of augmented vertebral bodies were measured by biomechanical tests.

RESULTS

Complete initial reduction of the fractured vertebral body height was achieved by both systems. Secondary loss of reduction after balloon deflation was significantly greater in the BKP group (2.36 ± 0.63 mm vs. 0.34 ± 0.43 mm in the MIVBS group; P < 0.05). Height gain was significantly higher in the MIVBS group (77.68% ± 11.46% vs. 34.87% ± 13.16% in the BKP group; P < 0.05). Increase in the kyphotic angle gain (relative to the preoperative kyphotic angle) was significantly more in the MIVBS group (95.60% ± 6.12% vs. 77.0% ± 4.94% in the BKP group; P < 0.05). Failure load was significantly higher in the MIVBS group (189% ± 16% vs. 146% ± 14%; P < 0.05). However, stiffness was not significantly different between the two groups.

CONCLUSION

The deflation effect after BKP can be significantly decreased with the use of the MIVBS technique.

LEVEL OF EVIDENCE

N/A.

Degeneration of injured intervertebral discs affected by anterior longitudinal ligament injury in rabbits

Spinal trauma can cause simultaneous injury of intervertebral discs (IVD) and anterior longitudinal ligaments (ALL). Injury of IVD is an important factor causing intervertebral disc degeneration (IDD). However, the relationship between ALL injury and IDD has rarely been discussed. Therefore, the purpose of this study was to investigate the effects of ALL injury on degeneration of injured IVD. Thirty-two rabbits were randomly and evenly divided into four groups including sham group, Group A (simple IVD punctured), Group B (IVD punctured with half transverse injury of ALL), and Group C (IVD punctured with entirely transverse injury of ALL). Then, computed tomography, HE staining, intraoperative exploration, immunohistochemistry, and TUNEL staining were used in detecting the degenerative changes in corresponding IVD. At 2 weeks postoperatively, in response to the extent of ALL injury, the middle height of the punctured intervertebral space was reduced. The IVD structure was disorganized and the number of IVD cells was decreasing. The percentage of IL-1β- and TNF-α-immunopositive cells was increased and the percentage of TUNEL-positive IVD cells was also increased. There was a significant difference between Group C and the other groups in the results of immunohistochemistry and TUNEL staining (P<0.05). At 8 weeks postoperatively, the middle height of intervertebral space was significantly lower in Group C than in other groups (P<0.05). Intraoperative exploration found that there was obvious instability of intervertebral space in Group C. Compared with 2 weeks postoperation, the pathological changes were severe. The percentage of IL-1β- and TNF-α-immunopositive cells was decreased and the percentage of TUNEL-positive cells was increased in the corresponding groups. There was a significant difference between Group C and the other groups in the results of immunohistochemistry and TUNEL staining (P<0.05). These findings indicate that IVD injury companied with completed ALL injury might cause obvious spinal instability, which might correspond to severe IDD.

MicroRNA-125b-1-3p mediates intervertebral disc degeneration in rats by targeting teashirt zinc finger homeobox 3

The present study aimed to investigate the association between Teashirt zinc finger homeobox 3 (TSHZ3) and the nucleus pulposus (NP) of intervertebral discs in rats. TSHZ3 was identified from the differentially expressed micro (mi)RNAs in the expression profile of GSE63492 by identifying the overlapped target genes of microRNA (miR)-125b-1-3p across different databases. TSHZ3 small interfering RNA (siRNA) and an miR-125b-1-3p inhibitor were used for gene silencing and gene silencing efficiency was assessed by reverse transcription-polymerase chain reaction. Western blotting was performed to detect the cell cycle proteins cyclin D1 and B1 and the proteins associated with DNA damage in NP. The results revealed that in normal NPs, the expression of TSHZ3 increased following the inhibition of miR-125b-1-3p and in DNA damaged NPs, the expression of TSHZ3 was associated with the degree of DNA damage. The present study demonstrated that TSHZ3, as a target gene of miR-125b-1-3p, may serve a protective role in intervertebral disc degeneration and that this protective function may be inhibited by high levels of miR-125b-1-3p.

[Injuries of the thoracolumbar spine in children]

BACKGROUND

Injuries of the thoracolumbar spine in children are rare and challenging for the treating physician. Besides knowledge of fracture treatment, the anatomical particularities of the spine in children are of great importance.

METHODS

The article gives an overview of the diagnosis and therapy with the most common classification of injuries of the thoracolumbar spine.

RESULTS

Taking into account the children's age and the fracture morphology most cases can be treated conservatively, especially because the young spine has great potential for remodelling. The older the child becomes, the more smoothly the transition to adult treatment occurs; thus, unstable fractures should be treated with surgery.

CONCLUSION

The difficult indication and the specific characteristics of surgery necessitate treatment in a spine centre with experience with surgery on children.

Role of Expression of Inflammatory Mediators in Primary and Recurrent Lumbar Disc Herniation

Objective

To assess role of some inflammatory mediators in patients with primary and recurrent lumbar disc herniation. Expression of IL-6, transforming growth factor (TGF)-1, insulin-like growth factor (IGF)-1, and Bcl-2-associated X protein (BAX) have been shown to be more intense in the primary group than the recurrent goup, but this mediators may be important aspects prognostic.

Methods

19 patients underwent primary and revision operations between June 1, 2009 and June 1, 2014, and they were included in this study. The 19 patients’ intervertebral disc specimens obtained from the primary procedures and reoperations were evaluated. Expression of IL-6, TGF-1, IGF-1, and BAX were examined immunohistochemically in the 38 biopsy tissues obtained from the primary and recurrent herniated intervertebral discs during the operation.

Results

For IL-6 expression in the intervertebral disc specimens, there was no difference between the groups. The immunohistochemical study showed that the intervertebral disc specimens in the primary group were stained intensely by TGF-1 compared with the recurrent group. Expression of IGF-1 in the primary group was found moderate. In contrast, in the recurrent group of patients was mild expression of IGF-1. The primary group intervertebral disc specimens were stained moderately by BAX compared with the recurrent group.

Conclusion

The results of our prognostic evaluation of patients in the recurrent group who were operated due to disc herniation suggest that mediators may be important parameters.

Aloperine attenuates hydrogen peroxide-induced injury via anti-apoptotic activity and suppression of the nuclear factor-κB signaling pathway

Aloperine is an alkaloid that exerts significant inhibitive effects on acute inflammation and Type III and IV hypersensitivity caused by a variety of inflammatory agents. The aims of the present study were to investigate whether the protective effect of aloperine attenuates hydrogen peroxide (H₂O₂)-induced injury, and to identify the underlying mechanisms involved. Nucleus pulposus cells were extracted from adult male Sprague-Dawley rats, and incubated with fresh medium containing 200 µM H₂O₂ for 24 h. In the study, treatment with aloperine significantly increased cell viability and suppressed apoptosis in H₂O₂-treated nucleus pulposus cells in a dose-dependent manner. In addition, 10 and 100 nM aloperine significantly inhibited H₂O₂-induced tumor necrosis factor-α and interleukin-6 activities, and significantly increased the H₂O₂-reduced superoxide dismutase and glutathione peroxidase activities in nucleus pulposus cells (all P<0.01). However, aloperine treatment (10 and 100 nM) significantly reduced the H₂O₂-induced caspase-9 activity in nucleus pulposus cells. Furthermore, addition of 10 and 100 nM aloperine significantly suppressed nuclear factor-κB (NF-κB) and phosphorylated-protein kinase B expression levels in H₂O₂-treated nucleus pulposus cells. In conclusion, the protective effect of aloperine attenuated H₂O₂-induced injury via hyperproliferation, its anti-apoptotic activity and suppression of the NF-κB signaling pathway.

Minimal Invasive Circumferential Management of Thoracolumbar Spine Fractures

Introduction. While thoracolumbar fractures are common lesions, no strong consensus is available at the moment. Objectives. The aim of this study was to evaluate the results of a minimal invasive strategy using percutaneous instrumentation and anterior approach in the management of thoracolumbar unstable fractures. Methods. 39 patients were included in this retrospective study. Radiologic evaluation was based on vertebral and regional kyphosis, vertebral body height restoration, and fusion rate. Clinical evaluation was based on Visual Analogic Score (VAS). All evaluations were done preoperatively and at 1-year follow-up. Results. Both vertebral and regional kyphoses were significantly improved on postoperative evaluation (13° and 7° versus −1° and −9°  P < 0.05, resp.) as well as vertebral body height (0.92 versus 1.16, P < 0.05). At 1-year follow-up, mean loss of correction was 1°. A solid fusion was visible in all the cases, and mean VAS was significantly reduced form 8/10 preoperatively to 1/10 at the last follow-up. Conclusion. Management of thoracolumbar fractures using percutaneous osteosynthesis and minimal invasive anterior approach (telescopic vertebral body prosthesis) is a valuable strategy. Results of this strategy offer satisfactory and stable results in time.

Leukocytes Enhance Inflammatory and Catabolic Degenerative Changes in the Intervertebral Disc After Endplate Fracture In Vitro Without Infiltrating the Disc

STUDY DESIGN

An established rabbit intervertebral disc (IVD)/endplate explant fracture model was extended with physiologic post-traumatic dynamic loading (PTDL) and coculturing of peripheral blood mononuclear cells (PBMCs).

OBJECTIVE

The aim of this study was to quantify the effects of PTDL and of cocultured PBMCs on post-traumatic disc degeneration (DD) and to determine whether PTDL facilitates homing of PBMC to fractured IVD/endplates.

SUMMARY OF BACKGROUND DATA

DD is associated with endplate fracture. In vivo studies suggest a key role of immune cells in the pathogenesis of DD. However, the complexity of in vivo systems impedes the investigation of single factors governing the pathogenesis.

METHODS

Seventy-two IVD/endplate specimens were divided into 4 groups. In group A, endplate fractures were induced with a high-velocity axial load and exposed to PTDL in coculture with PBMCs for 14 days. Group A was compared with 3 control groups, with single-factor removal, in order to assess the relative contribution of PTDL (group B), PBMCs (group C), and endplate fracture (group D) to the biological response of the IVD. Disc gene transcription and serum nitric oxide (NO) serum concentration were measured to investigate differences in anabolism, catabolism, and inflammatory response between the groups. Changes in matrix composition and disc structure were assessed histologically.

RESULTS

PBMCs did not home to fractured IVDs, with or without PTDL. Group A compared with group D showed an enhanced transcription of anabolic, catabolic, and pro-inflammatory genes during the entire experiment, and an increased NO concentration for the first 3 days. Changes typical for DD were also found in histological sections. Group A compared with group C showed significant increases in catabolic and pro-inflammatory gene transcription after at least 7 days. No differences were found between groups A and B.

CONCLUSION

Trauma induces degenerative changes; PTDL neither aggravates nor ameliorates this response. Although PBMCs do not infiltrate the disc, they aggravate the degenerative changes.

LEVEL OF EVIDENCE

N/A.

Importance of IL-6, MMP-1, IGF-1, and BAX Levels in Lumbar Herniated Disks and Posterior Longitudinal Ligament in Patients with Sciatic Pain

PURPOSE

The aim of this study was to evaluate prognostic importance of interleukin-6 (IL-6), matrix metalloproteinase (MMP)-1, insulin-like growth factor (IGF)-1, and Bcl-2-associated X protein (BAX) levels in biopsy specimens taken from the intervertebral disk specimens and the posterior longitudinal ligaments of patients with sciatic pain.

METHODS

The specimens of the intervertebral disk and the posterior longitudinal ligament were obtained from 52 patients undergoing herniectomy and diskectomy at the Neurosurgery Department of the Abant Izzet Baysal University Izzet Baysal Training and Research Hospital between April 2012 and February 2014. The immunohistochemical expressions of IL-6, MMP-1, IGF-1, and BAX were evaluated in three categories: mild, moderate, and intense.

RESULTS

The IL-6 expression in the intervertebral disk specimens was intense in the sequestration group when compared with that of the "protrusion" and "extrusion" groups. The intervertebral disk specimens in "extrusion" and "sequestration" groups were stained intensely for MMP-1. The IGF-1 expression was stained intensely in the intervertebral disk tissue of the extrude group patients. For the "extrusion" and "sequestration" groups, the intervertebral disk specimens were stained intensely for BAX compared with the protrude group. The IL-6 expression in the posterior longitudinal ligament specimens was more intense in the "sequestration" and "extrusion" groups when compared with that of the protrude group. The MMP-1 expressions were milder in the sequestration group when compared with that of the "extrusion" and "protrusion" groups.

CONCLUSIONS

Our findings suggest that the cytokines, enzymes, growth factors, and proapoptotic proteins, such as IL-6, MMP-1, IGF-1, and BAX, may be critical factors in the pathophysiology of the degeneration of the intervertebral disks in patients with symptomatic degenerative disk disease.

Morphological changes in the human cervical intervertebral disc post trauma: response to fracture-type and degeneration grade over time

PURPOSE

In the first 24 h post-intervertebral disc (IVD) trauma, up to 75 % cell death has been reported. In addition, burst fractures cause post-traumatic disc degeneration by elevated pro-apoptotic and pro-inflammatory gene transcription. Moreover, some patients have pre-trauma degenerative disc disease. The aim of the study was to assess histological changes and cell-death over a time period of up to 1 year caused by mechanical and structural factors.

METHODS

116 anterior portions of IVDs of the cervical spine were studied histologically by light microscopy and ultrastructurally by transmission electron microscopy (TEM). The group was investigated with regard to three main parameters: fracture mechanism (compressive vs. tensile/shear loads), degeneration grade (low vs. high) and endplate fracture (with vs. without). Disc architecture (e.g. ruptures) was studied histologically. Cell morphology was examined ultrastructurally to quantify cell-death, healthy and balloon cells. According to ultrastructural observations, two time-groups (up to 6 days vs. later) were established. Statistical analyses were carried out within and between time-groups.

RESULTS

Histological changes were obvious in the annulus fibrosus where ruptures with haematoma were replaced by granulation tissue. Significant differences in cell-death were seen in the first few days due to different loads. In contrast to the more degenerated segments, low degenerated ones revealed significantly less cell death with time post-trauma. Interestingly, no difference was found between groups after the sixth day. Cell-death (mean 44 % for all investigated groups) remained high after day 6 post-trauma.

CONCLUSION

IVDs retrieved from low grade degenerated segments revealed a significant recovery, with less cell-death and a partially restored disc matrix, although cell-death remained high. Long-term clinical studies of stabilized segments arising from different fracture mechanisms are required.

Paeoniflorin inhibits nucleus pulposus cell apoptosis by regulating the expression of Bcl-2 family proteins and caspase-9 in a rabbit model of intervertebral disc degeneration

Apoptosis plays a key role in the pathogenesis of internal disc disruption (IDD); therefore, the inhibition of apoptosis may offer a novel approach for treating IDD diseases. The aim of the present study was to investigate the effects and the underlying mechanisms of paeoniflorin through the detection of relevant indicators in a rabbit model of IDD. In total, 144 rabbits were used in the study and divided into four groups (n=36 per group). Rabbits successfully modeled with IDD received an intragastric injection of 120 mg/kg·day paeoniflorin (high-dose group), 30 mg/kg·day paeoniflorin (low-dose group) or saline (model saline group), while rabbits without IDD were used as a normal control group. The apoptosis rate of disc nucleus pulposus cells was detected using flow cytometry. In addition, the expression levels of Bcl-2, Bax and caspase-9 in the disc tissues were detected using immunohistochemistry and western blot analysis prior to and following the treatment. The results indicated that the expression levels of Bax in the low- and high-dose paeoniflorin groups were significantly reduced, while the Bcl-2 expression levels were significantly increased when compared with the model saline group (P<0.01). In addition, the expression levels of cleaved caspase-3 and cleaved caspase-9 were reduced in the low- and high-dose paeoniflorin groups, as compared with the model saline group (P<0.05). Furthermore, the average apoptotic index of the high- and low-dose paeoniflorin groups was decreased when compared with the model saline group (P<0.05). In conclusion, paeoniflorin was demonstrated to inhibit the apoptosis of nucleus pulposus cells and the activation of caspase-3 and caspase-9 through the regulation of Bcl-2 family protein expression. These results provide an experimental basis for the future treatment of IDD with paeoniflorin.

Closing-opening wedge osteotomy for thoracolumbar traumatic kyphosis

Background

Surgical treatment modalities for post-traumatic kyphosis (PTK) remain controversial. Like vertebral column resection, closing-opening wedge osteotomy (COWO) can achieve satisfactory results for kyphosis with multiple etiologies. However, few studies have assessed this procedure for PTK. Our purpose was to evaluate the radiographic and clinical outcomes of COWO in a selected series of patients with PTK via a single posterior approach.

Methods

In this retrospective case series, seven patients with symptomatic PTK in the thoracolumbar spine were reviewed. Five patients underwent surgery at the time of initial injury, and the other two initially underwent conservative treatment. All seven patients underwent COWO procedures through a single posterior approach. The Cobb angle was assessed preoperatively, postoperatively, and at the final follow-up. A visual analog scale (VAS) and the American Spinal Injury Association scale were used to evaluate back pain and neurological function preoperatively and at final follow-up, respectively. Operation-associated complications were also recorded.

Results

The mean follow-up period was 34.3 months (range, 24 to 43 months). The mean kyphotic angle was significantly (P <0.05) reduced from 57.7° (range, 36° to 100°) preoperatively to 8° postoperatively (range, −12° to 50°). The mean VAS improved from 5.9 to 2.1 (P <0.05). Three patients exhibited improved neurological function. Bony fusion was achieved in all patients. No significant correction loss or permanent complication was noted.

Conclusions

Though technically demanding, COWO via a single posterior approach can provide satisfactory outcomes for selected patients with PTK. Additional studies are required to improve patient selection and outcomes for this condition.

[Release of moveable segments after dorsal stabilization : Impact on affected discs]

BACKGROUND

Bisegmental dorsal stabilization is a common treatment option for instable compression fractures of the thoracolumbar spine; however, it remains unknown to what extent bridging compromises intervertebral discs.

OBJECTIVES

The purpose of this study was to determine the disc height and functional features in comparison to healthy intervertebral discs after removal of the dorsal fixator and particularly under consideration of the time span between dorsal stabilization and implant removal (IR).

MATERIAL AND METHODS

The IR was performed in 19 patients after an average of 13 months (range 8-24 months) after dorsal stabilization of instable vertebral compression fractures of the thoracolumbar junction and lumbar spine. An additional ventral monosegmental spondylodesis was performed in 10 patients with incomplete burst fractures. Thus, a total of 28 intervertebral discs were temporarily bridged (bridged discs), with an adjacent endplate fracture in 10 (injured discs) and no adjacent bony lesion in 18 discs (healthy discs). The intervertebral discs superior and inferior to the instrumentation were selected as controls (control discs). Standardized conventional lateral radiographs were taken prior to and after IR as well as after 6 months. Additionally, standardized lateral radiographs in flexion and extension were taken. The intervertebral disc height (disc height) was determined by two independent board approved orthopedic observers by measuring the anterior, central and dorsal intervertebral disc spaces on all lateral radiographs as well as the intervertebral disc angles (disc angle) defined by the intervertebral upper and lower endplates in the flexion and extension views. Intradisc function (disc function) was defined as the difference between the disc angle in extension and flexion. The measurements were repeated after 12 months. Univariate analysis was performed using ANOVA and significance was set at p < 0.05. Interobserver and intraobserver comparisons of the disc heights and the disc angles were determined with intraclass correlation coefficients.

RESULTS

No significant differences were seen in disc function and disc height between the controls and the bridged discs at all times of measurement; however, injured discs showed a significantly reduced disc height and disc angle in extension compared to healthy discs (p = 0.028 and p = 0.027, respectively). Additionally, patients with IR during the first 12 months had significantly reduced disc heights compared to those patients with delayed IR within the second postoperative year (p = 0.018). Interobserver and intraobserver agreement for disc function was 0.80 (95 % confidence interval CI: 0.68-0.88) and 0.85 (95 % CI 0.76-0.90), respectively. The interobserver and intraobserver correlations for disc height were 0.85 (95 % CI: 0.76-0.90) and 0.93 (95 % CI 0.88-0.95), respectively.

CONCLUSION

Bridging of an intervertebral disc with IR within 24 months does not cause immediate loss of disc function or reduction of disc height; however, temporary bridging in combination with an adjacent endplate fracture causes significant reduction of disc height and loss of extension. Additionally, no beneficial effects could be seen by reducing the time span between stabilization and IR to below 12 months.

Cell and molecular biology of intervertebral disc degeneration: current understanding and implications for potential therapeutic strategies

Intervertebral disc degeneration (IDD) is a chronic, complex process associated with low back pain; mechanisms of its occurrence have not yet been fully elucidated. Its process is not only accompanied by morphological changes, but also by systematic changes in its histological and biochemical properties. Many cellular and molecular mechanisms have been reported to be related with IDD and to reverse degenerative trends, abnormal conditions of the living cells and altered cell phenotypes would need to be restored. Promising biological therapeutic strategies still rely on injection of active substances, gene therapy and cell transplantation. With advanced study of tissue engineering protocols based on cell therapy, combined use of seeding cells, bio-active substances and bio-compatible materials, are promising for IDD regeneration. Recently reported progenitor cells within discs themselves also hold prospects for future IDD studies. This article describes the background of IDD, current understanding and implications of potential therapeutic strategies.

Comparison of biomechanical properties of single- and two-segment fusion for Denis type B spinal fractures

OBJECTIVE

To compare the biomechanical properties of single- and two-segment fusion for Denis type B spinal fracture.

METHODS

Two female patients with Denis type B L1 vertebral fractures were studied. Both patients had achieved intervertebral fusion by 1 year postoperatively, at which time CT data were collected, including data of one patient before and after removal of pedicle screws and of another whose pedicle screws were not removed. The data were imported into Mimics software and T11 -L2 three dimensional models established. After construction of the models, they were imported into ANSYS software. An axial load (260 N) and 10 Nm torque were loaded to simulate the flexion, extension, lateral bending and rotation of the spine, respectively.

RESULTS

There was no significant difference in the average displacement of the spine motion between the two-segment and single-segment fusion patients without removal of pedicle screws. However, for all motion forms, the average displacement of the single-segment fusion patient' spine after removal of pedicle screws was significantly greater than that before removal of pedicle screws and that of the two-segment fusion patient. The average Von Mises stress of T11-12 intervertebral disc of two-segment fusion patient was significantly greater than that of the one-segment fusion patient. Moreover, the average Von Mises stress of T11-12 intervertebral disc of single-segment fusion patient was greater before than after removal of pedicle screws.

CONCLUSION

Provided there is satisfactory interbody fusion, removal of pedicle screws after one-segment fusion can increase spinal motion, reduce the stress on adjacent intervertebral discs and delay disc degeneration.

Severity and pattern of post-traumatic intervertebral disc degeneration depend on the type of injury

BACKGROUND CONTEXT

The burst fracture of a vertebra is the result of a complex loading procedure and is often associated with intervertebral disc (IVD) degeneration. Likewise, the presumed etiologies are (i) the structural perturbation of the IVD/end plate, (ii) the impact of loading energy alone, and (iii) the depressurization of the nucleus pulposus.

PURPOSE

To describe the pathogenesis of post-traumatic disc degeneration (DD) by comparing the severity and patterns of degeneration with different injury models.

STUDY DESIGN

New data from an in vitro organ culture study are compared with the previous work on the same model system.

METHODS

To investigate in detail the contribution of each factor (i-iii) to DD, we extended our previous work to compare three different segmental trauma processes in a rabbit full-organ in vitro model: burst fracture (Group A, etiologies i-iii), equienergetic loading without a fracture (Group B, ii), and endplate puncturing (Group C, iii). DD markers (apoptosis, necrosis, matrix remodeling, inflammation) were monitored up to 28 days posttrauma. Gene transcription data were subjected to principal component analysis and agglomerative hierarchical clustering to identify and compare pathologic patterns.

RESULTS

Only Group A showed the full profile of DD: reduced glycosaminoglycan content, increased caspase-3/7 and lactate dehydrogenase (LDH) activity, and elevated messenger RNA of catabolic (matrix metalloproteinase-1, -3, -13) and proinflammatory (tumor necrosis factor-alpha, interleukin [IL]-6, IL-8, and monocyte chemotactic protein-1) genes. In Group B, only catabolic and proinflammatory genes were slightly upregulated. In Group C, LDH but not caspase-3/7 activity was increased. Catabolic and proinflammatory genes were upregulated, although less compared with Group A. Principal component analysis revealed different transcription patterns for Group C.

CONCLUSIONS

The structural perturbation of the end plate/IVD, but not the loading energy or nuclear depressurization, promotes DD. In addition, end-plate puncturing triggers a different pathogenesis, consistent with a more continuous matrix remodeling process.

Persistent degenerative changes in the intervertebral disc after burst fracture in an in vitro model mimicking physiological post-traumatic conditions

PURPOSE

Post-traumatic disc degeneration (DD) is currently investigated with models not fully matching the clinical condition, in particular post-traumatic loading of the disc is not considered. Therefore, the aim was to establish an in vitro burst fracture model that more closely mimics the in vivo situation by including post-traumatic physiological loading and to investigate DD under these conditions.

METHODS

72 rabbit spinal segments (disc/endplates + 1/3 of adjacent vertebrae) were harvested from T8/9 to L5/6 and assigned to control (n = 36) or trauma groups (n = 36). Burst fractures were induced at day 0 in the trauma group using a dropped-weight device. From day 1 to 28, all specimens were cultured at 37 °C and were dynamically loaded daily (~1 MPa nominal pressure, 1 Hz, 2,500 cycles). At day 1, 7, 14, and 28, 9 specimens from each group were taken for analysis: histology (n = 2), total disc glycosaminoglycan (GAG) content (n = 3) normalized to DNA, and qPCR of DD marker genes (n = 4) in the nucleus pulposus and the annulus fibrosus.

RESULTS

Burst fracture with post-traumatic physiological loading resulted in a 65 % loss of GAG/DNA by day 28. Histological sections confirmed the remodeling of the matrix. Catabolic (MMP-1/-3), pro-apoptotic (TNF-α, fas ligand), and pro-inflammatory (IL-1/-6, iNOS) gene transcription was substantially up-regulated in the nucleus after the trauma and did not normalize to control within 28 days. Similar results were found for the annulus on lower levels.

CONCLUSION

An in vitro burst fracture model with physiological post-traumatic loading was established. Under these conditions, burst spinal segments undergo strong and persistent degenerative changes.

Mechanical stress-induced apoptosis of nucleus pulposus cells: an in vitro and in vivo rat model

BACKGROUND

Un-physiological loads play an important role in the degenerative process of inter-vertebral discs (IVD). In this study, we used an in vitro and in vivo rat model to investigate the mechanism of nucleus pulposus (NP) cells apoptosis induced by mechanical stress.

METHODS

Static compressive load to IVDs of rat tails was used as the in vivo model. For the in vitro model, NP cells were tested under the physiological and un-physiological loading. For histological examination, apoptotic index study, and apoptotic gene expression, we also selected cytokines [bone morphogenetic protein (BMP)-2/7, insulin-like growth factor (IGF)-1, platelet-derived growth factor (PDGF)] to be analyzed.

RESULTS

Under mechanical loading, cellular density was significantly decreased, but there was an increase of TUNEL positive cells and apoptosis index. In a dose-dependent manner; the necrosis became apparent in the un-physiologic strain. The selected cytokines (BMP-2/7, IGF-1, PDGF) can significantly reduce the percentage of apoptotic and necrotic cells.

CONCLUSIONS

We conclude that the intrinsic (mitochondrial) apoptotic pathway plays an important role in the compressive load-induced apoptosis of NP cells. Combination therapy reducing the mechanical load and selected cytokines (BMP-2/7, IGF-1 and PDGF) may have considerable promise in the treatment of spine disc degeneration.

Characterization of microRNA expression profiles in patients with intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is associated with lower back pain and is a global burden with severe healthcare and socioeconomic consequences. However, the underlying mechanisms of IDD remain largely unelucidated. Accumulating evidence has indicasted that newly defined gene regulators, microRNAs (miRNAs), play a vital role in neurodegenerative, pathophysiological and certain reproductive disorders. To characterize the differential miRNA expression profiles between IDD and spinal cord injury, specimens from 3 patients with IDD and 3 with spinal cord injury were selected for microarray analysis. Total RNA from these 6 specimens was extracted and subjected to global miRNA expression analysis using the Exiqon miRCURY™ LNA Array (v.16.0). The microarray data were then validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). In addition, bioinformatics analysis was performed to investigate the dysregulated miRNA target genes and signaling pathways involved. Among the miRNAs analyzed, 25 miRNAs were found to be upregulated and 26 were found to be downregulated in the IDD group compared with the spinal cord injury group. The qRT-PCR results validated the microarray data. Bioinformatics analysis indicated that the signaling pathways most likely to be controlled by these miRNAs were the phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK), epidermal growth factor receptor (EGFR; ErbB) and Wnt pathways. Our results demonstrated that the miRNA expression in patients with IDD differed significantly from that in patients who sustained injury to the intervertebral disc. Our data indicate that the dysregulated miRNAs control the signaling pathways important for the maintenance of IDD. Further studies on miRNA target gene identification and biological functions may address the specific regulatory mechanisms of miRNAs in IDD, and may provide valuable insight into the diagnosis and treatment of IDD.

Morphological differences in adolescent idiopathic scoliosis: a histological and ultrastructural investigation

STUDY DESIGN

Histological and ultrastructural evaluation of cell morphologies at the concave and convex side of apical intervertebral discs (IVD) of adolescent idiopathic scoliosis (AIS).

OBJECTIVE

To determine changes in cell morphology, viability, and cell death after asymmetric disc loading in AIS and to compare the findings with the tilt angles.

SUMMARY OF BACKGROUND DATA

The reaction of cells to loading stimuli in the IVD seems to be specific. Although dynamic loads are more beneficial to the disc cells and maintain the matrix biosynthesis, static compressive loads suppress gene expression.

METHODS

Apical IVDs (Th8-Th9 to L1-L2) from 10 patients with AIS were studied histologically (including TUNEL [TdT-mediated dUTP-biotin nick end labeling] staining to identify disc cell death by apoptosis) and ultrastructurally for matrix evaluations and to quantify healthy, balloon, chondroptotic, apoptotic, and necrotic cells on the concave and convex sides. Patients' spines were classified according to the Lenke classification. Degeneration was assessed according to the Pfirrmann grading system. Two groups were established; group 1 (G1) with a tilt of 5° to 9° and group 2 (G2) with a tilt of 10° to 19°.

RESULTS

Balloon cells were found in significantly higher numbers at the concave side (G1-annulus fibrosus [AF]: mean 16%), with almost none found at the convex side. Mean numbers of healthy cells did not show differences comparing both sides. Significantly higher numbers of healthy cells were found with increasing tilt angle at the concave side. Necrosis (mean, 47%) increased toward the center of the disc but did not differ between the sides of the IVDs. The fibrils found in the outer AF on the convex side were 30% thinner.

CONCLUSION

This study was able to show significant differences in cell morphologies in the AF on both sides and in correlation to the different tilt angles. The type and magnitude of load seem to influence disc cells. Further studies are required to provide more information on disc and cell changes in scoliosis.

Radiographic and safety details of vertebral body stenting: results from a multicenter chart review

Background

Up to one third of BKP treated cases shows no appreciable height restoration due to loss of both restored height and kyphotic realignment after balloon deflation. This shortcoming has called for an improved method that maintains the height and realignment reached by the fully inflated balloon until stabilization of the vertebral body by PMMA-based cementation. Restoration of the physiological vertebral body height for pain relief and for preventing further fractures of adjacent and distant vertebral bodies must be the main aim for such a method. A new vertebral body stenting system (VBS) stabilizes the vertebral body after balloon deflation until cementation. The radiographic and safety results of the first 100 cases where VBS was applied are presented.

Methods

During the planning phase of an ongoing international multicenter RCT, radiographic, procedural and followup details were retrospectively transcribed from charts and xrays for developing and testing the case report forms. Radiographs were centrally assessed at the institution of the first/senior author.

Results

100 patients (62 with osteoporosis) with a total of 103 fractured vertebral bodies were treated with the VBS system. 49 were females with a mean age of 73.2 years; males were 66.7 years old. The mean preoperative anterior-middle-posterior heights were 20.3-17.6-28.0 mm, respectively. The mean local kyphotic angle was 13.1°. The mean preoperative Beck Index (anterior edge height/posterior edge height) was 0.73, the mean alternative Beck Index (middle height/posterior edge height) was 0.63. The mean postoperative heights were restored to 24.5-24.6-30.4 mm, respectively. The mean local kyphotic angle was reduced to 8.9°. The mean postoperative Beck Index was 0.81, the mean alternative one was 0.82. The overall extrusion rate was 29.1%, the symptomatic one was 1%. In the osteoporosis subgroup there were 23.8% extrusions. Within the three months followup interval there were 9% of adjacent and 4% of remote new fractures, all in the osteoporotic group.

Conclusions

VBS showed its strengths especially in realignment of crush and biconcave fractures. Given that fracture mobility is present, the realignment potential is sound and increases with the severity of preoperative vertebral body deformation.

Thoracoscopically assisted corpectomy and percutaneous transpedicular instrumentation in management of burst thoracic and thoracolumbar fractures

STUDY DESIGN

This is a prospective observational study.

PURPOSE

The aim of this study was to determine whether the combination of thoracoscopically assisted corpectomy with posterior percutaneous transpedicular instrumentation in prone position achieves treatment goals in burst thoracic or thoracolumbar fractures and minimizes the associated morbidities.

METHODS

Between December 2007 and December 2008, 26 patients with acute burst spinal fractures were operated upon in our hospital. Those patients underwent posterior percutaneous stabilization plus anterior thoracoscopically assisted corpectomy and fusion in prone position. Clinical and radiological outcomes of these patients were evaluated after a minimum follow-up period of 2 years. The Oswestry Disability Index (ODI) combined with clinical examination was used for clinical evaluation. Plain X-ray in two views was used for the radiological evaluation.

RESULTS

The mean operative time was 248 min. The average blood loss was 765 ml. Ten patients had preoperative neurological deficits ranging from Frankel A to D. One patient did not show any neurological improvement at the final follow-up. The mean ODI at final follow-up was about 7. The mean preoperative kyphosis angle was 25.58°, improved to 9.2° postoperatively and to 13.8° at the final follow-up. No cases of implant failure were reported at the final follow-up.

CONCLUSIONS

Minimal invasive spinal techniques including thoracoscopic decompression and fusion and short segment posterior percutaneous instrumentation showed good clinical outcomes and can be considered as alternative to open procedures with decreased rates of morbidities in managing burst thoracic and thoracolumbar fractures.

Apoptosis in temporomandibular joint disc with internal derangement involves mitochondrial-dependent pathways. An in vivo study

OBJECTIVE

Two main apoptosis pathways have been identified: an extrinsic (or death receptor-mediated) and an intrinsic (or mitochondrial) pathway. Apoptotic cell death through the extrinsic pathway has just been described in temporomandibular joint disc (TMJ) with internal derangement (ID); in contrast, no data are available on the involvement of the intrinsic pathway in this tissue. The aim of this work was to investigate whether the intrinsic pathway participates in apoptosis activation in patients with TMJ ID and anterior disc displacement without reduction.

MATERIALS AND METHODS

Apoptosis activation was studied in TMJ discs from 15 patients with ID and in six unaffected discs using bcl-2-associated X protein (bax), B-cell lymphoma 2 (bcl-2), cytochrome c and caspase 9 immunohistochemistry. A correlation was sought between immunohistochemical findings and degree of disc damage.

RESULTS

None of the pathological TMJ disc sections were immunopositive for bcl-2; negative bcl-2 immunostaining was detected in affected discs; cytochrome c and caspase 9 immunoreactivity was greater in pathological compared to unaffected discs; the difference was significant and correlated with histopathological degeneration score data (Spearman's rho = 0.617).

CONCLUSION

The present findings suggest that in-human TMJ with ID and anterior disc displacement without reduction of cell apoptosis occurs, at least partly, via the mitochondrial pathway, which contributes to the subsequent disc degeneration. These data may have clinical implications and could help devise improved treatment strategies.

Commentary: Thoracolumbar spine fractures: is more knowledge better?

Verlaan J-J, Dhert WJA, Oner FC. Intervertebral disc viability after burst fractures of the thoracic and lumbar spine treated with pedicle screw fixation and direct end-plate restoration. Spine J 2013;13:217-21 (in this issue).

The molecular basis of intervertebral disc degeneration

BACKGROUND

Intervertebral disc (IVD) degeneration remains a clinically important condition for which treatment is costly and relatively ineffective. The molecular basis of degenerative disc disease has been an intense focus of research recently, which has greatly increased our understanding of the biology underlying this process.

PURPOSE

To review the current understanding of the molecular basis of disc degeneration.

STUDY DESIGN

Review article.

METHODS

A literature review was performed to identify recent investigations and current knowledge regarding the molecular basis of IVD degeneration.

RESULTS

The unique structural requirements and biochemical properties of the disc contribute to its propensity toward degeneration. Mounting evidence suggests that genetic factors account for up to 75% of individual susceptibility to IVD degeneration, far more than the environmental factors such as occupational exposure or smoking that were previously suspected to figure prominently in this process. Decreased extracellular matrix production, increased production of degradative enzymes, and increased expression of inflammatory cytokines contribute to the loss of structural integrity and accelerate IVD degeneration. Neurovascular ingrowth occurs, in part, because of the changing degenerative phenotype.

CONCLUSIONS

A detailed understanding of the biology of IVD degeneration is essential to the design of therapeutic solutions to treat degenerative discs. Although significant advances have been made in explaining the biologic mediators of disc degeneration, the inhospitable biochemical environment of the IVD remains a challenging environment for biological therapies.

Fracture of the vertebral endplates, but not equienergetic impact load, promotes disc degeneration in vitro

Vertebral endplate damage is associated with intervertebral disc (IVD) degeneration (DD) in vivo as confirmed by in-vitro investigations. Our aims were to further characterize the process of DD using an in vitro full-organ culture model and to elucidate whether significant endplate damage or impact loading alone is pivotal for the initiation of DD. Rabbit spinal segments (n = 80) were harvested, subjected to pure axial impact loading (n = 40) using a custom-made device, and cultured for 28 days. The applied threshold energy (0.76 J) induced endplate fractures in 21 specimens (group A); 19 remained intact (group B). Markers for DD (cell viability, apoptosis, necrosis, matrix remodeling, and inflammation) were monitored for 28 days post-trauma in the annulus fibrosus (AF) and nucleus pulposus and compared to non-impacted control discs. Cell viability in both groups stayed at a control level. Group A compared to group B showed enhanced lactate dehydrogenase (LDH) and caspase-3/7 activity, reduced glycosaminoglycan content, reduced aggrecan mRNA, but elevated mRNA for collagen-2, catabolic enzymes (MMP-1/-3/-13), and pro-inflammatory (TNFα, IL-6, IL-8, MCP-1) and pro-apoptotic (fas ligand, caspase-3) proteins. Group B compared to control only showed small changes in mRNA levels. Our findings demonstrate that burst endplates, but not equienergetic loading, promotes DD.

Morphological changes in disc herniation in the lower cervical spine: an ultrastructural study

INTRODUCTION

The basis of disc degeneration is still unknown, but is believed to be a cell-mediated process. Apoptosis might play a major role in degenerative disc disease (DDD). The aim of this study was to correlate the viability of disc cells with the radiological degeneration grades (rDG) in disc herniation.

MATERIALS AND METHODS

Forty anterior IVD's (C4-C7) from 39 patients with DDD were studied histologically and ultrastructurally to quantify healthy, "balloon", chondroptotic, apoptotic and necrotic cells. Patients were classified to their rDG, as having either prolapse (P: DGII + III) and/or osteochondrosis (O: DGIV + V). Similar studies were undertaken on eight control discs.

RESULTS

Cell death by necrosis (mean 35%) was common but differed not significantly in both groups. All patients with a disc prolapse DGII + III revealed balloon cells (iAF: mean 32%). All appeared alive and sometimes were hypertrophic. However, significantly less balloon cells were found in the O-Group. Control samples revealed no evidence of "balloon" cells in DGII and only a minor rate in DGIII.

CONCLUSION

According to the different rDG, quantitative changes were obvious in healthy and "balloon" cells, but not for cell death. At the moment it can only be hypothesized if "balloon" cells are part of a repair strategy and/or cause of disc herniation.

Tumor necrosis factor-related apoptosis-inducing ligand expression correlates to temporomandibular joint disk degeneration

This study investigated if tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) immunohistochemical expression in human temporomandibular joint (TMJ)-degenerated disks correlates to the degree of tissue damage to elucidate the possible involvement of this apoptotic pathway in TMJ disk degeneration. Twenty-one TMJ displaced disk from 12 patients were affected by anterior disk displacement with reduction and 9 by anterior disk displacement without reduction processed immunohistochemically with TRAIL antibody. Histopathologic grading of the disk degeneration was carried out in each specimen. The mean histopathologic score of the TMJ degenerated disks was 4.77±1.26 (minimum, 2; maximum, 7). Immunolabeling for TRAIL was detected in the cytoplasm of the TMJ disk cells in every sample, although with different patterns of reactivity. The degree of TRAIL immunostaining was correlated to the histopathologic degeneration score obtained from the sample (Spearman ρ=0.617). Therefore, cell loss due to the involvement of TRAIL apoptotic pathway seems, in part, responsible for TMJ disk degeneration.

Degenerative disc disease of herniated intervertebral discs is associated with extracellular matrix remodeling, vimentin-positive cells and cell death

We studied patients with degenerative disc disease (DDD) to demonstrate that i) remodeling of the extracellular matrix (ECM) in the intervertebral disc (IVD), particularly the elastic fiber system, of subjects with herniated discs is dysregulated and that ii) it is accompanied by accelerated elastin degradation due to increased expression of matrix metalloprotease-9 (MMP-9). Moreover we wanted to obtain a deeper insight into the pathogenesis of DDD through the study of ECM calcification, DNA fragmentation using TUNEL analysis, BAX, bcl-2 and vimentin immunopositive cells. We studied herniated discs from patients of three age groups (group 1=30-40 years; group 2=40-50 years; and group 3=50-65 years) to evaluate the oxytalan fiber systemMMP-9, apoptosis and vimentin immunopositive cells. The results demonstrated the presence of oxytalan fibers in the annulus fibrosus (AF) and the nucleus pulposus (NP) of herniated discs. In the AF oxytalan fibers replaced disrupted mature elastic fibers in calcified areas, while in the NP they were mostly found in nests at the periphery of chondrocytes. MMP-9 was prevalently observed in NP nests above all in group 1 and group 3 discs while group 2 exhibited a lower MMP-9 immunostaining. Activation of the apoptotic process was demonstrated by upregulated BAX expression in group 3. BAX immunopositivity was inversely mirrored by a significant decrease in bcl-2 expression. Intermediate filament protein vimentin was strongly expressed only in group 1 samples. A large number of apoptotic TUNEL+ cells was observed in group 3 specimens. The presence of oxytalan fibers may be the result of a process of incomplete elastogenesis, or a response to mechanical stress trying to functionally replace the lack of elastic fibers. MMP-9 expression seems to relate to disc damage, while chondrocyte BAX upregulation and TUNEL+ cell staining revealed apoptosis activation regardless of patient age. Vimentin immunopositivity was clearly detected in group 1 annulus fibrosus and nucleus pulposus cells. In conclusion, as demonstrated by the vimentin-positive cells, the injured IVD has endogenous resources that can stem the DDD damage, including substitution of damaged elastic fibers by oxytalan fibers. In addition, induction of apoptosis suggests an increased cell turnover in response to repair needs.

The effect of two clinically relevant fusionless scoliosis implant strategies on the health of the intervertebral disc: analysis in an immature goat model

STUDY DESIGN

Immature goat spines were instrumented at 5 levels with 2 different fusionless scoliosis implants. Instrumented and subadjacent spinal segments were analyzed to determine the effect on the disc and endplate.

OBJECTIVE

Analyze the regional biochemistry and histology of spinal motion segments in healthy goat spines treated with 2 clinically relevant, fusionless scoliosis implants.

SUMMARY OF BACKGROUND DATA

Fusionless scoliosis surgery is thought to be more physiologic than fusion as it preserves the growth, motion, and function of the spine. There are presently little data supporting this belief.

METHODS

Scoliosis was created in twelve 8-week-old female goats (n = 6 per group) using 1 of 2 fusionless scoliosis implant strategies: 2 SMA staples per level or a bone anchor/ligament tether. A third group served as controls (n = 6). Goats were analyzed after 6 months. Qualitative and quantitative analyses were performed on spinal motion segments using H&E, TUNEL, and caspase-3 staining.

RESULTS

Neither implant strategy produced degenerative changes in the disc. However, discs at instrumented levels in both groups demonstrated decreased cell density (P < 0.01) and increased cellular apoptosis (P < 0.001) compared to controls. Subadjacent discs demonstrated preservation of viable cells and endplate vascularity compared to instrumented discs.

CONCLUSION

Fusionless scoliosis implants result in alterations in viable cell density within the disc and reduced vascularity in the vertebral endplates of instrumented but not subadjacent discs. Though obvious disc degeneration was not observed, the implications of the cellular and histologic changes are not known. Additional study will be necessary to better understand various fusionless scoliosis surgery strategies and their effect on surrounding tissues.

Expression of TRAIL and the death receptors DR4 and DR5 correlates with progression of degeneration in human intervertebral disks

Intervertebral disks degenerate far earlier than other musculoskeletal tissues and apoptosis has been suggested to have a vital function in promoting the degeneration process that is strongly associated with back pain. However, the molecular mediators of apoptosis in the intervertebral disk are poorly understood. Fas/FasL, TRAIL/DR4, TRAIL/DR5 and TNF-alpha/TNFR1 are ligand/receptor pairs of the tumor necrosis factor/nerve growth factor family, which are able to induce apoptosis by trimerization of the receptor by its corresponding ligand. We investigated which of these molecules are expressed in intervertebral disks and whether their expression correlates to disk degeneration. Intervertebral disks from 28 donors (age 12-70 years) suffering from scoliosis, vertebrae fracture or disk degeneration were scored histologically for degeneration and analyzed for gene expression of FasL/Fas, TRAIL/DR4, TNF-alpha/TNFR1 and caspase 8. Protein expression of FasL and TRAIL was assessed by immunohistology and apoptotic cell death was quantified by poly(ADP-ribose) polymerase (PARP) p85 staining. Isolated disk cells were analyzed by flow cytometry for Fas, FasL, TRAIL, DR4 and DR5 expression. Gene expression of TRAIL (P=0.002) and caspase 8 (P=0.027) significantly correlated with degeneration. TRAIL expression further correlated with cellularity (P=0.04), muccoid matrix changes (P=0.009) and tears and cleft formation (P=0.019). FasL and TRAIL expression was confirmed by immunohistology and PARP cleavage was significantly associated with degeneration (P=0.027). Flow cytometry on isolated disk cells revealed correlations between DR4 and degeneration (P=0.014), DR4/DR5 double-positive cells and degeneration (P=0.019), as well as DR5 and changes in tissue granularity (P=0.03). This is the first study that shows that intervertebral disk cells express TRAIL, DR4 and DR5, which correlate to the degenerative state of the disk. Therefore, disk cells inherit the molecular machinery to induce and undergo cellular apoptosis, and the frequency of cytokine expression suggests that the TRAIL/DR4/DR5 axis is an important molecular mediator of apoptosis induction in disk tissue.

ATLS(R) and damage control in spine trauma

Substantial inflammatory disturbances following major trauma have been found throughout the posttraumatic course of polytraumatized patients, which was confirmed in experimental models of trauma and in vitro settings. As a consequence, the principle of damage control surgery (DCS) has developed over the last two decades and has been successfully introduced in the treatment of severely injured patients. The aim of damage control surgery and orthopaedics (DCO) is to limit additional iatrogenic trauma in the vulnerable phase following major injury. Considering traumatic brain and acute lung injury, implants for quick stabilization like external fixators as well as decided surgical approaches with minimized potential for additional surgery-related impairment of the patient's immunologic state have been developed and used widely. It is obvious, that a similar approach should be undertaken in the case of spinal trauma in the polytraumatized patient. Yet, few data on damage control spine surgery are published to so far, controlled trials are missing and spinal injury is addressed only secondarily in the broadly used ATLS(R) polytrauma algorithm. This article reviews the literature on spine trauma assessment and treatment in the polytrauma setting, gives hints on how to assess the spine trauma patient regarding to the ATLS(R) protocol and recommendations on therapeutic strategies in spinal injury in the polytraumatized patient.

Intervertebral disc cell death in the porcine and human injured cervical spine after trauma: a histological and ultrastructural study

STUDY DESIGN

Histologic and ultrastructural study of disc cell death after traumatic injury to the human cervical spine and postmortem (p-m) in the porcine cervical spine.

OBJECTIVE

To determine the changes in disc cell morphology, viability, and manner of cell death after trauma in human discs and p-m in porcine discs.

SUMMARY OF BACKGROUND DATA

Similarities in the morphology of human and porcine spine have been shown in many histologic and biomechanical investigations. It is known that compressive or traumatic injuries to cartilage and intervertebral discs can result in cell death by necrosis or apoptosis. An additional form of apoptosis, chondroptosis, has been reported in articular cartilage, but not to date in the disc.

METHODS

The anterior portion of intervertebral discs and endplates of 30 patients with traumatic injuries to the cervical spine were studied histologically (including trypan blue exclusion and TUNEL staining) and ultrastructurally. Fractures were classified according to Magerl and degeneration of the intervertebral disc according to Thompson and Benneker. Similar studies of disc and endplate were undertaken on porcine cervical spine 0 to 24 hours p-m.

RESULTS

Electron and light microscopy showed up to 75% of human disc cells die within the first 24 hours of trauma, mainly by necrosis, similar to that seen in pig discs p-m. This study reports on 2 morphologies, chondroptosis and balloon cells, previously not described in the disc. Chondroptosis had been significantly higher and ballooned cells were exclusively seen in discs from fractures with compression, where apoptosis was also most common. Porcine samples revealed comparable rates of apoptosis and chondroptosis as fractures with less compression. Glycogen was commonly found in disc cells after trauma.

CONCLUSION

Traumatic injuries of the human cervical spine lead to rapid changes in disc cell morphology and cell death, particularly via necrosis. The type of fracture and load seems to influence cell death.

Intervertebral disc cells as competent phagocytes in vitro: implications for cell death in disc degeneration

INTRODUCTION

Apoptosis has been reported to occur in the intervertebral disc. Elsewhere in the body, apoptotic cells are cleared from the system via phagocytosis by committed phagocytes such as macrophages, reducing the chance of subsequent inflammation. These cells, however, are not normally present in the disc. We investigated whether disc cells themselves can be induced to become phagocytic and so have the ability to ingest and remove apoptotic disc cells, minimising the damage to their environment.

METHOD

Bovine nucleus pulposus cells from caudal intervertebral discs were grown in culture and exposed to both latex particles (which are ingested by committed phagocytes) and apoptotic cells. Their response was monitored via microscopy, including both fluorescent and video microscopy, and compared with that seen by cell lines of monocytes/macrophages (THP-1 and J774 cells), considered to be committed phagocytes, in addition to a nonmacrophage cell line (L929 fibroblasts). Immunostaining for the monocyte/macrophage marker, CD68, was also carried out.

RESULTS

Disc cells were able to ingest latex beads at least as efficiently, if not more so, than phagocytic THP-1 and J774 cells. Disc cells ingested a greater number of beads per cell than the committed phagocytes in a similar time scale. In addition, disc cells were able to ingest apoptotic cells when cocultured in monolayer with a UV-treated population of HeLa cells. Apoptotic disc cells, in turn, were able to stimulate phagocytosis by the committed macrophages. CD68 immunostaining was strong for THP-1 cells but negligible for disc cells, even those that had ingested beads.

CONCLUSION

In this study, we have shown that intervertebral disc cells are capable of behaving as competent phagocytes (that is, ingesting latex beads) and apoptotic cells. In terms of number of particles, they ingest more than the monocyte/macrophage cells, possibly due to their greater size. The fact that disc cells clearly can undergo phagocytosis has implications for the intervertebral disc in vivo. Here, where cell death is reported to be common yet there is normally no easy access to a macrophage population, the endogenous disc cells may be encouraged to undergo phagocytosis (for example, of neighbouring cells within cell clusters).

Apoptosis of human intervertebral discs after trauma compares to degenerated discs involving both receptor-mediated and mitochondrial-dependent pathways

Post-traumatic disc degeneration with consecutive loss of reduction and kyphosis remains a debatable issue within both the operative and nonoperative treatment regimen of thoracolumbar spine fractures. Intervertebral disc (IVD) cell apoptosis has been suggested to play a vital role in promoting the degeneration process. To evaluate and compare apoptosis-regulating signaling mechanisms, IVDs were obtained from patients with thoracolumbar spine fractures (n = 21), patients suffering from symptomatic IVD degeneration (n = 6), and from patients undergoing surgical resection of a primary vertebral tumor (n = 3 used as control samples). All tissues were prospectively analyzed in regards to caspase-3/7, -8, and -9 activity, apoptosis-receptor expression levels, and gene expression of the mitochondria-bound apoptosis-regulating proteins Bax and Bcl-2. Morphologic changes characteristic for apoptotic cell death were confirmed by H&E staining. Statistical significance was designated at p < 0.05 using the Student's t-test. Both traumatic and degenerative IVD demonstrated a significant increase of caspase-3/7 activity with evident apoptosis. Although caspase-3/7 activation was significantly greater in degenerated discs, both showed equally significant activation of the initiator caspases 8 and 9. Traumatic IVD alone demonstrated a significant increase of the Fas receptor (FasR), whereas the TNF receptor I (TNFR I) was equally up-regulated in both morbid IVD groups. Only traumatic IVD showed distinct changes in up-regulated TNF expression, in addition to significantly down-regulated antiapoptotic Bcl-2 protein. Our results suggest that post-traumatic disc changes may be promoted and amplified by both the intrinsic mitochondria-mediated and extrinsic receptor-mediated apoptosis signaling pathways, which could be, in part, one possible explanation for developing subsequent disc degeneration.