Search

Background Context: Vertebral endplate defects are often implicated in degenerative disc disorders, yet their connection to patient-reported symptoms remains unclear. COX-2 and PGE-2 are known for their roles in inflammation and pain, with EP-4 receptor involvement in pain signaling. Examining their expression in vertebral endplate tissues may provide insights into pathomechanism of low back pain., Purpose: To investigate the association between endplate defects and patient-reported symptoms and to further clarify the role of the COX-2/PGE-2/EP-4 axis in the pathogenesis of chronic low back pain., Study Design/setting: Retrospective study., Patient Sample: A total of 71 patients who had undergone single-level L4/5 or L5/S1 modified laminectomy decompression preserving proximal upper laminae and transforaminal lumbar interbody fusion surgery were included in this study, including 18 patients diagnosed with lumbar disc herniation, 19 with lumbar disc herniation accompanied by degenerative lumbar spinal stenosis, and 34 with degenerative spondylolisthesis., Outcome Measures: Demographic data, Pfirrmann grade, Modic changes, endplate defect score, visual analog scale (VAS) for back and leg pain, and Oswestry Disability Index (ODI) before surgery, 3-month and 6-month follow-up, and the percentage of immune-positive cells (COX-2, PGE-2, and EP-4) in endplate tissue sections., Methods: Patients were divided into defect and nondefect groups according to endplate morphology on lumbar MR. All intraoperative endplate specimens were immediately fixed in 10% formaldehyde, and then embedded in paraffin 3 days later for tissue sections. The outcome measures were compared between the defect group and nondefect group. Data were analyzed using independent t-tests and χ² tests. Pearson's rank correlation test was used to assess correlations between patient-reported symptoms and the percentage of immune-positive cells in the groups. Multivariable logistic regression models using the forward stepwise likelihood ratio method were used to identify the factors that were independently associated with endplate defects., Results: The age of Defect group was significantly higher than that of nondefect group (52.5±7.7 vs 57.2±9.1. p=.024). There were no significant differences in gender, diagnosis, BMI, comorbidities, or surgical level between the two groups. Modic changes (Type Ⅱ/Type Ⅲ) were more common in patients of Defect group than nondefect group (38.5% vs 11.1%, p<.001), and so was disc degeneration (Pfirrmann grade Ⅳ/Ⅴ) (69.2% vs 33.3%, p<.001). Defect group had significantly higher VAS-Back (6.5±2.0 vs 4.9±1.6, p<.001) and ODI scores (62.9±10.7 vs 45.2±14.8, p<.001) than nondefect group, while there was no significant differences between the two groups during the 3 and 6-month follow-up after surgery. Histologically, Defect group was characterized by upregulation of COX-2, PGE-2, and EP-4 in endplate tissue sections. Both in defect and nondefect groups, VAS-Back showed moderate positive correlations with the expressions of COX-2 (r=0.643; r=0.558, p both<.001), PGE-2 (r=0.611; r=0.640, p both<.001), and EP-4 (r=0.643; r=0.563, p both<.001). Multivariate regression analyses reveled that percentage of COX-2-positive cells was associated with endplate defects (OR=1.509, 95%CI [1.048-2.171], p=.027), as well as percentage of PGE-2-positive (OR=1.291, 95%CI [1.106-1.508], p=.001) and EP-4-positive cells (OR=1.284, 95%CI [1.048∼2.171], p=.003)., Conclusions: Patients with endplate defects had worse quality of life, more severe disc degeneration and Modic changes, and up-regulated COX-2/PGE-2/EP-4 axis expression in cartilage endplates in patients with defected endplates. Inflammatory factors may significantly contribute to the onset and progression of chronic low back pain in patients with endplate defects, consequently impacting patient-reported symptoms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background Context: Macrophages play important roles in the progression of intervertebral disc herniation and radiculopathy., Purpose: To better understand the roles of macrophages in this process, we developed a new mouse model that mimics human radiculopathy., Study Design/setting: A preclinical randomized animal study., Methods: Three types of surgeries were performed in randomly assigned Balb/c mice. These were spinal nerve exposure, traditional anterior disc puncture, and lateral disc puncture with nerve exposure (n=16/group). For the nerve exposure group, the left L5 spinal nerve was exposed without disc injury. For the traditional anterior puncture, L5/6 disc was punctured by an anterior approach as previously established. For lateral puncture with nerve exposure, the left L5 spinal nerve was exposed by removing the psoas major muscle fibers, and the L5/6 disc was punctured laterally on the left side with a 30G needle, allowing the nucleus to protrude toward the L5 spinal nerve. Mechanical hyperalgesia (pain sensitivity) of hind paws was assessed with electronic von Frey assay on alternative day for up to 2 weeks. MRI, histology, and immunostaining were performed to confirm disc herniation and inflammation., Results: Ipsilateral pain in the lateral puncture with nerve exposure group was significantly greater than the other groups. Pro-inflammatory cytokines IL-1β and IL-6 were markedly elevated at the hernia sites of both puncture groups and the spinal nerve of lateral puncture with never exposure group on postoperative day 7. Heterogeneous populations of macrophages were detected in the infiltration tissue of this mouse model and in tissue from patients undergone discectomy., Conclusions: We have established a new mouse model that mimics human radiculopathy and demonstrated that a mixed phenotype of macrophages contribute to the pathogenesis of acute discogenic radiculopathy., Clinical Significance: This study provides a clinically relevant in vivo animal model to elucidate complex interactions of disc herniation and radicular pain, which may present opportunities for the development of macrophage-anchored therapeutics to manage radiculopathy., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background Context: Intervertebral disc (IVD) degeneration is related to numerous risk factors, including obesity. Leptin, one of the commonly measured adipokines, is proven to play an important role in the pathogenesis of IVD degeneration. In the context of IVD degeneration, matrix metalloproteinase-1 (MMP-1), which is upregulated and activated by leptin, is the most abundant catabolic enzyme. It remains unclear which of the factors mentioned above is most strongly associated with IVD degeneration., Purpose: To investigate the influence of MMP-1 in IVD degeneration, we determined the strength of different predictors, including age, sex, magnetic resonance imaging (MRI), Modic changes (MCs), body mass index (BMI), leptin, and MMP-1. This was achieved by assessing the correlation among these factors and histologic degeneration score (HDS)., Study Design: This study included 89 patients undergoing cervical discectomy for disc herniation, 93 who underwent lumbar discectomy, and 90 control subjects. Herniated disc tissue and plasma were used after the study was approved by the Human Ethics Review Committee at the authors' institution., Methods: Hematoxylin and eosin (H&E), Alcian blue-PAS and immunohistochemical (IHC) staining were performed to measure the expression levels of leptin and MMP-1. Circulating plasma levels of leptin and MMP-1 were measured using an enzyme-linked immunosorbent assay. To assess the correlation with HDS, measurements of age, sex, BMI, MRI scale, MCs scale, leptin/MMP-1 plasma concentration, and leptin/MMP-1 IHC expression were analyzed., Results: Patients with cervical or lumbar discectomy had significantly higher BMI than controls. Significantly more men than women were involved in the lumbar patients as compared with the cervical patients and the control subjects. After adjustment for age and sex, plasma leptin and leptin IHC score correlated significantly with BMI in patients with cervical or lumbar discectomy. Age, sex, MRI scale, MCs scale, and leptin/MMP-1 plasma concentration were not positively correlated with HDS. HDS was significantly associated with BMI, leptin IHC score, and MMP-1 IHC score. After a stepwise-multiple linear regression analysis to evaluate the strength of the correlations between HDS and various factors, only the MMP-1 IHC score demonstrated an independent association with HDS in patients with degeneration of the cervical or lumbar disc., Conclusions: MMP-1 IHC score is an independent predictor of the severity of cervical or lumbar IVD degeneration., Clinical Significance: MMP-1 IHC score may be used as an indicator of IVD degeneration., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background Context: The cartilaginous and bony material that can be present in herniated tissue suggests that failure can involve both cartilaginous and vertebral-endplates. How structural integration is achieved across the junction between these two distinct tissue regions via its fibril and mineral components is clearly relevant to the modes of endplate failure that occur., Purpose: To understand how structural integration is achieved across the cartilaginous-vertebral endplate junction., Study Design: A micro- and fibril-level structural analysis of the cartilage-vertebral endplate region was carried out using healthy, mature ovine motion segments., Methods: Oblique vertebra-annulus-vertebra samples were prepared such that alternate layers of lamellar fibers extended from vertebra to vertebra. The endplate region of each sample was then decalcified in a targeted manner before being loaded in tension along the fiber direction to achieve incomplete rupture within the region of the endplate. The failure regions were then analyzed with differential interference contrast microscopy and scanning electron microscopy., Results: Microstructural analysis revealed that failure within the endplate region was not confined to the cement line. Instead, rupture continued into the underlying vertebral endplate with bony material still attached to the now unanchored annular bundles. Ultrastructural analysis of the partially ruptured regions of the cement line revealed clear evidence of blending/interweaving relationships between the fibrils of the annular bundles, the calcified cartilage and the bone with no one pattern of association appearing dominant. These findings suggest that fibril-based structural cohesion exists across the cement line at the site of annular insertion, with strengthening via a mechanism somewhat analogous to steel-reinforced concrete. The fibrils are brought into a close intermingling association with interfibril forces mediated via the mineral component., Conclusions: This study provides clear evidence of structural connectivity across the cartilaginous-vertebral endplate junction by the intermingling of their fibrillar components and mediated by the mineral phase. This is consistent with the clinical observation that in some disc herniations bony material can be still attached to the extruded soft tissue., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background Context: Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness., Purpose: The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions., Study Design/setting: This is a multicenter international prospective cohort study., Patient Sample: This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine., Outcome Measures: The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade., Materials and Methods: The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America., Results: Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p<.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe., Conclusions: Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background Context: Prolonged microgravity exposure is associated with localized low back pain and an elevated risk of post-flight disc herniation. Although the mechanisms by which microgravity impairs the spine are unclear, they should be foundational for developing in-flight countermeasures for maintaining astronaut spine health. Because human spine anatomy has adapted to upright posture on Earth, observations of how spaceflight affects the spine should also provide new and potentially important information on spine biomechanics that benefit the general population., Purpose: This study compares quantitative measures of lumbar spine anatomy, health, and biomechanics in astronauts before and after 6 months of microgravity exposure on board the International Space Station (ISS)., Study Design: This is a prospective longitudinal study., Sample: Six astronaut crewmember volunteers from the National Aeronautics and Space Administration (NASA) with 6-month missions aboard the ISS comprised our study sample., Outcome Measures: For multifidus and erector spinae at L3-L4, measures include cross-sectional area (CSA), functional cross-sectional area (FCSA), and FCSA/CSA. Other measures include supine lumbar lordosis (L1-S1), active (standing) and passive (lying) flexion-extension range of motion (FE ROM) for each lumbar disc segment, disc water content from T2-weighted intensity, Pfirrmann grade, vertebral end plate pathology, and subject-reported incidence of chronic low back pain or disc injuries at 1-year follow-up., Methods: 3T magnetic resonance imaging and dynamic fluoroscopy of the lumbar spine were collected for each subject at two time points: approximately 30 days before launch (pre-flight) and 1 day following 6 months spaceflight on the ISS (post-flight). Outcome measures were compared between time points using paired t tests and regression analyses., Results: Supine lumbar lordosis decreased (flattened) by an average of 11% (p=.019). Active FE ROM decreased for the middle three lumbar discs (L2-L3: -22.1%, p=.049; L3-L4: -17.3%, p=.016; L4-L5: -30.3%, p=.004). By contrast, no significant passive FE ROM changes in these discs were observed (p>.05). Disc water content did not differ systematically from pre- to post-flight. Multifidus and erector spinae changed variably between subjects, with five of six subjects experiencing an average decrease 20% for FCSA and 8%-9% for CSA in both muscles. For all subjects, changes in multifidus FCSA strongly correlated with changes in lordosis (r 2 =0.86, p=.008) and active FE ROM at L4-L5 (r 2 =0.94, p=.007). Additionally, changes in multifidus FCSA/CSA correlated with changes in lordosis (r 2 =0.69, p=.03). Although multifidus-associated changes in lordosis and ROM were present among all subjects, only those with severe, pre-flight end plate irregularities (two of six subjects) had post-flight lumbar symptoms (including chronic low back pain or disc herniation)., Conclusions: We observed that multifidus atrophy, rather than intervertebral disc swelling, associated strongly with lumbar flattening and increased stiffness. Because these changes have been previously linked with detrimental spine biomechanics and pain in terrestrial populations, when combined with evidence of pre-flight vertebral end plate insufficiency, they may elevate injury risk for astronauts upon return to gravity loading. Our results also have implications for deconditioned spines on Earth. We anticipate that our results will inform new astronaut countermeasures that target the multifidus muscles, and research on the role of muscular stability in relation to chronic low back pain and disc injury., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background Context: Classification criteria are recommended for diseases that lack specific biomarkers to improve homogeneity in clinical research studies. Because imaging evidence of lumbar disc herniations (LDHs) may not be associated with symptoms, clinical classification criteria based on patient symptoms and physical examination findings are required., Purpose: This study aimed to produce clinical classification criteria to identify patients with radicular pain caused by LDH., Study Design: The study design was a two-stage process. Phase 1 included a Delphi process and Phase 2 included a cohort study., Patient Sample: The patient sample included outpatients recruited from spine clinics in five countries., Outcome Measures: The outcome measures were items from history and physical examination., Materials and Methods: In Phase 1, 17 spine experts participated in a Delphi process to select symptoms and signs suggesting radicular pain caused by LDH. In Phase 2, 19 different clinical experts identified patients they confidently classified as presenting with (1) radicular pain caused by LDH, (2) neurogenic claudication (NC) caused by lumbar spinal stenosis, or (3) non-specific low back pain (NSLBP) with referred leg pain. Patients completed survey items and specialists documented examination signs. A score to predict radicular pain caused by LDH was developed based on the coefficients of the multivariate model. An unrestricted grant of less than US$15,000 was received from MSD: It was used to support the conception of the Delphi, data management, and statistical analysis. No fees were allocated to participating spine specialists., Results: Phase 1 generated a final list of 74 potential symptoms and signs. In Phase 2, 209 patients with pain caused by LDH (89), NC (63), or NSLBP (57) were included. Items predicting radicular pain caused by LDH (p<.05) were monoradicular leg pain distribution, patient-reported unilateral leg pain, positive straight leg raise test <60° (or femoral stretch test), unilateral motor weakness, and asymmetric ankle reflex. The score had an AUC of 0.91. An easy-to-use weighted set of criteria with similar psychometric characteristics is proposed (specificity 90.4%, sensitivity 70.6%)., Conclusions: Classification criteria for identifying patients with radicular pain caused by LDH are proposed. Their use could improve the homogeneity of patients enrolled in clinical research studies., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Osteoblastoma is rare and accounts for 3% of all benign tumors and 1% of all bone tumors. The spine is the most common site of occurrence, constituting 32% to 45% of all osteoblastomas. It has a strong predilection for the posterior elements, most often occurring in the lumbar spine., Method: In this case report, we describe an unusual presentation of spinal osteoblastoma presenting as thoracic T9 vertebra plana in a 20-year-old female. She presented with discomfort over the midback with unsteadiness of gait. The patient underwent detailed investigations including computed tomography (CT), magnetic resonance imaging, and CT-guided biopsy. To our knowledge, this is the first case report of vertebra plana due to spinal osteoblastoma in the English literature., Result: The patient successfully underwent posterior decompression of T9 with laminectomy followed by minimally invasive surgery posterior instrumentation from T7 to T11. Histopathology of the intraoperative specimen was consistent with osteoblastoma. The patient had an uneventful postoperative recovery and no evidence of tumor recurrence could be demonstrated on positron emission tomography scan at 15 months' follow-up., Conclusion: In conclusion, the differential diagnosis for vertebra plana is extensive and we add spinal osteoblastoma as another etiology to the existing list. Diagnosis and treatment of vertebra plana involve multimodality radiological imaging, and careful histological and surgical evaluation to identify the underlying etiology., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background Context: In canine intervertebral disc (IVD) extrusion, a spontaneous animal model of spinal cord injury, hemorrhage is a consistent finding. In rodent models, hemorrhage might be involved in secondary tissue destruction by biochemical mechanisms., Purpose: This study aimed to investigate a causal association between the extents of intramedullary, subdural and epidural hemorrhage and the severity of spinal cord damage following IVD extrusion in dogs., Study Design/setting: A retrospective study using histologic spinal cord sections from 83 dogs euthanized following IVD extrusion was carried out., Methods: The degree of hemorrhage (intramedullary, subdural, epidural), the degree of spinal cord damage in the epicenter (white and gray matter), and the longitudinal extent of myelomalacia were graded. Associations between the extent of hemorrhage and the degree of spinal cord damage were evaluated statistically., Results: Intramedullary and subdural hemorrhages were significantly associated with the degree of white (p<.001/ p=.004) and gray (both p<.001) matter damage, and with the longitudinal extension of myelomalacia (p<.001/p=.005). Intriguingly, accumulation of hemorrhagic cord debris inside or dorsal to a distended and ruptured central canal in segments distant to the epicenter of the lesion was observed exhibiting a wave-like pattern on longitudinal assessment. The occurrence of this debris accumulation was associated with high degrees of tissue destruction (all p<.001)., Conclusions: Tissue liquefaction and increased intramedullary pressure associated with hemorrhage are involved in the progression of spinal cord destruction in a canine model of spinal cord injury and ascending or descending myelomalacia. Functional and dynamic studies are needed to investigate this concept further., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: Human studies have revealed a link between muscle degeneration and low back pain, although the cause and effect of this relationship is not clear. Dogs provide a naturally developing model of intervertebral disc (IVD)-related low back pain that may provide insight into relationships between IVD and muscle degeneration., Purpose: This study aimed to quantify, via magnetic resonance imaging (MRI), the magnitude and location of fatty infiltration in spine muscles of chondrodystrophic (CD) and non-chondrodystrophic (NCD) dogs suffering from both intervertebral disc herniation (IVDH) and non-disc-related spinal disorders, and relate this to intervertebral disc degeneration (IVDD)., Study Design: This study used retrospective MRI-based analysis of IVDD and muscle fatty infiltration in CD and NCD dogs., Methods: A portion of this study was funded ($1,000) by the Pet Trust Fund, Ontario Veterinary College. Magnetic resonance imaging from 180 dogs were separated into four groups: (1) CD with IVDH; (2) CD with non-IVDH spinal pathology; (3) NCD with IVDH; (4) NCD with non-IVDH spinal pathology. For each dog at intervertebral levels T12-T13 to L6-L7, IVDD was subjectively graded and muscle-fat indices (MFIndices) were quantified for multifidus, erector spinae, and psoas muscle groups., Results: Intervertebral disc degeneration grade was higher (p<.0001) for CD compared with NCD dogs, and for dogs diagnosed with IVDH compared with dogs with non-IVDH pathology. Muscle-fat indices of multifidus and psoas were higher (p<.01), indicating greater fatty infiltration, for NCD compared with CD dogs, and for dogs with non-IVDH pathology compared with dogs with IVDH. Erector spinae demonstrated higher (p<.0001) MFIndices compared with multifidus and psoas; however, this level of fatty infiltration was not dependent upon breed or pathology., Conclusions: Dog groups with higher average IVDD grades demonstrated less fatty infiltration within their multifidus and psoas muscles, compared with groups with lower IVDD grades. This finding was consistent across both CD and NCD breeds as well as across dogs presenting with IVDH and those presenting with a non-IVDH spinal pathology. Thus, the presence or severity of IVDD is not uniquely related to fatty infiltration in these muscles, but rather the presence, or possibly severity or chronicity, of general spine pathology is likely a better predictor of fatty infiltration., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: Posterior epidural migrated lumbar disc fragments is an extremely rare disorder. Surgical treatment was performed in all reported cases. To the best of our knowledge, there are no reported cases of the use of conservative treatment for posterior epidural migrated lumbar disc fragments., Purpose: To report the possibility of a spontaneous regression of posterior epidural migrated lumbar disc fragments., Study Design: Case series., Methods: Four patients with posterior epidural migrated lumbar disc fragments were treated at Karatsu Red Cross Hospital between April 2008 and August 2010. Spontaneous regression of the posterior epidural migrated lumbar disc fragments with relief of symptoms was observed on magnetic resonance imaging (MRI) in three cases. Another patient underwent surgical treatment. The present and previously reported cases of posterior epidural migrated lumbar disc fragments were analyzed with respect to patient age, imaging features on MRI, the level of the lesion, clinical symptoms, treatment, and outcomes., Results: Conservative treatment was successful, and spontaneous lesion regression was seen on MRI with symptom relief in three cases., Conclusions: Although posterior epidural migrated lumbar disc fragment cases are generally treated surgically, the condition can regress spontaneously over time, as do sequestrated disc fragments. Spontaneous regression of lumbar disc herniations is a widely accepted observation at present. Posterior epidural migrated lumbar disc fragments fall under the sequestrated type of disc herniation. In fact, the course of treatment for posterior epidural migrated lumbar disc fragments should be determined based on the symptoms and examination findings, as in cases of ordinary herniation. However, providing early surgical treatment is important if the patient has acute cauda equina syndrome or the neurologic symptoms worsen over time., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: The relation between specific types of lumbosacral transitional vertebra and the degree of degeneration at and adjacent to the transitional level is unclear. It is also unknown whether the adjacent cephalad segment to a transitional vertebra is prone to greater degeneration than a normal L5-S1 level., Purpose: The purpose of this study was to evaluate the relation between specific lumbosacral transitional vertebra subtypes according to the Castellvi classification, and to determine the severity of degeneration at the transitional level and the adjacent cephalad segment., Study Design: This study was a retrospective review., Patient Samples: Ninety-two subjects with lumbosacral transitional vertebra grade 2 or higher and 94 control subjects without were retrieved from a picture archiving and communication system (PACS) search., Outcome Measures: Disc degeneration parameters at the transitional and at the adjacent cephalad level were measured., Methods: After institutional review board approval, 92 subjects (42 men; mean age, 57±16 years) with lumbosacral transitional vertebra grade 2 or higher and 94 control subjects (41 men; mean age, 51±16 years) without were retrieved from a PACS search. Degeneration of the last two segments of the lumbar spine was quantified using the Pfirrmann and Modic classifications, along with documentation of annular tears, disc herniations, and disc height, and were compared between the two groups. Furthermore, L5-S1 levels in the control subjects were compared with the adjacent cephalad segments of the transitional vertebrae for the same parameters., Results: Although the control subjects, at L5-S1, had moderate to severe degeneration by Pfirrmann grades (31%) and Modic changes ([MC] 20%), in comparison, the discs at the transitional level of the lumbosacral transitional vertebra group demonstrated significant less degeneration (3% and 1%, respectively; each p<.05). The adjacent cephalad segments of the lumbosacral transitional vertebra group showed significantly greater degeneration (Pfirrmann grade 5, 39%; MC, 30%) compared with the L4-L5 level in control subjects (16% and 11%, respectively; each p<.05). The severity of disc degeneration using all parameters correlated with the type of lumbosacral transitional vertebra. The degree of degeneration of L5-S1 in control subjects was similar to the adjacent cephalad segment in lumbosacral transitional vertebrae., Conclusion: Increasing the mechanical connection of a lumbosacral transitional vertebra protects the disc at the transitional level and predisposes the adjacent cephalad segment to greater degeneration. The adjacent cephalad segment had a comparable degree of degeneration as the L5-S1 level in control subjects., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: The optimal surgical treatment of thoracic disc herniations remains controversial and depends on the consistency of the herniation and its location related to the spinal cord., Purpose: To compare the outcomes of patients with symptomatic thoracic disc herniations treated with anterolateral mini-transthoracic approach (TTA) versus posterior transpedicular discectomy., Study Design: This is a prospective comparative cohort study., Patient Sample: One hundred consecutive patients with symptomatic thoracic herniated discs were operated by mini-TTA (56 patients) or transpedicular discectomy (44 patients)., Outcome Measures: Neurologic assessment by American Spinal Injury Association (ASIA) Impairment Scale and patients' self reported perceived recovery and complications., Methods: The consistency and location of the herniated disc in relation to the spinal cord was evaluated by preoperative computed tomography and magnetic resonance imaging. Patients were assessed neurologically before surgery and at regular outpatient controls at 2 months or later. Long-term follow-up was achieved by questionnaires sent by mail., Results: In both groups, most patients had symptoms of myelopathy and radicular pain; patients who underwent mini-TTA, more frequently suffered from spasticity. Fifty-eight percent of the herniated discs were calcified and 77% were larger than one-third of the spinal canal. All patients presented with ASIA Grade C or D (64%) or ASIA Grade E (36%). Postoperatively, 50% of the patients treated with mini-TTA and 37% of the transpedicular group improved at least one grade on the ASIA scale (p=.19). The duration of surgery, blood loss, hospital stay, and complication rate were significantly higher in patients treated with mini-TTA and were mainly related to the magnitude and consistency of the herniated disc. At long-term follow-up, 72% of the mini-TTA patients reported good outcome versus 76% of the transpedicular discectomy group (p=.80)., Conclusions: Surgical treatment of a symptomatic herniated disc contributed to a clinical improvement in most cases. The approach is dependent on the location, the magnitude, and the consistency of the herniated thoracic disc. Medially located large calcified discs should be operated through an anterolateral approach, whereas noncalcified or lateral herniated discs can be treated from a posterior approach as well. For optimal treatment of this rare entity, the treatment should be performed in selected centers., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background Context: It has been claimed that lumbar radiculopathy induced by foraminal disc herniations had poorer outcome and different clinical features, including: 1-more progressive onset, but shorter duration between the first sign and request of medical care; 2-more severe radiculopathy; 3-less frequent/severe back pain; 4-less limitation of straight leg raising (SLR); 5-more frequent neurologic deficiencies; 6-poorer outcome., Purpose: To check whether this still holds true when including only patients without other reasons for foraminal stenosis, that is, whether patients with medial disc herniations had different features and outcome than those with more lateral disc herniations., Study Design: All patients hospitalized to treat a lumbar radiculopathy within a 6-month period in two French rheumatology units in 2012 were included in this prospective study each time computed tomography scan or magnetic resonance imaging had already been performed and showed clear disc bulging/herniation but no features of medial or lateral spinal stenosis., Patient Sample: Fifty-nine patients (31 males, 49 with sciatica only) were included: 31 (53%) had medial disc herniations and 28 (47%) had more lateral herniations (posterolateral in 3, foraminal in 20, and far lateral in 5)., Outcome Measures: Outcome was assessed by a phone call 1 year after the baseline assessment using a standardized questionnaire. Patients were asked whether they experienced a relapse of their radiculopathy after discharge from the hospital; whether they had been operated or not; whether they felt it had improved or not; whether they felt cured or not; to assess their level of pain radiating in the leg when standing on a 0 to 10 verbal scale; and how long they could walk., Methods: Features of patients with medial disc herniations were compared with patients with more lateral herniations., Results: No significant differences according to the location of herniations were noticed for the speed of radiculopathy onset, time elapsed since onset, back pain (both lying or standing), and leg pain (both lying or standing), but slight significant differences (t test<0.05) were observed for other items: the 28 patients with lateral herniations were 8 years older (53.4 ±15.8 vs. 45.2±12.6), their herniations involved discs from upper levels of the lumbar spine (above L4-L5: 7/28 vs. 3/31), motor weakness was more frequent (25% vs. 3%), SLR was less restricted (65.0°±24.5° vs. 51.1°±25.7°), DN4 score of neuropathic pain was higher (4.4±2.1 vs. 3.2±1.8), anxiety level was higher (10.3±4.1 vs. 7.9±3.2), length of hospital stay was longer (5.7±2.4 days vs. 4.5±1.4 days), and physician's prognosis of a good outcome was poorer (6.6±2.2 vs. 8.0±1.6). However, at the end of follow-up (12.2±3.3 months), outcome was similar: 37% (vs. 41% for medial herniations) had transiently relapsed, 66% felt finally improved (vs. 63%), and walking capacity was nearly identical despite the fact that only 18% had to be operated (vs. 32% of those with medial herniations)., Conclusions: Despite differences in clinical presentation, the outcome of radiculopathy induced by the more lateral lumbar disc herniations was not worse than the outcome of patients with only medial disc herniations. Previous claims of poorer outcome in foraminal herniations might be explained by the inclusion of patients with associated foraminal stenosis., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background Context: Existing research on lumbar disc degeneration has remained inconclusive regarding its etiology, pathogenesis, symptomatology, prevention, and management. Degenerative disc disease (DDD) and disc prolapse (DP) are common diseases affecting the lumbar discs. Although they manifest clinically differently, existing studies on disc degeneration have included patients with both these features, leading to wide variations in observations. The possible relationship or disaffect between DDD and DP is not fully evaluated., Purpose: To analyze the patterns of lumbar disc degeneration in patients with chronic back pain and DDD and those with acute DP., Study Design: Prospective, magnetic resonance imaging-based radiological study., Methods: Two groups of patients (aged 20-50 years) were prospectively studied. Group 1 included patients requiring a single level microdiscectomy for acute DP. Group 2 included patients with chronic low back pain and DDD. Discs were assessed by magnetic resonance imaging through Pfirmann grading, Schmorl nodes, Modic changes, and the total end-plate damage score for all the five lumbar discs., Results: Group 1 (DP) had 91 patients and group 2 (DDD) had 133 patients. DP and DDD patients differed significantly in the number, extent, and severity of degeneration. DDD patients had a significantly higher number of degenerated discs than DP patients (p<.000). The incidence of multilevel and pan-lumbar degeneration was also significantly higher in DDD group. The pattern of degeneration also differed in both the groups. DDD patients had predominant upper lumbar involvement, whereas DP patients had mainly lower lumbar degeneration. Modic changes were more common in DP patients, especially at the prolapsed level. Modic changes were present in 37% of prolapsed levels compared with 9.9% of normal discs (p<.00). The total end-plate damage score had a positive correlation with disc degeneration in both the groups. Further the mean total end-plate damage score at prolapsed level was also significantly higher., Conclusion: The results suggest that patients with disc prolapse, and those with back pain with DDD are clinically and radiologically different groups of patients with varying patterns, severity, and extent of disc degeneration. This is the first study in literature to compare and identify significant differences in these two commonly encountered patient groups. In patients with single-level DP, the majority of the other discs are nondegenerate, the lower lumbar spine is predominantly involved and the end-plate damage is higher. Patients with back pain and DDD have larger number of degenerate discs, early multilevel degeneration, and predominant upper lumbar degeneration. The knowledge that these two groups of patients are different clinically and radiologically is critical for our improved understanding of the disease and for future studies on disc degeneration and disc prolapse., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background Context: Lumbar intradural disc herniation (IDH) is rare, and intradural cyst associated with IDH is quite rare. Only seven cases of an intradural cyst associated with lumbar disc herniation have been reported, and all were gas-filled cysts. We report the first case, to our knowledge, of a fluid-filled intradural cyst associated with IDH., Purpose: To report an extremely rare case of a fluid-filled intradural cyst associated with lumbar IDH and suggests the possible pathogenesis., Study Design: Case report., Methods: An 82-year-old woman presented with right leg pain and motor weakness. Computed tomography and magnetic resonance imaging (MRI) scans showed calcified lumbar disc herniation and an intradural cystic mass at the L1-L2 level. An MRI, which was performed 2 years before admission, showed an IDH without a cyst at the same level., Results: Surgical resection of the intradural cyst was performed. Intraoperative finding showed a fluid-filled intradural cyst with 1-cm diameter of displacing nerve rootlets. The cyst was connected with extradural cystic components through a ventral dural hole, but the tract was blocked by fibrous septum. Histopathologic examination showed a pseudocyst that consisted of degenerative cartilaginous and fibrous tissues, including degenerative disc materials. We concluded that the cyst was an intradural cyst transformed from the intradural disc fragment., Conclusions: The current case is the first report to our knowlege of a fluid-filled intradural cyst associated with IDH. The possible mechanism may be focal degeneration and spontaneous absorption of the intradural disc with fluid production. Unlike the gas-filled intradural cysts, the cause of the pure fluid-filled cyst may be disconnection from the intervertebral vacuum because of a calcified disc and septation of the cyst., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background Context: An extraforaminal disc herniation may present as a retroperitoneal mass and is thus a differential diagnosis for a malignant lesion., Purpose: To highlight the difficulty in the accurate preoperative differentiation between an extraforaminal disc herniation and a malignant retroperitoneal mass despite the use of advanced anatomical and metabolic imaging., Study Design: Case report., Methods: The authors present a case of a 55-year-old man, with a family history of neurofibromatosis, who presented to us 2 months after the insidious occurrence of severe, unrelenting, right-sided, L5 dermatomal pain. He subsequently developed rapidly progressive motor weakness in the same myotome, which caused a foot drop. On examination, his straight-leg raise test was normal. Magnetic resonance imaging demonstrated a peripherally enhancing, complex, cystic mass continuous with the L5 nerve, displacing its fascicles medially, as it descended over the right sacral ala. A positron emission tomography scan demonstrated increased radiotracer uptake. The clinicoradiologic presentation was that of a malignant peripheral nerve sheath tumor., Results: At surgery, an intraneural disc herniation was seen., Conclusions: Several pitfalls exist in establishing the uncommon diagnosis of an extraforaminal disc herniation. This entity occurs ventrally and must remain a consideration when elaborating the differential diagnosis of a retroperitoneal mass in close proximity to the vertebral column., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background Context: Several reports suggest that level- and side-specific multifidus atrophy or fat infiltration may be related to localized spinal pathology and symptoms. In particular, a study using a porcine model reported rapid level- and side-specific multifidus atrophy and adipocyte enlargement resulting from anterolateral disc or nerve root lesions., Purpose: To investigate asymmetry in cross-sectional area (CSA) and fat infiltration in multifidus and other paraspinal muscles in patients with acute or subacute unilateral symptoms of radiculopathy and concordant posterolateral disc herniation. If multifidus asymmetry is indeed related to local pathology, this may serve as a marker for helping to target the search for less clearly identifiable pathology responsible for low back-related symptoms, which currently remains elusive in approximately 85% of those seeking care., Study Design: Cross-sectional observational study., Patient Sample: Subjects were patients referred to magnetic resonance imaging (MRI) with unilateral leg symptoms of less than 6 weeks onset suggestive of radiculopathy, with a consistent posterolateral lumbar disc herniation verified on imaging., Methods: Using T2-weighted axial MRI, measurements were obtained for total muscle CSA and signal intensity, functional (fat-free) CSA, and the ratio of functional CSA to total CSA., Results: Forty-three subjects met the inclusion criteria. The ratio of functional CSA to total muscle CSA was smaller on the side of the herniation than on the unaffected side, both below (mean 0.69 vs. 0.72, p=.007) and at the level of herniation (mean 0.78 vs. 0.80, p=.031). Multifidus signal intensity (fat infiltration) was greater on the side of the herniation at the level below the herniation (p=.014). Contrary to expectation, greater total multifidus CSA was found ipsilateral to the pathology at the level of herniation (p=.033). No asymmetries were found at the level above the herniation or in any other paraspinal muscles, with the exception of higher signal in the erector spinae at the level and side of herniation., Conclusions: Multifidus may be particularly responsive to, or indicative of, localized lumbar disc or nerve root pathology within the first 6 weeks of symptoms as expressed through fat infiltration, but not through CSA asymmetry on MRI. However, such measurements are not reliable markers of lumbar pathology on an individual basis for use in clinical or research settings., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background Context: Vascular disease has been proposed as a risk factor for disc height loss (DHL)., Purpose: To examine the relationship between quantitative measures of abdominal aortic calcifications (AACs) as a marker of vascular disease, and DHL, on computed tomography (CT)., Study Design: Cross-sectional study in a community-based population., Patient Sample: Four hundred thirty-five participants from the Framingham Heart Study., Outcome Measures: Quantitative AAC scores assessed by CT were grouped as tertiles of "no" (reference), "low," and "high" calcification. Disc height loss was evaluated on CT reformations using a four-grade scale. For analytic purposes, DHL was dichotomized as moderate DHL of at least one level at L2-S1 versus less than moderate or no DHL., Methods: We examined the association of AAC and DHL using logistic regression before and after adjusting for cardiovascular risk factors and before and after adjusting for age, sex, and body mass index (BMI)., Results: In crude analyses, low AAC (odds ratio [OR], 2.05 [1.27-3.30]; p=.003) and high AAC (OR, 2.24 [1.38-3.62]; p=.001) were strongly associated with DHL, when compared with the reference group of no AAC. Diabetes, hypercholesterolemia, hypertension, and smoking were not associated with DHL and did not attenuate the observed relationship between AAC and DHL. Adjustment for age, sex, and BMI markedly attenuated the associations between DHL and low AAC (OR, 1.20 [0.69-2.09]; p=.51) and high AAC (OR, 0.74 [0.36-1.53]; p=.42)., Conclusions: Abdominal aortic calcification was associated with DHL in this community-based population. This relationship was independent of cardiovascular risk factors. However, the association of AAC with DHL was explained by the effects of age, sex, and BMI., (Published by Elsevier Inc.)

Background Context: Recurrent herniation of the nucleus pulposus (HNP) frequently causes poor outcomes after lumbar discectomy. The relationship between obesity and recurrent HNP has not previously been reported., Purpose: The purpose of this study was to investigate the association of obesity with recurrent HNP after lumbar microdiscectomy., Study Design: Retrospective Cohort., Patient Sample: We reviewed all cases of one- or two-level lumbar microdiscectomy from L2-S1 performed by a single surgeon with a minimum follow-up of 6 months., Outcome Measures: The primary clinical outcomes were evidence of recurrent HNP on magnetic resonance imaging (MRI) and need for repeat surgery., Methods: All patients with recurrent radicular pain or new neurological deficits underwent a postoperative MRI scan. Recurrent HNP was defined as a HNP at the same side and same level as the index procedure., Results: Seventy-five patients were included in the study. The average body mass index (BMI) was 27.6+/-4.6. Thirty-two patients received an MRI scan. The time from operation to repeat MRI scan varied widely (3 days to 15 months). Eight patients (10.7%) had recurrent HNP. Four patients had persistent symptoms requiring reoperation (5.3%). The mean BMI of patients with recurrent HNP was significantly higher than that of those without recurrence (33.6+/-5.1 vs. 26.9+/-3.9, p<.001). In univariate analysis, obese patients (BMI >or=30) were 12 times more likely to have recurrent HNP than nonobese patients (odds ratio [OR]: 12.46, 95% confidence interval [CI]: 2.25-69.90). Obese patients were 30 times more likely to require reoperation (OR: 32.81, 95% CI: 1.67-642.70). Age, sex, smoking, and being a manual laborer were not significantly associated with recurrent HNP. A logistic regression analysis supported the findings of the univariate analysis. In a survival analysis using a Cox proportional hazards model, the hazard ratio of recurrent HNP for obese patients was 17 (OR: 17.08, 95% CI: 2.85-102.30, p=.002)., Conclusions: Obesity was a strong and independent predictor of recurrent HNP after lumbar microdiscectomy. Surgeons should incorporate weight loss counseling into their preoperative discussions with patients., (Copyright 2010 Elsevier Inc. All rights reserved.)

Background Context: The population of senescent disc cells has been shown to increase in degenerated or herniated discs. However, the mechanism and signaling pathway involved in the senescence of nucleus pulposus (NP) chondrocytes are unknown., Purpose: To demonstrate the mechanisms involved in the senescence of NP chondrocytes., Study Design/setting: Senescence-related markers were assessed in the surgically obtained human NP specimens., Patient Sample: NP specimens remaining in the central region of the intervertebral disc were obtained from 25 patients (mean: 49 years, range: 20-75 years) undergoing discectomy. Based on the preoperative magnetic resonance images, there were 3 patients with Grade II degeneration, 17 patients with Grade III degeneration, and 5 patients with Grade IV degeneration., Outcome Measures: We examined cell senescence markers (senescence-associated beta-galactosidase [SA-beta-gal], telomere length, telomerase activity, p53, p21, pRB, and p16) and the hydrogen peroxide (H(2)O(2)) content as a marker for an oxidative stress in the human NP specimens., Methods: SA-beta-gal expression, telomere length, telomerase activity, and H(2)O(2) content as well as their relationships with age and degeneration grades were analyzed. For the mechanism involved in the senescence of NP chondrocytes, expressions of p53, p21, pRB, and p16 in these cells were assessed with immunohistochemistry and Western blotting., Results: The percentages of SA-beta-gal-positive NP chondrocytes increased with age (r=.82, p<.001), whereas the telomere length and telomerase activity declined (r=-.41, p=.045; r=-.52, p=.008, respectively) However, there was no significant correlation between age and H(2)O(2) contents (p=.18). The NP specimens with Grade III or Grade IV degeneration showed significantly higher percentages of SA-beta-gal-positive NP chondrocytes than those with Grade II degeneration (p=.01 and p=.025, respectively). Immunohistochemistry showed that the senescent NP chondrocytes in all the specimens expressed p53, p21, and pRB, but a few NP chondrocytes in only two specimens expressed p16. Western blotting showed that the expressions of p53, p21, and pRB displayed a corresponding pattern, that is, a strong p53 expression led to strong p21 and pRB expressions and vice versa., Conclusions: Our in vivo study demonstrated that senescent NP chondrocytes increased or accumulated in the NP with increasing age and advancing disc degeneration. The NP chondrocytes in the aging discs exhibited characteristic senescent features such as an increased SA-beta-gal expression, shortened telomeres, and decreased telomerase activity. We further demonstrated that the telomere-based p53-p21-pRB pathway, rather than the stress-based p16-pRB pathway, plays a more important role in the senescence of NP chondrocytes in an in vivo condition. Our results suggest that prevention or reversal of the senescence of NP chondrocytes can be a novel therapeutic target for human disc degeneration.

Background Context: Different strategies to supplement/replenish the disc cell population have been proposed. Recently, adult stem cells have shown promise as a cell source for a variety of tissue engineering and cell therapy applications. A stem cell can renew itself through cell division and can be induced to develop into many different specialized cell types. Moreover, stem cells have shown ability to migrate and engraft within various tissues, as well as to exert stimulatory effects on other cell types through various mechanisms (eg, paracrine effects, cell-cell interactions). These characteristics make stem cells worthy of investigation as a source of cells for intervertebral disc (IVD) tissue engineering and cell therapy., Purpose: To determine feasibility of a stem cell therapy of IVD degeneration., Study Design: In vitro studies of adult human cells to examine interactions between nucleus pulposus cells (NPCs) and mesenchymal stem cells (MSCs) at different ratios in 3-D pellet culture. In vivo studies of healthy adult rabbit discs injected with allogenic adult rabbit MSCs to examine stem cell survival and engraftment in living disc tissue., Methods: In vitro study: Human NPCs were cocultured with human MSCs in different ratios (75:25, 50:50, 25:75) for 2 weeks in pellet culture, for comparison with pure NPC (100:0) and pure MSC (0:100) pellet cultures. Proteoglycan synthesis rate and glycosaminoglycan (GAG) content were measured by radioactive sulfate incorporation and dimethylmethylene blue assay, respectively. In vivo study: MSCs were isolated from the bone marrow of a New Zealand White (NZW) rabbit, retrovirally transduced with the lacZ marker gene, and injected into the nucleus pulposi of the L2-3, L3-4, and L4-5 lumbar discs of 12 other NZW rabbits. Three rabbits each were sacrificed at 3, 6, 12, or 24 weeks after cell implantation, and X-Gal staining was done to assess survival and localization of MSCs in the disc tissues., Results: In vitro study: the 75:25 and 50:50 NPC:MSC cocultures yielded the greatest increases in extracellular matrix (ECM) production. In vivo study: MSCs were detected in histological sections of rabbit discs up to 24 weeks after allogenic stem cell implantation, without evidence of systemic illness in the recipient rabbits. The 24-week results in particular suggested the possibility of stem cell migration and engraftment into the inner annulus fibrosus., Conclusions: These encouraging results support feasibility of a stem cell therapy approach toward supplementation/replenishment of IVD cells and synthesis/maintenance of a more functional ECM in a degenerated disc. Moreover, the in vivo results demonstrate that transplanted MSCs survive and successfully engraft into the IVD tissue, and are effective vehicles for exogenous gene delivery to the IVD--thus there appear to be multiple mechanisms whereby stem cells might able to confer therapeutic effects in a stem cell therapy of IVD degeneration.

Study Design: The study is a prospective observational study of 48 continuous patients with symptomatic lumbar degenerative disk disease. Each patient underwent discography, MRI, and a biochemical analysis of disk lavage fluid., Objectives: The purpose of this study was to correlate concordant pain on discography with MRI grade and biochemical markers of inflammation in a clinical setting., Summary of Background Data: The pathophysiology of degenerative disk disease is complex. Discography is used to differentiate symptomatic from asymptomatic levels. MRI is used to image changes in disk water content. Biochemical assays have identified molecular markers of inflammation. To date, no study has correlated concordant pain on discography with MRI findings and biochemical markers., Methods: Forty-eight (48) continuous patients with symptomatic lumbar degenerative disk disease gave informed consent for study entry. Patient sex, age, insurance, work status and visual analog score (VAS) were recorded. MRI was obtained and Pfirrmann grading was performed by a single spine surgeon. Discography with disc lavage was performed by a single anesthesiologist. Lavage samples were tested for inflammatory markers with high resolution multi-plex bead immunoassays and ELISA with >5 pg/ml resolution., Results: None of demographic variables was significantly related to concordant pain on discogram by chi-squared tests and Mann-Whitney U-test. The Pfirrmann score was significantly different for patients with and without concordant pain at L3-L4 (p<0.001), but was insignificant at other levels after multitest correction. Pfirrmann scores were significantly different at any level in patients with and without concordant pain. VAS scores were not significantly correlated with opening pressures at any level. Despite the presence of serum proteins in the disk lavage fluid, none of the tested inflammatory mediators was identified by multi-plex bead immunoassays and ELISA., Conclusions: There are only weak correlations between demographic, discogram, and radiographic variables. Response to discogram cannot be predicted by non-invasive means. The disk lavage method was unable to identify the presence of specific inflammatory peptides with multi-plex immunoassays and ELISA.

Background Context: Although crystal deposition in cartilage and synovial fluid has received much attention, crystal formation and the role that crystal deposits play are virtually unexplored in the intervertebral disc. In articular cartilage matrix, crystal deposits are associated with altered extracellular matrix (ECM) and cell phenotypic features, but crystal deposition in the human intervertebral disc has received much less attention., Purpose: To determine the incidence of crystal deposits in the annulus and to evaluate associated disc cell and ECM features., Study Design/setting: Human intervertebral disc annulus tissue was obtained in a prospective study of the presence of crystals in the disc ECM. Human Subjects Institutional Review Board approved experimental studies., Patient Sample: Two hundred eight sequential disc specimens were submitted from surgical disc procedures performed on individuals with herniated discs, degenerative disc disease, or recurrent disc herniation. During this same time period, three disc specimens were received from nonsurgical donors and added to the study population., Outcome Measures: Histologic features with special attention to crystal deposition., Methods: Specimens were processed undecalcified and examined for the histologic presence of crystal deposits and ECM features around the crystals., Results: The proportion of specimens containing crystals was determined to be 14.7%; crystals displayed varying sizes, morphology, and polarized light birefringence features. Pyrophosphate crystals were most common, but oxalate-like crystals were also present. ECM in crystal regions showed previously recognized alterations., Conclusions: This study shows that the incidence of crystal deposits in discs is approximately 15% and is thus a relatively common occurrence. These data are important because masses of crystals not only disrupt disc ECM but may also accelerate preexisting degenerative changes via an elevation in matrix metalloproteinases (as previously recognized in cartilage). Because failure of the structural integrity of the disc can result in annular tears and subsequent disc herniation, the mechanisms of crystal formation and the relationship between crystals and disc degeneration merit further investigations.

Background Context: The sagittal profile of the lumbar end plates on magnetic resonance imaging (MRI) has not been investigated in patients with degenerative disc disease (DDD) or herniated nucleus pulposus (HNP)., Purpose: To examine the shape of the end plates in patients treated surgically for a) low back pain or b) radiculopathy with HNP. Furthermore, to investigate the correlation between end plate shape and disc degeneration on the one, and end plate shape and symptoms on the other., Study Design/setting: Retrospective review of charts and radiographs., Methods: The charts, operative reports, preoperative lateral plain radiographs, and MRI scans of 178 patients (85 with low back pain and 93 with HNP) were reviewed. End plate shape was determined on midsagittal MRI cuts, disc degeneration was graded on T2 sequences, and disc height was measured on lateral plain radiographs from L1 to S1 in all patients. Student t-test and chi(2) test were used to detect significant differences and associations., Results: Flat and irregular levels were most common in the lower lumbar spine. The L5/S1 segment was flat in most cases, due to a flat sacral end plate. In DDD patients, disc degeneration on MRI and plain radiographs worsened from concave to flat, to irregular levels. In HNP patients, MRI demonstrated concave levels to be less degenerated, whereas no difference was detected between flat and irregular levels. Disc height of irregular levels was well preserved in HNP patients. Comparing the two groups, flat levels were more degenerated on MRI in HNP patients. Despite similar degrees of degeneration on MRI, concave and irregular levels in DDD patients had lower disc heights. A higher frequency of symptoms was found in flat and irregular levels for both patient groups., Conclusions: The sagittal profile of end plates in the lumbar spine was described for patients with DDD on the one and HNP on the other. A higher association with symptoms was observed for flat and irregular levels in both patient groups. In DDD patients, disck degeneration on both MRI and plain radiographs increased from concave to flat, to irregular levels. In HNP patients, MRI demonstrated concave levels to be less degenerated, whereas no difference was detected between flat and irregular levels. Disc height of irregular levels was well preserved in HNP patients. Comparing the two groups of patients, flat levels were more degenerated on MRI in HNP patients. Despite similar degrees of degeneration on MRI, concave and irregular levels in DDD patients had lower disc heights. The correlation of symptoms and disc degeneration with the end plate shapes is not definitive evidence of end plate remodeling around degenerated discs. It may simply represent the higher rate of disc degeneration in the lower lumbar levels. This analysis did not provide any hints as to which degenerated discs are more likely to herniated and cause leg symptoms or cause predominantly low back pain.

Background Context: Discography has been successfully used to distinguish painful from asymptomatic intervertebral discs., Purpose: To report a case of chronic back pain following two-level interbody and posterolateral fusion in the lumbar spine that was evaluated with marcaine injection into the disc space., Study Design: Case report., Methods: A patient with chronic back pain after a two-level anteroposterior lumbar fusion was evaluated. A complete description of the history, physical examination, and relevant radiographic images along with a brief review of the pertinent literature are included., Results: Injection of marcaine into the area of previous interbody fusion resolved the painful symptoms, and surgery confirmed the nonunion., Conclusions: In cases of interbody lumbar fusion with questionable solidity, marcain injection within the disc space can help in the assessment of the source of pain even at the intervertebral spaces with cages.

Background Context: Intraradicular lumbar disc herniation is rare, having been reported to date in only three postoperative patients. The diagnosis is typically made intraoperatively., Purpose: To report a fourth case of intraradicular disc herniation, to emphasize its radiological characteristics and operative findings., Study Design: Case report., Patient Sample: A 41-year-old female., Methods: Retrospective case review., Results: The patient underwent a second operation and intraradicular disc fragment was removed. She was completely well at her 9-month check up., Conclusions: The diagnosis, mechanism, and surgical treatment of intraradicular lumbar disc herniation are reviewed. The round shape of the sequestrated fragment, as seen on magnetic resonance imaging, may help to establish the correct diagnosis.

Background Context: Gout of the spine is very rare. Forty-one cases of gout affecting the spine have been reported., Purpose: To present a patient with tophaceous gout of the lumbar spine mimicking pyogenic discitis., Study Design: Case report., Methods: The medical record, including operative notes, progress notes, discharge summary, clinical notes, radiological study, and pathological studies was reviewed., Results: The patient had acute low back pain and radiculopathy with high spiking fever. Therefore, pyogenic discitis was suspected. However, histological diagnosis revealed tophaceous gout., Conclusions: Tophaceous gout of the spine is very rare. However, when a patient presents with acute back pain and fever, spinal gout should be considered, particularly in a patient with a previous history of hyperuricemia or gout.

Background: Posterior epidural migration is an interesting but rare path taken by a prolapsed intervertebral disc fragment. There are only seven cases reported of a similar migration of the disc fragment in the lumbar spine., Purpose: To diagnose the unusual presentation and interpretation of the sequestrated disc in the posterior epidural space., Study Design: Case report., Methods: Two cases of migration of the sequestrated disc into the posterior epidural space are presented. In one patient there was weakness of the ankle dorsiflexors, foot invertors, and toe extensors of the left foot, with sensory loss over the back of the calf and over the lateral three toes. The left ankle jerk was also absent. However, in the other case, there was no objective evidence of neurological deficit distally., Results: Gadolinium magnetic resonance imaging scans showed ring enhancement preoperatively. Biopsy of the specimen taken from surgery confirmed it to be sequestrated disc fragment., Conclusion: Diagnosis of posterior epidural migration of the sequestrated discs may be difficult. It may present with subtle clinical features even though the disc transgresses through numerous anatomic restraints including the nerve roots in such cases.

Background Context: Although previous work has shown that greater age, greater disc degeneration, female gender, and surgical derivation of disc tissue had deleterious effects on cell proliferative potential, relatively little is known about the association between disc cell proliferation in vitro and clinical donor characteristics., Purpose: To identify the relationships between donor characteristic and the in vitro proliferative potential of human disc cells from the annulus., Study Design/setting: Studies were approved by the human subjects Institutional Review Board. Donor data included donor source, ethnicity, age, gender, smoking history, height, weight, number of years of back pain, and Thompson score. Cells cultured from the annulus were tested for proliferation., Patient Sample: There were two study populations: 1) Comparison Group (32 control donors and 33 control surgical subjects; 60 Caucasians, 5 African-Americans). Cell proliferation, age, Thompson score, height, weight, and smoking history were statistically analyzed for control donors versus control surgical group. No significant differences were present, and these two groups were pooled to form the Comparison Group. 2) Nineteen subjects from the United Arab Emirates who underwent disc surgery., Outcome Measures: Linear models were fit to the data to determine the best prediction of cell proliferation as the outcome variable; multiple R-squared was used to determine model goodness of fit., Methods: Control donor specimens were obtained from the National Cancer Institute Cooperative Human Tissue Network, and control donor surgical specimens from disc surgeries. A standardized cell proliferation assay was used to evaluate monolayer and three-dimensional agarose cell proliferation. Data were expressed as mean cpm[(3)H]-thymidine per microgram deoxyribonucleic acid+/-SEM. Standard statistical methods used the SAS system for data analysis., Results: No differences were present in the Comparison Group versus the Middle Eastern group for mean Thompson score (both averaged grade III), mean age (44.3 vs. 43.0 years, respectively), gender, height, weight, length of time with back pain (1.9 years vs. 2.1 years respectively), or smoking history. Three-dimensional proliferation in agarose was not significantly different for the two groups. Monolayer proliferation, however, was significantly different (17,434+/-2,929 vs. 6,693+/-2,103, respectively), p=.019. Linear regression models were fit to the data to determine the best prediction using proliferation as the outcome variable. In the Middle Eastern group, monolayer cell proliferation bore a significant negative correlation to age (p=.02, r=-.32), whereas the Comparison Group showed no such relationship. The following equation was derived to fit these data: Log(10) of proliferation (cpm/mug deoxyribonucleic acid)=10.915-0.7919 (Middle Eastern ethnicity)-0.0296 (Age). The r(2) for this equation is 0.203 (ie, 20.3% of the change in proliferation is explained by age and Middle Eastern ethnicity). Middle Eastern ethnicity and age were significant in this equation (p=.04 and .0003, respectively)., Conclusions: Studies have shown that familial history, age, and smoking are important risk factors for disc degeneration in Arabic pedigrees. It is interesting that our present findings also point to age and familial history as important significant factors influencing monolayer proliferation. Further research is needed to identify the cellular basis for this influence on cellular proliferative capacity.

Background: Traditional approaches to thoracic disc herniation are technically demanding and, if incorporating thoracotomy, can be associated with significant morbidity. New procedures have allowed discectomy with less pain and morbidity., Purpose: To assess the feasibility, safety, and early outcome of a minimally invasive extracavitary approach (MI-ECA) for thoracic disc disease., Study Design: Cadaver sessions and a short-term human study were performed on four cadavers and 10 patients, respectively. Operative results and complications were studied, and early outcome was assessed using a Visual Pain Analog Scale, neurological status, and American Spinal Injury Association (ASIA) classification., Methods: Four fresh cadaver sessions, attempting all thoracic levels, were completed to determine the feasibility of the technique. Ten patients with thoracic myelopathy caused by herniated disc were treated using the minimally invasive extracavitary approach., Results: Intervertebral discs were successfully removed from all four cadavers using this procedure. No operative complications in the human series were documented. The mean operative time was 171 minutes (150-220), mean estimated blood loss was 215 cc (60-350), and hospital stay for all patients was one night. No operative or postoperative complications were encountered. All patients returned to work within 4 weeks after discharge. Postoperative ASIA scores improved in three patients who had motor or sensory findings. Tone improved in all patients. Mean pain outcome using the Visual Pain Analog Scale was 1.5 (0-3)., Conclusion: Our early experience suggests that MI-ECA may be a valuable option in the management of thoracic disc herniation.

Debilitating low back pain as a result of symptomatic lumbar disc degeneration places a significant burden on an industrial society. Traditionally surgical treatment involving fusion of the anterior and posterior spinal elements has resulted in unpredictable and frequently irreproducible results, especially with regard to return to work rates. A new surgical method of managing symptomatic disc degeneration recalcitrant to nonoperative measures involves the partial or complete removal of the intervertebral disc with replacement with a motion-sparing device. A review of the English-speaking literature will be discussed evaluating the historical development, design considerations, animal models, basic science studies, cadaveric research, and clinical outcomes of the partial removal of the intervertebral disc (nucleus pulposus) and replacement with a motion-sparing implant. An overview of traditional methods of surgical management of lumbar degenerative disc disease will then be followed by an introduction to the concept of motion-sparing implants (nucleus pulposus replacement) intended to remove the pain generator without the associated morbidity of a surgical fusion.

Background Context: Although symptomatic disc degeneration is thought to be the leading cause of chronic low back pain, no available biologic therapy is yet available to treat this highly prevalent condition., Purpose: In this article, the cellular, biomechanical and molecular alterations that occur during disc degeneration are reviewed to provide a better understanding of this pathologic process., Study Design: The cellular and molecular aspects of disc degeneration are reviewed., Methods: The available studies detailing the molecular and cellular changes during disc degeneration are reviewed in an effort to provide a basis for understanding the biologic strategies for disc repair., Results: Disc degeneration begins early in life and involves a cascade of changes at the cellular and molecular level that results in degradation of the extracellular matrix of the disc, leading to biomechanical failure of this complex structure., Conclusion: With a thorough understanding of the cellular and molecular events causing degeneration of the intervertebral disc, rational strategies for disc repair can be understood and evaluated. It appears that biologic disc repair will be feasible in the future although challenges remain in this blossoming field.

Background Context: Recent advances in our understanding of the biologic makeup and environment of the intervertebral disc (IVD) have led to increased interest in the development of novel treatments for disc degeneration. Certain genes found to alter rates of matrix synthesis and catabolism within the disc have provided targets for scientists seeking to alter the balance between the two. To this end, gene therapy has emerged as a potential therapeutic option, and recent research efforts have yielded very promising results., Purpose: To update and consolidate information regarding the recent advances in gene therapy and its application to IVD degeneration., Study Design/setting: Review of recent and ongoing research in the field of gene therapy, particularly regarding its application to the treatment of IVD degeneration., Methods: Literature review., Results: With its unique ability to provide sustained delivery of potentially therapeutic agents, gene therapy has shown much promise with regard to the treatment of IVD degeneration. There have been many exciting developments such as safer and more reliable vector constructs, favorable results using therapeutic transgenes in disc cells both in vitro and in vivo, and improvement in transgene regulation, and investigators continue to explore ways in which gene therapy can become a powerful tool in the future treatment of disc degeneration., Conclusions: With continued perseverance and dedication, many advances have been made in the application of gene therapy to the IVD, and it continues to demonstrate great potential to become a powerful tool in the future treatment of disc degeneration.

Background Context: Currently, no biologic treatment is available for disc degeneration. However, many different molecules of potential therapeutic benefit are being investigated., Purpose: Review and categorize the molecules under investigation for potential therapy in preventing or reversing disc degeneration., Study Design: Review article., Methods: Review of published articles on molecules that may be useful in biologic therapy of the intervertebral disc., Results: The list of molecules under investigation for potential benefit in biologic therapy of the intervertebral disc repair continues to grow. These molecules are so diverse that they no longer all fall into the classic terminology of "growth factor." Some of these molecules are not growth factors at all and some are not even cytokines. At least four different classes of molecules may be effective in disc repair. These include anticatabolics (eg, tissue inhibitors of metalloproteinase [TIMPs]), mitogens (eg, insulin-like growth factor-1 [IGF-1], platelet-derived growth factor [PDGF]), chondrogenic morphogens (transforming growth factor beta [TGF-beta] and bone morphogenetic proteins [BMPs]), and intracellular regulators (LIM mineralization protein-1 [LMP-1] and Sox9). Although some in vitro data are available on all of these molecules, few of these molecules have been tested in vivo with an animal model of disc degeneration., Conclusions: As the current screening experiments are concluded, more definitive in vivo systems involving a more realistic degeneration model will be a necessary step before attempting human studies.

Despite the significant impairment associated with degenerative disc disease, a clear understanding of its pathogenesis is still lacking. Currently, no particular model parallels the complex nature of human disc degeneration. Naturally occurring animal models have the drawback that the basis for the high rate of disc degeneration is not known. Although the interventions in artificial animal models that create disc degeneration are known, the relationship of those to the events leading to disc degeneration in humans is not. With the recent progress in biomechanics, cell biology and molecular biology, an easily reproducible and valid animal model may help unlock the complex cascade of events surrounding human disc degeneration.

Background Context: One of the most promising therapies for symptomatic disc degeneration involves the implantation of therapeutic cells into the degenerative disc., Purpose: In this article, the rationale and approaches for cell-based tissue engineering of the intervertebral disc are discussed., Study Design: The scientific literature related to cell-based tissue engineering of the intervertebral disc is reviewed., Methods: A variety of cell types have been used in various research models to affect matrix repair of the intervertebral disc. The use of cellular scaffolds and growth factors or genes also appears promising for achieving meaningful tissue repair of the intervertebral disc., Results: Disc tissue engineering is a promising approach for achieving repair of the intervertebral disc. Using cell-based approaches, various research models suggest that improvements in the complex matrix of the disc may be achieved., Conclusion: A cell-based approach to repair of the intervertebral disc appears promising. More research is needed to define the optimal cell type, cellular scaffold and mixture of growth factors that may allow meaningful repair of the human symptomatic degenerative disc.

Background Context: Cervical spine suffers degenerative changes with age and activity., Purpose: The aim is to study the cervical spine of African head bearers by analyzing clinical changes and radiographic degenerative signs in comparison with a control group., Study Design: Two groups of bearers, 28 bearers of heavy loads (50 to 60 kg) over short stretches and 33 bearers who carried bundles or lighter loads (30 to 35 kg) over long distances were clinically and radiographically examined and compared with a control group of 36 building industry workers who did not bear weights on their heads., Methods: We noted the age, height, weight, body mass index (BMI), weight of load, years they had been working, width and length of the neck and any painful symptoms. We carried out a functional exploration of the cervical spine and a lateral radiograph of the cervical spine to assess degenerative changes and quantified the degenerative changes in the vertebral bodies and the discs. The angle of lordosis was measured., Results: We found more prolapsed discs (p < .01) in the heavy-load bearing group than in the control group. The heavy-load bearers had larger neck width (p < .01) and more disc herniations (p < .05) than the bundler bearers. The frequency of prolapsed discs was higher at C5-C6 and C6-C7 levels. The listhesis was more frequent among bundle bearers than in heavy-load bearers and control group. A correlation between the number of disc herniations and age (p < .01) and years of work (p < .05) was observed. When all the bearers were compared with the control group, the differences found were the number of prolapsed discs, stiffness in the neck and reported pain (p < .01)., Conclusion: Load bearing on the head, particularly bearers of heavy loads, produced more radiographic degenerative signs, much stiffness in the neck and more reported pain than the control group.

Background: No conclusive evidence exists to determine that spinal steroid injections give lasting improvement in patients with predominantly axial low back pain resulting from lumbar degenerative disc disease (DDD)., Purpose: The objectives of the study were to determine the effect of epidural steroid injections (ESIs) and intradiscal steroid injections (ISIs) in patients who exhibit DDD symptoms for more than 1 year and to determine whether patients with inflammatory end-plate changes are a unique subgroup of DDD patients in terms of treatment response., Study Design: Pain and function in patients with DDD were prospectively assessed by an outcomes questionnaire before and after various spinal injections. Further correlation was made with end-plate inflammatory (Modic Type 1) changes identified on magnetic resonance imaging (MRI)., Patient Sample: ESI was performed in 232 patients who were referred for treatment of DDD, and discography with or without intradiscal steroid was performed in 171 patients who were possible spinal arthrodesis candidates., Outcome Measures: Pain and function were determined by a self-administered outcomes questionnaire that consisted of a visual analog pain scale, pain drawing, Oswestry Disability Index, use of pain medication and opinion of treatment success., Methods: ESI was performed in 93 patients with DDD and inflammatory end-plate changes and in 139 patients without inflammatory end-plate changes. Patients with inflammatory end-plate changes (n=78) or without inflammatory end-plate changes (n=93), all of whom were considered fusion candidates, underwent discography with or without intradiscal steroid in a randomized fashion. Pain and function were prospectively determined by a self-administered outcomes survey (VAS pain, Oswestry Disability index [ODI], pain diagram [PD] and opinion of success) before and after the patients' injection for a 2-year follow-up period. MRI and discography results were correlated with patient outcomes scores., Results: ESI was effective in improving pain and function, as assessed by outcomes scores at short-term follow-up. However, at 2 years, less than one-third had not had additional invasive treatment. Patients with inflammatory end-plate changes had greater improvement in ODI and PD scores in the first 6 months than did those patients without the end-plate changes. Intradiscal steroid injections into discs with concordant pain at the time of discography led to significant improvement in patients with inflammatory end-plate changes in all outcomes scales, but only minimal temporary improvement in patients without the end-plate changes. Disc pressure manometry at the time of discography found that discs with adjacent inflammatory end-plate changes reproduced symptoms at pressures significantly lower than those in other types of discs., Conclusions: Spinal steroid injections, both ESI and ISI, are beneficial for a small number of patients with advanced DDD and chronic low back pain. For those patients in whom a beneficial effect is found, spinal steroid injection is a low-risk and rapid treatment option. Spinal steroid injections are more effective in patients with MRI findings of discogenic inflammation, specifically adjacent inflammatory end-plate changes.

Background Context: Discectomy is a surgical technique commonly used to treat bulging or herniated discs causing nerve root compression. Clinical data suggest discectomy may also help patients with contained discs and no clear neural compromise. However, the mechanisms of clinical efficacy are uncertain, and consequently bases for treatment optimization are limited., Purpose: To determine the effect of percutaneous plasma decompression on the histologic, morphologic, biochemical and biomechanical features of degenerating intervertebral discs., Study Design: An adult porcine model of disc degeneration was used to establish a degenerative baseline against which to evaluate discectomy efficacy., Outcome Measures: Cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha were measured from tissue samples using enzyme-linked immunosorbent assay. Histology and morphology images were rated for degenerative findings (of cells and matrix) in both the nucleus and annulus. Proteoglycan content was determined, and intact specimen stiffness and flexibility were measured biomechanically. Magnetic resonance images were collected for biomechanical specimens., Methods: Using a retroperitoneal surgical approach, stab incisions were made in four or five lumbar discs per spine in 12 minipigs. Animals were allocated into one of three groups: 6-week recovery, 12-week recovery and percutaneous plasma decompression using an electrosurgical device at 6 weeks with recovery for 6 additional weeks. Four additional animals served as controls., Results: Discs treated with discectomy had a significant increase in IL-8 and a decrease in IL-1 as compared with the 12-week, nontreated discs. There were no significant differences in morphologic and biomechanical parameters or proteoglycan content between treated discs and time-matched, nontreated discs., Conclusions: Our results demonstrate that percutaneous plasma discectomy alters the expression of inflammatory cytokines in degenerated discs, leading to a decrease in IL-1 and an increase in IL-8. Whereas both IL-1 and IL-8 have hyperalgesic properties, IL-1 is likely to be a more important pathophysiologic factor in painful disc disorders than IL-8. Therefore, the alteration in cytokine expression that we observed is consistent with this effect as a mechanism of pain relief after discectomy. In addition, given that IL-1 is catabolic in injured tissue and IL-8 is anabolic, our results suggest that a percutaneous plasma discectomy may be capable of initiating a repair response in the disc.

Background Context: Partial removal of the nucleus has been shown to decompress herniated discs, relieving pressure on nerve roots and, in some cases, offering relief from disc pain. The nucleoplasty technique builds on earlier surgical approaches that helped validate the strategy of intranuclear tissue removal. Nucleoplasty, a new minimally invasive procedure using patented coblation technology, combines coagulation and ablation for partial removal of the nucleus pulposus to decompress the disc., Purpose: To determine if histologic changes of the intervertebral discs and surrounding tissues occur after nucleoplasty., Study Design: A light microscopic study of intervertebral disc and adjacent neural tissues after disc decompression by nucleoplasty in pig cadavers., Methods: Light microscopy was used to examine disc and neural tissues in two pig cadaveric specimens (T12 to sacrum). Nucleoplasty was performed by 1) advancing a radiofrequency wand to a predetermined depth in the disc (ablation), and 2) withdrawing the wand to the starting point (coagulation). Discs and adjacent tissues were removed from treated and nontreated segments, and examined under light microscopy., Results: Histologic examination revealed no evidence of direct mechanical or thermal damage to the surrounding tissues. There was clear evidence of coblation channels with clean coagulation borders of the nucleus pulposus. Normal histologic findings of the annulus and end plate, with normal neural elements of the spinal cord and nerve roots at the level of the procedure, were observed., Conclusions: The histologic findings of this study suggest that the nucleoplasty achieves volumetric removal of target disc tissue without overt thermal or structural damage to the adjacent tissues. Further studies in live animals will be needed to assess the effects of nucleoplasty on the annulus, end plate and neural tissues under physiologic conditions, including assessment of cell viability.

Background Context: This is a case report of a right posterolateral L5-S1 disc herniation that migrated to the left cephalad level to impinge on the left L5 nerve root as it exited the dura. The resultant free fragment migration is a rare variation of a posterolateral disc disruption., Purpose: The purpose is to report a rare variation of lumbar disc herniation not previously reported in the literature., Study Design/setting: Case report., Patient Sample: A 60-year-old white woman., Outcome Measures: Resolution of the patient's left lower extremity symptoms., Methods: Not applicable., Results: The patient experienced resolution of most of her left lower extremity symptoms after a slightly modified microscopically assisted lumbar hemilaminectomy, discectomy and nerve root decompression., Conclusions: This is a rare right to left migration of a sequestrated disc herniation, which was effectively treated with surgery.

Background Context: A relationship between degenerative changes of the intervertebral disc and biomechanical functions of the lumbar spine has been suggested. However, the exact relationship between the grade of disc degeneration and the flexibility of the motion segment is not known., Purpose: To investigate the relationship between degenerative grades of the intervertebral disc and three-dimensional (3-D) biomechanical characteristics of the motion segment under multidirectional loading conditions., Study Design/setting: A biomechanical and imaging study of human cadaveric spinal motion segments., Methods: One hundred fourteen lumbar motion segments from T12-L1 to L5-S1 taken from 47 fresh cadaver spines (average age at death, 68 years; range, 39 to 87 years) were used in this study. The severity of degeneration (grades I to V according to Thomson's system) was determined using magnetic resonance (MR) images and cryomicrotome sections. Pure unconstrained moments with dead weights were applied to the motion segments in six load steps. The directions of loading included flexion, extension, right and left axial rotation, and right and left lateral bending., Results: When the MR images were graded, 2 segments had grade I disc degeneration; 45, grade II; 20, grade III; 26, grade IV; and 21, grade V. When the cryomicrotome sections were graded, 14 segments had grade I disc degeneration; 31, grade II; 22, grade III; 26, grade IV; and 21, grade V. Segments from the upper lumbar levels (T12-L1 to L3-4) tended to have greater rotational movement in flexion, extension, and axial rotation with disc degeneration up to grade IV, whereas the motion decreased when the disc degenerated to grade V. In the lower lumbar spine at L4-5 and L5-S1, motion in axial rotation and lateral bending was increased in grade III., Conclusions: These results suggest that kinematic properties of the lumbar spine are related to disc degeneration. Greater motion generally was found with disc degeneration, particularly in grades III and IV, in which radial tears of the annulus fibrosus are found. Disc space collapse and osteophyte formation as found in grade V resulted in stabilization of the motion segments.