Relationship Between Central Sensitization-Related Symptoms and Pain-Related Disability After Cervical Spine Surgery: A Structural Equation Model.

BACKGROUND: It is unknown if central sensitization (CS)-related symptoms have an intermediate role that might explain how disability develops from pain after cervical spinal surgery. AIMS: The study aim was to investigate the role of CS-related symptoms in the relationship between pain and disability reported after cervical spinal surgery. DESIGN: Cross-sectional study. SETTINGS: Tertiary care spinal surgery center. PARTICIPANTS/SUBJECTS: The participants included individuals with a cervical degenerative condition who had undergone surgery. METHODS: The following patient-reported outcome measures were evaluated: (1) Numerical Rating Scale; (2) Neck Disability Index; and (3) Short Form of the Central Sensitization Inventory. A hypothesized model containing the CS-related symptoms and the relationships between pain and disability was constructed and tested by structural equation modeling. RESULTS: Questionnaires were mailed to 280 individuals, and responses were obtained from 145 participants. Of these respondents, 99 (68.3%) were males and 46 (31.7%) were females, with a mean age of 64.4 ± 12.3 years. The latent variable for pain, represented by the neck (coefficient: 0.856, p < .001) and upper limb pain (0.568, p < .001), influenced CS-related symptoms (coefficient: 0.504, p < .001). Pain directly affected disability (coefficient: 0.497, p < .001) and indirectly through CS-related symptoms. Bootstrap analysis confirmed this indirect effect (point estimate: 2.85, 95% confidence interval: 1.04 to 6.30, p = .04). CONCLUSIONS: The results revealed that neck and upper limb pain affected disabilities both directly and through CS-related symptoms. Future research should focus on the efficacy of biopsychosocial approaches for patients after cervical spine surgery with a high risk of disability due to CS-related symptoms.

Influence of radiological factors, psychosocial factors, and central sensitization-related symptoms on clinical symptoms in patients with lumbar spinal canal stenosis.

BACKGROUND: No study to date has concurrently evaluated the impact of radiological factors, psychosocial factors, and central sensitization (CS) related symptoms in a single lumbar spinal canal stenosis (LSS) patient cohort. OBJECTIVE: To investigate the associations between these factors and clinical symptoms in LSS patients. METHODS: We recruited 154 patients with LSS scheduled for surgery. Patient-reported outcome measures and imaging evaluation including clinical symptoms, psychosocial factors, CS-related symptoms, and radiological classifications. Spearman's rank correlation coefficient and multiple regression analyses were employed. RESULTS: Spearman's correlation revealed CS-related symptoms positively correlated with low back pain (r= 0.25, p< 0.01), leg pain (r= 0.26, p< 0.01), and disability (r= 0.32, p< 0.01). Pain catastrophizing positively correlated with leg pain (r= 0.23, p< 0.01) and disability (r= 0.36, p< 0.01). Regression analysis showed that pain catastrophizing was associated with disability (ß= 0.24, 95%CI = 0.03-0.18), and CS-related symptoms with low back pain (ß= 0.28, 95%CI = 0.01-0.09). Radiological classifications were not associated with clinical symptoms. CONCLUSION: Our findings suggest that psychosocial factors and CS-related symptoms, rather than radiological factors, seem to contribute to clinical symptoms in patients with LSS.

Association of central sensitization, visceral fat, and surgical outcomes in lumbar spinal stenosis.

BACKGROUND: Controversy remains regarding predictors of surgical outcomes for patients with lumbar spinal stenosis (LSS). Pain sensitization may be an underlying mechanism contributing to LSS surgical outcomes. Further, obesity is associated with dissatisfaction and poorer outcomes after surgery for LSS. Therefore, this study aimed to examine the relationship between central sensitization (CS), visceral fat, and surgical outcomes in LSS. METHODS: Patients with LSS were categorized based on their central sensitization inventory (CSI) scores into low- (CSI < 40) and high- (CSI ≥ 40) CSI subgroups. The participants completed clinical outcome assessments preoperatively and 12 months postoperatively. RESULTS: Overall, 60 patients were enrolled in the study (28 men, 32 women; mean age: 62.1 ± 2.8 years). The high-CSI group had significantly higher mean low back pain (LBP), leg pain, and leg numbness visual analogue scale (VAS) scores than the low-CSI group (p < 0.01). The high-CSI group had a significantly higher mean visceral fat area than the low-CSI group (p < 0.01). Postoperatively, LBP VAS score was significantly worse in the high-CSI group. Relative to preoperatively, postoperative leg pain and leg numbness improved significantly in both groups. CONCLUSIONS: We believe that neuro decompression can be effective for LSS surgical outcomes in patients with CS; nonetheless, it should be approached with caution owing to the potential for worsening LBP. Additionally, visceral fat is an important indicator suggesting the involvement of CS.

Intravoxel Incoherent Motion Factors Affecting Collapse and Nonunion of Osteoporotic Vertebral Fracture.

STUDY DESIGN: Longitudinal study. OBJECTIVES: Intravoxel incoherent motion (IVIM), a magnetic resonance imaging (MRI) scanning technique that applies diffusion-weighted imaging (DWI), is effective for the quantitative assessment of malignant tumors of the vertebral bone. We hypothesized that IVIM parameters of vertebral bodies are associated with the prognosis of osteoporotic vertebral fracture (OVF). We aimed to explore the relationships between IVIM parameters for vertebral collapse and non-union after OVF and calculate the cut-off values of these parameters for vertebral collapse and non-union. METHODS: A total of 150 patients with acute OVF (150 women; mean age: 79.1 ± 7.4 years) were included and treated conservatively with bracing. MRI was performed at the time of injury. IVIM parameters, such as apparent diffusion coefficient (ADC), molecular diffusion coefficient (D), and perfusion-related diffusion (D*) were recorded. The patients were classified into 3 groups: low-collapse (height loss of ≤50%), high-collapse (height loss of >50%), and non-union. We compared ADC, D, and D* among the low-collapse, high-collapse, and non-union groups and performed a receiver operating characteristic (ROC) curve analysis to determine the boundary values of the high-collapse and non-union groups. RESULTS: The low-collapse, high-collapse, and non-union groups had no significant differences in ADC and D. However, D* differed significantly among the 3 groups. ROC analysis revealed cut-off values of 19.0 × 10-3 mm2/s and 12.3 × 10-3 mm2/s for the high-collapse and non-union groups, respectively. CONCLUSIONS: D* is a significant prognostic indicator for high-collapse and non-union groups with OVF. This suggests that D* should be considered when assessing OVF.

Influence of Pain Self-Efficacy and Gender on Disability in Postoperative Cervical Myelopathy.

BACKGROUND: Pain self-efficacy and gender may influence disability in patients with musculoskeletal disorders. The direct and interactive influence of pain self-efficacy and gender on postoperative disability with degenerative cervical myelopathy (DCM) is unclear. AIM: This study aimed to determine the effects of age, pain, and pain self-efficacy on disability postoperatively in patients with DCM, and explore whether these effects differ by gender. METHOD: A total of 180 participants who underwent DCM surgery were consecutively recruited. The following were evaluated: (1) demographic/descriptive data (age, gender, diagnosis, surgery date, procedure); (2) numerical rating scale pain and dysesthesia intensity; (3) Neck Disability Index; and (4) Pain Self-Efficacy Questionnaire. Hierarchical multiple regression analysis and simple slope analysis determined the effect of patients' biologic and psychosocial factors, and their interaction in terms of disability. RESULTS: The responses of 82 participants were analyzed. The hierarchical multiple regression final model analysis determined 57.1% participant disability variance; gender (B = 3.388; p < .01); pain (B = 3.574; p < .01); pain self-efficacy (B = -0.229; p < .01); age and gender (B = -0.201; p < .05); pain and gender (B = -3.749; p < .01); pain self-efficacy and gender (B = -0.304; p < .01) were significantly associated with disability. Simple slope test indicated that women showed weaker pain associations and stronger age and pain self-efficacy associations with disability than men. CONCLUSIONS: Pain self-efficacy improvement should be focused on after surgery in patients with DCM, especially women.

Effect of Minimally Invasive Selective Laminectomy for Cervical Spondylotic Myelopathy on Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective analysis of prospectively collected observational data. OBJECTIVE: This study aimed to evaluate the slippage, sagittal alignment, and range of motion (ROM) after selective laminectomy (SL) in patients who had cervical spondylotic myelopathy (CSM) with degenerative spondylolisthesis (DS). SUMMARY OF BACKGROUND DATA: Clinical outcomes have been reported for both decompression and fusion surgeries for DS of the lumbar spine. However, only a few reports have examined cervical spine spondylolisthesis. MATERIALS AND METHODS: This study included 178 patients who underwent SL for CSM. Those with ossification of the posterior longitudinal ligament were excluded. Slippage >2 mm was defined as spondylolisthesis, and spondylolisthesis progression was defined as an additional displacement >2 mm on a neutral radiograph. The slippage, translational motion, C2-C7 angle, local kyphosis, and ROM were examined before and ≥2 years after surgery. Radiologic parameters were evaluated according to the slip direction and the number of laminae removed. RESULTS: DS was observed in 29 patients (16.3%); 24 patients, comprising 9 and 15 in the anterolisthesis and retrolisthesis groups, respectively, were successfully followed up for more than 2 years. Preoperative and postoperative radiologic changes in slippage, translational motion, C2-C7 angle, local kyphosis, and ROM were not remarkable in either group regardless of the number of laminae removed. Revision surgery for the progression of DS and alignment deterioration was not required in any patient of either group. CONCLUSIONS: SL does not affect DS, sagittal alignment, or ROM irrespective of the slip direction and the number of laminae removed, even after >2 years after surgery. Given the preservation of the posterior elements, SL may be an effective treatment for CSM with DS. LEVEL OF EVIDENCE: Level IV.

Effects of Central Sensitivity Syndrome and Psychological Factors on the Clinical Features of Patients with Cervical Degenerative Disease: A Cross-Sectional Study.

STUDY DESIGN: Single-center cross-sectional study. PURPOSE: The present study aimed to clarify the effects of central sensitivity syndrome (CSS) and psychological factors on the clinical features in patients with cervical degenerative disease (CDD). OVERVIEW OF LITERATURE: The presence of CSS and psychological factors can influence the clinical features of patients with musculoskeletal disorders including CDD. However, the precise effects of CSS are unclear. METHODS: Patients admitted for surgical treatment of CDD were recruited. The following patient-reported outcome measures were recorded on the day before the surgery: the Numerical Rating Scale (NRS) for neck pain intensity, Neck Disability Index (NDI), EuroQol 5-Dimensions (EQ-5D) survey, Central Sensitization Inventory (CSI), Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and the Hospital Anxiety and Depression Scale were used. We performed three multiple regression analyses to investigate the effects of CSS and psychological factors on the clinical features. RESULTS: Multiple regression analysis revealed that CSI had a significant effect on NRS (ß, 0.50; 95% confidence interval [CI], 0.29 to 0.71), NDI (ß, 0.64; 95% CI, 0.45 to 0.82), and EQ-5D (ß, -0.55; 95% CI, -0.75 to -0.35). Multiple regression analysis revealed that psychological factors did not exert a significant effect on the clinical features. CONCLUSIONS: Our results demonstrated that CSI was able to identify the clinical features in CDD patients, suggesting that CSS does affect the clinical features of such patients.

Association between Spinopelvic Alignment and Lumbar Intervertebral Disc Degeneration Quantified with Magnetic Resonance Imaging T2 Mapping in Patients with Chronic Low Back Pain.

INTRODUCTION: Although intervertebral disc degeneration (IVDD) and spinopelvic malalignment are likely key structural features of spinal degeneration and chronic low back pain (CLBP), the correlation analysis has not been fully conducted. This cross-sectional quantitative magnetic resonance imaging (MRI) T2 mapping study aimed to elucidate the association between IVDD and spinopelvic alignment in CLBP patients. METHODS: The subjects included 45 CLBP patients (19 men and 26 women; mean age, 63.8 ± 2.0 years; range, 41-79 years). The T2 values of the anterior annulus fibrosus (AF), the nucleus pulposus (NP), and the posterior AF were evaluated using MRI T2 mapping. We compared the possible correlations of spinopelvic parameters with T2 values of anterior AF, NP, and posterior AF using Pearson's correlation coefficient analysis. T2 values in these regions were classified into upper (L1-L2 and L2-L3), middle (L3-L4), and lower (L4-L5 and L5-S1) disc levels, and we analyzed the correlations with spinopelvic parameters. RESULTS: There were significant correlations of the anterior AF T2 values with lumbar lordosis (r = 0.51, p < 0.01), sacral slope (r = 0.43, p < 0.01), sagittal vertical axis (r = -0.40, p < 0.01), and pelvic tilt (r = -0.33, p < 0.01). In all lumbar levels, T2 values of anterior AF had significantly positive correlation with LL and significantly negative correlation with SVA. In lower disc level, T2 values of anterior AF had significantly positive correlation with SS and significantly negative correlation with PT. T2 values of NP and posterior AF had no significant correlations with spinopelvic parameters in all lumbar disc levels. CONCLUSIONS: In summary, this study indicated that the anterior AF degeneration is associated with hypolordosis of the lumbar spine, anterior translation of the body trunk, and posterior inclination of the pelvis in CLBP. Anterior AF degeneration in all lumbar disc levels was associated with hypolordosis of the lumbar spine and anterior translation of the body trunk. Anterior AF degeneration in lower disc level was associated with posterior inclination of the pelvis.

Quantitative Analysis Concerning Atrophy and Fat Infiltration of the Multifidus Muscle with Magnetic Resonance Spectroscopy in Chronic Low Back Pain.

INTRODUCTION: Magnetic resonance spectroscopy (MRS) enables detailed analysis of the composition of muscular fat tissues such as intramyocellular lipids (IMCLs) and extramyocellular lipids (EMCLs). The aim of this study was to analyze the EMCL and IMCL of the multifidus muscle (Mm) using MRS in chronic low-back pain (CLBP) patients and identify their possible correlations with age, body mass index (BMI), low-back pain (LBP) visual analog scale (VAS) score, cross-sectional area (CSA), and fat infiltration of the Mm. METHODS: Eighty patients (32 men and 48 women; mean age, 64.7 ± 1.3 years; range, 22-83 years) with VAS scores >30 mm for CLBP were included. We analyzed the gender difference and the possible correlations of age, BMI, LBP VAS, CSA, and fat infiltration of the Mm with the IMCL and EMCL of the Mm. The subjects were divided into five groups as per their age range: < 40s, 50s, 60s, 70s, and 80s. We also analyzed the EMCL and IMCL of the Mm as per the fat infiltration classification. RESULTS: CSA was larger in the male group, EMCL was higher in the female group, and there was no significant difference in IMCL between the female and male groups. There was a significant positive correlation of EMCL with age (r = 0.33, p < 0.01) and BMI (r = 0.42, p < 0.01) and a significant negative correlation of EMCL with CSA (r = -0.61, p < 0.01). There was a significant positive correlation between IMCL and VAS (r = 0.43, p < 0.01). The EMCL and CSA of the Mm decreased with age, whereas fat infiltration increased with age. CONCLUSIONS: These results suggest that EMCL could indicate Mm degeneration associated with aging, and IMCL could be an effective objective indicator of CLBP. The EMCL and IMCL of the Mm may be useful prognostic markers in rehabilitation strategies.

Differentiating spinal intradural-extramedullary schwannoma from meningioma using MRI T2 weighted images.

OBJECTIVE:: Prior studies advocate the subjective visual differences between meningioma and schwannoma on T2 weighted images, however objective measurement of signal intensity differences may be useful in certain cases. The aim of this study was to investigate whether an objective evaluation of SIs on T2 weighted images would be useful to differentiate spinal schwannomas from meningiomas. METHODS:: The patients with spinal MRIs demonstrating path proven and subsequently treated intradural extramedullary spinal tumors were selected between April 2008 and May 2017. Regions of interest (ROIs) were measured in the tumor and subcutaneous fat on the same image, and we calculated the SI ratio between tumor and fat ROIs. RESULTS:: Twenty patients each with meningioma and schwannoma were enrolled. The SI ratios of schwannomas were significantly higher than those of meningiomas (both researcher 1 and 2: p = 0.002). The areas under the curve by researchers 1 and 2 were 0.780. The cutoff value of SI ratio by both of researchers 1 and 2 to differentiate between schwannomas from meningiomas was 0.420 (sensitivity: 80.0%, specificity: 70.0-75.0%). CONCLUSION:: The SI ratio, calculated from the SIs of the tumor and fat on T2 weighted images, is useful for differentiating spinal schwannomas from meningiomas to obtain an accurate diagnosis. ADVANCES IN KNOWLEDGE:: Signal intensity ratio of the spinal tumor and fat on T2 weighted images is useful for differentiating schwannomas from meningiomas to obtain an accurate diagnosis.

Short-term Results of Microendoscopic Muscle-preserving Interlaminar Decompression versus Spinal Process Splitting Laminectomy.

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: To compare retrospectively the clinical results and surgical invasiveness of two different types of minimally invasive surgery for lumbar spinal canal stenosis: microendoscopic muscle-preserving interlaminar decompression (ME-MILD) and spinal process splitting laminectomy (SPSL). SUMMARY OF BACKGROUND DATA: ME-MILD and SPSL are minimally invasive procedures. However, the two procedures have not been compared in the literature. MATERIALS AND METHODS: We retrospectively enrolled patients who underwent ME-MILD or SPSL from 2011 to 2015. The surgical invasiveness of each technique was determined by evaluating the time required for the surgical procedure, amount of blood loss, serum creatine kinase (CK) levels on postoperative day (POD) 1, C-reactive protein (CRP) levels on POD 3 and 7, and the hospitalization. The clinical results were evaluated using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire score, the Short Form (36) Health Survey patient-reported outcome score, the visual analog scale for pain, a patient satisfaction score, and the incidence of surgical complications. RESULTS: A total of 97 patients were evaluated: 58 patients underwent ME-MILD, and 39 patients underwent SPSL. No significant differences were observed in the clinical results between the two groups. Regarding surgical invasiveness, no significant difference was found in the amount of blood loss, levels of CK, hospitalization, or time required for the procedure. However, CRP levels were significantly lower in the ME-MILD group. CONCLUSIONS: ME-MILD and SPSL are both minimally invasive procedures. In a comparison of these two procedures, CRP was significantly lower in the ME-MILD group.

The Difference in Gender Affects the Pathogenesis of Ligamentum Flavum Hypertrophy.

INTRODUCTION: Gender differences may play a role in the pathogenesis of lumbar spinal stenosis. However, few reports that discuss the effects of gender differences in ligamentum flavum (LF) hypertrophy have been published, and no study has investigated the relationship between LF thickness and the quantitative value of intervertebral disc (IVD) degeneration. This study aimed to investigate the impact of gender on the pathomechanisms underlying LF hypertrophy, focusing on the relationship among LF thickness, IVD degeneration, and age. METHODS: The subjects include 100 patients with low back pain and leg numbness, tingling, or pain. We measured LF thickness and the T2 values of IVDs using MR imaging and analyzed the relationship among LF thickness, T2 values of IVDs, and age. The interclass correlation coefficient (ICC) was calculated as the inter-rater reliability between the LF thickness values measured by two investigators. RESULTS: ICC was calculated for the two measurements of LF thickness (r = 0.923, 95% CI: 0.907-0.936). No statistically significant difference in the T2 values of IVDs was observed between females and males from L2/3 to L5/S. There were significantly negative linear correlations between LF thickness and the T2 values of IVDs at all levels, but this correlation was not observed in females at L4/5. There were significantly negative linear correlations between age and the T2 values of IVDs from L2/3 to L5/S for all patients, females, and males (r = 0.422-0.756). In addition, there were significantly positive linear correlations between age and LF thickness from L2/3 to L4/5 for all patients (r = 0.329-0.361) and females (r = 0.411-0.481). Correlations were not observed for males at all levels or for all patients at L5/S. CONCLUSIONS: The relationships identified among LF thickness, age, and IVD degeneration suggest that gender differences play a role in the pathogenesis of LF hypertrophy.

Suppression of Sympathetic Nerve Sprouting by Local Administration of an α-antagonist Around the Dorsal Root Ganglion in a Lumbar Radiculopathy Model.

STUDY DESIGN: Animal experimental study with intervention. OBJECTIVE: The purpose of this study was to elucidate whether local administration of an α-antagonist around the dorsal root ganglion (DRG) suppressed sympathetic nerve sprouting, from the acute to the chronic pain development phase, in a lumbar radiculopathy model using immunohistochemical methods. SUMMARY OF BACKGROUND DATA: The abnormal sympathetic-somatosensory interaction may underlie some forms of neuropathic pain. There were several reports suggesting α-antagonists are effective to treat neuropathic pain. However, its pathophysiological mechanisms remain obscure. METHODS: We used 70 male Sprague-Dawley rats. After root constriction (RC), rats received a series of three local injections of the nonselective α-antagonist phentolamine around the DRG for 3 days. There were three groups of rats: those that were injected from the day of surgery and those injected from day 4 and third group injected from day 11. The control rats were subjected to RC but equal-volume normal saline injections, and the naïve rats were not subjected to any surgical procedures. At the 14th postoperative day, the left L5 DRG was removed, embedded in paraffin, and sectioned. Sections were then immunostained with antibodies to tyrosine hydroxylase (TH). To quantify the extent of the presence of sympathetic nerve fibers, we counted TH-immunoreactive fibers in the DRG using a light microscope equipped with a micrometer graticule. We counted the squares of the graticule, which contained TH-immunoreactive fibers for each of five randomly selected sections of the DRG. RESULTS: In the naïve group, TH-immunoreactive fibers were scarce in the DRG. α-antagonist injections from postoperative day 0 and 4 suppressed sympathetic nerve sprouting compared with the control group. α-antagonist injections from postoperative day 11 had no suppressant effect compared with the control group. CONCLUSION: The α-antagonist administered around the DRG could suppress neural plastic changes in the early phase after nerve injury. LEVEL OF EVIDENCE: N/A.

Long-Term Outcome of Microendoscopic Diskectomy for Lumbar Disk Herniation. A Clinical Study of Consecutive 112 Cases with More than 5-Year Follow-Up.

Background Clinical results and recurrence rate after microendoscopic diskectomy (MED) with long-term follow-up is still unclear, in spite of its relatively long history. Materials and Methods A total of 112 who underwent MED participated in this study. Operative time, blood loss, serum C-reactive protein (CRP), creatine kinase (CK), and visual analog scale (VAS) were evaluated as indexes of surgical invasiveness. The 36-Item Short Form Survey Instrument (SF-36), Japanese Orthopaedic Association (JOA) score, patient satisfaction, and recurrence were also evaluated with a follow-up of at least 5 years. Results The mean operative time was 86.7 minutes, and the mean blood loss was 35.7 mL. The mean CRP on postoperative day 3 and CK on the first postoperative day was 0.72 mg/dL and 224.6 IU/L, respectively, and VAS to assess surgical site pain on the first postoperative day was 24.9 mm on average. The improvement rate in the JOA score was 68.7%. The physical component summary of SF-36 in norm-based scoring was improved from 23.4 to 48.6. Overall, 90.8% of patients evaluated their response to the surgery as extremely satisfied or satisfied. The recurrence rate was 10.5%, and reoperation was performed in 7.9% of patients. Conclusions MED is a technique that offers both reduced invasiveness and good long-term clinical results.

Factors affecting survival of patients in the acute phase of upper cervical spine injuries.

INTRODUCTION: In recent years, on the one hand, the mortality rates of upper cervical spine injuries, such as odontoid fractures, were suggested to be not so high, but on the other hand reported to be significantly high. Furthermore, it has not been well documented the relationship between survival rates and various clinical features in those patients during the acute phase of injury because of few reports. This study aimed to evaluate survival rates and acute-phase clinical features of upper cervical spine injuries. METHODS: We conducted a retrospective review of all patients who were transported to the advanced emergency medical center and underwent computed tomography of the cervical spine at our hospital between January 2006 and December 2015. We excluded the patients who were discovered in a state of cardiopulmonary arrest (CPA) and could not be resuscitated after transportation. Of the 215 consecutive patients with cervical spine injuries, we examined 40 patients (18.6%) diagnosed with upper cervical spine injury (males, 28; females, 12; median age, 58.5 years). Age, sex, mechanism of injury, degree of paralysis, the level of cervical injury, injury severity score (ISS), and incidence of CPA at discovery were evaluated and compared among patients classified into the survival and mortality groups. RESULTS: The survival rate was 77.5% (31/40 patients). In addition, complete paralysis was observed in 32.5% of patients. The median of ISS was 34.0 points, and 14 patients (35.0%) presented with CPA at discovery. Age, the proportion of patients with complete paralysis, a high ISS, and incidence of CPA at discovery were significantly higher in the mortality group (p = 0.038, p = 0.038, p < 0.001, and p < 0.001, respectively). CONCLUSIONS: Elderly people were more likely to experience upper cervical spine injuries, and their mortality rate was significantly higher than that in injured younger people. In addition, complete paralysis, high ISS, a state of CPA at discovery, was significantly higher in the mortality group.

Intravenous infusion of mesenchymal stem cells promotes functional recovery in a model of chronic spinal cord injury.

Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow improves behavioral function in rat models of spinal cord injury (SCI). However, most studies have focused on the acute or subacute phase of SCI. In the present study, MSCs derived from bone marrow of rats were intravenously infused 10weeks after the induction of a severe contusive SCI. Open field locomotor function was assessed weekly until 20weeks post-SCI. Motor recovery was greater in the MSC-treated group with rapid improvement beginning in earlier post-infusion times than in the vehicle-treated group. Blood spinal cord barrier (BSCB) integrity was assessed by the intravenous infusion of Evans Blue (EvB) with spectrophotometric quantitation of its leakage into the parenchyma. In MSC-treated rats, BSCB leakage was reduced. Immunohistochemical staining for RECA-1 and PDGFR-ß showed increased microvasculature/repair-neovascularization in MSC-treated rats. There was extensive remyelination around the lesion center and increased sprouting of the corticospinal tract and serotonergic fibers after MSC infusion. These results indicate that the systemic infusion of MSCs results in functional improvement that is associated with structural changes in the chronically injured spinal cord including stabilization of the BSCB, axonal sprouting/regeneration and remyelination.

Microendoscopic discectomy for far lateral lumbar disk herniation: less surgical invasiveness and minimum 2-year follow-up results.

STUDY DESIGN: A retrospective review of data collected prospectively on 24 consecutive patients who underwent microendoscopic discectomy (MED) for far lateral lumbar disk herniation. OBJECTIVE: To evaluate the level of surgical invasiveness of the procedure and clinical results with a follow-up of at least 2 years. SUMMARY OF BACKGROUND DATA: To the best of our knowledge, there have only been 2 small-size and short-term clinical studies reporting the feasibility of MED for far lateral lumbar disk herniation, despite its relatively long history. Moreover, these 2 articles did not include detailed evaluations of surgical invasiveness and did not comprise any cases with disk herniation at L5-S1, which should account for a considerable proportion of cases. METHODS: Twenty-four consecutive patients, including L5-S1 patients, who underwent MED for far lateral lumbar disk herniation participated in this study. Ninety-three consecutive patients with intracanalicular disk herniation, who underwent MED also participated as control subjects. Operative time, intraoperative blood loss, serum C-reactive protein and creatine kinase, visual analog scale, and Japanese Orthopaedic Association score were evaluated. RESULTS: The procedure was successfully performed in all cases. The operative time in patients with far lateral disk herniation (143.9 min) was significantly longer than in patients with intracanalicular disk herniation (90.2 min) (P<0.01). There were no differences between the groups in terms of intraoperative blood loss (39.6 and 40.4 mL, respectively), serum C-reactive protein level on postoperative day 3 (0.71 and 0.73 mg/dL), serum creatine kinase level on postoperative day 1 (161.8 and 225.7 IU/L), visual analog scale scores to assess surgical site pain on the first postoperative day (19.4 and 24.0 mm), or improvement rate in Japanese Orthopaedic Association score at final follow-up (76.0% and 77.0%). CONCLUSIONS: MED is a well-balanced technique which offers both reduced invasiveness and good clinical results without sacrificing reliability.

Effect of cryotherapy after spine surgery.

STUDY DESIGN: Historical controlled trial. PURPOSE: To clarify the usefulness of cryotherapy after spine surgery. OVERVIEW OF LITERATURE: Cryotherapy has generally been performed subsequent to surgery on joints and in this application its clinical effects are well understood. However, cryotherapy has yet to be used following spine surgery. Its clinical efficacy in this context is unknown. METHODS: Thirty six patients had undergone one level microendoscopic surgery. Sixteen were enrolled into the cooling group, with the remaining 20 making up the no postoperative cryotherapy control group. Cryotherapy was performed at 5℃ using an icing system. A silicone balloon catheter with a thermo sensor on the tip was placed in the surgical wound. The temperature in the wound was recorded every 30 minutes until the next morning. The relationship between the depth of the sensor and the temperature in the wound were investigated using simple linear regression analysis. Laboratory data, visual analogue scale (VAS) for wound pain and postoperative bleeding were investigated. RESULTS: The mean temperature in the surgical wound was 37.0 in the control group and 35.0℃ in the cooling group (p<0.001). There was a positive correlation between the depth of the thermo sensor and the temperature in the wound in the cooling group (y=0.91x+30.2, r=0.67, p=0.004). There were no significant differences between the groups in terms of laboratory data, VAS or postoperative bleeding. CONCLUSIONS: The temperature in the wound was decreased significantly by spinal surgery cryotherapy.

Microendoscopy-assisted muscle-preserving interlaminar decompression for lumbar spinal stenosis: clinical results of consecutive 105 cases with more than 3-year follow-up.

STUDY DESIGN: A retrospective review of data collected prospectively on patients who underwent microendoscopy-assisted muscle-preserving interlaminar decompression (MILD) for lumbar spinal stenosis. OBJECTIVE: To evaluate the clinical results including surgical invasiveness and reduction rate of facet joint with a follow-up of more than 3 years. SUMMARY OF BACKGROUND DATA: Hatta et al reported microscopic posterior decompression procedure, MILD for lumbar spinal stenosis with reference to the cervical central approach put forth by Shiraishi. Mikami et al applied spinal microendoscopy to MILD procedure (microendoscopy-assisted MILD). METHODS: One hundred five consecutive patients, who underwent microendoscopy-assisted MILD, participated in this study. Operative time, blood loss, visual analogue scale (VAS), serum creatine kinase and C-reactive protein, surgical complications, reduction rate of the facet joint, Japanese Orthopaedic Association score, and Short-Form 36 were evaluated. RESULTS: The operative time was 99.3 minutes and the intraoperative bleeding was 15.7 mL on average. The mean VAS score to assess surgical site pain was 20.6 mm on postoperative day 1. The mean serum creatine kinase on postoperative day 1 and C-reactive protein on postoperative day 3 were 145.4 IU/L and 2.7 mg/dL, respectively. Surgical complications were identified in 2 cases, cauda equina injury and dural tear. The mean reduction rate of the facet joint was 3%. The follow-up rate was 83.3% and the mean follow-up period was 52.7 months. The Japanese Orthopaedic Association score improved significantly from 14.8 to 23.7 points on average. Significant improvements in Short-Form 36 were observed in all subscales except in General Health. Revision surgical procedures were performed in 8 cases at the operated level including 4 of juxtafacet cyst, 3 of disc herniation, and 1 of insufficient decompression. CONCLUSION: Microendoscopy-assisted MILD is a minimally invasive procedure and favorable clinical results can be expected for lumbar spinal stenosis. LEVEL OF EVIDENCE: 4.

Spinal surgery in a patient with essential thrombocythemia resulting in leg paraplegia: a case report.

BACKGROUND CONTEXT: Essential thrombocythemia (ET) is a chronic myeloproliferative disorder characterized by a relatively benign clinical course that may be complicated by conflicting thrombosis and bleeding. Postoperative spinal epidural hematoma is an uncommon, but well-known, complication after spinal surgery. PURPOSE: To describe a patient with ET who underwent surgery for lumbar spinal canal stenosis resulting in leg paraplegia and discuss the perioperative management for ET. STUDY DESIGN: Case report. RESULTS: The patient with ET underwent laminoplasty and posterolateral fusion for degenerative spondylolisthesis and spinal stenosis at L4-L5. A hematoma was observed in the epidural cavity after surgery, and emergency surgical evacuation was performed. After revision surgery, bleeding from the wound continued for 2 months, despite transfusions of platelets and coagulation factors, and right unilateral leg paralysis developed. CONCLUSIONS: This case presentation increases the awareness of this disorder to the spinal community and the need to establish guidelines for the perioperative management of patients who require surgery in similar settings.