T1rho, T2, and T2* relaxation time based on grading of intervertebral disc degeneration.

BACKGROUND: Previous studies have explored the biochemical changes of disc degeneration and its relevance in low back pain using various quantitative magnetic resonance imaging (MRI) techniques. However, quantitative evaluation of intervertebral disc (IVD) with MRI such as T1rho, T2, and T2* have not been previously analyzed and compared directly in the same patients. PURPOSE: To investigate T1rho, T2, and T2* of IVD degeneration in the same patients, reveal the correlation coefficients of these values, and evaluate which values are more sensitive to detect the degree of IVD degeneration. MATERIAL AND METHODS: The participants were 55 patients who underwent MRI examinations which the investigator classified the degree of IVD degeneration according to the Pfirrmann classification. The T1rho, T2, and T2* values of IVD were analyzed for their classification and were compared. RESULTS: T1rho, T2, and T2* values were 74.3 ± 7.1, 61.2 ± 6.7, and 46.5 ± 16.3 ms (grade II); 61.6 ± 11.8, 48.9 ± 8.2, and 34.1 ± 11.8 ms (grade III); 50.8 ± 10.8, 38.9 ± 9.8, and 25.4 ± 8.1 ms, (grade IV); 44.5 ± 13.3, 34.8 ± 9.5, and 11.2 ± 6.6 ms (grade V), respectively. Those values significantly decreased with increasing grades, but T1rho and T2 values for grades IV and V were not different. CONCLUSION: The T1rho and T2 values were excellent for the evaluation of initial to moderate IVD degeneration with water and proteoglycan content. In contrast, the T2* value was suitable for detailed evaluation of progressive IVD, even with poor water content.

Factors associated with low back pain in patients with lumbar spinal stenosis: a cross-sectional study.

BACKGROUND: Low back pain (LBP) is a major symptom of symptomatic lumbar spinal stenosis (SLSS). It is important to assess LBP in patients with SLSS to develop better treatment. This study aimed to analyse the factors associated with LBP in patients with SLSS. METHODS: This cross-sectional study included consecutive patients with SLSS aged between 51 and 79 years who had symptoms in one or both the legs, with and without LBP. The participants were classified into two groups: the high group (LBP visual analogue scale [VAS] score ≥ 30 mm) and the low group (LBP VAS score < 30 mm). We performed multiple logistic regression analysis with the high and low groups as dependent variables, and a receiver operating characteristic (ROC) analysis. RESULTS: A total of 80 patients with LSS were included (35 men and 45 women; mean age 64.5 years), with 47 and 30 patients in the high and low groups, respectively. Multivariate logistic regression analysis revealed that the sagittal vertical axis (SVA; + 10 mm; odds ratio, 1.331; 95% confidence interval, 1.051 - 1.660) and pelvic incidence-lumbar lordosis (PI-LL; + 1°; odds ratio, 1.065; 95% confidence interval, 1.019-1.168) were significantly associated with LBP. A receiver operating characteristic analysis revealed cut-off values of 47.0 mm of SVA and 30.5° of PI-LL, respectively. CONCLUSION: Our results indicated that SVA and PI-LL were significant predictors for LBP in SLSS. It is suggested that these parameters should be taken into consideration when assessing LBP in patients with SLSS.

Risk Factors for Postoperative Loss of Correction in Thoracolumbar Injuries Caused by High-Energy Trauma Treated via Percutaneous Posterior Stabilization without Bone Fusion.

Background and Objectives: Percutaneous pedicle screws were first introduced in 2001, soon becoming the cornerstone of minimally invasive spinal stabilization. Use of the procedure allowed adequate reduction and stabilization of spinal injuries, even in severely injured patients. This decreased bleeding and shortened surgical time, thereby optimizing outcomes; however, postoperative correction loss and kyphosis still occurred in some cases. Thus, we investigated cases of percutaneous posterior fixation for thoracolumbar injury and examined the factors affecting the loss of correction. Materials and Methods: Sixty-seven patients who had undergone percutaneous posterior fixation for thoracolumbar injury (AO classifications A3, A4, B, and C) between 2009 and 2016 were included. Patients with a local kyphosis angle difference ≥10° on computed tomography at the postoperative follow-up (over 12 months after surgery) or those requiring additional surgery for interbody fusion were included in the correction loss group (n = 23); the no-loss group (n = 44) served as the control. The degree of injury (injury level, AO classification, load-sharing score, local kyphosis angle, cuneiform deformity angle, and cranial and caudal disc injury) and surgical content (number of fixed intervertebral vertebrae, type of screw used, presence/absence of screw insertion into the injured vertebrae, and presence/absence of vertebral formation) were evaluated as factors of correctional loss and compared between the two groups. Results: Comparison between each group revealed that differences in the wedge-shaped deformation angle, load-sharing score, degree of cranial disc damage, AO classification at the time of injury, and use of polyaxial screws were statistically significant. Logistic regression analysis showed that the differences in wedge-shaped deformation angle, AO classification, and cranial disc injury were statistically significant; no other factors with statistically significant differences were found. Conclusion: Correction loss was seen in cases with damage to the cranial intervertebral disc as well as the vertebral body.

Efficacy of intraoperative direct electrical stimulation of the spinal root and measurement of distal motor latency in lumbar spinal stenosis.

PURPOSE: The measurement of distal motor latency (DML) is an established method for diagnosing entrapment peripheral neuropathy. DML can also serve as an index for disease severity and prognosis. We considered that measuring DML could be useful in estimating the severity of spinal root impairment and predicting prognosis in patients with lumbar spinal stenosis (LSS). The purpose of this study was to investigate the efficacy of intraoperative direct electrical stimulation of the spinal root and the measurement of DML in LSS. METHODS: In 39 patients with LSS, a total of 93 spinal roots were stimulated, and evoked electromyography was recorded at the leg muscles after decompression. DML was measured and its correlation with clinical severity, as evaluated by Zurich claudication questionnaire (ZCQ) and Short Form 36 (SF-36), was investigated. RESULTS: For the stimulation of the L3, L4, and L5 spinal root, the mean DML (ms) were 6.8 (±1.4), 7.4 (±1.3), and 6.0 (±1.3) in gluteus medius, 9.3 (±1.5), 9.2 (±1.5), and 9.0 (±1.6) in biceps femoris, 9.7 (±1.0), 9.8 (±1.8), and 9.4 (±1.2) in vastus medialis, 16.1 (±1.0), 14.7 (±1.3), and 14.1 (±1.5) in tibialis anterior, and 16.4 (±1.4), 14.3 (±1.8), and 13.9 (±1.9) in gastrocnemius muscles. Statistically significant positive correlations were observed between DML and height. Preoperative symptom and function scores of ZCQ and postoperative bodily pain scores of SF-36 were significantly worse in the patients with prolonged DML. CONCLUSIONS: DML is thought to be useful for estimating the severity of spinal root impairment and for predicting the prognosis.

Analysis of chronic low back pain with magnetic resonance imaging T2 mapping of lumbar intervertebral disc.

BACKGROUND: Magnetic resonance imaging (MRI) T2 mapping utilizes the T2 values for quantification of moisture content and collagen sequence breakdown. Recently, attempts at quantification of lumbar disc degeneration through MRI T2 mapping have been reported. We conducted an analysis of the relationship between T2 values of degenerated intervertebral discs (IVD) and chronic low back pain (CLBP). METHODS: The subjects who had CLBP comprised 28 patients (15 male, 13 female; mean age 48.9 ± 9.6 years; range 22-60 years). All subjects underwent MRI and filled out the low back pain visual analog scale (VAS) and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The disc was divided into the anterior annulus fibrosus (AF), the nucleus pulposus (NP), and the posterior AF, and each T2 value was measured. This study involved 25 asymptomatic control participants matched with the CLBP group subjects for gender and age (13 male, 12 female; mean age 43.8 ± 14.5 years; range 23-60 years). These subjects had no low back pain, and constituted the control group. RESULTS: T2 values for IVD tended to be lower in the CLBP group than in the control group, and these values were significantly different within the posterior AF. The correlation coefficients between the VAS scores and T2 values of anterior AF, NP and posterior AF were r = 0.30, -0.15 and -0.50. The correlation coefficient between the JOABPEQ scores (low back pain) and T2 values of anterior AF, NP and posterior AF were r = -0.0041, 0.11 and 0.42. Similarly, the JOABPEQ scores (lumbar function) were r = -0.22, -0.12 and 0.57. CONCLUSIONS: The results indicated a correlation between posterior AF degeneration and CLBP. This study suggests that MRI T2 mapping could be used as a quantitative method for diagnosing discogenic pain.

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.

Microendoscopic discectomy in athletes.

BACKGROUND: Management of lumbar disc herniation in athletes is challenging because a prolonged period of postoperative rehabilitation prevents the athlete from participating in sporting activity, resulting in loss of competitive form. No study reporting the clinical results of microendoscopic discectomy (MED) in athletes was identified in a literature search through PubMed, in spite of the relatively long history of this treatment. The objective of this study was to evaluate the efficacy of MED for athletes, focusing on their ability to quickly resume their sports activity. METHODS: Twenty-five competitive athletes, who underwent MED participated in this study. The level of sporting activity patients were capable of achieving, and the time until complete return to competitive level were assessed. The Japanese Orthopaedic Association (JOA) score and short form 36 (SF-36) were also evaluated. RESULTS: Two patients did not return to sporting activity for reasons unrelated to the lumbar diseases. Among the remaining 23 cases, 19 (82.6 %) successfully returned to their original levels of sporting activity. One patient (4.4 %) could not return to his pre-injury level of sporting activity because of residual pain. He changed his field from a high school sports team to a low-level sports society. The mean period until complete return to competition was 10.8 weeks (range 5-16 weeks). Three patients (13.0 %) could not resume sporting activity because of residual pain. The mean improvement rate of JOA score at final follow-up was 80.4 %. Significant improvements in SF-36 were observed in all subscales except in general health perceptions. CONCLUSIONS: MED is a well-balanced technique which offers a high probability of return and an early return to the same level of sporting activity, both of which are optimal aims in treatment of athletes with lumbar disc herniation.

Minimum invasive posterior decompression for cervical spondylotic amyotrophy.

BACKGROUND: Cervical spondylotic amyotrophy (CSA), characterized by amyotrophy and muscular weakness of the upper limbs, is caused by damage to anterior spinal root or anterior horn of the spinal cord. Formerly, anterior decompression and fusion were performed for treatment of CSA, but it has recently been reported that posterior decompression is also effective. However, a consensus on the choice of procedure has not yet been reached. Selective laminoplasty as minimally invasive surgery is a posterior decompression procedure that alleviates axial neck pain. Because, for CSA patients, the responsible lesion level is localized, this procedure combined with foraminotomy enables simultaneous spinal cord and root decompression. Therefore, we report the results of this treatment for CSA. METHODS: Subjects were 28 patients (25 males, 3 females), average age 50.6 years and average follow-up 43.5 months. The muscles involved were deltoid for 14 patients, biceps for 11, and extensor digitorum communis and/or intrinsic muscles of the hand for 9. MMT scores were grade 2 for 23 cases and grade 3 for 5 cases. To evaluate the results of minimally invasive surgery, cervical ROM (C2-7) and postoperative neck pain (VAS) on the first postoperative day and 1 week after surgery were evaluated. RESULTS: Muscle strength improvement was rated as "excellent" for 18 patients, "good" for 9, and "fair" for 1, with none rated "poor". Four of 10 patients whose muscle strength did not fully improve had distal type CSA and/or had preoperative MMT scores of 2. Average %ROM was 91.2 % and almost complete cervical ROM was maintained. The average postoperative VAS score was 2.6 on the first postoperative day and 1.2 1 week after surgery. CONCLUSIONS: Selective laminoplasty with segmental decompression is advantageous for minimizing postoperative neck pain and for simultaneous decompression of the affected spinal cord segment and nerve root.

Effects and limitations of home-based motor-control exercise for chronic low back pain: A single center prospective study.

STUDY DESIGN: Prospective single-center observational study. OBJECTIVE: To investigate the effects and limitations of self-motor-control exercise in patients with chronic low back pain. SUMMARY OF BACKGROUND DATA: Although exercise therapy and physical therapy have been shown to be effective in treating chronic low back pain, these therapies are often discontinued due to patients' non-compliance, and their effectiveness cannot be fully demonstrated. METHODS: Fifteen patients with low back pain, no apparent organic disease, who had been symptomatic for at least three months, and could continue motor-control exercise at home for at least six months were included in the study. Low back pain (visual analog scale [VAS]), locomotor 25, stand-up test, two-step test, trunk and total body muscle mass by the impedance method, and spinal sagittal alignment were examined before the intervention to establish a baseline, and at two and six months after the intervention. RESULT: Significant improvement was observed in the back pain VAS (p<0.01), stand-up test (p = 0.03), two-step test (p = 0.01), and locomotor 25 (p = 0.04) before and after the intervention. In contrast, there were no significant changes in muscle mass and sagittal alignment. The effect of long-term exercise was more pronounced in patients without spinal deformity. CONCLUSIONS: Self-exercise for patients with chronic low back pain was effective in improving pain and function, although it did not directly affect muscle mass or alignment. Moreover, strength training of the lumbar back muscles alone was not found to be effective in patients with spinal deformities.

How Much Experience is Required to Acquire the Skills to Independently Perform Spine Surgery? What Milestones are Needed for Successful Surgery?

Purpose: To assess the number of surgeries needed to acquire the necessary skills to perform spine surgery independently. Patients and Methods: A questionnaire on 12 different spinal procedures was sent to orthopedic surgeons affiliated with the spine teams of orthopedic departments at either the Akita University or Sapporo Medical University. Participants were asked to identify whether they (A) could independently perform each procedure, (B) could perform each procedure with the assistance of a senior doctor, or (C) were unable to perform each procedure. Those whose response was (A) were asked how many surgeries were required to acquire the necessary skills. Those who responded to (B) or (C) were asked how many surgeries they believed were required to acquire the skills necessary to operate independently. Participants also responded to 10 questions on surgical training techniques and rated the usefulness of each method. Results: A total of 55 spine surgeons responded to the questionnaire. Group A required significantly fewer surgeries in the following categories to become independent than required Group C: upper cervical spine surgery (7.3/19.3), anterior cervical decompression/fusion (6.7/28.8), posterior cervical decompression/fusion (9.5/27.3), lumbar discectomy (12.6/26.7), endoscopic lumbar discectomy (10.2/24.2), spinal tumor resection (6.5/37.2), and spinal kyphosis surgery (10.3/32.3). Over 80% of participants responded that the following were effective methods: "surgeries where a senior doctor is the main surgeon, and the respondent is the assistant and observer"; "surgeries where the respondent is the main surgeon, and a senior doctor is an assistant"; "self-study using surgery manuals, articles, and textbooks"; and "training through video surgery sessions". Conclusion: Surgeons who do not perform specific procedures independently require more surgical experience than those who operate independently. Our results may help develop more efficient training methods for spine surgeons.

Osteophyte Bridge Formation Correlates with Vascular Calcification and Cardiovascular Disease in Diffuse Idiopathic Skeletal Hyperostosis.

Diffuse idiopathic skeletal hyperostosis (DISH) is a noninflammatory spondyloarthropathy characterized by ectopic calcification of spinal cord tissue. Its etiology is possibly polygenic. However, its pathogenesis and systemic effects remain unclear. Recent studies have reported a high prevalence of DISH in heart failure patients. The authors investigated how the incidence and severity of DISH are associated with vascular calcification and the occurrence of cardiovascular events. In this retrospective chart review study, 500 patients with cardiovascular disease who underwent surgery (cardiovascular events group) and 500 patients with non-cardiovascular disease who underwent computed tomography scans (non-cardiovascular events group) were randomly selected to investigate the degree of ossification of the anterior longitudinal ligament and the incidence of DISH. We found that the incidence of DISH was higher in patients with cardiovascular events and that patients with DISH had more calcification of the coronary arteries and aorta. Next, we examined the relationship between the degree of coronary and aortic calcification, the incidence of DISH, and the degree of ossification of the anterior longitudinal ligament in the non-cardiovascular event group. The prevalence of DISH in the cardiovascular and non-cardiovascular groups was 31.4% and 16.5%, respectively (p = 0.007). Aortic calcification and a predominant degree of vascular calcification with a certain level of ossification of the anterior longitudinal ligament suggest some correlation between DISH and cardiovascular events. This study is important in understanding the pathophysiology and pathogenesis of DISH.

Repeated intravenous infusion of mesenchymal stem cells enhances recovery of motor function in a rat model with chronic spinal cord injury.

Spinal cord injury (SCI) can cause paralysis with a high disease burden with limited treatment options. A single intravenous infusion of mesenchymal stem cells (MSCs) improves motor function in rat SCI models, possibly through the induction of axonal sprouting and remyelination. Repeated infusions (thrice at weekly intervals) of MSCs were administered to rats with chronic SCI to determine if multiple-dosing regimens enhance motor improvement. Chronic SCI rats were randomized and infused with vehicle (vehicle), single MSC injection at week 6 (MSC-1) or repeatedly injections of MSCs at 6, 7, and 8 weeks (MSC-3) after SCI induction. In addition, a single high dose of MSCs (HD-MSC) equivalent to thrice the single dose was infused at week 6. Locomotor function, light and electron microscopy, immunohistochemistry and ex vivo diffusion tensor imaging were performed. Repeated infusion of MSCs (MSC-3) provided the greatest functional recovery compared to single and single high-dose infusions. The density of remyelinated axons in the injured spinal cord was the greatest in the MSC-3 group, followed by the MSC-1, HD-MSC and vehicle groups. Increased sprouting of the corticospinal tract and serotonergic axon density was the greatest in the MSC-3 group, followed by MSC-1, HD-MSC, and vehicle groups. Repeated infusion of MSCs over three weeks resulted in greater functional improvement than single administration of MSCs, even when the number of infused cells was tripled. MSC-treated rats showed axonal sprouting and remyelination in the chronic phase of SCI.

Broad and Asymmetric Lower Extremity Myotomes: Results from Intraoperative Direct Electrical Stimulation of the Lumbosacral Spinal Roots.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: This study aimed to accurately map the lower extremity muscles innervated by the lumbar spinal roots by directly stimulating the spinal roots during surgery. SUMMARY OF BACKGROUND DATA: Innervation of the spinal roots in the lower extremities has been estimated by clinical studies, anatomical studies, and animal experiments. However, there have been discrepancies between studies. Moreover, there are no studies that have studied the laterality of lower limb innervation. MATERIALS AND METHODS: In 73 patients with lumbar degenerative disease, a total of 147 spinal roots were electrically stimulated and the electromyographic response was recorded at the vastus medialis (VM), gluteus medius (GM), tibialis anterior (TA), biceps femoris (BF), and gastrocnemius (GC). The asymmetry index (AI) was obtained using the following equation to represent the left-right asymmetry in the CMAP amplitude. Paired t-tests were used to compare CMAP amplitudes on the right and left sides. Differences in the AI among the same spinal root groups were determined using one-way analysis of variance. RESULTS: The frequency of compound muscle action potentials (CMAP) elicitation in VM, GM, TA, BF, and GC were 100%, 75.0%, 50.0%, 83.3%, and 33.3% in L3 spinal root stimulation, 90.4%, 78.8%, 59.6%, 73.1%, and 59.6% in L4 spinal root stimulation, 32.2%, 78.0%, 93.2%, 69.5%, and 83.1% in L5 spinal root stimulation, and 40.0%, 100%, 80.0%, 70.0%, and 80.0% in S1 spinal root stimulation, respectively. The most frequent muscle with maximum amplitude of the CMAP in L3, L4, L5, and S1 spinal root stimulation was the VM, GM, TA, and GM respectively. Unilateral innervation occurred at high rates in the TA in L4 root stimulation and the VM in L5 root stimulation in 37.5% and 42.3% of patients, respectively. Even in patients with bilateral innervation, a 20-38% asymmetry index of CMAP amplitude was observed. CONCLUSIONS: The spinal roots innervated a much larger range of muscles than what is indicated in general textbooks. Furthermore, a non-negligible number of patients showed asymmetrical innervation of lower limb by the lumbar spinal roots.

Evaluation of segmental mobility in patients with lumbar spondylolisthesis : A comparison of images from standing flexion-extension and standing/supine slippage.

PURPOSE: To evaluate segmental mobility with degenerative lumbar spondylolisthesis (DLS), upright lateral flexion-extension radiographs (FE) are widely used. However, some authors have described that a combination of lateral radiographs in the standing position and supine sagittal image (SS) reveal more segmental mobility than FE. The purpose of this study was to investigate the optimal method for evaluating segmental mobility with DLS. METHODS: We included 92 consecutive Japanese patients diagnosed with DLS. Sagittal translation (ST) determined by FE and SS were compared. Pathological instability was defined as ST more than 8% of the upper vertebra. Patients were divided into those diagnosed with pathological instability in FE (PI-FE) and those diagnosed with SS (PI-SS), and lumbar lordosis (LL) in the standing position in each group were compared. RESULTS: ST in FE was significantly greater than in SS. Of 92 patients, 31 had pathological instability in FE or SS ; 17 patients had PI-FE, and 10 patients had PI-SS. LL in the standing position in PI-FE was significantly smaller than in PI-SS. CONCLUSIONS: ST in FE was greater than that in SS, contrary to previous studies' reports on Caucasians. Since Japanese individuals have smaller LL than Caucasians, FE tends to reveal more segmental mobility than SS. J. Med. Invest. 70 : 135-139, February, 2023.

Correlation between T2 relaxation time and intervertebral disk degeneration.

OBJECTIVE: Magnetic resonance T2 mapping allows for the quantification of water and proteoglycan content within tissues and can be used to detect early cartilage abnormalities as well as to track the response to therapy. The goal of the present study was to use T2 mapping to quantify intervertebral disk water content according to the Pfirrmann classification. MATERIALS AND METHODS: This study involved 60 subjects who underwent lumbar magnetic resonance imaging (a total of 300 lumbar disks). The degree of disk degeneration was assessed in the midsagittal section on T2-weighted images according to the Pfirrmann classification (grades I to V). Receiver operating characteristic (ROC) analysis was performed among grades to determine the cut-off values. RESULTS: In the nucleus pulposus, T2 values tended to decrease with increasing grade, and there was a significant difference in T2 values between each grade from grades I to IV. However, there was no significant difference in T2 values in the anterior or posterior annulus fibrosus. T2 values according to disk degeneration level classification were as follows: grade I (>116.8 ms), grade II (92.7-116.7 ms), grade III (72.1-92.6 ms), grade IV (<72.0 ms). CONCLUSION: T2 values decreased with increasing Pfirrmann classification grade in the nucleus pulposus, likely reflecting a decrease in proteoglycan and water content. Thus, T2 value-based measurements of intervertebral disk water content may be useful for future clinical research on degenerative disk diseases.

[Acute cervical spinal cord injury].

Cervical spinal cord injury is a tragic trauma causing immediate serious quadriplegia and respiratory paralysis. In unstable injuries with paralysis, emergency surgery must be performed immediately to achieve spinal cord decompression and spinal column stabilization. In the treatment of dislocation fractures, first priority should be given to reducing the dislocation, by which the spinal cord is decompressed. A successful attempt to reduce the dislocation using skeletal traction is followed by elective surgery for fixation. In the case of a failure in reducing the dislocation, surgery with a posterior approach is performed to reduce the dislocation and provide internal fixation. In patients with considerably affected anterior column stability and those with any anterior compression that must be eliminated, such as intervertebral disc herniation or a vertebral body fragment, anterior decompression and fixation surgery is indicated.

Extraforaminal Stenosis at L2-L3 Treated with Microendoscopic Surgery: Report of Two Cases.

Introduction: The many cases of far-out syndrome that have been reported have involved extraforaminal stenosis at L5-S1. We report two cases of extremely rare extraforaminal stenosis at L2-L3. Case Report 1: A 59-year-old man presented with a 1/2-year history of the right leg pain. Radiological examination revealed stenosis of the right L2 spinal nerve between the osteophyte of the vertebral body and the L3 right transverse process. The right L2 spinal nerve was decompressed with microendoscopic surgery. Postoperatively, the pain in the right lower extremity was relieved. Case Report 2: An 80-year-old man presented with a ½-year history of the right leg pain. He had undergone posterior lumbar fusion (L4-L5 and L5-S1) approximately 30 years earlier. Radiological examination revealed stenosis of the right L2 spinal nerve between the osteophyte of the vertebral body and the L3 right transverse process. The right L2 spinal nerve was decompressed with microendoscopic surgery. Postoperatively, the patient had no symptoms and his course over the next 6 months was good. Conclusions: In both cases, we performed microendoscopic decompression of the L2 spinal nerve with good post-operative results. In both our patients, extraforaminal stenosis was caused by osteophytes that formed as a result of degenerative spondylosis.

Associations between visceral fat chronic low back pain and central sensitization in patients with lumbar spinal stenosis.

BACKGROUND: Pain sensitization may be one of the mechanisms contributing to chronic low back pain (CLBP). OBJECTIVE: To evaluate the association between visceral fat, CLBP, and central sensitization (CS); describe the relationship between low back pain (LBP) intensity and CS; and identify possible correlation between visceral fat and LBP intensity. METHODS: Patients with CLBP were divided using their CS inventory (CSI) scores into low- (CSI < 40) and high-CSI (CSI ⩾ 40) subgroups. We compared computed tomography (CT) measurements and scores for association with pain according to the visual analogue scale (VAS) between the two groups. RESULTS: The low-CSI and the high-CSI groups had 47 patients (67.1%; 21 men, 26 women) and 23 patients (32.9%; 11 men and 12 women), respectively. The high-CSI group had a significantly higher mean VAS score (p< 0.01) and estimated mean visceral fat area (p< 0.05) than the low-CSI group. There was a moderate positive correlation between VAS score and visceral fat (standardised partial regression coefficient: 0.659, p< 0.01) in the high-CSI group according to multiple linear regression analysis adjusted for age and sex. CONCLUSIONS: Visceral fat is associated with CLBP, regardless of sex or age, and may be a potential therapeutic target for CLBP with CS.

Degenerative Lumbar Spondylolisthesis Patients With Movement-related Low Back Pain Have Less Postoperative Satisfaction After Decompression Alone.

STUDY DESIGN: Retrospective analysis of prospectively collected multicenter observational data. OBJECTIVE: The aim was to examine the preoperative factors affecting postoperative satisfaction following posterior lumbar interbody fusion (PLIF) and microendoscopic muscle-preserving interlaminar decompression (ME-MILD) in patients with degenerative lumbar spondylolisthesis (DLS). SUMMARY OF BACKGROUND DATA: The technique involved in DLS surgery may either be decompression alone or decompression-fixation. Poor performance may occur after either of these surgical treatments. The author hypothesized that evaluating the correlation between preoperative quality of life and postoperative performance would aid in determining the optimal procedure. MATERIALS AND METHODS: This study included 138 patients who underwent surgery for 1-level mild DLS. The authors performed PLIF for 79 patients and ME-MILD for 59 patients. When the satisfaction subscale of the Zurich Claudication Questionnaire exceeded 2 points, postoperative satisfaction was considered poor. The clinical characteristics were investigated. Responses to preoperative health-related quality of life questionnaires, such as the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), short form-36 health survey (SF-36), and visual analog scale, were compared between the satisfied and unsatisfied groups. RESULTS: In the PLIF group, no endogenous factors influenced postoperative satisfaction. The ME-MILD cohort's satisfied and unsatisfied patients differed significantly in terms of preoperative lumbar spine dysfunction ( P <0.001) items of the JOABPEQ, role physical ( P =0.03), and role emotional ( P =0.03) items of the SF-36. A strong correlation ( r =-0.609 P =0.015) was found between preoperative lumbar spine dysfunction and postoperative satisfaction. CONCLUSIONS: In the ME-MILD group, preoperative lumbar spine function was correlated with postoperative satisfaction. Decompression alone may be ineffective in cases with decreased lumbar spine function prior to surgery. The degree of low back pain on movement should be considered before selecting the surgical method. LEVEL OF EVIDENCE: 3.

Enhanced Network in Corticospinal Tracts after Infused Mesenchymal Stem Cells in Spinal Cord Injury.

Although limited spontaneous recovery occurs after spinal cord injury (SCI), current knowledge reveals that multiple forms of axon growth in spared axons can lead to circuit reorganization and a detour or relay pathways. This hypothesis has been derived mainly from studies of the corticospinal tract (CST), which is the primary descending motor pathway in mammals. The major CST is the dorsal CST (dCST), being the major projection from cortex to spinal cord. Two other components often called "minor" pathways are the ventral and the dorsal lateral CSTs, which may play an important role in spontaneous recovery. Intravenous infusion of mesenchymal stem cells (MSCs) provides functional improvement after SCI with an enhancement of axonal sprouting of CSTs. Detailed morphological changes of CST pathways, however, have not been fully elucidated. The primary objective was to evaluate detailed changes in descending CST projections in SCI after MSC infusion. The MSCs were infused intravenously one day after SCI. A combination of adeno-associated viral vector (AAV), which is an anterograde and non-transsynaptic axonal tracer, was injected 14 days after SCI induction. The AAV with advanced tissue clearing techniques were used to visualize the distribution pattern and high-resolution features of the individual axons coursing from above to below the lesion. The results demonstrated increased observable axonal connections between the dCST and axons in the lateral funiculus, both rostral and caudal to the lesion core, and an increase in observable axons in the dCST below the lesion. This increased axonal network could contribute to functional recovery by providing greater input to the spinal cord below the lesion.