Diffusion Tensor Imaging of the Spinal Canal in Quantitative Assessment of Patients with Lumbar Spinal Canal Stenosis

Methods@#Study participants comprised five healthy volunteers (mean age, 27.2 years) and 27 patients with LSS (mean age, 58.4 years) who were individually assessed using 3.0 Tesla magnetic resonance imaging. Intraspinal ADC and FA values of 10 intervertebral discs from healthy volunteers and 52 intervertebral discs from LSS patients were measured. Also, intraspinal canal area, Schizas classification (A: normal, B: mild stenosis, C: severe stenosis) and correlations with symptoms were investigated. Clinical symptoms were checked for the presence of low back pain (LBP), intermittent claudication (IMC), and bladder and bowel dysfunction (BBD). @*Results@#Compared to healthy individuals, LSS patients had significantly lower ADC (pppr=0.63, pp=−0.61, ppp<0.05) in patients with IMC or BBD. @*Conclusions@#Intraspinal DTI parameters such as ADC and FA values were associated with the Schizas classification, intraspinal canal area, and clinical symptoms, suggesting that ADC and FA may be useful for quantitative assessment of LSS.

Diffusion Tensor Imaging of the Spinal Canal in Quantitative Assessment of Patients with Lumbar Spinal Canal Stenosis

Methods@#Study participants comprised five healthy volunteers (mean age, 27.2 years) and 27 patients with LSS (mean age, 58.4 years) who were individually assessed using 3.0 Tesla magnetic resonance imaging. Intraspinal ADC and FA values of 10 intervertebral discs from healthy volunteers and 52 intervertebral discs from LSS patients were measured. Also, intraspinal canal area, Schizas classification (A: normal, B: mild stenosis, C: severe stenosis) and correlations with symptoms were investigated. Clinical symptoms were checked for the presence of low back pain (LBP), intermittent claudication (IMC), and bladder and bowel dysfunction (BBD). @*Results@#Compared to healthy individuals, LSS patients had significantly lower ADC (pppr=0.63, pp=−0.61, ppp<0.05) in patients with IMC or BBD. @*Conclusions@#Intraspinal DTI parameters such as ADC and FA values were associated with the Schizas classification, intraspinal canal area, and clinical symptoms, suggesting that ADC and FA may be useful for quantitative assessment of LSS.

Elevated Levels of Serum Pentosidine Are Associated with Dropped Head Syndrome in Older Women

STUDY DESIGN: A retrospective observational study was performed. PURPOSE: We investigated the prevalence of sarcopenia in dropped head syndrome (DHS), and the relationship between biochemical markers, including major advanced glycation end products (AGEs), pentosidine, and DHS in older women. OVERVIEW OF LITERATURE: AGEs have been implicated in the pathogenesis of sarcopenia. METHODS: We studied 13 elderly women with idiopathic DHS (mean age, 77.2 years) and 20 healthy volunteers (mean age, 74.8 years). We used a bioelectrical impedance analyzer to analyze body composition, including appendicular skeletal muscle mass index (SMI; appendicular lean mass [kg]/[height (m)]2). Cervical sagittal plane alignment, including C2–C7 sagittal vertical axis (C2–C7SVA), C2–C7 angle, and C2 slope (C2S), was measured. Biochemical markers, such as serum and urinary pentosidine, serum homocysteine, 1, 25-dihydroxyvitamin D, and 25-hydroxyvitamin D, were measured. The level of each variable was compared between DHS and controls. The relationship between biochemical markers and DHS was examined. RESULTS: Sarcopenia (SMI < 5.75) was observed at a high prevalence in participants with DHS (77% compared to 22% of healthy controls). Height, weight, femoral bone mineral density, appendicular lean mass, total lean mass, and SMI all had significantly lower values in the DHS group. Serum and urinary pentosidine, and serum homocysteine were significantly higher in the DHS group compared to controls. Analysis of cervical alignment revealed a significant positive correlation of serum pentosidine with C2–C7SVA and C2S. CONCLUSIONS: Sarcopenia was involved in DHS, and high serum pentosidine levels are associated with severity of DHS in older women.

Influence of Skeletal Muscle Mass and Spinal Alignment on Surgical Outcomes for Lumbar Spinal Stenosis

STUDY DESIGN: Retrospective observational study. PURPOSE: We considered the relationship between spinal alignment and skeletal muscle mass on clinical outcomes following a surgery for lumbar spinal stenosis (LSS). OVERVIEW OF LITERATURE: There are no reports of preoperative factors predicting residual low back pain following surgery for LSS. METHODS: Our target population included 34 women (mean age, 74.4 years) who underwent surgery for LSS. Prior to and 6 months after the surgery, systemic bone mineral density and lean soft tissue mass were measured using dual-energy X-ray absorptiometry. Skeletal muscle mass index (SMI) was calculated as the sum of the arm and leg lean mass in kilograms divided by height in meters squared. The spinal alignment was also measured. Clinical outcomes were evaluated using the Japanese Orthopedic Association scoring system, leg and low back pain Visual Analog Scale, and Roland–Morris Disability Questionnaire (RDQ). Additionally, we examined the bone mineral density, skeletal muscle mass, and spinal alignment before and after the surgery. We used the Spearman correlation coefficient to examine the associations among clinical outcomes, preoperative muscle mass, and spinal alignment. RESULTS: Sarcopenia (SMI 6.12), RDQ was significantly higher in subjects with sarcopenia (p=0.04). RDQ was significantly negatively correlated with SMI (r=−0.42, p<0.05). There was a significant positive correlation between postoperative RDQ and pelvic tilt (PT; r=0.41, p<0.05). SMI and PT were significantly negatively correlated (r=−0.39, r<0.05). CONCLUSIONS: Good postoperative outcomes were negatively correlated with low preoperative appendicular muscle mass, suggesting that postoperative outcomes were inferior in cases of decreased appendicular muscle mass (sarcopenia). Posterior PT due to decreased limb muscle mass may contribute to postoperative back pain, showing that preoperatively reduced limb muscle mass and posterior PT are predictive factors in the persistence of postoperative low back pain.

Correlation Between Walking Ability and Monthly Care Costs in Elderly Patients After Surgical Treatments for Hip Fractures

OBJECTIVE: To validate the relationship between residual walking ability and monthly care cost as well as long-term care insurance (LTCI) certification level in elderly patients after surgical treatment for hip fractures in Japan. METHODS: Elderly patients aged >75 years who underwent surgical treatment for hip fractures in our hospital were included. The preand post-surgical (6-month) walking ability and LTCI certification and the presence or absence of dementia was determined from medical records and questionnaires. Walking ability was classified into 6 levels used in our daily medical practice. Based on these data, we correlated the relationship between walking ability and the LTCI certification level. Further, based on the official statistics pertaining to the average monthly costs per person at each LTCI certification level, we evaluated the relationship between walking ability and monthly care cost. RESULTS: A total of 105 cases (mean age, 80.2 years; 16 men; 39 patients with dementia) were included. The correlation between walking ability and average monthly cost per person as well as LTCI certification level at 6 months postoperatively (r=0.58) was demonstrated. The correlation was found in both groups with and without dementia. CONCLUSION: The ability to walk reduced the cost of care in elderly patients who experienced hip fracture, regardless of the presence of dementia.

Correlation among Inflammatory Cytokine Expression Levels, Degree of Disk Degeneration, and Predominant Clinical Symptoms in Patients with Degenerated Intervertebral Discs

STUDY DESIGN: Observational study. PURPOSE: To assess the correlation among inflammatory cytokine expression levels, degree of intervertebral disk (IVD) degeneration, and predominant clinical symptoms observed in degenerative disk disease (DDD). OVERVIEW OF LITERATURE: Low back pain (LBP) is associated with inflammatory cytokine expression levels, including those of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and nerve growth factor (NGF). However, the association between cytokine expression levels and the physiological mechanisms of disk degeneration and clinical pain remain controversial. METHODS: Using the enzyme-linked immunosorbent assay, TNF-α, IL-6, and NGF expression levels were analyzed in 58 IVD samples that were harvested from patients with lumbar DDD. Patient samples were grouped according to the degree of IVD degeneration using the Pfirrmann grading system and magnetic resonance imaging, and the correlations between the disease groups and each cytokine expression level were assessed. In addition, on the basis of their predominant preoperative symptoms, the patients were assigned to either an LBP or leg pain group to determine the correlation among these disease manifestations and individual cytokine expression levels. RESULTS: A gradual increase in TNF-α (R=0.391) and IL-6 (R=0.388) expression levels correlated with the degree of IVD degeneration, whereas NGF (R=0.164) expression levels exhibited a minimal decrease with disease progression. Regarding the predominant clinical manifestation, only the LBP group exhibited a significant increase in TNF-α expression levels (p=0.002). CONCLUSIONS: These results suggested that TNF-α and IL-6 play an important role in the pathophysiology of IVD degeneration at any stage, whereas NGF plays an important role during the early disease stages. Moreover, because TNF-α expression levels were significantly high in the LBP group, we propose that they are involved in LBP onset or progression.

Assessment of Clinical Symptoms in Lumbar Foraminal Stenosis Using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire

OBJECTIVE: It is important to develop an easy means of diagnosing lumbar foraminal stenosis (LFS) in a general practice setting. We investigated the use of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) to diagnose LFS in symptomatic patients. METHODS: Subjects included 13 cases (mean age, 72 years) with LFS, and 30 cases (mean age, 73 years) with lumbar spinal canal stenosis (LSCS) involving one intervertebral disc. The visual analogue scale score for low back pain and leg pain, the JOABPEQ were evaluated. RESULTS: Those with LFS had a significantly lower JOA score (p<0.001), while JOABPEQ scores (p<0.05) for lumbar dysfunction and social functioning impairment (p<0.01) were both significantly lower than the scores in LSCS. The following JOABPEQ questionnaire items (LFS vs. LSCS, p-value) for difficulties in: sleeping (53.8% vs. 16.6%, p<0.05), getting up from a chair (53.8% vs. 6.6%, p<0.001), turning over (76.9% vs. 40%, p<0.05), and putting on socks (76.9% vs. 26.6%, p<0.01) such as pain during rest, and signs of intermittent claudication more than 15 minutes (61.5% vs. 26.6%, p<0.05) were all significantly more common with LFS than LSCS. CONCLUSION: Results suggest that of the items in the JOABPEQ, if pain during rest or intermittent claudication is noted, LFS should be kept in mind as a cause during subsequent diagnosis and treatment. LFS may be easily diagnosed from LSCS using this established patient-based assessment method.

Freeze-Dried Human Platelet-Rich Plasma Retains Activation and Growth Factor Expression after an Eight-Week Preservation Period

STUDY DESIGN: Controlled laboratory study. PURPOSE: This study aimed to evaluate the efficacy of platelet-rich plasma (PRP) stored at room temperature (RT), frozen, or after freeze-drying. OVERVIEW OF LITERATURE: PRP enriches tissue repair and regeneration, and is a novel treatment option for musculoskeletal pathologies. However, whether biological activity is preserved during PRP storage remains uncertain. METHODS: PRP was prepared from blood of 12 healthy human volunteers (200 mL/person) and stored using three methods: PRP was stored at RT with shaking, PRP was frozen and stored at −80℃, or PRP was freeze-dried and stored at RT. Platelet counts and growth factor content were examined immediately after preparation, as well as 2, 4, and 8 weeks after storage. Platelet activation rate was quantified by flow cytometry. RESULTS: Platelet counts were impossible to determine in many RT samples after 2 weeks, but they remained at constant levels in frozen and freeze-dried samples, even after 8 weeks of storage. Flow cytometry showed approximately 80% activation of the platelets regardless of storage conditions. Almost no growth factors were detected in the RT samples after 8 weeks, while low but significant expression was detected in the frozen and freeze-dried PRP. Over time, the mean relative concentrations of various growth factors decreased significantly or disappeared in the RT group. In the frozen group, levels were maintained for 4 weeks, but decreased significantly by 8 weeks (p <0.05). The freeze-dried group maintained baseline levels of growth factors for the entire 8-week duration. CONCLUSIONS: Freeze-drying enables PRP storage while maintaining bioactivity and efficacy for extended periods.

Long-Term Outcomes of In Situ Fusion for Treating Dysplastic Spondylolisthesis

STUDY DESIGN: Retrospective, observational, single-center study. PURPOSE: To investigate the long-term outcomes of in situ fusion procedures for treating dysplastic spondylolisthesis. OVERVIEW OF LITERATURE: In situ fusion performed in patients with dysplastic spondylolisthesis avoids the development of nerve complications. METHODS: In total, 12 of 28 patients who underwent in situ fusion for treating dysplastic spondylolisthesis at Chiba University Hospital from 1974 to 2004 were followed up in August 2013. Surgical complications were evaluated. Low back pain and leg pain were assessed using a visual analog scale (VAS). Vertebral alignment, including the lumbosacral angle and lumbar lordosis angle measurement on radiographic images (profile view in the neutral standing position), was evaluated during preoperative, postoperative, and final examinations. RESULTS: The mean follow-up duration, patient age at the final examination, and patient age at operation were 20.0±7.2, 42.3±13.3, and 22.3±11.4 years, respectively. No complications were reported. Mean VAS scores for low back pain and leg pain were significantly lower at the final examination than at the preoperative examination (p<0.05). At the preoperative, postoperative, and final examinations, the mean lumbosacral angle was 32.3°±14.2°, 33.7°±11.8°, and 36.5°±16.4°, while the mean lumbar lordosis angle was 51.0°±14.8°, 48.6°±18.8°, and 49.6°±15.5°, respectively. No significant differences were noted among these values across the different time periods (p<0.05). CONCLUSIONS: In situ fusion performed in patients with dysplastic spondylolisthesis avoids the development of nerve complications such as nerve paralysis that may occur after repositioning operation and maintains appropriate long-term sagittal alignment, even 20 years after operation.

Does Discontinuing Teriparatide Treatment and Replacing It with Bisphosphonate Maintain the Volume of the Bone Fusion Mass after Lumbar Posterolateral Fusion in Women with Postmenopausal Osteoporosis?

STUDY DESIGN: Retrospective case series. PURPOSE: The purpose of this study was to determine whether discontinuing teriparatide treatment and replacing it with bisphosphonate treatment maintains the volume of the fusion mass after posterolateral fusion (PLF) in women with postmenopausal osteoporosis. OVERVIEW OF LITERATURE: Clinical data support the efficacy of parathyroid hormone (PTH) for lumbar PLF. However, the use of PTH is limited to 2 years. METHODS: We treated 19 women diagnosed with osteoporosis and degenerative spondylolisthesis with teriparatide (20 µg daily subcutaneously). All patients underwent one-level instrumented PLF. Teriparatide was used during 2 months prior to surgery and more than 8 months after surgery. After discontinuing teriparatide treatment, all patients used bisphosphonate (17.5 mg risedronate weekly, oral administration). Area of the fusion mass across the transverse processes at one segment was determined on an anteroposterior radiograph at 1, 2, and 3 years after surgery. RESULTS: We followed 19 patients for 3 years. The average duration of teriparatide treatment was 11.5 months. The bone union rate was 95%. The average area of the bone fusion mass was not significantly different between the right and left sides at 1, 2, or 3 years after surgery (p>0.05). CONCLUSIONS: This study showed that replacing teriparatide treatment with bisphosphonate maintained the bone fusion mass volume after PLF in women with postmenopausal osteoporosis.

Response to: “Long-term Outcomes of In Situ Fusion for Treating Dysplastic Spondylolisthesis”

No abstract available.

Evaluation of Histological Changes in Back Muscle Injuries in Rats over Time

STUDY DESIGN: Animal model study. PURPOSE: The purpose of this study was to evaluate the histological variation in the injured muscle and production of calcitonin gene-related peptide in rats over time. OVERVIEW OF LITERATURE: Vertebral surgery has been reported to cause atrophy of the back muscles, which may result in pain. However, few reports have described the time series histological variation in the injured muscle and changes in the dominant nerve. METHODS: We used 30 male, 8-week-old Sprague-Dawley rats. The right and left sides of the paravertebral muscle were considered as the injured and uninjured sides, respectively. A 115 g weight was dropped from a height of 1 m on the right paravertebral muscle. Hematoxylin and eosin (H&E) staining of the muscle was performed 1–3 weeks after injury for histological evaluation. Fluoro-Gold (FG) was injected into the paravertebral muscle. The L2 dorsal root ganglia on both sides were resected 1, 2, and 3 weeks after injury, and immunohistochemical staining for calcitonin gene-related peptide was performed. RESULTS: H&E staining of the paravertebral muscle showed infiltration of inflammatory cells and the presence of granulation tissue in the injured part on the ipsilateral side 1 week after injury. Muscle atrophy occurred 3 weeks after injury, but was repaired via spontaneous replacement of muscle cells/fibers. In contrast, compared with the uninjured side, the percentage of cells double-labeled with FG and calcitonin gene-related peptide in FG-positive cells in the dorsal root ganglia of the injured side was significantly increased at each time point throughout the study period. CONCLUSIONS: These results suggest that sensitization of the dominant nerve in the dorsal root ganglia, which may be caused by cicatrix formation, can protract injured muscle pain. This information may be helpful in elucidating the underlying mechanism of persistent pain after back muscle injury.

Inhibiting Vascular Endothelial Growth Factor in Injured Intervertebral Discs Attenuates Pain-Related Neuropeptide Expression in Dorsal Root Ganglia in Rats

STUDY DESIGN: An experimental animal study. PURPOSE: To evaluate effects of anti-vascular endothelial growth factor (VEGF) on the content and distribution of the calcitonin gene-related peptide (CGRP) in the dorsal ganglia in a rat model. OVERVIEW OF LITERATURE: Increased expression of VEGF in degenerative disc disease increases the levels of inflammatory cytokines and nerve ingrowth into the damaged discs. In animal models, increased levels of VEGF can persist for up to 2 weeks after an injury. METHODS: Through abdominal surgery, the dorsal root ganglia (DRG) innervating L5/L6 intervertebral disc were labeled (FluoroGold neurotracer) in 24, 8-week old Sprague Dawley rats. The rats were randomly allocated to three groups of eight rats each. The anti-VEGF group underwent L5/6 intervertebral disc puncture using a 26-gauge needle, intradiscal injection of 33.3 µg of the pegaptanib sodium, a VEGF165 aptamer. The control-puncture group underwent disc puncture and intradiscal injection of 10 µL saline solution, and the sham-surgery group underwent labeling but no disc puncture. Two rats in each group were sacrificed on postoperative days 1, 7, 14, and 28 after surgery. L1–L6 DRGs were harvested, sectioned, and immunostained to detect the content and distribution of CGRP. RESULTS: Compared with the control, the percentage of CGRP-positive cells was lower in the anti-VEGF group (p<0.05; 40.6% and 58.1% on postoperative day 1, 44.3% and 55.4% on day 7, and 42.4% and 59.3% on day 14). The percentage was higher in the control group compared with that of the sham group (p<0.05; sham group, 34.1%, 40.7%, and 33.7% on postoperative days 1, 7, and 14, respectively). CONCLUSIONS: Decreasing CGRP-positive cells using anti-VEGF therapy provides fundamental evidence for a possible therapeutic role of anti-VEGF in patients with discogenic lower back pain.

Efficacy of TachoSil, a Fibrin-Based Hemostat, for Anterior Lumbar Spine Surgery

STUDY DESIGN: Retrospective case series. PURPOSE: To examine the efficacy of TachoSil for vessel injury in 6 patients who underwent anterior lumbar fusion surgery (ALF). OVERVIEW OF LITERATURE: ALF for the lumbar spine has a high rate of success, although intraoperative concerns and iatrogenic complications are known, and injury of a major vessel is sometimes a complication. The efficacy of TachoSil, a fibrin-based hemostat, has been reported for several types of surgery; however, use of TachoSil for ALF surgery has not been described. Here, we report on the efficacy of TachoSil in 6 patients, who underwent ALF after vascular surgeons having difficulty in repairing vessels. METHODS: Two man and 4 women with average age of 50.8±10.9 (mean±standard deviation) were diagnosed with a vertebral tumor (2 patients), L4 degenerative spondylolisthesis (2 patients), and L5 spondylolytic spondylolisthesis (2 patients) and underwent ALF. The blood vessels injured included the common iliac vein in 2 patients and a branch of a segmental artery from the aorta in 4 patients. We consulted a vascular surgeon to suture or repair the vessels during surgery, and although the vascular surgeon attempted to address the injuries, suturing or repair was not possible in these cases. For this reason, we used TachoSil to repair the injury in the vessels walls or to stop the bleeding. RESULTS: Time to pressure hemostasis using TachoSil was 34±12 minutes, and total blood loss was 1,488±1,711 mL. Nevertheless, all vessel injuries were controlled by the use of TachoSil. CONCLUSIONS: We recommend the use of TachoSil for vessel injuries that vascular surgeons cannot suture or repair during ALF surgery.

Classification of Chronic Back Muscle Degeneration after Spinal Surgery and Its Relationship with Low Back Pain

STUDY DESIGN: Retrospective case series. PURPOSE: To classify back muscle degeneration using magnetic resonance imaging (MRI) and investigate its relationship with back pain after surgery. OVERVIEW OF LITERATURE: Back muscle injury and degeneration often occurs after posterior lumbar surgery, and the degeneration may be a cause of back pain. However, the relationship between back muscle degeneration and back pain remains controversial. METHODS: A total of 84 patients (average age, 65.1 years; 38 men, 46 women) with lumbar spinal stenosis underwent posterior decompression surgery alone. MRI (1.5 tesla) was evaluated before and more than a year after surgery in all patients. Muscle on MRI was classified into three categories: low intensity in T1-weighted imaging, high intensity in T2-weighted imaging (type 1), high intensity in both T1- and T2-weighted images (type 2), and low intensity in both T1- and T2-weighted imaging (type 3). The prevalence of the types and their relationship with back pain (determined on a visual analog scale) were evaluated. RESULTS: MRI revealed muscle degeneration in all patients after surgery (type 1, 6%; type 2, 82%; and type 3, 12%). Type 2 was significantly more frequent compared with types 1 and 3 (p0.05). CONCLUSIONS: Various pathologies of back muscle degeneration after posterior lumbar surgery were revealed. Type 2 (fatty) change was most frequent, and other patients had type 3 (scar) or type 1 (inflammation or water-like) changes. According to the Modic classification of bone marrow changes, Modic type 1 change is associated with inflammation and back pain. However, no particular type of back muscle degeneration was correlated with back pain after surgery.

Classification of Chronic Back Muscle Degeneration after Spinal Surgery and Its Relationship with Low Back Pain

STUDY DESIGN: Retrospective case series. PURPOSE: To classify back muscle degeneration using magnetic resonance imaging (MRI) and investigate its relationship with back pain after surgery. OVERVIEW OF LITERATURE: Back muscle injury and degeneration often occurs after posterior lumbar surgery, and the degeneration may be a cause of back pain. However, the relationship between back muscle degeneration and back pain remains controversial. METHODS: A total of 84 patients (average age, 65.1 years; 38 men, 46 women) with lumbar spinal stenosis underwent posterior decompression surgery alone. MRI (1.5 tesla) was evaluated before and more than a year after surgery in all patients. Muscle on MRI was classified into three categories: low intensity in T1-weighted imaging, high intensity in T2-weighted imaging (type 1), high intensity in both T1- and T2-weighted images (type 2), and low intensity in both T1- and T2-weighted imaging (type 3). The prevalence of the types and their relationship with back pain (determined on a visual analog scale) were evaluated. RESULTS: MRI revealed muscle degeneration in all patients after surgery (type 1, 6%; type 2, 82%; and type 3, 12%). Type 2 was significantly more frequent compared with types 1 and 3 (p0.05). CONCLUSIONS: Various pathologies of back muscle degeneration after posterior lumbar surgery were revealed. Type 2 (fatty) change was most frequent, and other patients had type 3 (scar) or type 1 (inflammation or water-like) changes. According to the Modic classification of bone marrow changes, Modic type 1 change is associated with inflammation and back pain. However, no particular type of back muscle degeneration was correlated with back pain after surgery.

Discrimination between Lumbar Intraspinal Stenosis and Foraminal Stenosis using Diffusion Tensor Imaging Parameters: Preliminary Results

STUDY DESIGN: Retrospective observational study. PURPOSE: To examine fractional anisotropy (FA) values and apparent diffusion coefficient (ADC) values of damaged nerves to discriminate between lumbar intraspinal stenosis (IS) and foraminal stenosis (FS) using diffusion tensor imaging (DTI) OVERVIEW OF LITERATURE: It is important in the selection of surgical procedure to discriminate between lumbar IS and FS, but such discrimination is difficult. METHODS: There were 9 cases of IS, 7 cases of FS, and 5 healthy controls. The regions of interest were established in the lumbar intraspinal zone (Iz), nerve root (N), and extraforaminal zone (Ez). The FA and ADC values were measured on the affected and unaffected sides of the nerves. The FA ratio and the ADC ratio were calculated as the affected side/unaffected side ×100 (%). RESULTS: In the Ez, the FA value was significantly lower in FS than in IS (p<0.01). FA ratio was significantly lower in FS than in IS for the Ez (p<0.01). In the Iz, the ADC value was significantly higher in IS than FS (p<0.01). ADC ratio was significantly higher in FS than in IS for the N and Ez (p<0.05). For the Ez, receiver operating characteristic analysis of parameters revealed that the FA values showed a higher accuracy for the diagnosis of FS than the ADC values, and the FA value cut-off value was 0.42 (sensitivity: 85.7%, false positive: 11.1%) and the FA ratio cut-off value was 83.9% (sensitivity: 85.7%, false positive: 22.2%). CONCLUSIONS: The low FA value in the extraforaminal zone suggests the presence of foraminal stenosis. When the FA value and FA ratio cut-off value were established as 0.42 and 83.9%, respectively, the accuracy was high for the diagnosis of foraminal stenosis. It may be possible to use DTI parameters to help in the discrimination between IS and FS.

Diagnosis of Lumbar Foraminal Stenosis using Diffusion Tensor Imaging

Diagnosis of lumbar foraminal stenosis remains difficult. Here, we report on a case in which bilateral lumbar foraminal stenosis was difficult to diagnose, and in which diffusion tensor imaging (DTI) was useful. The patient was a 52-year-old woman with low back pain and pain in both legs that was dominant on the right. Right lumbosacral nerve compression due to a massive uterine myoma was apparent, but the leg pain continued after a myomectomy was performed. No abnormalities were observed during nerve conduction studies. Computed tomography and magnetic resonance imaging indicated bilateral L5 lumbar foraminal stenosis. DTI imaging was done. The extraforaminal values were decreased and tractography was interrupted in the foraminal region. Bilateral L5 vertebral foraminal stenosis was treated by transforaminal lumbar interbody fusion and the pain in both legs disappeared. The case indicates the value of DTI for diagnosing vertebral foraminal stenosis.

Dose Optimization for Single Intradiscal Administration of the Tumor Necrosis Factor-α Inhibitor, Etanercept, in Rat Disc Injury Models

STUDY DESIGN: Experimental animal study. PURPOSE: We aimed to determine the optimal dose of a single direct injection of the tumor necrosis factor (TNF)-α inhibitor, etanercept, by using the rat model of degenerative intervertebral disc from injury. OVERVIEW OF LITERATURE: The pain-related peptide expression was suppressed in the etanercept (100 µg and 1,000 µg)-administered groups in a dose-dependent manner. METHODS: The neurotracer FluoroGold (FG) was applied to the surfaces of L4/5 discs to label their innervating dorsal root ganglion (DRG) neurons (n=50). Ten rats were included in the nonpunctured disc sham surgery control group, whereas the other 40 were included in the experimental group in which intervertebral discs were punctured with a 23-gauge needle. Saline or etanercept (10 µg, 100 µg, or 1,000 µg) was injected into the punctured discs (n=10 for each treatment). After 14 days of surgery, DRGs from L1 to L6 were harvested, sectioned, and immunostained for calcitonin gene-related peptide (CGRP). The proportion of FG-labeled CGRP-immunoreactive DRG neurons was evaluated in all the groups. RESULTS: There were no significant differences between the puncture+saline group and the puncture+10-µg etanercept group (p >0.05). However, a significant decrease in the percentage of FG and CGRP double-positive cells in FG-positive cells was observed in the etanercept (100 µg and 1,000 µg)-administered groups in a dose-dependent manner (p <0.05). CONCLUSIONS: When a low dose of the TNF-α inhibitor (10 µg of etanercept) was directly administered to the rat intervertebral disc in the rat model of degenerative intervertebral disc from injury, no suppressive effect on the pain-related peptide expression was observed. However, when a higher dose of etanercept (100 µg and 1,000 µg) was administered, the pain-related peptide expression was suppressed in a dose-dependent manner.

Low-Dose Tramadol and Non-Steroidal Anti-Inflammatory Drug Combination Therapy Prevents the Transition to Chronic Low Back Pain

STUDY DESIGN: Retrospective study. PURPOSE: To determine whether low-dose tramadol plus non-steroidal anti-inflammatory drug combination therapy could prevent the transition of acute low back pain to chronic low back pain. OVERVIEW OF LITERATURE: Inadequately treated early low back pain transitions to chronic low back pain occur in approximately 30% of affected individuals. The administration of non-steroidal anti-inflammatory drugs is effective for treatment of low back pain in the early stages. However, the treatment of low back pain that is resistant to non-steroidal anti-inflammatory drugs is challenging. METHODS: Patients who presented with acute low back pain at our hospital were considered for inclusion in this study. After the diagnosis of acute low back pain, non-steroidal anti-inflammatory drug administration was started. Forty patients with a visual analog scale score of >5 for low back pain 1 month after treatment were finally enrolled. The first 20 patients were included in a non-steroidal anti-inflammatory drug group, and they continued non-steroidal anti-inflammatory drug therapy for 1 month. The next 20 patients were included in a combination group, and they received low-dose tramadol plus non-steroidal anti-inflammatory drug combination therapy for 1 month. The incidence of adverse events and the improvement in the visual analog scale score at 2 months after the start of treatment were analyzed. RESULTS: No adverse events were observed in the non-steroidal anti-inflammatory drug group. In the combination group, administration was discontinued in 2 patients (10%) due to adverse events immediately following the start of tramadol administration. At 2 months, the improvement in the visual analog scale score was greater in the combination group than in the non-steroidal anti-inflammatory drug group (p<0.001). CONCLUSIONS: Low-dose tramadol plus non-steroidal anti-inflammatory drug combination therapy might decrease the incidence of adverse events and prevent the transition of acute low back pain to chronic low back pain.