Efficacy and Safety of Condoliase Disc Administration as a New Treatment for Lumbar Disc Herniation.

INTRODUCTION: Condoliase is a newly approved drug that improves symptoms associated with lumbar disk herniation (LDH) by intradiscal administration. This study aimed to evaluate the mid-term outcomes of condoliase injection, examine the adverse events, including cases that required surgery after condoliase administration, and verify cases in which condoliase could be effective. METHODS: We enrolled patients with LDH who were treated conservatively for at least six weeks and received condoliase. We assessed the visual analog scale (VAS) score, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, Oswestry Disability Index, disk height, and disk degeneration for up to 6 months, and we examined the complications. Furthermore, a 50% or more improvement in leg pain VAS score was considered effective. Factors related to symptom improvement were investigated by determining whether lower limb pain improved in six months. RESULTS: In total, 84 patients were recruited (52 men, 32 women; mean age, 44.2 ± 17.1 [16-86 years]). The duration of illness was 6.7 ± 6.8 (1.5-30) months. All patient-based outcomes significantly improved at 4 weeks after the administration compared with pretreatment. The intervertebral disc height decreased significantly at four weeks after condoliase administration compared with that before administration. Progression of intervertebral disc degeneration occurred in 50% of the patients. Eleven patients underwent herniotomy due to poor treatment effects. Moreover, treatment in 77.4% of the patients was considered effective. A logistic regression analysis revealed that L5/S1 disk administration (p = 0.029; odds ratio, 5.94; 95% confidence interval, 1.20-29.45) were significantly associated with clinical effectiveness. CONCLUSIONS: Condoliase disk administration improved pain and quality of life over time. Condoliase disk administration was more effective in L5/S1 intervertebral administration.

Multicenter cross-sectional study of the clinical features and types of treatment of spinal cord-related pain syndrome.

BACKGROUND: We termed chronic neuropathic pain (NeP) in patients with diseases associated with spinal cord damage as "spinal cord-related pain syndrome". We conducted a survey of patients with the syndrome to assess the type and severity of NeP and its effect on QOL, and treatment modalities. METHODS: This cross-sectional study was conducted in 185 patients recruited from 15 medical institutions. We analyzed the questionnaires sent to clinicians (basic information, magnetic resonance imaging (MRI) findings, type and effectiveness of medications) and patients [modified Neuropathic Pain Symptom Inventory (NPSI) and short form (SF)-36 healthy survey]. RESULTS: The incidence of spinal cord-related pain syndrome was highest in patients with cervical spondylotic myelopathy, ossification of posterior longitudinal ligament (OPLL) and spinal cord injury. The number of patients with at-level pain was higher than those with below-level pain; dysesthesia/paresthesia, spontaneous and evoked pain types were mainly seen in patients with at-level pain and dysesthesia/paresthesia was common among those with below-level pain. NPSI score was higher than 10 in the majority of patients, and the subscore for dysesthesia/paresthesia was significantly the highest. The NPSI score was the highest in patients with severe hyperintense signal increase on MRI. The scores of all SF-36 sub-items were significantly lower than the national average. The majority of patients used non-steroid anti-inflammatory drugs and gabapentin/pregabalin; the latter was significantly effective for allodynia, compared with other medications, regardless of the pain level. CONCLUSIONS: The majority of patients with spinal cord-related pain syndrome suffered from severe NeP, which affected physical activity. The pain phenotype varied according to the level of the lesion and dysesthesia/paresthesia was the most intense. Compared with other medications, gabapentin/pregabalin was significantly effective especially for dysesthesia/paresthesia and evoked pain regardless of the pain level.

Normative data for parameters of sagittal spinal alignment in healthy subjects: an analysis of gender specific differences and changes with aging in 626 asymptomatic individuals.

PURPOSE: This study aims to establish normative data for parameters of spino-pelvic and spinal sagittal alignment, gender related differences and age-related changes in asymptomatic subjects. METHODS: A total of 626 asymptomatic volunteers from Japanese population were enrolled in this study, including 50 subjects at least for each gender and each decade from 3rd to 8th. Full length, free-standing spine radiographs were obtained. Cervical lordosis (CL; C3-7), thoracic kyphosis (TK; T1-12), lumbar lordosis (LL; T12-S1), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) and sagittal vertical axis (SVA) were measured. RESULTS: The average values (degrees) are 4.1 ± 11.7 for CL, 36.0 ± 10.1 for TK, 49.7 ± 11.2 for LL, 53.7 ± 10.9 for PI, 14.5 ± 8.4 for PT, and 39.4 ± 8.0 for SS. Mean SVA is 3.1 ± 12.6 mm. Advancing age caused an increase in CL, PT and SVA, and a decrease in LL and SS. There was a significant gender difference in CL, TK, LL, PI, PT and SVA. From 7th decade to 8th decade, remarkable decrease of LL & TK and increase of PT were seen. A large increase of SVA was also seen between 60' and 70'. CONCLUSION: Standard values of spino-pelvic sagittal alignment were established in each gender and each decade from 20' to 70'. A remarkable change of spino-pelvic sagittal alignment was seen from 7th decade to 8th decade in asymptomatic subjects.

The nature of osteoporotic low back pain without acute vertebral fracture: A prospective multicenter study on the analgesic effect of monthly minodronic acid hydrate.

BACKGROUND: Patients with osteoporosis but no evidence of fracture can sometimes report low back pain. However, few studies have evaluated the nature of osteoporotic low back pain in a clinical situation. Therefore, the aim of this study was to examine the nature of osteoporotic low back pain without fracture, and the analgesic effect of minodronic acid hydrate on such pain. METHODS: The current study examined 136 patients with osteoporotic low back pain and no lower extremity symptoms. The following factors were evaluated before and after minodronic acid hydrate administration: the nature of osteoporotic low back pain was evaluated using the painDETECT questionnaire, numeric rating scale (NRS) score for low back pain at rest and in motion, bone mineral density (BMD) of the lumbar spine, and the serum concentration of tartrate-resistant acid phosphatase 5b (TRACP-5b) as a bone metabolism marker. RESULTS: A total of 113 patients were enrolled. The painDETECT questionnaire revealed the percentage of patients with nociceptive pain and neuropathic or mixed pain was approximately 85% and 15%, respectively. the average NRS scores for low back pain at rest decreased significantly 2 months after treatment (p = 0.01), while those in motion decreased significantly 1 month after treatment (p = 0.04). The average lumbar spine BMD tended to increase after treatment, but not significantly. On the other hand, the changes in the average serum concentration of TRACP-5b did significantly decrease 1 month after treatment. There was a significant positive correlation between the rate of NRS score improvement for low back pain at rest, and the rate of improvement in serum concentration of TRACP-5b (p < 0.05). CONCLUSIONS: Osteoporotic low back pain consisted of 85% nociceptive pain and 15% neuropathic or mixed pain. The pain is strongly related to pain at rest rather than that in motion.

Perioperative Complications in 155 Patients Who Underwent Oblique Lateral Interbody Fusion Surgery: Perspectives and Indications From a Retrospective, Multicenter Survey.

STUDY DESIGN: A retrospective multicenter survey. OBJECTIVE: To investigate the perioperative complications of oblique lateral interbody fusion (OLIF) surgery. SUMMARY OF BACKGROUND DATA: OLIF has been widely performed to achieve minimally invasive, rigid lumbar lateral interbody fusion. The associated perioperative complications are not yet well described. METHODS: The participants were patients who underwent OLIF surgery under the diagnosis of degenerative lumbar diseases between April 2013 and May 2015 at 11 affiliated medical institutions. The collected data were classified into intraoperative and early-stage postoperative (≤1 mo) complications. The intraoperative complications were then subcategorized into organ damage (neural, vertebral, vascular, and others) and other complications, mainly related to instrumental failure. The collected data were also divided and analyzed based on whether the surgeon was certified to perform the surgery and the incidence of complications in the early (April 2013-March 2014) and late stages (April 2014-May 2015) of OLIF introduction. RESULTS: In the 155 included patients, 75 complications were reported (incidence rate, 48.3%). The most common complication was endplate fracture/subsidence (18.7%), followed by transient psoas weakness and thigh numbness (13.5%) and segmental artery injury (2.6%). Almost all these complications were transient, except for three patients who had permanent damage: one had ureteral injury and two had neurological injury. Postoperative complications included surgical site infection (1.9%) and reoperation (1.9%). Whether the primary operator was experienced did not affect the incidence of complications. Regarding the introductory stage, the incidence of complications was 50% in the early stage and 38% in the late stage. CONCLUSION: The overall incidence of perioperative complications of OLIF surgery reached 48.3%, of which only 1.9% resulted in permanent damage. Our analysis based on surgeon experience indicated that the OLIF procedure could be performed without increasing incidence of complications, under the guidance of experienced supervisors. LEVEL OF EVIDENCE: 3.

Narrow cervical canal in 1211 asymptomatic healthy subjects: the relationship with spinal cord compression on MRI.

PURPOSE: Narrow cervical canal (NCC) has been a suspected risk factor for later development of cervical myelopathy. However, few studies have evaluated the prevalence in asymptomatic subjects. The purpose of this study was to investigate the prevalence of NCC in a large cohort of asymptomatic volunteers. METHODS: This study was a cross-sectional study of 1211 asymptomatic volunteers. Approximately 100 men and 100 women representing each decade of life from the 20s to the 70s were included in this study. Cervical canal anteroposterior diameters at C5 midvertebral level on X-rays, and the prevalence of spinal cord compression (SCC) and increased signal intensity (ISI) changes on MRI were evaluated. Receiver operating characteristic analysis was performed to determine the cut-off value of the severity of canal stenosis resulting in SCC. RESULTS: NCC (<14 mm) was observed in 123 (10.2 %) subjects. SCC and ISI were found in 64 (5.3 %) and 28 (2.3 %) subjects, respectively. The prevalence of NCC was significantly higher in females and older subjects, but the occurrence of severe NCC (<12 mm) did not increase with age. The canal size in subjects with SCC or ISI was significantly smaller than in those without SCC (p < 0.0001). The cut-off values of cervical canal stenosis resulting in SCC were 14.8 and 13.9 mm in males and females, respectively. CONCLUSIONS: The prevalence of NCC was considerably lower among asymptomatic healthy volunteers; the cervical canal diameter in subjects with SCC or ISI was significantly smaller than in asymptomatic subjects; NCC is a risk factor for SCC.

Relatively Large Cervical Spinal Cord for Spinal Canal is a Risk factor for Development of Cervical Spinal Cord Compression: A Cross-Sectional Study of 1211 Subjects.

STUDY DESIGN: A cross-sectional study. OBJECTIVE: This study aims to investigate the correlation of the cervical canal and spinal cord size, and evaluate whether the size of the spinal cord relative to the spinal canal is a risk factor for development of cervical spinal cord compression (SCC). SUMMARY OF BACKGROUND DATA: There is little knowledge regarding the relationship between cervical bony canal and spinal cord diameters. Although developmental canal stenosis has been recognized as a risk factor for SCC, the size of the spinal cord relative to the spinal canal has not been similarly discussed. METHODS: Cervical canal anteroposterior (AP) diameters on X-rays and AP diameters and cross-sectional areas of dural sacs and spinal cords on magnetic resonance imaging (MRI) were measured in 1211 healthy volunteers. Correlation between cervical canal diameter on X-rays and AP diameter and cross-sectional area of dural sacs and spinal cords on MRI were assessed. The ratio of the AP diameter of the spinal cord/dural sac was compared between subjects with and without SCC. RESULTS: Spinal canal diameters were not highly correlated with spinal cord AP diameters and cross-sectional areas, although spinal canal diameters were significantly correlated with dural sac AP diameters. The individual difference in the ratio of the AP diameter of the spinal cord/dural sac was large (35%-93%), and the ratio was significantly larger in the subjects with SCC. An AP diameter ratio more than 62% at the C2 to C3 disc level is a risk factor for developing SCC. CONCLUSION: The spinal cord diameter was independent of the spinal canal diameter and the relative size of a spinal cord and spinal canal differed on an individual basis. In addition, the ratio of spinal cord/dural sac in subjects with SCC was significantly larger. Therefore, a relatively large spinal cord could be a risk factor for SCC.

Retrospective exploration of risk factors for L5 radiculopathy following lumbar floating fusion surgery.

BACKGROUND: Lumbar floating fusion occasionally causes postoperative adjacent segment disorder (ASD) at lumbosacral level, causing L5 spinal nerve disorder by L5-S1 foraminal stenosis. The disorder is considered to be one of the major outcomes of L5-S1 ASD, which has not been evaluated yet. The present study aimed to evaluate the incidence and risk factors of postoperative L5 spinal nerve disorder after lumbar interbody fusion extending to the L5 vertebra. METHODS: We evaluated 125 patients with a diagnosis of spondylolisthesis who underwent floating fusion surgery with transforaminal lumbar interbody fusion with average postoperative period of 25.2 months. The patients were regarded as symptomatic with postoperative L5 spinal nerve disorder such as radicular pain/numbness in the lower limbs and/or motor dysfunction. We estimated and compared the wedging angle (frontal view) and height (lateral view) of the lumbosacral junction in pre- and postoperative plain X-ray images and the foraminal ratio (ratio of the narrower foraminal diameter to the wider diameter in the craniocaudal direction) in the preoperative magnetic resonance image. Risk factors for the incidence of L5 spinal nerve disorder were explored using multivariate logistic regression. RESULTS: Eight of the 125 patients (6.4%) were categorized as symptomatic, an average of 13.3 months after surgery. The wedging angle was significantly higher, and the foraminal ratio was significantly decreased in the symptomatic group (both P < 0.05) compared to the asymptomatic group. Multivariate logistic regression analysis of possible risk factors revealed that the wedging angle, foraminal ratio, and multileveled fusion were statistically significant. CONCLUSIONS: Higher wedging angle and lower foraminal ratio in the lumbosacral junction were significantly predictive for the incidence of L5 nerve root disorder as well as multiple-leveled fusion. These findings indicate that lumbosacral fixation should be considered for patients with these risk factors even if they have few symptoms from the L5-S1 junction.

Cervical Disc Protrusion Correlates With the Severity of Cervical Disc Degeneration: A Cross-Sectional Study of 1211 Relatively Healthy Volunteers.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: The purposes of this study were (1) to investigate the frequency and degree of cervical disc degeneration and protrusion on cervical spine magnetic resonance (MR) images and (2) to analyze the correlation between the severity of disc degeneration and disc protrusion. SUMMARY OF BACKGROUND DATA: Cervical disc degenerative changes or protrusion is commonly observed on MR images in healthy subjects. However, there are few large-scale studies, and the frequency and range of these findings in healthy subjects have not been clarified. Moreover, there are no reports regarding the correlation between cervical disc degeneration and disc protrusion. METHODS: Cervical disc degeneration and protrusion were prospectively measured using magnetic resonance imaging in 1211 relatively healthy volunteers. These included at least 100 males and 100 females in each decade of life between the 20s and the 70s. Cervical disc degeneration was defined according to the modified Pfirrmann classification system, and the amount of disc protrusion was evaluated using the anteroposterior diameter of disc protrusion on sagittal MR image. RESULTS: Mild disc degeneration was very common, including 98.0% of both sexes in their 20s. The severity of cervical disc degeneration significantly increased with age in both sexes at every level. The disc degeneration predominantly occurred at C5-C6 and C6-C7. The difference between sexes was not significant except for individuals in their 50s. The average anteroposterior diameter of disc protrusion increased with aging, especially from the 20s to the 40s. The anteroposterior diameter of disc protrusion increased with a progression in the disc degeneration grade. CONCLUSION: Cervical disc degeneration and protrusion were frequently observed in healthy subjects even in their 20s and deteriorated with age. Cervical disc protrusion was significantly correlated with cervical disc degeneration, and spatial cervical disc protrusion was affected by biochemical degenerative changes as observed on MR images. LEVEL OF EVIDENCE: 2.

Abnormal findings on magnetic resonance images of the cervical spines in 1211 asymptomatic subjects.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: The purpose of this study was to determine the prevalence and distribution of abnormal findings on cervical spine magnetic resonance image (MRI). SUMMARY OF BACKGROUND DATA: Neurological symptoms and abnormal findings on MR images are keys to diagnose the spinal diseases. To determine the significance of MRI abnormalities, we must take into account the (1) frequency and (2) spectrum of structural abnormalities, which may be asymptomatic. However, no large-scale study has documented abnormal findings of the cervical spine on MR image in asymptomatic subjects. METHODS: MR images were analyzed for the anteroposterior spinal cord diameter, disc bulging diameter, and axial cross-sectional area of the spinal cord in 1211 healthy volunteers. The age of healthy volunteers prospectively enrolled in this study ranged from 20 to 70 years, with approximately 100 individuals per decade, per sex. These data were used to determine the spectrum and degree of disc bulging, spinal cord compression (SCC), and increased signal intensity changes in the spinal cord. RESULTS: Most subjects presented with disc bulging (87.6%), which significantly increased with age in terms of frequency, severity, and number of levels. Even most subjects in their 20s had bulging discs, with 73.3% and 78.0% of males and females, respectively. In contrast, few asymptomatic subjects were diagnosed with SCC (5.3%) or increased signal intensity (2.3%). These numbers increased with age, particularly after age 50 years. SCC mainly involved 1 level (58%) or 2 levels (38%), and predominantly occurred at C5-C6 (41%) and C6-C7 (27%). CONCLUSION: Disc bulging was frequently observed in asymptomatic subjects, even including those in their 20s. The number of patients with minor disc bulging increased from age 20 to 50 years. In contrast, the frequency of SCC and increased signal intensity increased after age 50 years, and this was accompanied by increased severity of disc bulging. LEVEL OF EVIDENCE: 2.

Incidence of nocturnal leg cramps in patients with lumbar spinal stenosis before and after conservative and surgical treatment.

PURPOSE: To examine the effects of conservative and surgical treatments for nocturnal leg cramps in patients with lumbar spinal stenosis (LSS). Nocturnal leg cramps is frequently observed in patients with peripheral neuropathy. However, there have been few reports on the relationship between nocturnal leg cramps and LSS, and it remains unknown whether conservative or surgical intervention has an impact on leg cramps in patients with LSS. MATERIALS AND METHODS: The subjects were 130 LSS patients with low back and leg pain. Conservative treatment such as exercise, medication, and epidural block was used in 66 patients and surgical treatment such as decompression or decompression and fusion was performed in 64 patients. Pain scores and frequency of nocturnal leg cramps were evaluated based on self-reported questionnaires completed before and 3 months after treatment. RESULTS: The severity of low back and leg pain was higher and the incidence of nocturnal leg cramps was significantly higher before treatment in the surgically treated group compared with the conservatively treated group. Pain scores improved in both groups after the intervention. The incidence of nocturnal leg cramps was significantly improved by surgical treatment (p=0.027), but not by conservative treatment (p=0.122). CONCLUSION: The findings of this prospective study indicate that the prevalence of nocturnal leg cramps is associated with LSS and severity of symptoms. Pain symptoms were improved by conservative or surgical treatment, but only surgery improved nocturnal leg cramps in patients with LSS. Thus, these results indicate that the prevalence of nocturnal leg cramps is associated with spinal nerve compression by LSS.

Conservative and surgical treatment improves pain and ankle-brachial index in patients with lumbar spinal stenosis.

PURPOSE: The pathological mechanism of lumbar spinal stenosis is reduced blood flow in nerve roots and degeneration of nerve roots. Exercise and prostaglandin E1 is used for patients with peripheral arterial disease to increase capillary flow around the main artery and improve symptoms; however, the ankle-brachial index (ABI), an estimation of blood flow in the main artery in the leg, does not change after treatment. Lumbar spinal nerve roots contain somatosensory, somatomotor, and unmyelinated autonomic nerves. Improved blood flow by medication with prostaglandin E1 and decompression surgery in these spinal nerve roots may improve the function of nerve fibers innervating muscle, capillary, and main vessels in the lower leg, resulting in an increased ABI. The purpose of the study was to examine whether these treatments can improve ABI. MATERIALS AND METHODS: One hundred and seven patients who received conservative treatment such as exercise and medication (n=56) or surgical treatment (n=51) were included. Low back pain and leg pain scores, walking distance, and ABI were measured before treatment and after 3 months of conservative treatment alone or surgical treatment followed by conservative treatment. RESULTS: Low back pain, leg pain, and walking distance significantly improved after both treatments (p<0.05). ABI significantly increased in each group (p<0.05). CONCLUSION: This is the first investigation of changes in ABI after treatment in patients with lumbar spinal stenosis. Improvement of the spinal nerve roots by medication and decompression surgery may improve the supply of blood flow to the lower leg in patients with lumbar spinal stenosis.

Failure of conservative treatment for thoracic spine fracture in ankylosing spondylitis: delayed neurological deficit due to spinal epidural hematoma.

Patients with ankylosing spondylitis (AS) are prone to spinal fracture after even minor trauma. We report a case of thoracic spinal fracture in a patient with AS who developed a secondary neurological deficit due to delayed diagnosis and prolonged conservative treatment. When the neurological deficit occurred, the fractured segment showed no displacement, but a spinal epidural hematoma was present. Surgical treatment produced significant neurological improvement, although incomplete paralysis persisted.

A prospective randomized controlled study comparing transforaminal lumbar interbody fusion techniques for degenerative spondylolisthesis: unilateral pedicle screw and 1 cage versus bilateral pedicle screws and 2 cages.

OBJECT: Many surgeons currently prefer to use transforaminal lumbar interbody fusion (TLIF), placing 1 unilateral pedicle screw (PS) and 1 cage. However, no study has examined whether unilateral fixation improves surgical outcome. The authors conducted a prospective randomized controlled trial with a minimum 2-year follow-up to analyze TLIF outcomes for 2 techniques: placement of a unilateral PS and a cage compared with placement of bilateral PSs and 2 cages. METHODS: Fifty patients with degenerative spondylolisthesis undergoing single-level TLIF were randomly assigned to receive either unilateral or bilateral fixation. Parameters compared between the groups were surgical invasiveness, severity of intermittent claudication, pre- and postoperative visual analog scale (VAS) scores (from 0 to 10 for back pain, lower-extremity pain, and lower-extremity numbness), postoperative disability scores for lumbar spinal disorders (Japanese Orthopaedic Association Back Pain Evaluation Questionnaire [JOABPEQ]), and fusion rates. RESULTS: The mean operative time for TLIF was significantly (p = 0.05) shorter and mean estimated blood loss was significantly lower in the unilateral than in the bilateral group. Intermittent claudication improved in response to each technique, but there was no significant intergroup difference. The unilateral group had a nonsignificant tendency toward less improvement in VAS score for back pain (1.5 vs 3.7 for the bilateral group) and exhibited significantly less improvement in VAS score for lower-extremity pain (2.1 vs 5.1, respectively) and numbness (1.7 vs 4.4). There were no significant differences between the groups in postsurgical scores for all 5 items of the JOABPEQ. The fusion rates were 87.5% (21 of 24 patients) in the unilateral group and 95.7% (22 of 23) in the bilateral group. CONCLUSIONS: Transforaminal lumbar interbody fusion involving unilateral PS fixation and a single-cage technique is less invasive than a 2-cage technique and bilateral fixation, and it improved patients' symptoms. However, it resulted in less improvement in back pain, lower-extremity pain, and lower-extremity numbness. When considering unilateral PS fixation and a single cage, the surgeon should be aware of the potential limitations of this technique. Clinical trial registration no.: UMIN000007833 (UMIN).

Normal morphology, age-related changes and abnormal findings of the cervical spine. Part II: Magnetic resonance imaging of over 1,200 asymptomatic subjects.

PURPOSE: The aim of this study is to establish standard MRI values for the cervical spinal canal, dural tube, and spinal cord, to evaluate age-related changes in healthy subjects, and to assess the prevalence of abnormal findings in asymptomatic subjects. METHODS: The sagittal diameter of the spinal canal and the sagittal diameter and cross-sectional area of the dural tube and spinal cord were measured on MRIs of 1,211 healthy volunteers. These included at least 100 men and 100 women in each decade of life between the third (20s) and eighth (70s). Abnormal findings such as spinal cord compression and signal changes in the spinal cord were recorded. RESULTS: The sagittal diameter of the spinal canal was 11.2 ± 1.4 mm [mean ± standard deviation (SD)]/11.1 ± 1.4 mm (male/female) at the mid-C5 vertebral level, and 9.5 ± 1.8/9.6 ± 1.6 mm at the C5/6 disc level. The cross-sectional area of the spinal cord was 78.1 ± 9.4/74.4 ± 9.4 mm² at the mid-C5 level and 70.6 ± 11.7/68.9 ± 11.3 mm² at the C5/6 disc level. Both the sagittal diameter and the axial area of the dural tube and spinal cord tended to decrease with increasing age. This tendency was more marked at the level of the intervertebral discs than at the level of the vertebral bodies, especially at the C5/6 intervertebral disc level. The spinal cord occupation rate in the dural tube at the C5 vertebral body level averaged 58.3 ± 7.0%. Spinal cord compression was observed in 64 cases (5.3%) and a T2 high-signal change was observed in 28 cases (2.3%). CONCLUSIONS: Using MRI data of 1,211 asymptomatic subjects, the standard values for the cervical spinal canal, dural tube, and spinal cord for healthy members of each sex and each decade of life and the age-related changes in these parameters were established. The relatively high prevalence of abnormal MRI findings of the cervical spine in asymptomatic individuals emphasizes the dangers of predicating operative decisions on diagnostic tests without precisely correlating these findings with clinical signs and symptoms.

Age-related changes in osseous anatomy, alignment, and range of motion of the cervical spine. Part I: Radiographic data from over 1,200 asymptomatic subjects.

PURPOSE: This study aimed to establish radiographic standard values for cervical spine morphometry, alignment, and range of motion (ROM) in both male and female in each decade of life between the 3rd and 8th and to elucidate these age-related changes. METHODS: A total of 1,230 asymptomatic volunteers underwent anteroposterior (AP), lateral, flexion, and extension radiography of the cervical spine. There were at least 100 men and 100 women in each decade of life between the 3rd and 8th. AP diameter of the spinal canal, vertebral body, and disc were measured at each level from the 2nd to 7th cervical vertebra (C2-C7). C2-C7 sagittal alignment and ROM during flexion and extension were calculated using a computer digitizer. RESULTS: The AP diameter of the spinal canal was 15.8 ± 1.5 [mean ± standard deviation (SD)] mm at the mid-C5 level, and 15.5 ± 2.0 mm at the C5/6 disc level. The disc height was 5.8 ± 1.3 mm at the C5/6 level, which was the minimum height, and the maximum height was at the C6/7 level. Both the AP diameter of the spinal canal and disc height decreased gradually with increasing age. The C2-C7 sagittal alignment and total ROM were 13.9 ± 12.3° in lordosis and 55.3 ± 16.0°, respectively. The C2-C7 lordotic angle was 8.0 ± 11.8° in the 3rd decade and increased to 19.7 ± 11.3 in the 8th decade, whereas the C2-C7 ROM was 67.7 ± 17.0° in the 3rd decade and decreased to 45.0 ± 12.5 in the 8th decade. The extension ROM decreased more than the flexion ROM, and lordotic alignment progressed with increasing age. There was a significant difference in C2-C7 alignment and ROM between men and women. CONCLUSIONS: The standard values and age-related changes in cervical anatomy, alignment, and ROM for males and females in each decade between the 3rd and 8th were established. Cervical lordosis in the neutral position develops with aging, while extension ROM decreases gradually. These data will be useful as normal values for the sake of comparison in clinical practice.

An unusually rapid spontaneous recovery in a patient with spinal epidural hematoma.

BACKGROUND: Spontaneous epidural hematoma is a rare condition, which usually requires urgent surgical treatment. OBJECTIVES: To report two cases of spontaneous epidural hematoma, one of which was treated conservatively, and the other surgically, and discuss the possibility of unusual spontaneous recovery and treatment decision-making. CASE REPORT: We encountered 2 patients with spontaneous spinal epidural hematoma, both of whom were taking an anti-platelet agent, producing severe paraplegia. One patient with a hematoma at C2-T3 experienced a rapid neurological recovery while a magnetic resonance imaging scan was being performed. A complete resolution of the hematoma and complete neurological recovery ensued without surgical intervention. A second patient with a hematoma at T10-12 showed no neurological recovery up to the time emergency surgery started and was treated surgically by T10-12 laminectomy and excision of the hematoma. Neurological function returned to normal in both patients. CONCLUSION: The occurrence of spontaneous recovery in some patients makes the decision for surgery difficult. Emergency physicians need to be aware of the possibility of spontaneous rapid neurological recovery in patients with spinal epidural hematoma. To avoid unnecessary surgery in patients who will spontaneously have neurological recovery, neurological evaluations need to be repeatedly performed up to the time the emergency surgery begins. However, unfortunately, there is no diagnostic tool at present to identify the patients who recover spontaneously, and the interval between onset and surgery is correlated with clinical results, therefore, conservative treatment should be prescribed only for those patients who exhibit improving neurological signs early in the clinical course.

Single-level instrumented posterolateral fusion versus non-instrumented anterior interbody fusion for lumbar spondylolisthesis: a prospective study with a 2-year follow-up.

BACKGROUND: Surgery for lumbar spondylolisthesis is widely performed. However, there have been no reports comparing posterolateral and anterior interbody fusion prospectively. We compared instrumented posterolateral fusion with anterior interbody fusion for L4 spondylolisthesis in a prospective study. METHODS: Forty-six patients diagnosed with L4 degenerated spondylolisthesis were divided into two groups. Twenty-two consecutive patients underwent non-instrumented anterior interbody fusion using an iliac bone graft (ALIF; L4-L5 level), and 24 consecutive patients underwent instrumented posterolateral fusion with local bone (PLF; L4-L5 level). The rates of bone union, visual analog scale (VAS) score, Japanese Orthopedic Association (JOA) score, Oswestry Disability Index (ODI), surgical invasion, and complications were evaluated before and 2 years after surgery. RESULTS: Age, VAS score, JOA score, and ODI were not significantly different between the two groups before surgery (P > 0.05). Success of bone union between the two groups was not significantly different (P > 0.05). Blood loss during surgery was significantly less; however, periods of bed rest and hospital stay were significantly longer in the ALIF group (P < 0.05). Overall patient satisfaction, and low back and leg pain in both groups were significantly improved after surgery; however, low back pain showed greater improvement in the ALIF group compared with the PLF group (P < 0.05). Complications such as donor site pain (4 patients in the ALIF group) and dural tearing (3 patients in the PLF group) were observed. CONCLUSIONS: If single level fusion for L4 spondylolisthesis is performed, both anterior and posterior methods reduce patients' low back and leg pain. Improvement of low back pain was significantly greater after ALIF; however, periods of hospital stay and of bed rest were significantly longer.

Effectiveness of L2 spinal nerve infiltration for selective discogenic low back pain patients.

BACKGROUND: It has been reported that rat L5/6 lumbar discs are innervated mainly by L2 dorsal root ganglion neurons. We previously reported that L2 spinal nerve infiltration was effective for discogenic low back pain (DLBP) patients, although the diagnosis was based only on the results of physical examination, plain films, and magnetic resonance imaging (MRI). The purpose of the current study was to evaluate L2 spinal nerve block for DLBP patients retrospectively based on MRI findings and surgical results. METHODS: A total of 62 patients with only LBP and no accompanying radicular pain were investigated. Patients had only one level of disc degeneration on MRI. When pain was provoked during discography, we performed surgery at the next stage (40 patients). In all, 22 patients were excluded owing to negative discography results. Of the 40 patients, we evaluated 25 strictly selected patients suffering from DLBP. DLBP was diagnosed when the patient experienced pain relief at least 2 years after anterior lumbar interbody fusion. Fifteen patients who did not show pain relief after surgery were used for the non-DLBP group. L2 spinal nerve infiltration using 1.5 ml of lidocaine was performed in all 40 patients before surgery. The visual analogue scale (VAS) score after L2 spinal nerve infiltration was recorded, and an association of L2 spinal nerve infiltration and DLBP was explored. RESULTS: Low back pain scores assessed using the VAS score, the Japanese Orthopedic Association score, and the Oswestry Disability Index score in the two groups were not significantly different. L 2 spinal nerve infiltration was effective for 27 patients but not effective for 13 patients; the VAS score after 15 min and 2 h improved in the DLBP group compared with that of the non-DLBP group (P < 0. 05). L2 spinal nerve infiltration was more effective in DLBP patients (21 patients, 84%) than in the non-DLBP group (6 patients, 40%) (P < 0.05). CONCLUSIONS: In the current study, L2 spinal nerve infiltration was effective in 84% of selected DLBP patients and is thought to be a useful tool for diagnosing DLBP. However, we should take into consideration that the L2 spinal nerve infiltration was effective in 40% of non-DLBP patients as well.

Examining risk factors for posterior migration of fusion cages following transforaminal lumbar interbody fusion: a possible limitation of unilateral pedicle screw fixation.

OBJECT: Because the authors encountered 4 cases of hardware migration following transforaminal lumbar interbody fusion, a retrospective study was conducted to identify factors influencing the posterior migration of fusion cages. METHODS: Patients with lumbar degenerative disc disease (125 individuals; 144 disc levels) were treated using transforaminal lumbar interbody fusion and followed for 12-33 months. Medical records and pre- and postoperative radiographs were reviewed, and factors influencing the incidence of cage migration were analyzed. RESULTS: Postoperative cage migration was found in 4 patients at or before 3 months. Because all the cages that migrated postoperatively were bullet-shaped (Capstone), only these cages were analyzed. The analysis of preoperative radiographs revealed that higher posterior disc height ([PDH] > or = 6 mm) significantly increased the incidence of postoperative cage migration, but percent slippage, translation, range of motion, and Cobb angle did not. The incidence of cage migration in patients with unilateral fixation (3 [8.3%] of 36) was not significantly different from that in patients with bilateral fixation (1 [2.1%] of 48). Patients who had scoliotic curvature with a Cobb angle > 10 degrees when treated with unilateral fixation demonstrated a tendency to have more frequent postoperative cage migration than patients treated with bilateral fixation. To examine the influence of the height of fusion cages, a value obtained by subtracting preoperative anterior disc height (ADH) or PDH from cage height was defined as "Cage height - ADH" (or "Cage height -PDH"). The analysis revealed that the value for "Cage height -ADH" as well as "Cage height -PDH" was significantly lower in migrated levels than in nonmigrated levels, suggesting that the choice of undersized cages may increase the incidence of cage migration. CONCLUSIONS: The results suggest that the use of a bullet-shaped cage, higher PDH, the presence of scoliotic curvature, and undersized fusion cages are possible risk factors for cage migration. One patient with postoperative cage migration following bilateral screw fixation underwent revision surgery, and the pedicle screw fixation was found to be disrupted. Other than in this patient, cage migration occurred only in those treated by unilateral fixation. The potential for postoperative cage migration and limitations of unilateral fixation should be considered by spine surgeons.