Are T1-Weighted Three-Dimensional Magnetic Resonance Images Inferior to T2-Weighted Images for Diagnosing Lumbar Foraminal Stenosis in the Fifth Lumbar Nerve Root? A Prospective, Comparative Study in Identical Patients.

Introduction: Imaging analysis of foraminal stenosis in the fifth lumbar (L5) nerve root remains to be a challenge because of the anatomical complexity of the lumbosacral transition. T2-weighted three-dimensional (3D) magnetic resonance images (MRI) have been dominantly used for diagnosis of lumbar foraminal stenosis, while the reliability of T1-weighted images (WI) has also been proven. In this study, we aim to compare the reliability and reproducibility of T1- and T2-weighted 3D MRI in diagnosing lumbar foraminal stenosis (LFS) of the L5 nerve root. Methods: In this study, 39 patients with unilateral L5 radiculopathy (20 had L4-L5 intracanal stenosis; 19 had L5-S foraminal stenosis) were enrolled, prospectively. T1- and T2-weighted 3D lumbar MRI were obtained from each patient. T1WI and T2WI were blinded and then separately reviewed twice by four examiners randomly. The examiners were instructed to answer the side of LFS or absence of LFS. The correct answer rate, sensitivity, specificity, and area under the curve were analyzed and compared between T1WI and T2WI. Also, intra- and interobserver agreements were calculated using kappa (κ)-statistics and compared in the same manner. Results: The average correct answer rate, sensitivity, specificity, and area under the curve of the T1WI/T2WI were 84.6%/80.1%, 82.9%/80.3%, 86.3%/81.3%, and 0.846/0.801, respectively. The intraobserver κ-values of the four examiners ranged from 0.692 to 0.916 (average: 0.762) and from 0.669 to 0.801 (average: 0.720) for T1WI and T2WI, respectively. The interobserver κ-values calculated in a round-robin manner (24 combinations in total) ranged from 0.544 to 0.790 (average: 0.657) and from 0.524 to 0.828 (average: 0.652), respectively. Conclusions: As per our findings, T1- and T2-weighted 3D MRI were determined to have nearly equivalent reliability and reproducibility in terms of diagnosing LFS of the L5 nerve root.

Photoexcited Anhydrous Proton Conductivity in Coordination Polymer Glass.

Optically switchable proton-conductive materials will enable the development of artificial ionic circuits. However, most switchable platforms rely on conformational changes in crystals to alter the connectivity of guest molecules. Guest dependency, low transmittance, and poor processability of polycrystalline materials hinder overall light responsiveness and contrast between on and off states. Here, we optically control anhydrous proton conductivity in a transparent coordination polymer (CP) glass. Photoexcitation of tris(bipyrazine)ruthenium(II) complex in CP glass causes reversible increases in proton conductivity by a factor of 181.9 and a decrease in activation energy barrier from 0.76 eV to 0.30 eV. Modulating light intensity and ambient temperature enables total control of anhydrous protonic conductivity. Spectroscopies and density functional theory studies reveal the relationship between the presence of proton deficiencies and the decreasing activation energy barrier for proton migrations.

Facet cysts in the subaxial cervical spine: Case series focused on radiological and histopathological findings with a scoping review.

BACKGROUND: Facet cysts in the subaxial cervical spine are a relatively rare cause of neuropathy. This case series aimed to investigate the radiological and histopathological features and surgical results of these lesions, and provide possible mechanisms of cyst development. METHODS: Thirteen subaxial cervical facet cysts in 12 patients were diagnosed on the basis of magnetic resonance imaging and computed tomography with facet arthrography. Surgical outcomes were evaluated according to the Japanese Orthopaedic Association scores for cervical myelopathy, or Tanaka's scores for cervical radiculopathy. These results were presented in combination with a scoping review of the literature. RESULTS: Seven cysts were found in the posteromedial region, and six in the posterolateral portion of the spinal canal. Computed tomography revealed degeneration of all involved facet joints. All patients underwent decompression, and the mean recovery rates of Japanese Orthopaedic Association scores and Tanaka's scores were 57.1% and 87.5%, respectively. Histopathologically, all cysts were continuous with the degenerated ligamentum flavum. In the scoping review, the patients' mean age was 65.1 years. The cysts were distributed as follows: 3.6% at C2-3, 10.7% at C3-4, 14.3% at C4-5, 5.4% at C5-6, 7.1% at C6-7, and 58.9% at C7-T1. The presenting symptoms were myelopathy (49.4%) and radiculopathy (50.0%). Radiologically, 55% and 45% of the cysts were of the posteromedial and posterolateral types. Of the patients, 76.9% underwent decompression only, and 23.1% had concomitant fusion. Cyst recurrence was not observed in the mean follow-up period of 15.1 months. CONCLUSIONS: The pathogenesis of cysts is closely related to degenerative changes in the facet joint and ligamentum flavum, and rupture in degenerated ligaments can develop into a cavity, which contributes to cyst formation. The scoping review suggests that cyst resection generally results in positive outcomes without recurrence in either decompression alone or concomitant fusion.

Destructive Spondyloarthropathy due to Congenital Insensitivity to Pain with Anhidrosis: A Case Report of Long-Term Follow-Up.

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal-recessive hereditary neuropathy causing congenital loss of pain sensation, thermoception, and perspiration. CIPA sometimes causes destructive spondyloarthropathy, the so-called Charcot spine, because of insensitivity to pain stimuli. Herein, we report a case of CIPA with severe spinal destruction treated by multiple spinal reconstructive surgeries and over 15 years of follow-up. A 15-year-old male patient who had been diagnosed with CIPA at the age of 17 months presented to his previous spine clinic with gait disturbance due to muscle weakness in his lower extremities. Imaging studies revealed that collapsed L3 and L4 vertebral bodies involved the spinal canal, and it was treated by L3-L4 instrumented posterior fusion. Fourteen years after surgery, the patient became unable to walk again due to spinal canal stenosis at the proximal fusion segment. An L2-L3 posterior interbody fusion alleviated his gait ability for 2 years; however, he became unable to stand again because of the collapsed fusion segment that caused severe lumbar kyphosis. Subsequently, a two-staged posterior and anterior fusion surgery from the lower thoracic spine to the pelvis was performed, and spinal fusion and neurological recovery were achieved 3 years after surgery. A kyphotic deformity in patients with CIPA-associated Charcot spine could be favorably treated by a long spinal fusion in combination with a reconstruction of an anterior spinal column. This case report provides a significant lesson for a treatment of CIPA-associated Charcot spine.

Neurogenic lower urinary tract dysfunction in association with severity of degenerative spinal diseases: Short-term outcomes of decompression surgery.

OBJECTIVES: Cervical myelopathy (CM) and lumbar canal stenosis (LCS) are common degenerative spinal diseases among the elderly, and the major associated complaints include lower urinary tract symptoms (LUTS). The aim of this study was to investigate subjective and objective urological parameters of patients undergoing decompression surgery for CM and LCS. METHODS: We retrospectively reviewed patients who underwent evaluation by the International Prostate Symptom Score (IPSS) and uroflowmetry before decompression surgery for CM and LCS. Patients with comorbidities that can affect LUTS were excluded. Postoperative changes were evaluated in patients followed up within 1 month. RESULTS: Among referrals to urological consultations for LUTS, 231 patients were evaluated preoperatively. Moderate-severe urinary symptoms (IPSS ≥ 8) were present in 59.8% of 92 CM patients and 64.0% of 139 LCS patients. Poor voiding patterns defined as maximum urinary flow rate <12 mL/s or postvoid residual volume >100 mL were identified in 26.1% of CM and 25.2% of LCS. While IPSS did not associate with disease severity, poor voiders presented with worse Japanese Orthopedic Association scores. Moreover, poor voiders suffered for a longer period of time from orthopedic symptoms due to LCS. In followed-up patients (CM, n = 32; LCS, n = 47), total IPSS, storage subscores, and voiding subscores were significantly improved after surgery, as was voiding time from uroflowmetry. CONCLUSIONS: This study demonstrated high prevalence of lower urinary tract dysfunction of CM and LCS as well as short-term effectiveness of decompression surgery. These results would encourage urologists to consider an orthopedic consultation when lower urinary tract dysfunction is identified in patients with degenerative spinal diseases.

Anterior Decompression and Fusion Versus Laminoplasty for Cervical Myelopathy Caused by Soft Disk Herniation: A Long-term Prospective Multicenter Study.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: The purpose of this study was to determine whether laminoplasty (LP) is comparable for myelopathy caused by cervical disk herniation (CDH). SUMMARY OF BACKGROUND DATA: Anterior decompression and fusion (ADF) has conventionally been used for myelopathy caused by CDH with stable outcomes. However, recurrence of myelopathy due to adjacent segment degeneration are its drawbacks. The efficacy of LP without discectomy has been sporadically reported, but no long-term prospective study has been conducted to verify it. MATERIALS AND METHODS: Patients with cervical myelopathy caused by CDH were studied. The first 30 patients and the next 30 patients were treated with ADF and LP, respectively. The outcomes were compared between the 22 ADF patients and the 20 LP patients who had completed the follow-up examination scheduled 10 years after surgery. RESULTS: There was no statistically significant difference in the postoperative severity or recovery rate of myelopathy between the 2 groups 10 years after surgery. One patient in the ADF group underwent LP for secondary myelopathy due to adjacent segment degeneration 2 years after the surgery. Reoperation was not required for patients in the LP group. Postoperative neck pain was significantly more severe in the LP group than in the ADF group. CONCLUSIONS: ADF and LP for cervical myelopathy caused by CDH achieve similarly favorable outcomes. Recurrence of myelopathy caused by adjacent segment degeneration is a disadvantage of ADF while residual neck pain is a disadvantage of LP.

Rate of spinal surgery in a rapidly aging society: the 27-year changes in Miyagi prefecture, Japan.

BACKGROUND: Japan has had a rapidly aging population during the past 30 years. This study aimed to investigate longitudinal changes in the surgical rate for spinal disorders in Miyagi Prefecture (2.35 million inhabitants) with a similar population composition to Japan. METHODS: Data of spinal surgeries were collected using the spine registry by Tohoku University Spine Society. Data on the annual number of spinal surgeries between 1988 and 2014 of all populations, in those aged ≥65 years old, in those aged ≥75 years old, and for each pathology were collected. The annual surgical rate per 100,000 inhabitants was calculated. RESULTS: The surgical rate in 2010-2014 in total, at ≥65 years old, and at ≥75 years old showed 3.2-, 3.8- and 7.1-fold increases, respectively, compared with that in 1988-1989. Degenerative spinal disorders, spinal trauma and pyogenic spondylitis markedly increased, while metastatic spinal tumor and tuberculous spondylitis decreased over time. The surgical rate at ≥75 years with lumbar spinal stenosis showed a 12.6-time increase. CONCLUSIONS: During a rapid period of aging, the rate of spinal surgeries has markedly increased, particularly, that for degenerative disorders. This is the first report on the long-term longitudinal changes in the rate of spinal surgery.

Reoperation Rates after Laminoplasty for Cervical Disorders: A 26-Year Period Survival Function Method Analysis.

INTRODUCTION: Laminoplasty is a common surgery for cervical myelopathy. Previous studies have analyzed the reoperation rates in posterior decompression surgeries of the cervical spine. However, few studies have solely focused on midline-splitting laminoplasty (MSL) using a large number of patients. This aims to analyze the reoperation rates after MSL using the survival function method. METHODS: Between 1988 and 2013, 4,208 MSLs were performed as a primary operation for cervical myelopathy and enrolled in our spinal surgery registration system. The Kaplan-Meier survival function method was used to analyze the rates of reoperation. RESULTS: Of 4,208 patients with primary MSL, 40 underwent reoperation for neurological complications. The overall reoperation rate was 0.26%, 0.64%, 0.83%, 0.93%, and 0.95% at 1, 5, 10, 20, and >20 years, respectively. The causes of reoperation were postoperative cervical radiculopathy in 10 patients, stenosis at an adjacent level in 8, stenosis due to failed "open-door" lamina in 6, instability of the cervical spine in 4, cervical disc herniation in 3, elongation of ossification of the posterior longitudinal ligament in 3, spinal cord injury in 1, fracture of the cervical spine in 1, postoperative scar formation in 1, ossification of anterior longitudinal ligament in 1, and unknown in 2. The number of patients with surgical site infection (SSI) who needed surgical debridement was 34 (0.81%). CONCLUSIONS: Excluding reoperations for SSI, the reoperation rate of MSL was approximately 1.0% at the maximum of 26 years after surgery. MSL was determined to be a reliable surgical procedure regarding postoperative complications requiring additional surgeries.

An increase in the degree of olisthesis during axial loading reduces the dural sac size and worsens clinical symptoms in patients with degenerative spondylolisthesis.

BACKGROUND CONTEXT: Previous studies have shown that axial loading during magnetic resonance imaging (MRI) significantly reduces the size of the dural sac compared with conventional MRI in patients with degenerative lumbar disease. In our previous study, axial-loaded MRI showed a significantly larger degree of olisthesis than conventional MRI in patients with degenerative spondylolisthesis (DS). Furthermore, the degree of olisthesis on axial-loaded MRI correlated more strongly with that observed on X-ray in the upright position. However, no study has investigated whether or not the increase in the degree of olisthesis during axial loading correlates with the reduction in the dural sac size and affects the severity of clinical symptoms in patients with DS. PURPOSE: The objective of this study was to determine whether or not the increase in the degree of olisthesis correlates with the reduction of the dural sac cross-sectional area (DCSA) detected on axial-loaded MRI and worsens the severity of clinical symptoms in patients with DS. STUDY DESIGN/SETTING: This is an imaging cohort study. PATIENT SAMPLE: A total of 41 consecutive patients with DS were prospectively evaluated in this study. OUTCOME MEASURES: The outcome measures include the degree of olisthesis, the DCSA, the Pearson correlation coefficient, and the severity of clinical symptoms. MATERIALS AND METHODS: The differences in the degree of olisthesis and the DCSA between conventional and axial-loaded MRIs were determined. The Pearson correlation coefficient of the increase in the degree of olisthesis with the reduction in the DCSA during axial loading was calculated. The reduction in the DCSA and the severity of clinical symptoms in patients exhibiting a ≥2-mm increase in the degree of olisthesis were compared with those in patients exhibiting a <2-mm increase. RESULTS: The increase in the degree of olisthesis was significantly correlated with the reduction in the DCSA during axial loading (Pearson correlation coefficient=0.63, p<.001). The reduction in the DCSA during axial loading in patients with a ≥2-mm increase in the degree of olisthesis (26±3 mm2) was significantly greater than in those with a <2-mm increase (13±2 mm2) (p<.01). Clinical symptoms such as walking distance and activity of daily living evaluated using the Japanese Orthopaedic Association score were significantly worse in patients with a ≥2-mm increase in the degree of olisthesis (117±19 m and 6.7±0.5 points, respectively) than in those with a <2-mm increase (236±36 m and 8.4±0.4 points, respectively) (p<.05). CONCLUSIONS: The present study demonstrated that the increase in the degree of olisthesis was significantly correlated with the reduction in the dural sac size detected on axial-loaded MRI and worsened the severity of clinical symptoms in patients with DS. These results suggest that axial-loaded MRI may be a useful imaging study for detecting dynamic changes in the degree of olisthesis during axial loading to the lumbar spine related to the narrowing of the spinal canal and the severity of clinical symptoms in the assessment of patients with DS.

Increasing Incidence of Degenerative Spinal Diseases in Japan during 25 Years: The Registration System of Spinal Surgery in Tohoku University Spine Society.

Spinal disorders affect mainly older people and cause pain, paralysis and/or deformities of the trunk and/or extremities, which could eventually disturb locomotive functions. For ensuring safe and high-quality treatment of spinal disorders, in 1987, the Tohoku University Spine Society (TUSS) was established by orthopedic departments in Tohoku University School of Medicine and its affiliated hospitals in and around Miyagi Prefecture. All spine surgeries have been enrolled in the TUSS Spine Registry since 1988. Using the data from this registration system between 1988 and 2012, we demonstrate here the longitudinal changes in surgical trends for spinal disorders in Japan that has rushed into the most advanced "aging society" in the world. In total, data on 56,744 surgeries were retrieved. The number of spinal surgeries has annually increased approximately 4-fold. There was a particular increase among patients aged ≥ 70 years and those aged ≥ 80 years, with a 20- to 90-fold increase. Nearly 90% of the spinal operations were performed for degenerative disorders, with their number increasing approximately 5-fold from 705 to 3,448. The most common disease for surgery was lumbar spinal stenosis (LSS) (35.9%), followed by lumbar disc herniation (27.7%) and cervical myelopathy (19.8%). In 2012, approximately half of the patients with LSS and cervical myelopathy were ≥ 70 years of age. In conclusion, the number of spinal operations markedly increased during the 25-year period, particularly among older patients. As Japan has a notably aged population, the present study could provide a near-future model for countries with aging population.

Changes in lumbar spondylolisthesis on axial-loaded MRI: do they reproduce the positional changes in the degree of olisthesis observed on X-ray images in the standing position?

BACKGROUND CONTEXT: Axial-loaded magnetic resonance imaging (MRI) can partially simulate the lumbar spine in patients in a standing position and potentially provides additional imaging findings that cannot be obtained with conventional MRI in the clinical assessment of patients with degenerative lumbar disease. Previous studies have shown that axial-loaded MRI demonstrates a significant reduction in the size of the dural sac compared with conventional MRI. However, there has been no study to compare the degree of olisthesis among conventional MRI, axial-loaded MRI, and upright X-ray imaging in patients with degenerative spondylolisthesis (DS). PURPOSE: The purpose of the study is to determine whether axial-loaded MRI can demonstrate similar positional changes in lumbar olisthesis as those detected on upright lateral X-ray in patients with DS. STUDY DESIGN: This is an imaging cohort study. PATIENT SAMPLE: A total of 43 consecutive patients with DS exhibiting olisthesis of 3 mm or more on X-ray images in the standing position were prospectively evaluated in this study. OUTCOME MEASURES: The degree of olisthesis, intraclass correlation coefficient (ICC), and percentage of patients exhibiting olisthesis of 3 mm or more on MRI. METHODS: The degree of olisthesis was measured on conventional MRI, axial-loaded MRI, and lateral X-ray imaging performed in the upright position. The degree of olisthesis was compared among the three imaging techniques. The ICC values for the measurements of olisthesis between X-ray studies and conventional and axial-loaded MRI were calculated and compared. The percentage of patients exhibiting olisthesis of 3 mm or more was compared between conventional MRI and axial-loaded MRI. RESULTS: The degree of olisthesis on axial-loaded MRI (5.9±2.5 mm) was significantly greater than that observed on conventional MRI (4.4±2.4 mm) (p<.05) although the degrees on conventional and axial-loaded MRI were significantly smaller than that on upright X-ray images (7.1±2.8 mm) (p<.05). The ICC between axial-loaded MRI and X-ray imaging (0.75, 95% confidence interval: 0.58-0.85) was considerably greater than that observed between conventional MRI and X-ray imaging (0.40, 95% confidence interval: 0.11-0.62). The percentage of patients exhibiting olisthesis of 3 mm or more was significantly higher on axial-loaded MRI (91%) than on conventional MRI (63%) (p<.01). CONCLUSIONS: Axial-loaded MRI demonstrates a significantly larger degree of olisthesis than conventional MRI. In addition, the degree of olisthesis on axial-loaded MRI was found to be more strongly correlated with that observed on X-ray studies in the upright position. Furthermore, the use of axial-loaded MRI significantly reduced the misdiagnosis of olisthesis of 3 mm or more that was detected on X-ray imaging. These results suggest that axial-loaded MRI may be superior to identify the olisthesis of the lumbar spine and show the degrees of olisthesis correlated to those detected on upright X-ray imaging. Further studies should be needed to clarify the actual value of these findings on axial-loaded MRI and provide the evidence to support its clinical significance in the assessment of patients with DS.

Reoperation rates after fenestration for lumbar spinal canal stenosis: a 20-year period survival function method analysis.

PURPOSE: Fenestration is the gold standard surgery for lumbar spinal canal stenosis in Japan. Several previous studies have analyzed the reoperation rates in large numbers of patients undergoing several surgical procedures such as laminectomy with or without instrumented spinal fusion; however, there have been few studies focusing solely on fenestration. The purpose of this study was to calculate the reoperation rates after fenestration using the survival function method. METHODS: Form 1988-2007, 6,998 surgeries for lumbar spinal canal stenosis occurred in Miyagi prefecture, Japan, and these patients were enrolled by the spinal surgery registration system of the Department of Orthopaedic Surgery, Tohoku University. Among these, 5,835 surgeries involved fenestration as a primary surgery and for those who underwent ≥2 lumbar surgeries we analyzed the reoperation rates using the Kaplan-Meier method. RESULTS: Among the 5,835 patients undergoing primary fenestration, 215 patients underwent 221 revisions; 112 included the same spinal levels and 103 were revised only at other levels as primary fenestration. The overall reoperation rates were 0.8% at 1 year, 2.9% at 5 years, 5.2% at 10 years, 7.5% at 15 years and 8.6% at >17.7 years. Reoperation rates for those at the same spinal levels were 0.6% at 1 year, 1.7% at 5 years, 2.7% at 10 years, 3.8% at 15 years, and 4.1% at >17.0 years. CONCLUSIONS: Fenestration can be performed at low cost using standard spinal surgery equipments. The reoperation rates of this procedure were lower than previously reported for several other surgical procedures.

Bilateral spondylolysis of inferior articular processes of the fourth lumbar vertebra: a case report.

Lumbar spondylolysis, a well known cause of low back pain, usually affects the pars interarticularis of a lower lumbar vertebra and rarely involves the articular processes. We report a rare case of bilateral spondylolysis of inferior articular processes of L4 vertebra that caused spinal canal stenosis with a significant segmental instability at L4/5 and scoliosis. A 31-year-old male who had suffered from low back pain since he was a teenager presented with numbness of the right lower leg and scoliosis. Plain X-rays revealed bilateral spondylolysis of inferior articular processes of L4, anterolisthesis of the L4 vertebral body, and right lateral wedging of the L4/5 disc with compensatory scoliosis in the cephalad portion of the spine. MR images revealed spinal canal stenosis at the L4/5 disc level. Posterior lumbar interbody fusion of the L4/5 was performed, and his symptoms were relieved.

Reoperation for recurrent lumbar disc herniation: a study over a 20-year period in a Japanese population.

BACKGROUND: Many studies have been reported on recurrent lumbar disc herniations covering several pathological conditions. In those studies, reoperation rate of revised disc excisions was calculated by simple division between the number of reoperations and that of the total primary disc excisions. To determine the real reoperation rate, strict definition of pathologies, a large number of patients, a long observation period, and survival function method are necessary. METHODS: Between 1988 and 2007, 5,626 patients with disc excision were enrolled by the spine registration system of the Department of Orthopaedic Surgery, Tohoku University, Japan. Among them, 192 had revised disc surgery, and we obtained data of 186 patients whose clinical features were assessed and reoperation rates analyzed using the Kaplan-Meier method. RESULTS: In total, 205 disc herniations were excised in the revision surgery (including contralateral herniation at the same level and new herniation at a different level), and 101 were real recurrent herniations (recurrence at the same level and side as the primary herniation). The kappa coefficient of the spinal level and side between the primary and revision surgeries was 0.41, indicting moderate correlations. Real recurrent herniations showed shorter intervals between primary and revision surgeries. Male patients with surgery at a younger age carried a higher risk of reoperation. In the revision surgery, transligamentous extrusion was significantly more common than other types of herniation. On Kaplan-Meier analysis, the reoperation rate of overall revised excisions was 0.62% at 1 year, 2.4% at 5 years, 4.4% at 10 years, and 5.9% after 17 years. That of real recurrent herniations was 0.5%, 1.4%, and 2.1%, respectively, and 2.8% after 15.7 years. CONCLUSION: Reoperation rate of real recurrent herniations calculated using survival function method gradually increased year by year, from 0.5% at 1 year after primary surgery to 2.8% at 15.7 years.

Dynamic change of dural sac cross-sectional area in axial loaded magnetic resonance imaging correlates with the severity of clinical symptoms in patients with lumbar spinal canal stenosis.

STUDY DESIGN: Cross-sectional registry and imaging cohort study. OBJECTIVE.: To examine whether the dural sac cross-sectional area (DCSA) in axial loaded magnetic resonance imaging (MRI) correlates with the severity of clinical symptoms in patients with lumbar spinal canal stenosis (LSCS). SUMMARY OF BACKGROUND DATA: Many studies have analyzed the relationship between DCSA on conventional MRI and the severity of symptoms in LSCS, but the link is still uncertain. Recently, axial loaded MRI, which can stimulate the spinal canal of patients in the upright position, has been developed. Axial loaded MRI demonstrates significant reduction of DCSA and provides valuable radiologic findings in the assessment of LSCS. However, there has been no study of the correlation between DCSA in axial loaded MRI and the severity of symptoms in LSCS. METHODS: In 88 patients with LSCS, DCSA in conventional MRI, axial loaded MRI, and changes in the DCSA were determined at the single most constricted intervertebral level. The severity of symptoms was evaluated on the basis of the duration of symptoms, walking distance, visual analogue scale of leg pain/numbness, and Japanese Orthopaedic Association score. Spearman correlations of the DCSA in conventional MRI, axial loaded MRI, and changes in the DCSA with the severity of symptoms were analyzed. In addition, the severity of symptoms and DCSA in conventional and axial loaded MRI were compared, respectively, between patients with and without significant (>15 mm) changes in the DCSA. RESULTS: The DCSA in axial loaded MRI had good correlations with walking distance and Japanese Orthopaedic Association score (rs = 0.46 and 0.45, respectively; P < 0.001). In addition, the change in the DCSA significantly correlated to walking distance, visual analogue scale of leg numbness, and Japanese Orthopaedic Association score (rs = 0.59, 0.44, and 0.54, respectively; P < 0.001). Furthermore, the symptoms were significantly worse in patients with more than 15 mm change in the DCSA (P < 0.001). Axial loaded MRI, but not conventional MRI, showed a significantly smaller DCSA in patients with more than 15 mm change in the DCSA (P < 0.05). CONCLUSION: DCSA in axial loaded MRI significantly correlated with the severity of symptoms. Axial loaded MRI demonstrated that changes in the DCSA significantly correlated with the severity of symptoms, which conventional MRI could not detect. Thus, MRI with axial loading provides more valuable information than the conventional MRI for assessing patients with LSCS.

Axial loading during magnetic resonance imaging in patients with lumbar spinal canal stenosis: does it reproduce the positional change of the dural sac detected by upright myelography?

STUDY DESIGN: We compared the sizes of the dural sac among conventional magnetic resonance imaging (MRI), axial loaded MRI, and upright myelography in patients with lumbar spinal canal stenosis (LSCS). OBJECTIVE: To determine whether axial loaded MRI can demonstrate similar positional changes of the dural sac size as were detected by upright myelography in LSCS. SUMMARY OF BACKGROUND DATA: In patients with LSCS, constriction of the dural sac is worsened and symptoms are aggravated during standing or walking. To disclose such positional changes, upright myelography has been widely used. Recently, axial loaded MRI, which can simulate a standing position, has been developed. However, there has been no study to compare the dural sac size between axial loaded MRI and upright myelography. METHODS: Forty-four patients underwent conventional MRI, axial loaded MRI, and myelography. Transverse and anteroposterior diameters and the cross-sectional areas of the dural sac from L2-L3 to L5-S1 were compared. Pearson correlations of the diameters between the MRIs and the myelograms were analyzed. On the basis of the myelograms, all disc levels were divided into severe and nonsevere constriction groups. In each group, the diameters and the cross-sectional areas were compared. Sensitivity and specificity to detect severe constriction were calculated for the conventional and axial loaded MRI. RESULTS: Transverse and anteroposterior diameters at L4-L5 in the axial loaded MRI and myelogram were significantly smaller than those observed in the conventional MRI (P < 0.001). Cross-sectional areas in the axial loaded MRI were significantly smaller than those in the conventional MRI at L2-L3, L3-L4, and L4-L5 (P < 0.001). Between the axial loaded MRI and the myelography, Pearson correlation coefficients of the transverse and anteroposterior diameters were 0.85 and 0.87, respectively (P < 0.001), which were higher than those for conventional MRI. Reductions of the dural sac sizes in the axial loaded MRI were more evident in the severe constriction group. The axial loaded MRI detected severe constriction with a higher sensitivity (96.4%) and specificity (98.2%) than the conventional MRI. CONCLUSION: The axial loaded MRI demonstrated a significant reduction in the dural sac size and significant correlations of the dural sac diameters with the upright myelogram. Furthermore, the axial loaded MRI had higher sensitivity and specificity than the conventional MRI for detecting the severe constriction observed in the myelogram. Therefore, the axial loaded MRI can be used to represent positional changes of the dural sac size detected by the upright myelography in patients with LSCS.

Cervical myelopathy due to degenerative spondylolisthesis.

OBJECTIVE: To investigate clinical-radiological features of cervical myelopathy due to degenerative spondylolisthesis (DSL). METHODS: A total of 448 patients were operated for cervical myelopathy at Nishitaga National Hospital between 2000 and 2003. Of these patients, DSL at the symptomatic disc level was observed in 22 (4.9%) patients. Clinical features were investigated by medical records, and radiological features were investigated by radiographs. RESULTS: Disc levels of DSL were C3/4 in 6 cases and C4/5 in 16 cases. Distance of anterior slippage was 2 to 5 mm (average 2.9 mm) in flexion position. Space available for the spinal cord (SAC) was 11 to 15 mm (average 12.8 mm) in flexion position and 11 to 18 mm (average 14.6 mm) in extension position; 11 cases were reducible and 11 cases were irreducible in extension position. Myelograms demonstrated compression of spinal cord by the ligamentum flavum in extension position. Compression of spinal cord was not demonstrated in flexion position. C5-7 lordosis angle was lower than control. C5-7 range of motion (ROM) was reduced compared to controls. These alterations were statistically significant. CONCLUSIONS: DSL occurs in the mid-cervical spine. Lower cervical spine demonstrated restricted ROM and lower lordosis angle. Pathogenesis of cervical myelopathy due to DSL is compression of spinal cord by the ligamentum flavum in extension position and not by reduced SAC in flexion position.

Lumbar radiculopathy caused by foraminal stenosis in rheumatoid arthritis.

STUDY DESIGN: Case-series study. OBJECTIVE: To describe the clinical presentation, characteristic findings of imaging studies, and treatment of lumbar radiculopathy caused by foraminal stenosis in rheumatoid arthritis. BACKGROUND. Lumbar lesions in rheumatoid arthritis are relatively rare, with a limited number of systemic reports. METHODS: Six patients with lumbar radiculopathy caused by foraminal stenosis in rheumatoid arthritis were treated. The patients were all women with a mean age of 69 years and mean rheumatoid arthritis duration of 15 years. The medical records and imaging studies of all patients were reviewed. RESULTS: The affected nerve roots were L4 in four patients and L3 in two patients. Foraminal stenosis was not demonstrated in magnetic resonance images in four of the six patients. Selective radiculography with nerve root block reproduced pain, manifested blocking effect, and demonstrated compression of the nerve root by the superior articular process of the lower vertebra in all patients. Conservative treatment was performed on one patient, and surgery was conducted for the rest of the five patients; radiculopathy was improved in all patients. CONCLUSIONS: Lumbar foraminal stenosis is a characteristic pathology of rheumatoid arthritis, and should be kept in mind in the diagnosis of lumbar radiculopathy. Selective radiculography is useful in the diagnosis of affected nerve roots.

Anterior decompression and fusion versus laminoplasty for cervical myelopathy caused by soft disc herniation: a prospective multicenter study.

BACKGROUND: Anterior decompression and fusion (ADF) has conventionally been used, with stable outcomes, for cervical myelopathy caused by soft disc herniation. However, complications related to bone grafting and recurrence of myelopathy due to adjacent segment degeneration are its drawbacks. The efficacy of laminoplasty as an alternative has been sporadically reported, but no prospective study has been conducted to verify it. The purpose of this study was to determine whether laminoplasty is comparable for this condition. METHODS: Patients with cervical myelopathy caused by soft disc herniation whose preoperative disease period was less than 1 year were studied. The first 30 patients and the next 30 patients were treated by ADF and laminoplasty, respectively. All patients were given the same postoperative management. The outcomes were compared between the ADF and the laminoplasty groups consisting of 25 patients each who completed a follow-up examination 1 year after surgery. RESULTS: The two groups were found statistically matched regarding age at surgery, sex, disc level of herniation, anteroposterior diameter of the spinal canal, preoperative severity of myelopathy, cervical lordosis angle, and cervical range of motion (ROM). There was no statistically significant difference in the postoperative severity or recovery rate of myelopathy between the two groups. The amount of blood loss during surgery was significantly less in the laminoplasty group. Donor site pain and neck pain was minimal in all patients. Cervical lordosis angle and ROM were diminished postoperatively without a significant difference between the two groups. CONCLUSIONS: There was no critical difference between the ADF and laminoplasty groups with regard to neurological recovery and other surgery-related factors 1 year after surgery. Laminoplasty can be employed for cervical myelopathy caused by soft disc herniation in particular combined with multilevel spinal canal stenosis to avoid secondary myelopathy.