Recovery of the Japanese orthopedic association back pain evaluation questionnaire score and walking ability following lumbar spinal stenosis surgery.

PURPOSE: We investigated the recovery of the Japanese orthopedic association back pain evaluation questionnaire (JOABPEQ) scores and 6 min walk distance (6MWD) in patients after surgery for lumbar spinal stenosis and identified the items among 25 questions of JOABPEQ that showed recovery. METHODS: A total of 227 patients (average age 71.5 years; SD: 7.5; 121 men) were included from a single center. The outcome measures were JOABPEQ, visual analog scale (VAS), and 6MWD and obtained preoperatively and at 1, 3, 6, and 12 months postoperatively. Mixed-model repeated measures were used to compare the variables at each time point between the surgery groups. RESULTS: The JOABPEQ, VAS, and 6MWD scores generally improved at 1 month postoperatively compared with those obtained preoperatively, and some parameters further improved at 3 months. However, improvement in the lumbar spine dysfunction item of JOABPEQ was delayed, showing improvement at 3 months postoperatively for decompression surgery (average score: pre, 64.6; 3 months, 78.5) and 6 months postoperatively for fusion surgery (average score: Pre, 64.3; 6 months, 77.1). Responses to the individual JOABPEQ questions generally improved after surgery. No significant changes in lumbar spine dysfunction occurred in the fusion group. CONCLUSION: Our results demonstrated the early postoperative recovery course of JOABPEQ and 6MWD. In the fusion group, significant changes in lumbar spine dysfunction started at 6 months postoperatively. These findings could help medical staff explain postoperative recovery to patients after lumbar spinal stenosis surgery and in their decision making regarding surgery.

Minimal Clinically Important Difference of the 6-Minute Walk Distance in Patients Undergoing Lumbar Spinal Canal Stenosis Surgery: 12 Months Follow-Up.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: We evaluated the responsiveness of the 6-minute walk distance (6MWD) and determined the threshold of the minimal clinically important difference (MCID) in patients who underwent lumbar spinal stenosis (LSS) surgery. SUMMARY OF BACKGROUND DATA: Little evidence exists on the MCID of 6MWD after LSS surgery. The 6MWD is an objective gait assessment that can be measured quickly. MATERIALS AND METHODS: In total, 126 patients (74 men; average age, 72.2 ± 6.5 yr) were included and assessed preoperatively and at 12 months postoperatively. We used the Oswestry Disability Index (ODI), as an anchor to calculate the MCID for the 6MWD and measured internal and external responsiveness of the 6MWD. The external responsiveness was assessed in 2 ways: (1) One based on the anchoring questionnaire and (2) another based on the scale distribution. The anchor-based approach was evaluated using the Spearman rank correlation coefficient and receiver-operating characteristic curve. The distribution-based approach was evaluated using the minimal detectable change. RESULTS: The ODI scores and 6MWD for each anchor significantly improved postoperatively. The change in the 6MWD was significantly correlated with change in the ODI (6 mo, r = -0.45; 12 mo, r = -0.49). The receiver-operating characteristic analysis demonstrated good discriminative properties for the 6MWD using the ODI anchor (6 mo, 0.72; 12 mo, 0.78). The cutoff values for 6MWD were 102.3 and 57.5 at 6 and 12 months, respectively. In the distribution-based approach, the minimal detectable change for the 6MWD was 95.7 m. CONCLUSIONS: We validated both the internal and external responsiveness of the 6MWD using the ODI and estimated the MCID in the 6MWD for patients undergoing LSS surgery. However, there was lower validity for the MCID among those participants with the high walking ability and low disability at baseline.

Relationship between changes in physical function parameters and Roland-Morris disability questionnaire score after decompression surgery for lumbar spinal canal stenosis.

Although decompression surgery for lumbar spinal canal stenosis (LSS) improves leg symptoms, low back pain (LBP), and disability, the factors related to the improvement of subjective disability have not been studied sufficiently. The purpose of the study was to clarify the relationship between subjective disability and objective physical function parameters. A total of 51 patients who underwent decompression were included and evaluated preoperatively and 6 and 12 months postoperatively. Patient-reported outcomes related to activity limitation due to LBP were evaluated using Roland-Morris disability questionnaire (RDQ) and VAS (Visual Analog Scale). Physical function was assessed using 6-min walk distance (6MWD) and trunk muscle strength. Univariate analysis and multivariable linear regression analysis were performed to identify significant factors for RDQ score change. The 6- and 12-month postoperative RDQ scores, VAS scores, and trunk extensor strength significantly improved relative to the preoperative values. In the univariate analysis, age, changes in VAS (LBP, leg pain, and numbness) scores, and change in 6MWD were associated with the RDQ score change (p < 0.05). Multivariable linear regression showed that 6MWD changes were significantly associated with RDQ score changes, explaining 41% of the variance in the RDQ score change. This study showed the change in 6MWD was significantly associated with the RDQ score change. Our results suggest that improving 6MWD may reduce disability in activities of daily living.

Reliability and validity of lower limb joint range of motion measurements using a smartphone.

This study aimed to examine the reliability and validity of using a smartphone to measure the multi-joint range of motion of the lower limbs. We measured the straight leg raise angle, ankle dorsiflexion angle, and hip internal rotation angle in each of the 40 lower extremities of 20 healthy adults. Measurements were compared between a conventional method using a goniometer and a smartphone application method. The intraclass correlation coefficient (ICC) was used to evaluate the reliability of each smartphone measurement, and Bland-Altman analysis was used to examine measurement errors. The criterion-related validity of the two methods was also examined. Intra-rater reliability (ICC 0.668-0.939) was substantial to almost perfect, with no systematic errors found for all items, and the standard errors of measurement were acceptable. Inter-rater reliability (ICC 0.701-0.936) was also substantial to almost perfect, but the straight leg raise angle and hip internal rotation angle showed fixation errors. For these two measurements, with more than one examiner, the limit of agreement of error needs to be considered. No systematic errors were found in the ankle dorsiflexion angle, and the standard error of measurement was within the acceptable range. A moderate to strong correlation (r = 0.626-0.915) was found between the conventional and smartphone methods, demonstrating good criterion-related validity. However, in the ankle dorsiflexion angle measurements, the reliability and validity were shown to be lower than the other two items. This suggested the necessity of changing the measurement conditions in order to use the ankle dorsiflexion angle in clinical practice.

Responsiveness and Minimal Clinically Important Difference of the 6-minute Walk Distance in Patients Undergoing Lumbar Spinal Canal Stenosis Surgery.

STUDY DESIGN: This was a retrospective review of prospectively collected data. OBJECTIVE: We aimed to evaluate the responsiveness of the 6-minute walk distance (6MWD) and determine the threshold of the minimal clinically important difference (MCID) in the 6MWD in patients who underwent surgery for lumbar spinal canal stenosis (LSS) surgery. SUMMARY OF BACKGROUND DATA: The 6MWD rapidly and objectively assesses the walking distance in patients with LSS. To date, no study has assessed the MCID in the 6MWD in patients who underwent LSS surgery. MATERIALS AND METHODS: A total of 41 patients (16 women; average age: 69.4 y, SD: 7.8 y) were included and assessed preoperatively and at 6 months postoperatively. We evaluated the 6MWD and Oswestry Disability Index (ODI), which is a health-related patientrReported outcome, used as an anchor to calculate the MCID for in the 6MWD. We used 2 different approaches to examine the responsiveness of the 6MWD: internal and external responsiveness. The external responsiveness was assessed in 2 ways: one based on the anchoring questionnaire and the other based on the scale distribution of the scale. The anchor-based approach was evaluated using the Spearman rank correlation coefficient and the receiver operating characteristic curve. The distribution-based approach was evaluated using the minimal detectable change. RESULTS: The ODI scores and 6MWD for each anchor significantly improved postoperatively. The correlation coefficient between changes in the 6MWD and ODI was r=-0.58. The area under the receiver operating characteristic curve for the ODI anchor was 0.70 (95% confidence interval: 0.52-0.89), and the cutoff value for the ODI anchor was 50 m (sensitivity=0.57, specificity=0.71). In the distribution-based approach, the minimal detectable change for the 6MWD was 105.9 m. CONCLUSIONS: Both the internal and the external responsiveness of the 6MWD were validated using the ODI. Therefore, the MCID in the 6MWD in patients undergoing LSS surgery ranges from 50 to 105.9 m. LEVEL OF EVIDENCE: Level III.

Association between Trunk Muscle Strength, Lumbar Spine Bone Mineral Density, Lumbar Scoliosis Angle, and Skeletal Muscle Volume and Locomotive Syndrome in Elderly Individuals: A Dual-Energy X-ray Absorptiometry Study.

INTRODUCTION: The present study aimed to investigate the association between trunk muscle strength, lumbar spine bone mineral density (BMD), lumbar scoliosis angle (LSA), and appendicular skeletal muscle mass index (ASMI) and the severity locomotive syndrome (LS) using dual-energy X-ray absorptiometry (DXA) technology in elderly individuals. METHODS: In this cross-sectional study, we enrolled 168 individuals aged >60 years. We measured their trunk muscle strength (flexion and extension) and BMD, LSA, and ASMI using DXA. We defined degenerative lumbar scoliosis (DLS) as LSA ≥ 10° by the Cobb method using the DXA image. The locomotor function was evaluated using the timed up-and-go (TUG) test and the 25-question Geriatric Locomotive Function Scale (GLFS-25) score. Normal locomotor function, LS-1, and LS-2 were defined as a GLFS-25 score of <7, ≥7 and <16, and ≥16, respectively. We compared the three groups, analyzing the associations between all variables and the locomotor function using univariate and multivariate analyses. RESULTS: Although there was no significant difference in sex ratio, BMD, ASMI, and trunk-flexor strength, significant differences were observed in age (p < 0.01), the prevalence of DLS (p = 0.02), trunk-extensor strength (p < 0.01), and trunk-extensor/flexor strength ratio (p < 0.01) among the three groups. In multiple regression analyses, the significant risk factors of the TUG test were age (ß = 0.26), body mass index (ß = 0.36), LSA (ß = 0.15), ASMI (ß = -0.30), and trunk-extensor strength (ß = -0.19), whereas the significant factor of the GLFS-25 score was trunk-extensor strength (ß = -0.31). CONCLUSIONS: The results indicate that it is clinically important for LS to pay careful attention not only to BMD but also to lumbar scoliosis when DXA examination of the lumbar spine is routinely conducted. Moreover, it is essential to note that trunk-extensor strength is more important than trunk-flexor strength in maintaining locomotor function in elderly individuals.

Predictors of Prolonged Length of Stay After Lumbar Interbody Fusion: A Multicenter Study.

STUDY DESIGN: Retrospective analysis of a prospectively database. OBJECTIVES: To identify factors associated with prolonged length of stay (LOS) in posterior /transforaminal lumbar interbody fusion (PLIF/TLIF). METHODS: The subjects were patients who underwent PLIF/TLIF at 10 facilities from 2012 to 2014. A total of 1168 such patients with a mean age of 65.9 ± 12.5 years (range 18-87 years) were identified in the database. Operations were PLIF (n = 675), TLIF (n = 443), minimally invasive surgery (MIS)-PLIF (n = 22), and MIS-TLIF (n = 32). Age, gender, body mass index, ambulatory status, comorbidities, perioperative American Society of Anesthesiologists (ASA) grade, operative factors, and complications were examined. LOS was defined as the number of calendar days from the operation to hospital discharge. LOS was categorized as normal (<75th percentile) or prolonged (≥75th percentile). RESULTS: The average LOS was 20.8 ± 9.8 days (range 7-77 days). There was a significant correlation between LOS and age (P < .05). Reoperation during hospitalization was performed in 20 cases for surgical site infection (n = 12), epidural hematoma (n = 5), and screw misplacement (n = 3). In multivariate analysis, prolonged LOS was associated with preoperative variables of age ≥70 years (odds ratio [OR] 1.87, 95% CI 1.38-2.54), and ASA class ≥III (OR 1.52, 95% CI 1.04-2.25); surgical variables of open procedures (OR 5.84, 95% CI 1.74-19.63), fused levels ≥3 (OR 5.17, 95% CI 3.17-8.43), operative time ≥300 minutes (OR 1.88, 95% CI 1.15-3.07), and estimated blood loss ≥500 mL (OR 1.71, 95% 1.07-2.75). CONCLUSIONS: The factors identified in this study should help with obtaining informed consent, surgical planning and complication prevention to reduce health care costs associated with prolonged LOS.

Predictors of walking ability after surgery for lumbar spinal canal stenosis: a prospective study.

BACKGROUND CONTEXT: Few studies have investigated predictors of objective walking distance in patients with lumbar spinal stenosis (LSS). PURPOSE: This study aimed to clarify objective predictors of postoperative 6-minute walk distance (6MWD) in patients with LSS and to develop prediction equations. STUDY DESIGN: This was a prospective study. Data were analyzed by multiple linear regression analyses. PATIENT SAMPLE: Patients with LSS were enrolled. OUTCOME MEASURES: Predictors of 6MWD after surgery were evaluated, including patient characteristics (sex, age, height, and body weight), pain (visual analog scale; low back pain, lower limb pain, and lower limb numbness), surgical factors (number of operation segments [1 or ≥2], surgery type [fusion or decompression], and minimum area of the dural sac), and objective physical function (6MWD and trunk muscle strength). METHODS: Patients with LSS were consecutively included and assessed preoperatively (n=113) and 6 months postoperatively (n=78). Simple and multiple linear regression analyses were performed with 6MWD at 6 months postoperation as the dependent variable. We have study funding sources (Nagono Medical Foundation) and no study-specific conflicts of interest-associated biases. RESULTS: At 6-month follow-up, 6MWD (457.7±105.5 m) improved significantly compared with preoperative 6MWD (275.0±157.2 m; p<.01). Trunk muscle strength and pain improved significantly compared with the preoperative score (p<.01). The predictors of postoperative 6MWD were age, body weight, number of operation segments (1 or ≥2), surgery type (fusion or decompression), preoperative trunk extensor strength, and preoperative 6MWD (adjusted R2=0.65, p<.01). The proposed prediction equation was as follows: postoperative 6MWD (m)=549.5-5.3×age (years)-1.8×body weight (kg)-68.3×surgery type (0: decompression, 1: fusion)-58.6×operation segment (0: one segment, 1: ≥2 segments)+3.5×trunk extensor strength (kg)+0.2×preoperative 6MWD (m). CONCLUSIONS: Younger age, lower body weight, one level operative segment, decompression surgery, and better preoperative scores for trunk extensor strength and 6MWD predicted better scores for 6 months postoperative 6MWD. Preoperative reduction in body weight and increase of trunk extensor strength might be associated with improved postoperative 6MWD scores.

Reliability of an Intraoperative Radiographic Anteroposterior View of the Spinal Midline for Detection of Pedicle Screws Breaching the Medial Pedicle Wall in the Thoracic, Lumbar, and Sacral Spine.

OBJECTIVE: The purpose of this study was to determine the sensitivity and specificity of using the spinal midline (M line) on a radiographic anteroposterior (AP) view for detecting pedicle screws (PSs) breaching the medial pedicle wall. METHODS: We retrospectively reviewed 145 patients who underwent fusion surgery using PSs between January 2006 and May 2017. We defined the M line as a line that connected the upper and lower spinous processes through the fixed vertebrae. The M line was positive if the tip of the PS crossed the M line. The reference standard was a computed tomography scan. The reliability of the M line was examined. RESULTS: The subjects included 145 patients (70 men and 75 women; mean age, 63.4 years). A total of 599 PSs were examined. Most cases were because of spondylolisthesis (66.9%). Most screws were inserted at a lower lumber level (77.6%). Analysis of the diagnostic accuracy of the M line yielded a sensitivity of 74.1% and a specificity of 95.3%. In addition, the positive predictive value of the M line was 42.6%, and the negative predictive value of the M line was 98.7%. CONCLUSIONS: Assessment of the M line via an intraoperative radiographic AP view is a simple, readily available, complementary method for detecting PSs that have breached the medial pedicle wall in the thoracic, lumbar, and sacral spine. In particular, the M line has a strong negative predictive value, which is much more meaningful.

Trends of postoperative length of stay in spine surgery over 10 years in Japan based on a prospective multicenter database.

OBJECTIVES: To identify factors associated with prolonged length of stay (LOS) in spine surgery, with the goal of establishing details of LOS for multiple diseases and surgical procedures. PATIENTS AND METHODS: The subjects were patients who underwent spine surgery at 10 facilities in the Nagoya Spine Group from January 2005 to December 2015. Data were collected for patient background, primary spinal pathology, anatomical location of the lesion, and surgical methods. The primary outcome was LOS, which was defined as the calendar days from surgery to hospital discharge. RESULTS: A total of 10,829 patients (5953 males, 4876 females; age 5-93 years, mean 60.2 ± 28.8 years) were identified in the database. Average follow-up was 61 months (range: 13-120 months). Average LOS was 22.3 ± 21.3 days, and there was a gradual decrease in LOS over the study period. LOS was significantly correlated with age, and prolonged LOS was significantly associated with thoracic spine surgery and significantly longer after surgery with instrumentation. Average LOS was >30 days for intramedullary tumor resection and posterior cervical fusion, but only 10.2 days for microendoscopic discectomy. Reoperation was performed in 210 patients (1.9%) and these patients had a significantly higher average LOS of 43.1 days. CONCLUSION: These results will assist quality improvement in spine surgery. The identified risk factors for prolonged LOS will also assist in planning of surgery, postoperative care, and discharge, with the goal of reducing health care costs.

Variety of preoperative MRI changes in spinal cord ependymoma of WHO grade II: a case series.

PURPOSE: To report a case series of surgically proven spinal ependymomas of WHO grade II in which there were changes in the preoperative MRI characteristics over time. METHODS: A total of 71 patients with spinal cord ependymoma of WHO grade II underwent surgery. There were ten cases in which surgery was performed at an average of 2.2 years after the tumor was found. Cystic components, syringomyelia, hemorrhage "cap sign," Gd enhancement pattern, characteristic changes in MRI, MIB-1 index, and neurological assessment during the preoperative period were examined. RESULTS: Cases with a huge cyst showed further enlargement of the cyst on the caudal and rostral sides with hemosiderin formation over time and changes in the pattern of Gd enhancement. In contrast, cases without initial cyst did not show cyst formation, and nodular homogeneous lesion remained without changes in Gd enhancement. Regarding neurological status, two cases with cyst enlargement and hemosiderin formation had worsened non-independent gait preoperatively. CONCLUSIONS: MRI in cases of spinal ependymomas of WHO grade II showed characteristics such as hemorrhage and cyst formation that varied over time. In particular, cases with cyst and hemosiderin showed tumor enlargement, including enlargement of lesions on the caudal and rostral sides and enlargement of Gd-enhanced lesions. These characteristics might influence gait ability during preoperative period. We emphasize that early surgery is still the standard of care for cervical intramedullary ependymoma, and our findings in this study should not be interpreted to indicate that such early surgery is not necessary in symptomatic cases. These slides can be retrieved under electronic supplementary material.

Factors Affecting the Severity of Neurological Disorders in Thoracic Idiopathic Spinal Cord Herniation.

STUDY DESIGN: Retrospective multicenter case-controlled study. OBJECTIVE: The objective of this study was to quantitatively examine imaging findings of idiopathic spinal cord herniation (ISCH) and determine the relationship between the image findings and the severity of pre- and postoperative neurological symptoms. SUMMARY OF BACKGROUND DATA: Many radiographic types of ISCH have been identified with regard to the location of the hernial opening or amount of herniated spinal cord. However, few previous studies have investigated the relationship between radiographic findings and the severity of neurological symptoms. METHODS: Of 30,469 patients who underwent spinal surgery at 7 hospitals, 18 patients who underwent surgery for ISCH were identified. Their preoperative neurological severity, disease duration, magnetic resonance imaging findings, computed tomography myelography findings, surgical findings, and postoperative improvements were retrospectively examined. The spinal cord kink angle and minimum cord occupancy rate within the dural tube were measured. In addition, herniation was classified according to the location of the hiatus as either central (type C) or lateral (type L) type. RESULTS: A negative correlation was found between the spinal cord kink angle and the minimum cord occupancy rate. Patient age was significantly higher in the severe paralysis group than in the mild paralysis group. In addition, the number of patients with type C herniation and the kink angle were significantly higher in the severe paralysis group. The number of patients with type L herniation was higher in the significant recovery group than in the mild recovery group; however, the difference was not significant. CONCLUSION: Patients with a large spinal cord kink angle had a smaller spinal cord occupancy rate within the dural tube, and this resulted in severe preoperative conditions. Type C ISCH cases had a severe preoperative neurological deficit and poor postoperative neurological recovery, and the spinal cord in such cases might be damaged irreversibly. LEVEL OF EVIDENCE: 4.

A double-blind randomized controlled trial of the local application of vancomycin versus ampicillin powder into the operative field for thoracic and/or lumbar fusions.

OBJECTIVERetrospective studies have reported that the local application of vancomycin (VCM) powder into the operative field decreases the incidence of surgical site infection (SSI) in thoracic and/or lumbar fusion. Authors of the present study prospectively evaluated the effects of VCM in patients undergoing thoracic and/or lumbar fusion.METHODSIn this randomized double-blind trial, 230 patients undergoing thoracic and/or lumbar fusion were randomly assigned to the local administration of VCM (interventional group, 1 g) or ampicillin (AMP; control group, 1 g) into the surgical field. The primary outcome was SSI results within 1 year of surgery.RESULTSThe trial was prematurely stopped according to predetermined rules. The results showed one superficial infection (0.9%, Staphylococcus aureus) and one deep infection (0.9%, S. aureus) in the VCM group and two superficial infections (1.8%, Staphylococcus epidermidis and culture negative) and one deep infection (0.9%, methicillin-resistant S. aureus) in the AMP group. No significant differences in infection rates were observed between the groups (p = 0.8).CONCLUSIONSThis double-blind randomized controlled trial demonstrated that the local application of VCM or AMP powder into the operative field in short thoracic and/or lumbar fusion procedures resulted in a similar incidence of SSI.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized controlled trial; evidence: class III.Clinical trial registration no.: UMIN000009377 (umin.ac.jp/ctr).

Simple presurgical method of predicting C5 palsy after cervical laminoplasty using C5 nerve root ultrasonography.

OBJECTIVE: The incidence of C5 palsy after cervical laminoplasty is approximately 5%. Because C5 palsy is related to cervical foraminal stenosis at the C4-5 level, the authors hypothesized that cervical foraminal stenosis can be diagnosed by examining the C5 nerve root (NR) using ultrasonography. The purpose of this study was to investigate whether postoperative C5 palsy could be predicted using ultrasonography. METHODS: This study used a prospective diagnosis design. In total, 140 patients undergoing cervical laminoplasty were examined with ultrasound. The cross-sectional area (CSA) of the C5 NR was measured on both sides before surgery, and the incidence of postoperative C5 palsy was examined. The difference between the CSA of the patients with and without C5 palsy and the lateral differences in the C5 palsy group were determined. RESULTS: The incidence of C5 palsy was 5% (7 cases). Symptoms manifested at a median of 5 days after surgery (range 1-29 days). The CSA of the C5 NR on the affected side was significantly enlarged in the C5 palsy group compared with that in the no-C5 palsy group (p = 0.001). In addition, in the patients who had C5 palsy, the CSA of the C5 NR was significantly enlarged on the affected side compared with that on the unaffected side (p = 0.02). Receiver operating characteristic analysis indicated that the best threshold value for the CSA of the C5 NR was 10.4 mm2, which provided 91% sensitivity and 71% specificity. CONCLUSIONS: C5 palsy may be predicted preoperatively using ultrasound. The authors recommend the ultrasonographic measurement of the CSA of the C5 NR prior to cervical laminoplasty.

Regional Differences in Diffuse Idiopathic Skeletal Hyperostosis: A Retrospective Cohort Study from Sweden and Japan.

STUDY DESIGN: We retrospectively reviewed computed tomography (CT) records of patients in Japan and Sweden, which are both aging populations. OBJECTIVE: To research the influence of ethnicity and region on diffuse idiopathic skeletal hyperostosis (DISH) prevalence. SUMMARY OF BACKGROUND DATA: DISH can complicate non-surgical treatment of spinal fractures and often requires surgical intervention. We previously reported a prevalence of DISH in Japan that was higher than that reported in other studies. METHODS: We retrospectively reviewed CT records of patients in Japan and Sweden, which have both aging populations. Patients undergoing whole body CT during trauma examinations at an acute outpatient clinic in Uppsala University Hospital in a 1-year period were eligible for inclusion. Excluded were those less than 40 and more than or equal to 90 years old, and those with previous spinal surgery. The prevalence of DISH by sex and age was determined according to radiographic criteria by Resnick. Results from Sweden were compared with the Japan data, which we previously reported. RESULTS: Age of the eligible subjects (265 men and 153 women) ranged from 40 to 89 years, with a mean age of 63.4 years. Among men, 86 (32.5%) were diagnosed with DISH, and the results by age (40s, 50s, 60s, 70s, and 80s) were: 6 (10.7%), 13 (22%), 35 (46.1%), 17 (34%), and 15 (62.5%) patients, respectively. Among women, 16 (10.5%) had DISH, and the results by age were as follows: 1 (2.6%), 1 (3.3%), 2 (6.7%), 6 (22.2%), and 6 (22.2%) patients, respectively. These results did not differ from those previously published for Japan (Fisher exact test, men: P = 1, 0.27, 0.12, 0.06, and 1, respectively; women: P = 0.49, 0.62, 0.5, 0.8, and 0.3, respectively). CONCLUSION: The presented cohort study revealed that ethnicity and region may not be notable factors of DISH prevalence, since patients from both Japan and Sweden had similar DISH prevalence. LEVEL OF EVIDENCE: 3.

Surgical outcomes of spinal cord and cauda equina ependymoma: Postoperative motor status and recurrence for each WHO grade in a multicenter study.

BACKGROUND: The goals of the study are to analyze postoperative outcomes and recurrence in cases of spinal cord and cauda equina ependymoma in each World Health Organization (WHO) Grade, and to examine the influence of extent of surgical removal on prognosis. Spinal ependymoma has a relatively high frequency among intramedullary spinal cord tumors. The tumor is classified in WHO guidelines as grades I, II, and III, but few studies have examined postoperative prognosis based on these grades. METHODS: The records of 80 patients undergoing surgery for spinal cord and cauda equina ependymoma were examined in a multicenter study using a retrospective database. Neurological motor status, pathological type, extent of resection, and tumor recurrence were evaluated. RESULTS: The histopathological types were grade I in 23 cases (myxopapillary: 21, subependymoma: 2), grade II in 52 cases, and grade III in 5 cases (including all anaplastic cases). Total resection was performed in 60 cases (83%), and eight cases had recurrence, including 2 in WHO grade I, 2 in grade II, and 4 in grade III. The 5-year recurrence-free survival rates were 90%, 91%, and 20% in grades I, II and III, respectively. Adjuvant radiotherapy for the local site was performed in 8 cases, including 3 in grade I and 5 in grade III; however, 4 of the 5 grade III cases (80%) had recurrence after radiotherapy. Among 59 patients with normal ambulation or independence without external assistance (McCormick Grade I or II), 53 (90%) maintained the same mobility after surgery. In cases that underwent total resection, the recurrence rate was significantly lower (p < 0.01). A good preoperative motor status also resulted in significantly better postoperative recovery of motor status (p < 0.05). CONCLUSIONS: Total resection of spinal cord and cauda equina ependymoma leads to postoperative motor recovery and may reduce tumor recurrence. Therefore, early surgery for this tumor is recommended before aggravation of paralysis.

Reoperation within 2 years after lumbar interbody fusion: a multicenter study.

PURPOSE: Posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) can have complications that require reoperation. The goal of the study was to identify risk factors for reoperation within 2 years after PLIF/TLIF. METHODS: A retrospective analysis of a prospective multicenter database was performed for patients who underwent PLIF/TLIF. A total of 1363 patients (689 males and 674 females) were identified, with an average age of 65.9 years old. Comorbidities, perioperative ASA grade, and operative factors were compared between patients with and without reoperation. Risk factors for reoperation were identified in multivariate logistic analysis. RESULTS: There were 38 reoperations within 2 years after PLIF/TLIF (2.8%). The original surgical procedures were open PLIF (n = 26), open TLIF (n = 10), and minimally invasive surgery (n = 2). Reoperation was due to adjacent segment degeneration (ASD) (n = 10), surgical site infection (SSI) (n = 9), screw misplacement (n = 6), postoperative epidural hematoma (n = 6), pseudoarthrosis (n = 4), and cage protrusion (n = 3). Number of levels fused and dural tear were significantly associated with reoperation. In analysis of complications requiring reoperation, SSI was related to diabetes mellitus and dural tear, and postoperative epidural hematoma was related to fusion of two or more levels, EBL, and operation time. In multivariate logistic regression, fusion of two or more levels (HR 2.19) was significantly associated with reoperation. CONCLUSION: Surgical invasiveness, as reflected by number of fused levels, operation time, EBL and dural tear, was associated with reoperation. Fusion of two or more levels is a strong risk factor for reoperation within 2 years after initial PLIF/TLIF. These slides can be retrieved under Electronic Supplementary Material.

MRI Characteristics of Spinal Ependymoma in WHO Grade II: A Review of 59 Cases.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: The goal of this study is to determine the characteristic imaging features of spinal ependymoma in a review of magnetic resonance imaging (MRI) data for a large series of surgically proven cases. SUMMARY OF BACKGROUND DATA: Common spinal intramedullary neoplasms are mostly ependymomas and comprise 50% to 60% of spinal neuroepithelial tumors in adults. Preoperative prediction of the pathological diagnosis could enhance surgical planning and explanation of the procedure to patients. However, these types of tumors exhibit a variety of MRI findings. METHODS: Records were examined for 59 patients who underwent surgery for spinal cord ependymoma and had a pathological diagnosis of cellular ependymoma of World Health Organization classification grade II. RESULTS: The ependymomas included 28 in the cervical spine, 34 in the thoracic spine, and 3 conus lesions. All cases were isointense or hypointense on T1-weighted MRI, and 55 (93%) were hyperintense on T2-weighted MRI. Tumors were located centrally in all cases; 50 (85%) showed surrounding cord edema; and 52 (88%) had associated cysts, including 36 (61%) rostral or caudal cysts, 10 (17%) intratumoral cysts, and 6 (10%) with syringomyelia. Of the 59 tumors, 17 (29%) showed the "cap sign," a rim of extreme hypointensity seen around the tumor on T2-weighted images, due to hemosiderin. In gadolinium-enhanced MRI, all cases were enhanced, and 27 (46%), 16 (27%), 11 (19%), and 5 (8%) cases showed homogeneous, heterogeneous, rim, and nodular enhancement, respectively. CONCLUSION: Hypointense changes on T2-weighted MRI and hemosiderin deposition reflect easy bleeding. Tumors are associated with various types of cysts, and gadolinium-enhancement patterns reflect a variety of intratumor cellular components. In cases in which the whole tumor shows gadolinium enhancement on MRI, rostral, or caudal cyst and a cap sign with hemorrhage are characteristics of grade II classical ependymoma. LEVEL OF EVIDENCE: 3.

Prevalence, characteristics, and burden of failed back surgery syndrome: the influence of various residual symptoms on patient satisfaction and quality of life as assessed by a nationwide Internet survey in Japan.

We conducted a cross-sectional, Internet-based survey with a nationally representative sample of Japanese adults to assess the prevalence and characteristics of failed back surgery syndrome (FBSS). Data regarding the residual symptoms and patient satisfaction from an online survey of 1842 lumbar surgery patients revealed the prevalence of FBSS to be 20.6% (95% confidence interval [CI], 18.8-22.6). The prevalence of low back pain, dull ache, numbness, cold sensations, and paresthesia after surgery was 94.0%, 71.1%, 69.8%, 43.3%, and 35.3%, respectively. With a logistic regression model, severe residual low back pain (numerical rating scale 8-10), higher pain intensity, and multiple low back surgeries were strongly associated with FBSS, with odds ratios of 15.21 (95% CI, 7.79-29.7), 1.40 (95% CI, 1.32-1.49), and 1.87 (95% CI, 1.25-2.81), respectively. Respondents with FBSS had significantly lower EuroQol-5D (P<0.001) values and significantly higher scores on the Kessler six-item psychological distress scale (P<0.001), compared with the non-FBSS group. Our findings indicate that residual sensations have a significant effect on patient quality of life, similar to that of chronic low back pain. Precise presurgical provision of prognoses based on comprehensive epidemiologic data, as well as scrupulous attention to patient satisfaction and clinical progress may help reduce the incidence of FBSS.