So Kato

Validity and Reliability of the Japanese Version of the painDETECT Questionnaire: A Multicenter Observational Study

Objectives The aim of this study was to evaluate the validity and reliability of the Japanese version of the painDETECT questionnaire (PDQ-J). Materials and Methods The translation of the original PDQ into Japanese was achieved according to the published guidelines. Subsequently, a multicenter observational study was performed to evaluate the validity and reliability of PDQ-J, including 113 Japanese patients suffering from pain. Results Factor analysis revealed that the main component of PDQ-J comprises two determinative factors, which account for 62% of the variance observed. Moreover, PDQ-J revealed statistically significant correlation with the intensity of pain (Numerical Rating Scale), Physical Component Score, and Mental Component Score of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). The Cronbach alpha for the total score was 0.78 and for the main component was 0.80. In the analysis of test–retest method, the intraclass correlation coefficient between the two scores was 0.94. Conclusions We demonstrated the validity and reliability of PDQ-J. We encourage researchers and clinicians to use this tool for the assessment of patients who suffer suspected neuropathic pain.

The normative score and the cut-off value of the Oswestry Disability Index (ODI)

PurposeThe Oswestry Disability Index (ODI) is one of the most common scoring systems used for patients with low back pain (LBP). Although the normative score of the ODI was reported to be 10.19 in a review article, no study has calculated the normative score after adjusting the value based on the age distribution. In addition, none of the previous studies has estimated the cut-off value which separates LBP with disability from LBP without disability. The purpose of this study was to estimate the normative score by adjusting the data for age distribution in Japan, and to determine the cut-off value which separates LBP with disability from LBP without disability.MethodsWe conducted an internet survey on LBP using the Japanese version of the ODQ. A total of 1,200 respondents, composed of 100 males and 100 females in each age group (from the 20s to 70s), participated in this study. We also asked them to provide information about their backgrounds. We estimated the normative score after correcting for the age distribution of Japan. We also estimated the ODI of those with or without disability, the factors associated with the ODI, and the cut-off value which separates LBP with disability from LBP without disability.ResultsThe participants’ backgrounds were similar to the national survey. The normative score of the ODI was estimated at 8.73. The ODI of the LBP with disability group was 22.07. Those with sciatica and obese subjects showed higher ODI than those without. The optimal cut-off value was estimated to be 12.ConclusionsWe defined the normative score and the cut-off value of the ODI.

Comparison of the Japanese Orthopaedic Association (JOA) Score and Modified JOA (mJOA) Score for the Assessment of Cervical Myelopathy: A Multicenter Observational Study

Objectives The Japanese Orthopaedic Association (JOA) score is widely used to assess the severity of clinical symptoms in patients with cervical compressive myelopathy, particularly in East Asian countries. In contrast, modified versions of the JOA score are currently accepted as the standard tool for assessment in Western countries. The objective of the present study is to compare these scales and clarify their differences and interchangeability and verify their validity by comparing them to other outcome measures. Materials and Methods Five institutions participated in this prospective multicenter observational study. The JOA and modified JOA (mJOA) proposed by Benzel were recorded preoperatively and at three months postoperatively in patients with cervical compressive myelopathy who underwent decompression surgery. Patient reported outcome (PRO) measures, including Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), the Short Form-12 (SF-12) and the Neck Disability Index (NDI), were also recorded. The preoperative JOA score and mJOA score were compared to each other and the PRO values. A Bland-Altman analysis was performed to investigate their limits of agreement. Results A total of ninety-two patients were included. The correlation coefficient (Spearman’s rho) between the JOA and mJOA was 0.87. In contrast, the correlations between JOA/mJOA and the other PRO values were moderate (|rho| = 0.03 – 0.51). The correlation coefficient of the recovery rate between the JOA and mJOA was 0.75. The Bland-Altman analyses showed that limits of agreement were 3.6 to -1.2 for the total score, and 55.1% to -68.8% for the recovery rates. Conclusions In the present study, the JOA score and the mJOA score showed good correlation with each other in terms of their total scores and recovery rates. Previous studies using the JOA can be interpreted based on the mJOA; however it is not ideal to use them interchangeably. The validity of both scores was demonstrated by comparing these values to the PRO values.

Optimal schedule of preoperative embolization for spinal metastasis surgery.

Study Design. A retrospective study. Objective. To investigate the relationship between intraoperative blood loss during spinal metastasis surgery and the surgical delay after preoperative embolization. Summary of Background Data. Delaying surgery after embolization is thought to diminish its effectiveness because of revascularization, but there has been no scientific study that supports this hypothesis. Methods. We reviewed data from 66 consecutive posterior palliative decompression surgical procedures for spinal metastasis from thyroid and renal cell carcinoma (39 thyroid and 27 renal) in 58 patients between 2004 and 2012. All patients underwent preoperative angiography. The timing of preoperative embolization was determined on the basis of the operating room and interventional radiologist schedules. Excluding one case who did not receive embolization due to lack of hypervascularity, we analyzed 65 cases to compare intraoperative blood loss according to the completeness of embolization and the time lapse between embolization and surgery. Results. Surgical procedures were performed on the same day of embolization in 21 cases (same day-group), and on the next day after embolization in 39 cases (next-day group). Five surgical procedures were performed 2 days later. The intraoperative blood loss was significantly lesser with complete embolization than with partial embolization (mean ± standard deviation: 809 ± 835 vs. 1210 ± 904 mL, P = 0.03). Among those with complete embolization, the intraoperative blood loss as well as the perioperative transfusion requirement was significantly lesser in the same-day group than in the next-day group (mean ± standard deviation: blood loss: 433 ± 376 vs. 1012 ± 974 mL, P = 0.01; transfusion requirement: 1.5 ± 1.7 vs. 4.2 ± 4.1 units, P = 0.04). Conclusion. Preoperative embolization showed greater effectiveness in reducing intraoperative blood loss when surgery for spinal metastasis was performed on the same day than when surgery was delayed. Surgery should be performed on the same day of embolization if possible. Level of Evidence: 4

Degenerative cervical myelopathy

Cervical myelopathy is the most common cause of acquired spinal cord compromise. The concept of degenerative cervical myelopathy (DCM), defined as symptomatic myelopathy associated with degenerative arthropathic changes in the spine axis, is being introduced. Given its progressive nature, treatment options have to be chosen in a timely manner. Surgical options include anterior discectomy and fusion (ACDF), anterior corpectomy and fusion (ACCF), arthroplasty (in highly select cases), posterior laminectomy with/without fusion, and laminoplasty. Indications for each should be carefully considered in individual patients. Riluzole, a sodium-glutamate antagonist, is a promising option to optimize neurologic outcomes post-surgery and is being examined in the CSM-Protect Randomized Controlled Trial. Preoperative risk assessment is mandatory for prognostication. Sagittal alignment is known to play an important role to optimize surgical outcome. Guidelines for optimal management of DCM are in process. In principle, all but the mildest cases of DCM should be offered surgery for optimal outcome.

MRI analysis of the combined prospectively collected AOSpine North America and International Data: The Prevalence and Spectrum of Pathologies in a Global Cohort of Patients with Degenerative Cervical Myelopathy

Study Design. An ambispective analysis. Objective. The aim of this study was to report the global prevalence of specific degenerative cervical pathologies in patients with degenerative cervical myelopathy (DCM) through detailed review of magnetic resonance imaging (MRIs). Summary of Background Data. DCM encompasses a spectrum of age-related conditions that result in progressive spinal cord injury. Methods. MRIs of 458 patients (age 56.4 ± 11.8, 285 male, 173 female) were reviewed for specific degenerative features, directionality of cord compression, levels of spinal cord compression, and signal changes on sagittal T2-weighted imaging (T2WI) and sagittal T1-weighted imaging (T1WI). Data were analyzed for differences between sex using Chi-square tests and geographic variations using Kruskal-Wallis tests. Results. Spondylosis was frequently present (89.7%) and was commonly accompanied by enlargement of the ligamentum flavum (LF) (59.9%). Single-level disc pathology, ossification of posterior longitudinal ligament (OPLL), and spondylolisthesis had a prevalence of ∼10% each. OPLL was accompanied by spondylosis in 91.7%. Klippel-Feil syndrome was observed in 2.0%. The Asia-Pacific region had more OPLL (29%, P = 3 × 10−11) and less spondylolisthesis (1.9%, P = 0.002). Females presented more commonly with single-level disc pathology (13.9% vs. 6.7%; P = 0.013), and males with spondylosis (92.3% vs. 85.6%; P = 0.02) and enlargement of LF (61.4% vs. 49.1%; P = 0.01). C5 to C6 was the most frequent maximum compressed site (39.5%) and region for T2WI hyperintensity (38.9%). T2WI hyperintensity more commonly presented in males (82.4% vs. 66.7%; P < 0.001). Conclusion. This is the largest report on the prevalence and spectrum of pathology in patients with DCM. Herein, it has been demonstrated that degenerative features are highly interrelated, that females presented with milder MRI evidence of DCM, and that variations exist in the prevalence of pathologies between geographical regions. Level of Evidence. 2

Comparison of Anterior and Posterior Surgery for Degenerative Cervical Myelopathy: An MRI-Based Propensity-Score-Matched Analysis Using Data from the Prospective Multicenter AOSpine CSM North America and International Studies.

Background: Surgeons often choose between 2 different approaches (anterior and posterior) for surgical treatment of degenerative cervical myelopathy on the basis of imaging features of spinal cord compression, the number of levels affected, and the spinal alignment. However, there is a lack of consensus on which approach is preferable. The objective of the present study was to use magnetic resonance imaging (MRI)-based propensity-score-matched analysis to compare postoperative outcomes between the anterior and posterior surgical approaches for degenerative cervical myelopathy. Methods: A total of 757 patients were enrolled in 2 prospective multicenter AOSpine studies, which involved 26 international sites. Preoperative MRIs were reviewed to characterize the causes of the cord compression, including single-level disc disease, multilevel disc disease, ossification of the posterior longitudinal ligament, enlargement of the ligamentum flavum, vertebral subluxation/spondylolisthesis, congenital fusion, number of compressed levels, or kyphosis. The propensity to choose anterior decompression was calculated using demographic data, preoperative MRI findings, and the modified Japanese Orthopaedic Association (mJOA) scores in a logistic regression model. We then performed 1-to-1 matching of patients who had received anterior decompression with those who had the same propensity score but had received posterior decompression to compare 2-year postoperative outcomes and 30-day perioperative complication rates between the 2 groups after adjustment for background characteristics. Results: A total of 435 cases were included in the propensity score calculation, and 1-to-1 matching resulted in 80 pairs of anterior and posterior surgical cases; 99% of these matched patients had multilevel compression. The anterior and posterior groups did not differ significantly in terms of the postoperative mJOA score (15.1 versus 15.3, p = 0.53), Neck Disability Index (20.5 versus 24.1, p = 0.44), or Short Form-36 (SF-36) Physical Component Summary (PCS) score (41.9 versus 40.9, p = 0.30). The overall rates of perioperative complications were similar between the 2 groups (16% versus 11%, p = 0.48); however, dysphagia/dysphonia was reported only in the anterior group whereas surgical site infection and C5 radiculopathy were reported only in the posterior group. Conclusions: Anterior and posterior decompression for degenerative cervical myelopathy resulted in similar postoperative outcomes and rates of complications. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Prediction of outcome following surgical treatment of cervical myelopathy based on features of ossification of the posterior longitudinal ligament a systematic review

Background: Ossification of the posterior longitudinal ligament (OPLL) is defined as ectopic bone formation within the posterior longitudinal ligament. Although various OPLL features (including the extent, shape, and thickness of the OPLL as well as the presence of dural ossification) have been defined in the literature, we are not aware of any systematic reviews that have summarized the associations between these features and clinical outcomes following surgery. The objective of the present study was to conduct a systematic review of the literature to determine whether OPLL characteristics are predictive of outcome in patients undergoing surgery for the treatment of cervical myelopathy. Methods: An extensive search was performed using 4 electronic databases: MEDLINE, MEDLINE In-Process, Embase, and the Cochrane Central Register of Controlled Trials. Our search terms were OPLL and cervical. We identified studies in English or Japanese that evaluated the association between cervical OPLL features and surgical outcome. The overall body of evidence was assessed with use of a scoring system developed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group with recommendations from the Agency for Healthcare Research and Quality (AHQR). The present systematic literature review is formatted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Results: The search yielded a total of 2,318 citations. A total of 28 prognostic cohort studies were deemed relevant following a rigorous review process. Among them, only 7 retrospective studies involved a multivariate analysis that controlled for potential confounding variables. Sample sizes ranged from 47 to 133 patients. The main outcome was the postoperative Japanese Orthopaedic Association (JOA) score and/or recovery rate in 6 studies and the Nurick grade in 1. Of these, 2 were rated as Level-II evidence and 5 were rated as Level-III evidence. On the basis of our results, there was low evidence that patients with a hill-shaped ossification have a worse postoperative JOA score following laminoplasty than those with a plateau-shaped lesion; low evidence that the space available for the spinal cord cannot predict postoperative JOA scores; moderate evidence that there is no association between the occupying ratio and improvement on the Nurick scale; and insufficient evidence to determine the association between JOA outcomes and the type of OPLL, the presence of dural ossification, and the occupying ratio. Conclusions: Patients with hill-shaped OPLL have a worse postoperative JOA score than those with plateau-shaped ossification after laminoplasty. Because of limited evidence, it is unclear whether the occupying ratio, the type of OPLL, and the presence of dural ossification are predictive of surgical outcomes following either anterior or posterior decompression. A limited number of studies have used a multivariate analysis to evaluate the association between clinical outcomes and OPLL features. Additional studies representing high-quality evidence are needed. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect of Preoperative Sagittal Balance on Cervical Laminoplasty Outcomes.

Study Design. Retrospective case series. Objective. To clarify how preoperative global sagittal imbalance influences outcomes in patients with cervical compression myelopathy undergoing cervical laminoplasty. Summary of Background Data. The influence of sagittal balance on outcomes of cervical laminoplasty remains uncertain. Methods. The authors retrospectively reviewed data of 106 patients who underwent double-door cervical laminoplasty between 2004 and 2011 and investigated the influence of the C7 sagittal vertical axis (SVA) on outcome scores. Primary outcomes used were Japanese Orthopedic Association (JOA) scores, Numerical Rating Scale for neck or arm pain, the Short Form 36 Health Survey (physical and mental component summary scores ), and the Neck Disability Index (NDI). Results. Ninety-two patients with complete data were eligible for inclusion. The preoperative C7 SVA was ⩽5 cm in 64 patients (69.6%) and > 5 cm in 28 (30.4%). We compared each parameter by the magnitude of spinal sagittal balance (preoperative C7 SVA > 5 cm vs. C7 SVA ⩽ 5 cm) after adjusting for age via the least square mean analysis because the average age was significantly higher in patients with C7 SVA > 5 cm. As for the radiographic parameters, both C2–7 SVA and C7 SVA were larger in patients when the C7 SVA was > 5 cm. Numerical Rating Scale for postoperative arm pain, postoperative JOA scores, and both pre- and postoperative physical component summary and NDI were worse in patients with C7 SVA > 5 cm; however, the JOA score recovery rate and changes in physical component summary and NDI were not significantly different. Conclusion. Postoperative functional outcome scores were significantly lower in patients with C7 SVA > 5 cm, although the improvement after cervical laminoplasty was not greatly affected. The involvement of global sagittal balance and cervical regional alignment should be considered in evaluating surgical outcomes for patients undergoing cervical laminoplasty. Level of Evidence: 4

Phosphorylated neurofilament subunit levels in the serum of cervical compressive myelopathy patients

We investigated the serum levels of the phosphorylated form of the high molecular weight neurofilament subunit (pNF-H) in patients with cervical compressive myelopathy. pNF-H is becoming increasingly recognized as a biomarker for axonal injury, however, it remains unclear whether serum pNF-H is elevated in chronic spinal cord compression. We examined 26 patients who underwent surgery for cervical compressive myelopathy. Peripheral blood samples were obtained both preoperatively and 1 week after surgery to evaluate the serum pNF-H levels using an enzyme-linked immunosorbent assay. A history of recent aggravation of myelopathy was also investigated. Of the 26 myelopathy patients, the preoperative serum pNF-H level was negative in 20 patients and moderately elevated in six. Patients who were positive for pNF-H were more likely to have had a recent aggravation of myelopathy compared with the pNF-H negative patients (83 versus 25%; p=0.02). All patients who were positive for pNF-H before surgery remained positive after surgery. Two patients who became positive after surgery demonstrated a neurologic deterioration associated with the surgery. In conclusion, the serum pNF-H level was negative in the majority of patients with cervical compressive myelopathy. Our results suggest that an elevated serum level of pNF-H is associated with an acute worsening of myelopathy and that a positive conversion of pNF-H after surgery is a marker of perioperative neural damage.