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A case-control study.To evaluate the relationship between sacroiliac joint-related pain (SIJ-RP) and spinopelvic mobility.No specific radiological findings are available for the diagnosis of SIJ-RP. A previous study reported that a higher pelvic incidence and sacral slope (SS) values were significantly associated with sacroiliac joint pain. The concept of spinopelvic mobility, which is evaluated by the differences between SS in the standing and sitting positions, has been the focus of hip and spine surgeries in recent years.The SIJ-RP group comprised patients diagnosed with SIJ-RP based on physical findings and their response to analgesic injections. No other lumbar or hip joint diseases were observed. The non-SIJ-RP group comprised patients with lower back pain for reasons other than SIJ-RP. Radiographs of the lateral view of the pelvis in the standing and sitting positions were evaluated for all patients. We compared and analyzed the backgrounds, SS in the two positions, and difference in SS between the two positions in both groups.In total, 245 patients were included in the study, with 49 and 196 patients in the SIJ-RP and non-SIJ-RP groups, respectively. More female patients experienced SIJ-RP than male patients ( P =0.0361). There were significant differences between the groups for SS in standing ( P =0.0076), sitting ( P =0.0005), and those with a difference between sitting and standing of5° ( P =0.0278) in the univariate analyses. Logistic regression analyses, after adjustment for age and sex, revealed significant differences between the groups with an SS difference5° ( P =0.0088; 95% confidence interval, 1.280-5.519), with an odds ratio of 2.7.On evaluating spinopelvic mobility, we found that SIJ-RP was related to hypomobility of the sacrum, which could indicate the hypermobility of the sacroiliac joint.

Background Foraminotomy has been reported to be effective for the treatment of cervical radiculopathy (CR). Foraminotomy has been performed by an open approach or minimally invasive approach using a microscope or endoscope. A review of the literature has revealed that both the open and minimally invasive approach provide good clinical results. Since the introduction of full-endoscopic cervical foraminotomy (FECF) followed by microendoscopic cervical foraminotomy, we adopted FECF in 2016. The purpose of this study was to evaluate the degree of satisfaction following FECF for CR. Methods A total of 109 consecutive patients underwent FECF for CR. All operations were performed at Iwai Orthopaedic Medical Hospital. Patient background information and operative data were collected. The numerical rating scale (NRS) score for the arm was assessed preoperatively and postoperatively at the time of discharge from the hospital. The satisfaction score was also recorded at discharge and the 3 months after the operation. Results In total 109 patients, the mean age was 51.3 years; 22.9% were female and 77.1% were male. The cervical level most frequently operated on was C6/7, followed by C5/6. The mean hospital stay was 4.7 days. The mean operation time was 61.7 minutes. The estimated blood loss was 0 to 10 mg in all cases. One patient exhibited temporary postoperative muscle weakness, although he recovered within 1 year. There was one case of dural tear, and no cases of nerve root injury or surgical site infection. There was one case of reoperation by microendoscopic surgery in 3 months due to insufficient improvement. Preoperative NRS scores for the arm was 4.6 and it improved significantly postoperatively to 2.1 for the entire study group. The mean satisfaction score at discharge was 7.5. The mean score at 3 months after the operations was 7.4. Conclusions Degree of satisfaction following FECF for CR was high 3 months after the operation.

Study design Retrospective study using prospectively collected data. Objective This study aimed to investigate the effect of alternative antimicrobial prophylaxis agents on surgical site infections (SSIs) after spine surgery. Summary of background data Although the use of alternative antimicrobial prophylaxis agents might have a negative effect on SSI prevention, their association with SSI risk in spine surgery remains unclear. Methods We used the registry data of consecutive patients undergoing spine surgery from April 2017 to January 2020 in four institutions participating in the University of Tokyo Spine Group. Before March 2019, all institutions used cefazolin for antimicrobial prophylaxis. After March 2019, the institutions used broad-spectrum beta-lactam agents as an alternative due to a cefazolin shortage in Japan. Results Among the 3841 enrolled patients (2289 males), 2024 received cefazolin and 1117 received alternative agents. The risk of reoperation for deep SSI within 30 days of spine surgery was significantly higher in the alternative antimicrobial prophylaxis agent group (adjusted odds ratio [aOR] 1.96; 95% confidence interval [CI], 1.15-3.35; P = 0.014). In subgroup analyses, the SSI risk was significantly higher in the thoracolumbar surgery group (aOR 1.98; 95% CI, 1.06-3.73; P = 0.03). A nonsignificant consistent trend was found in all other subgroups: posterior decompression (aOR 1.91; 95% CI, 0.86-4.21; P = 0.11); posterior fixation (aOR 2.05; 95% CI, 0.99-4.24; P = 0.05); and cervical spine surgery (aOR 2.30; 95% CI, 0.82-6.46; P = 0.11). Conclusion Alternative antimicrobial prophylaxis agents increased the risk of reoperation for SSI after spine surgery compared with cefazolin. Our study supports the current practice of using first-generation cephalosporins as first-line antimicrobial prophylaxis agents in spine surgery as recommended in multiple guidelines.Level of Evidence: 3.

To evaluate the characteristics of the spinopelvic parameters on radiography in patients with sacroiliac joint pain (SIJP). Two hundred fifty patients were included and divided into the SIJP group (those diagnosed with SIJP based on physical findings and response to analgesic periarticular injections; n = 53) and the non-SIJP group (those with low back pain [LBP] because of other reasons; n = 197). We compared their demographic characteristics and spinopelvic parameters using radiography. All differences found in the patients’ demographic characteristics and spinopelvic parameters were analyzed. More female participants experienced SIJP than male participants (P = 0.0179). Univariate analyses revealed significant differences in pelvic incidence (PI) (P = 0.0122), sacral slope (SS) (P = 0.0034), and lumbar lordosis (LL) (P = 0.0078) between the groups. The detection powers for PI, SS, and LL were 0.71, 0.84, and 0.66, respectively. Logistic regression analyses, after adjustment for age and sex, revealed significant differences in PI (P = 0.0308) and SS (P = 0.0153) between the groups, with odds ratios of 1.03 and 1.05, respectively. More female participants experienced SIJP than male participants. Higher PI and SS values were related to SIJP among LBP patients.

A retrospective study, using prospectively collected data.The aim of this study was to evaluate the impact of evidence-based care bundles for preventing surgical site infections (SSIs) in spinal instrumentation surgery.About half of all SSIs are preventable via evidence-based methods. For successful SSI prevention, the bacterial load must be minimized, and methicillin-resistant Staphylococcus aureus (MRSA) protection must be maximized. However, it is difficult to cover all of these requirements by single preventative method.We screened consecutive patients scheduled for spinal instrumentation surgeries at a single tertiary referral hospital for high surgical, SSI, and MRSA colonization risks. Evidence-based care bundles were implemented for high-risk patients and included 1) additional vancomycin prophylaxis, 2) diluted povidone-iodine irrigation, and 3) nasal and body decontamination. Patient demographics, comorbidities, operative features, and SSIs reported to the Japanese Nosocomial Infections Surveillance system were prospectively obtained in the same method by the same assessor and were used for the analyses. The results were compared before and after the application of the bundle.There were 1042 spinal instrumentation surgeries (741 before and 301 after care bundles) performed from November 2010 to December 2015. Of 301 surgeries, 57 cases (18.9%) received care bundles. There were no significant differences in patient backgrounds before and after the intervention. The SSI rate decreased significantly from 3.8% to 0.7% (P 0.01) after the intervention, with an overall 82% relative risk reduction. A significant protective effect was observed in the multivariate analysis (adjusted odds ratio 0.18, 95% confidence interval: 0.04-0.77, P = 0.02). There were no MRSA-related SSIs among those that received care bundles, even though MRSA was the predominant pathogen in the study population.Evidence-based care bundles, applied in selected high-risk spinal instrumentation cases, minimized bacterial load, maximized MRSA protection, and significantly reduced SSI rates without topical vancomycin powder.4.

Importance The optimal management for acute traumatic cervical spinal cord injury (SCI) is unknown. Objective To determine whether early surgical decompression results in better motor recovery than delayed surgical treatment in patients with acute traumatic incomplete cervical SCI associated with preexisting canal stenosis but without bone injury. Design, Setting, and Participants This multicenter randomized clinical trial was conducted in 43 tertiary referral centers in Japan from December 2011 through November 2019. Patients aged 20 to 79 years with motor-incomplete cervical SCI with preexisting canal stenosis (American Spinal Injury Association [ASIA] Impairment Scale C; without fracture or dislocation) were included. Data were analyzed from September to November 2020. Interventions Patients were randomized to undergo surgical treatment within 24 hours after admission or delayed surgical treatment after at least 2 weeks of conservative treatment. Main Outcomes and Measures The primary end points were improvement in the mean ASIA motor score, total score of the spinal cord independence measure, and the proportion of patients able to walk independently at 1 year after injury. Results Among 72 randomized patients, 70 patients (mean [SD] age, 65.1 [9.4] years; age range, 41-79 years; 5 [7%] women and 65 [93%] men) were included in the full analysis population (37 patients assigned to early surgical treatment and 33 patients assigned to delayed surgical treatment). Of these, 56 patients (80%) had data available for at least 1 primary outcome at 1 year. There was no significant difference among primary end points for the early surgical treatment group compared with the delayed surgical treatment group (mean [SD] change in ASIA motor score, 53.7 [14.7] vs 48.5 [19.1]; difference, 5.2; 95% CI, −4.2 to 14.5;P = .27; mean [SD] SCIM total score, 77.9 [22.7] vs 71.3 [27.3];P = .34; able to walk independently, 21 of 30 patients [70.0%] vs 16 of 26 patients [61.5%];P = .51). A mixed-design analysis of variance revealed a significant difference in the mean change in ASIA motor scores between the groups (F1,49 = 4.80;P = .03). The early surgical treatment group, compared with the delayed surgical treatment group, had greater motor scores than the delayed surgical treatment group at 2 weeks (mean [SD] score, 34.2 [18.8] vs 18.9 [20.9]), 3 months (mean [SD] score, 49.1 [15.1] vs 37.2 [20.9]), and 6 months (mean [SD] score, 51.5 [13.9] vs 41.3 [23.4]) after injury. Adverse events were common in both groups (eg, worsening of paralysis, 6 patients vs 6 patients; death, 3 patients vs 3 patients). Conclusions and Relevance These findings suggest that among patients with cervical SCI, early surgical treatment produced similar motor regain at 1 year after injury as delayed surgical treatment but showed accelerated recovery within the first 6 months. These exploratory results suggest that early surgical treatment leads to faster neurological recovery, which requires further validation. Trial Registration ClinicalTrials.gov Identifier:NCT01485458; umin.ac.jp/ctr Identifier:UMIN000006780

Objective The generic STarT Back 5-item screening tool (STarT-G) is used to manage chronic pain in the lower back and elsewhere. This study evaluated the validity of the Japanese version of this generic screening tool. Materials and methods Japanese participants between the ages of 20 and 64 years completed online surveys regarding pain. Survey reliability was assessed with internal consistency, as calculated using Cronbach's alpha coefficients. Spearman's correlation coefficients were used to evaluate concurrent validity between the STarT-G score and standard reference questionnaires. Associations between STarT-G scores and the presence of a disability due to chronic pain (DCP) were analyzed using receiver operator characteristic (ROC) curves. Results Analyses ultimately included data obtained from 52,842 Japanese participants (54.4% male) with a mean (standard deviation) age of 47.7 (9.4) years. Approximately 1.5% of participants had DCP, and the mean STarT-G score was 1.2 (1.4). The Cronbach's alpha coefficient was 0.71, indicating an acceptable reliability. The STarT-G score moderately correlated with the pain numerical rating scale (NRS) score (Spearman's correlation coefficient: r = 0.34). When the STarT-G threshold was set at 4, the sensitivity and specificity of the DCP predictive model were 65.8% and 82.4%, respectively, and the area under the ROC was 0.808. Conclusion The STarT-G was internally consistent and was able to distinguish between subjects with and without a DCP. Therefore, the STarT-G can reliably be used in the Japanese population to identify patients with DCP.

Background: Percutaneous endoscopic lumbar discectomy (PELD) is one of the less invasive treatments of lumbar disc herniation (LDH), and has three different operative approaches. This study focused on the interlaminar approach (ILA) and investigated the appropriate operative route for this approach. Methods: ILA was performed in 41 patients with LDH. The width of the interlaminar space, LDH size, and positional relation between LDH and the corresponding nerve root were radiologically evaluated. Thirty-three LDHs were removed via the shoulder of the corresponding nerve root and eight were removed via the axilla of the corresponding nerve root and dural sac. Pre- and postoperative statuses were evaluated using the modified Japanese Orthopedic Association (mJOA) and numerical rating scale (NRS) scores. Results: Patients’ mean age was 41.5 years; there was single-level involvement, mostly at L5/S1 (33 cases). The mean recovery rate of mJOA score was 59.8% and mean pre- and postoperative NRS scores were 5.8 and 0.98, respectively. Relatively severe complications developed in three patients treated by ILA via the shoulder. There was persistent numbness in the corresponding nerve area, transient muscular weakness, and transient bladder and rectal disturbance, may be due to excessive compression of the nerve root and/or dural sac by the endoscopic sheath. Conclusions: ILA can be used to treat LDH revealing an interlaminar space of ≥20 mm. The procedure is minimally invasive and effective; however, appropriate selection of an operative route is important to avoid operative complications. Particularly for large LDH, the operative route via the axilla should be considered.

Background We examined the effectiveness of an intervention using a standing back extension exercise called “One Stretch”, based on the McKenzie method, in improving or preventing low back pain and disability in Japanese care workers. Methods We conducted a non-randomized controlled trial in Japan. Care workers in the intervention group received an exercise manual and a 30-minute seminar on low back pain and were encouraged to exercise in groups, while care workers in a control group were given only the manual. All care workers answered questionnaires at baseline and after one year on the subjective improvement in low back pain, whether they had had a medical consultation for low back pain, and the exercise compliance. Low back pain with disability was assessed by the Oswestry Disability Index. Results Participants included 89 workers in the intervention group and 78 in the control group. Background characteristics did not differ significantly between the two groups. Compared to the control group, a greater number of care workers in the intervention group showed improvements in low back pain or prevented it, did not have a medical consultation for low back pain, and exercised regularly. Furthermore, significantly fewer care workers in the intervention group suffered from low back pain with disability by the end of the study period than in the control group. Conclusion The population approach about the exercise “One Stretch” led to better compliance with the exercise, and was effective for improving or preventing low back pain and in decreasing the likelihood of having a medical consultation for low back pain.

To prospectively calculate the incidence of postoperative sacroiliac joint-related pain (SIJP) and investigate the association between spinopelvic parameters and postoperative SIJP after lumbar spine surgery. We prospectively enrolled consecutive patients who underwent lumbar spine surgery. We defined postoperative SIJP as unilateral buttock pain according to fulfillment of the following criteria within 3 months of the surgery: a sacroiliac joint (SIJ) score higher than 4/9 postoperatively; positive response to analgesic periarticular SIJ injection with fluoroscopy; no other complications related to the surgery. The patients were divided into the SIJP group and non-SIJP group. We compared the background information and analyzed the differences in spinopelvic parameters in both groups. Additionally, receiver-operating characteristic curve analyses were performed to evaluate the cutoff values of spinopelvic parameters. Of the 281 patients enrolled, 265 were included and eight developed postoperative SIJP (3.0%). There were no significant differences in the background information between groups. Preoperative and postoperative radiological evaluations revealed that the pelvic incidence (PI) in the SIJP group was significantly higher than that in the non-SIJP group, and there were no significant differences in lumbar lordosis (LL), pelvic tilt, sacral slope, and PI minus LL. For preoperative PI, the area under the curve, cutoff value, sensitivity, and specificity were 0.73739, 59, 62.5%, and 81.9%, respectively. The incidence of postoperative SIJP after lumbar spine surgery was 3.0%. Higher PI values were associated with a higher risk of postoperative SIJP. These slides can be retrieved under Electronic Supplementary Material.

Juichi Tonosu,1 Hiroyuki Oka,2,3 Kenichi Watanabe,1 Hiroaki Abe,1 Akiro Higashikawa,1 Koji Yamada,1 Takashi Kuniya,1 Koji Nakajima,1 Sakae Tanaka,3 Ko Matsudaira2,3 1Department of Orthopedic Surgery, Kanto Rosai Hospital, Kanagawa, Japan; 2Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo, Tokyo, Japan; 3Department of Orthopedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan Background: There are no specific radiological findings for the diagnosis of sacroiliac joint-related pain. A diagnostic scoring system had been developed in 2017. The score comprised the sum of scores of six items. The score ranged from 0 to 9 points, and the cutoff was calculated as 4. Objective: To evaluate the validity of the diagnostic scoring system for sacroiliac joint-related pain. Patients and methods: The sacroiliac joint-related pain group (n=31) comprised patients diagnosed with sacroiliac joint-related pain based on patient history, physical findings, and responses to analgesic periarticular injection. In addition, it was confirmed that they had no other lumbar or hip joint diseases. The non-sacroiliac joint-related pain group (n=123) comprised patients with low back pain due to a reason other than sacroiliac joint-related pain. We evaluated scores for all subjects. We analyzed the differences in each item between both groups and performed receiver-operating characteristic curve analysis to evaluate the score validity. Results: There were no significant differences in patient characteristics between groups. There were significant differences for the following four of six items: one-finger test results (P

Purpose To conduct a 10-year longitudinal analysis of the relationship between magnetic resonance imaging (MRI) findings and low back pain (LBP). Materials and methods Ninety-one volunteers with a history of LBP, but without current LBP were recruited between 2005 and 2006. Participants’ baseline demographics and MRI findings were recorded. All volunteers were invited for a follow-up MRI in 2016; of these, 49 volunteers (53.8%) participated in the follow-up. We enquired whether they had LBP history during the 10 years between the baseline and follow-up examinations. Sagittal T1 and T2-weighted MRI were used to assess the intervertebral space from T12/L1 to L5/S1. We evaluated the presence of disc degeneration by Pfirrmann’s grading system, disc bulging, high intensity zone (HIZ), spondylolisthesis, and any type of Modic changes in the follow-up MRIs. We compared the follow-up MRI findings with the baseline findings; the progress of each finding over the 10 years were also compared between the groups with (n = 36) and without (n = 13) LBP. Results Average age of the study participants at follow-up was 44.8 years; 25 were female and 24 were male. Average age, sex, body mass index, and smoking habits of those who did and did not participate in the follow-up study, as well as the demographic characteristics of those who did and did not have LBP history during the 10 years, were not significantly different. Compared with the group without LBP history, the group that had LBP history during the 10 years did not have a significantly increased prevalence of disc degeneration, disc bulging, and HIZ in the follow-up and baseline MRIs. Spondylolisthesis and any type of Modic changes were also not associated with LBP history during the 10 years. Conclusions Follow-up MRI findings consistent with Pfirrmann grading ≥4, disc bulging, HIZ, spondylolisthesis, and any type of Modic changes were not associated with LBP history during the 10 years between the baseline and follow-up study. The progresses of these findings were also not associated with the LBP history. In addition, baseline MRI findings were not associated with LBP history during the 10 years; therefore, our data suggest that baseline MRI findings cannot predict future LBP.

Juichi Tonosu,1 Hiroyuki Oka,2 Ko Matsudaira,2 Akiro Higashikawa,1 Hiroshi Okazaki,1 Sakae Tanaka3 1Department of Orthopedic Surgery, Kanto Rosai Hospital, Kawasaki, 2Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, 3Department of Orthopedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan Abstract: The objective of this study was to evaluate the relationship between magnetic resonance imaging (MRI) findings and previous low back pain (LBP) in participants without current LBP. Current LBP was defined as LBP during the past month. Previous LBP was defined as a history of medical consultation for LBP. Ninety-one participants without current LBP were included. Sagittal T2-weighted MRI was used to assess the intervertebral space from T12/L1 to L5/S1. These images were classified into five grades based on the Pfirrmann grading system. Furthermore, we evaluated the presence of disk bulging, high-intensity zone, and spondylolisthesis. We compared the MRI findings between groups with (27 participants) and without (64 participants) previous LBP without current LBP. Intraobserver and interobserver kappa values were evaluated. Participants had an average age of 34.9years; 47 were female and 44 were male; and their average body mass index was 21.8kg/m2. Compared to the group of participants without previous LBP, the group of participants with previous LBP had a significantly higher incidence of disk degeneration such as a Pfirrmann grade ≥3, disk bulging, and high-intensity zone in the analyses adjusted by age and sex. There were no significant differences in spondylolisthesis between the groups. An odds ratio of >10 was only found for Pfirrmann grade ≥3, ie, a Pfirrmann grade ≥3 was strongly associated with a history of previous LBP in participants without current LBP. Keywords: disk bulging, low back pain, magnetic resonance imaging, MRI, Pfirrmann grading, previous history, high-intensity zone

Neck pain is a common health problem that restricts activities of daily living. The Neck Disability Index (NDI) was developed to assess disability in patients with neck pain. The normative score and the cut-off value are mandatory to assess an individual patient or a certain patient group for clinically important neck pain with disability, by distinguishing it from nonsignificant pain. The objective of the present study was to determine the normative score and the cut-off value of the NDI.A total of 1,200 participants who registered with an internet research company were interviewed on the website about their episodes of neck pain during the previous 4 weeks, and completed the online NDI questionnaire. If the participants reported neck pain, they were also asked about the disability in activity of daily living it caused, and the presence of associated symptoms in upper limbs. Disability was defined according to the consensus study on the standardization of back pain definitions. The normative score was determined by calculating the mean in the participants, and the cut-off value was determined by the receiver-operating characteristic curve analysis.The prevalence of neck pain was 37.8 %. Demographic data of the participants also indicated that they were representative of the normal population in Japan. The mean score was 6.98, and the median was 2. The NDI score was higher in middle age, and at its peak in the 50s age group (50-59 years of age). The female mean was significantly higher. The NDI score was higher in those with upper limb symptoms. We have determined the cut-off value of the NDI to detect neck pain associated with disability to be 15.The normative score and the cut-off value of the NDI were determined. Our cut-off value is potentially useful in evaluating the therapeutic effectiveness of various interventions for neck pain.

The 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.We 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.The 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.We defined the normative score and the cut-off value of the ODI.

ObjectiveThis study aimed to evaluate the validity and reliability of the Japanese version of the Neuropathic Pain Symptom Inventory (NPSI-J).DesignCross-sectional study design.Subjects and methodsThe original Neuropathic Pain Symptom Inventory (NPSI) was translated into Japanese according to published guidelines. Subsequently, an observational study of 60 Japanese patients suffering from neuropathic pain was performed to evaluate the validity and reliability of the NPSI-J.ResultsThe NPSI-J exhibited a statistically significant correlation with pain intensity (Numerical Rating Scale). The Cronbach alpha value for Likert items was 0.86. Using the test-retest analysis method, the intraclass correlation coefficient between the two scores was 0.81. Factor analysis revealed that the main component of NPSI-J comprised three determinative factors.ConclusionsThe NPSI-J is a reliable and valid pain assessment tool.

The direct anterior screw fixation of odontoid fractures by a single cancellous screw, especially for osteoporotic vertebrae, has a potential risk of leading to insufficient stability and implant failures. We experienced good results following surgery using a single Acutrak 4/5 screw to obtain sufficient stability for an odontoid fracture in a patient with osteopenia. The screw is a cannulated self-tapping headless screw and has a tapered profile and full threads with variable pitches, and it can yield sufficient compression force as the screw is inserted. The preoperative severe neck pain of the patient was diminished immediately after the surgery. The patient achieved bone union in a short time and had a good clinical result for at least 3 years. Some biomechanical studies showed that the compression force of Acutrak standard screws was stronger than that of both 4.0-mm cancellous screws inserted with the lag screw technique and Herbert screws, and other studies showed that the compression force of Acutrak 4/5 screws was equivalent to that of 4.5-mm cortical screws. However, there has been no clinical report of surgery using an Acutrak 4/5 screw for odontoid fractures. This is the first clinical report of fixation by an Acutrak 4/5 screw.

ObjectivesThe aim of this study was to evaluate the validity and reliability of the Japanese version of the painDETECT questionnaire (PDQ-J).Materials and methodsThe 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.ResultsFactor 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.ConclusionsWe 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.