Paper

• Dose-response relationship between spino-pelvic alignment determined by sagittal modifiers and back pain-specific quality of life.
  Ryoji Tominaga; Noriaki Kurita; Yoshiyuki Kokubun; Takuya Nikaido; Miho Sekiguchi; Koji Otani; Masumi Iwabuchi; Osamu Shirado; Shunichi Fukuhara; Shin-Ichi Konno
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, Oct. 2021
  PURPOSE: To determine whether abnormalities of the sagittal modifiers (SMs) of the Scoliosis Research Society (SRS)-Schwab classification truly reflect back pain (BP)-specific quality of life (QOL), it is necessary to examine their dose-response relationships and to determine clinically impactful thresholds for declines in BP-specific QOL. This study aimed to analyse the continuous dose-response relationship between each SM and BP-specific QOL. METHODS: This cross-sectional study, using data from a Japanese population-based cohort study, included 519 community-dwelling residents aged ≥ 50 years who participated in the annual health examination. The participants completed the Roland-Morris Disability Questionnaire (RDQ) on BP-specific QOL. Spino-pelvic alignment based on SMs was assessed by whole-spine X-ray examinations. We fitted general linear models with or without nonlinear terms to estimate the dose-response relationship between each SM and BP-specific QOL. RESULTS: Pelvic tilt, pelvic incidence minus lumbar lordosis (PI-LL), and sagittal vertical axis showed dose-response relationships with BP-specific QOL measured as the RDQ score. PI-LL was most likely to predict a minimally clinically important RDQ score when its value exceeded the 90th percentile. A nonlinear relationship between PI-LL and the BP-specific QOL score was found. RDQ increased when PI-LL exceeded 10°. CONCLUSION: PI-LL might be the most sensitive of the three modifiers of the SRS-Schwab classification for determining BP-specific QOL. Moreover, BP-specific QOL worsens rapidly when the compensatory mechanism against malalignment exceeds a critical value. Therefore, we suggest that traditional classifications and surgical strategies should be re-examined regarding the dose-dependent abnormalities of the SMs to develop a more reliable classification strategy.

  DOI URL
• Sagittal imbalance and symptoms of depression in adults: Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study (LOHAS).
  Kazuyuki Watanabe; Koji Otani; Ryoji Tominaga; Yoshiyuki Kokubun; Miho Sekiguchi; Shingo Fukuma; Tsukasa Kamitani; Takuya Nikaido; Kinshi Kato; Hiroshi Kobayashi; Shoji Yabuki; Shin-Ichi Kikuchi; Shin-Ichi Konno
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, Sep. 2021
  PURPOSE: With spinal deformities, mental health can deteriorate due to sagittal imbalance of the spine. The purpose of this study was to clarify the relationship between sagittal imbalance and symptoms of depression among local residents in the community. METHODS: This study used data from the Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS) in 2010. The sagittal vertical axis (SVA) was identified as an indicator of sagittal imbalance. Symptoms of depression were assessed using the 5-item version of the Mental Health Inventory. Participants were classified into three categories based on the SVA balance as normal (< 40 mm), moderate imbalance (40-95 mm), and severe imbalance (> 95 mm). To evaluate the relationship between sagittal imbalance of the spine and symptoms of depression, the adjusted risk ratio (RR) and the 95% confidence interval (CI) were calculated using a generalized linear model with Poisson link. RESULTS: There were 786 participants included in the statistical analysis. Overall, the mean age was 68.1 y (standard deviation, 8.8 y), and 39.4% were men. The prevalence of symptoms of depression by SVA category was 18.6% for normal, 23.8% for moderate, and 40.6% for severe. On multivariate analysis, the RR of SVA for symptoms of depression compared to the normal category was 1.12 (95% CI 0.7-1.70) for the moderate category and 2.29 (95% CI 1.01-5.17) for the severe category. CONCLUSION: In local community residents, sagittal imbalance had a significant association with symptoms of depression.

  DOI URL