title: Lumbo-femoral angle: a novel sagittal parameter related to quality of life in patients with adult scoliosis.
abstract: OBJECTIVE
  PT and PI-LL sometimes offer limited utility in daily practice when evaluating QOL, especially in outpatient clinics with limited time and equipment facility. This study proposes a novel spino-pelvic parameter, lumbo-femoral angle (LFA). The purpose of this study is to analyze the correlation between LFA and HRQOL in adult scoliosis patients.
  
  
  METHODS
  A cohort of 100 asymptomatic adult volunteers and 50 patients with adult scoliosis were prospectively recruited. The following sagittal parameters including thoracic kyphosis (TK), LL, LFA, PI, PT and sacral slope (SS) were measured on the long-cassette standing upright lateral radiographs. Health-related QOL (HRQOL) measures included the VAS, ODI and SF-36 instruments for patients with adult scoliosis.
  
  
  RESULTS
  LFA, the novel regional lumbo-sacral parameter, averaged 0.68° ± 4.5° in normal adults with the 95 % CI value of -7° to 7°. Similar intra- and inter-observer intraclass correlations and less measurement time were observed in LFA compared to PI-LL indicating that it is easy to quantitatively evaluate the regional alignment directly from X-ray films. Although LFA in patients with adult scoliosis was found to be significantly larger (11.8° ± 8.7° vs. 0.68° ± 4.5°, p < 0.001), it showed strong correlations with the PT and PI-LL in both groups (p < 0.001). Additionally, a summary of correlations between LFA and QOL measurements was identified (p < 0.05).
  
  
  CONCLUSIONS
  LFA could be considered a novel, user-friendly sagittal parameter, correlated with previously established sagittal spino-pelvic parameters and HRQOL measurements. LFA showed high inter- and intra-observer reliability, faster measurement times and could be easily identified and read. Mean LFA in asymptomatic adult patients was nearly 0° with 95 % CI value of -7° to 7°, and significantly increased in adult scoliosis patients.
authors.affiliation: Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road 321, Nanjing, 210008, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Hongda
authors.initials: H
authors.lastname: Bao
authors.forename: Shouyu
authors.initials: S
authors.lastname: He
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Zezhang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry / Q000379:methods; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008161:Lumbosacral Region / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010384:Pelvic Bones / Q000000981:diagnostic imaging / Q000473:pathology; D011187:Posture; D011446:Prospective Studies; D011788:Quality of Life; D011859:Radiography; D015203:Reproducibility of Results; D012447:Sacrum / Q000000981:diagnostic imaging / Q000473:pathology; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000473:pathology* / Q000534:rehabilitation