title: TBS result is not affected by lumbar spine osteoarthritis.
abstract: The effect of lumbar osteoarthritis on bone density and trabecular bone score (TBS) was evaluated cross-sectionally and prospectively in postmenopausal women. Lumbar spine osteoarthritis was graded according to Kellgren and Lawrence grades. Lumbar osteoarthritis was found to increase lumbar spine bone density, but not TBS.
  
  
  BACKGROUND
  Lumbar osteoarthritis overestimates lumbar bone density (areal bone mineral density (aBMD)). A new texture parameter, the TBS, has been proposed. Calculation of aBMD uses grey level value, while TBS uses grey level variation. Therefore, our hypothesis was that TBS is not influenced by lumbar spine osteoarthritis.
  
  
  METHODS
  Menopausal women participating in osteoporosis and ultrasound (OPUS) study were included. They had an aBMD measurement of the spine and hip at baseline and 6-year visit. TBS was calculated on lumbar spine dual-energy X-ray absorptiometry (DXA) scans in an automated manner. The presence of lumbar osteoarthritis was evaluated on baseline radiographs using Kellgren and Lawrence (K&L) classification. Grades range from 0 to 4. In our study, osteoarthritis was defined by at least K&L grade 2.
  
  
  RESULTS
  This study included 1,254 menopausal women (66.7 ± 7.1 years). Among them, 727 attended the 6-year follow-up visit. Patients with lumbar osteoarthritis had an aBMD higher than those without lumbar osteoarthritis at the lumbar spine, but not at the hip. However, the aBMD significantly increased in all sites with the grade of K&L. In contrast, spine TBS was not different between patients with and without lumbar osteoarthritis (p = 0.70), and it was not correlated with K&L grade. Spine TBS and aBMD at all sites were negatively correlated with age (p < 0.0001). Body mass index was correlated positively with aBMD and negatively with spine TBS (p < 0.0001). The 6-year change of aBMD was significant in the hip and nonsignificant in the lumbar spine. That of TBS was significant, with a 3.3 % decrease (p < 0.0001), independent of K&L grade (p = 0.28).
  
  
  CONCLUSIONS
  In postmenopausal women, lumbar osteoarthritis leads to an increase in lumbar spine aBMD. In contrast, spine TBS is not affected by lumbar osteoarthritis.
authors.affiliation: INSERM, U 1153, Rheumatology Department, Cochin Hospital, Paris Descartes University, Paris, France, sami.kolta@cch.aphp.fr.
authors.forename: S
authors.initials: S
authors.lastname: Kolta
authors.forename: K
authors.initials: K
authors.lastname: Briot
authors.forename: J
authors.initials: J
authors.lastname: Fechtenbaum
authors.forename: S
authors.initials: S
authors.lastname: Paternotte
authors.forename: G
authors.initials: G
authors.lastname: Armbrecht
authors.forename: D
authors.initials: D
authors.lastname: Felsenberg
authors.forename: C C
authors.initials: CC
authors.lastname: Glüer
authors.forename: R
authors.initials: R
authors.lastname: Eastell
authors.forename: C
authors.initials: C
authors.lastname: Roux
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005272:Femur Neck / Q000503:physiopathology; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D008875:Middle Aged; D055013:Osteoarthritis, Spine / Q000503:physiopathology*; D017698:Postmenopause / Q000502:physiology; D012720:Severity of Illness Index; D055815:Young Adult