title: Incomplete recovery of lumbar intervertebral discs 2 years after 60-day bed rest.
abstract: METHODS
  Prospective longitudinal study.
  
  
  OBJECTIVE
  To evaluate the recovery of the lumbar intervertebral discs after bed rest.
  
  
  BACKGROUND
  Prolonged bed rest is a useful model to understand the modeling and remodeling of tissues due to disuse and reloading, yet this process in the lumbar intervertebral discs has not been examined in detail.
  
  
  METHODS
  A total of 24 male subjects completed 60 days of head-down tilt bed rest as part of the 2nd Berlin BedRest Study and returned for magnetic resonance scanning 180 days (n = 22) and 2 years (n = 21) after bed rest. Lumbar disc volume, anterior and posterior disc height, disc signal intensity, intervertebral length, and lordosis were measured on sagittal plane magnetic resonance images. RESULTS.: Compared with prior to bed rest, increases in disc volume, disc height, and intervertebral length persisted 180 days (P ≤ 0.0004) and 720 days (P ≤ 0.024) after bed rest. Disc signal intensity remained increased 180 days (P = 0.034) after bed rest but was then decreased (P = 0.018) compared with baseline at the next measurement date.
  
  
  CONCLUSIONS
  The recovery of the lumbar intervertebral discs after 60-day bed rest is a prolonged process and incomplete within 2 years.
authors.affiliation: Charité Universitätsmedizin Berlin, Zentrum für Muskel- und Knochenforschung, Hindenburgdamm, Berlin, Germany. belavy@gmail.com
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Belavý
authors.forename: Gabriele
authors.initials: G
authors.lastname: Armbrecht
authors.forename: Dieter
authors.initials: D
authors.lastname: Felsenberg
mesh_terms: D001510:Bed Rest / Q000379:methods*; D018475:Head-Down Tilt; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging* / Q000502:physiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011446:Prospective Studies; D011859:Radiography; D011795:Surveys and Questionnaires; D013997:Time Factors