title: Six weeks of continuous joint distraction appears sufficient for clinical benefit and cartilaginous tissue repair in the treatment of knee osteoarthritis.
abstract: BACKGROUND
  Knee joint distraction (KJD) is a surgical joint-preserving treatment in which the knee joint is temporarily distracted by an external frame. It is associated with joint tissue repair and clinical improvement. Initially, patients were submitted to an eight-week distraction period, and currently patients are submitted to a six-week distraction period. This study evaluates whether a shorter distraction period influences the outcome.
  
  
  METHODS
  Both groups consisted of 20 patients. Clinical outcome was assessed by WOMAC questionnaires and VAS-pain. Cartilaginous tissue repair was assessed by radiographic joint space width (JSW) and MRI-observed cartilage thickness.
  
  
  RESULTS
  Baseline data between both groups were comparable. Both groups showed an increase in total WOMAC score; 24±4 in the six-week group and 32±5 in the eight-week group (both p<0.001). Mean JSW increased 0.9±0.3mm in the six-week group and 1.1±0.3mm in the eight-week group (p=0.729 between groups). The increase in mean cartilage thickness on MRI was 0.6±0.2mm in the eight-week group and 0.4±0.1mm in the six-week group (p=0.277).
  
  
  CONCLUSIONS
  A shorter distraction period does not influence short-term clinical and structural outcomes statistically significantly, although effect sizes tend to be smaller in six week KJD as compared to eight week KJD.
authors.affiliation: Limb Deformity and Knee Reconstruction Unit, Dept of Orthopedic Surgery, Maartenskliniek Woerden, The Netherlands; Rheumatology & Clinical Immunology, UMC Utrecht, The Netherlands. Electronic address: j.a.d.vanderwoude@umcutrecht.nl.
authors.forename: J A D
authors.initials: JA
authors.lastname: van der Woude
authors.affiliation: Limb Deformity and Knee Reconstruction Unit, Dept of Orthopedic Surgery, Maartenskliniek Woerden, The Netherlands. Electronic address: vanheerwaarden@yahoo.com.
authors.forename: R J
authors.initials: RJ
authors.lastname: van Heerwaarden
authors.affiliation: Limb Deformity and Knee Reconstruction Unit, Dept of Orthopedic Surgery, Maartenskliniek Woerden, The Netherlands. Electronic address: s.spruijt@maartenskliniek.nl.
authors.forename: S
authors.initials: S
authors.lastname: Spruijt
authors.affiliation: Institute of Anatomy, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Chondrometrics Gmbh, Ainring, Germany. Electronic address: felix.eckstein@pmu.ac.at.
authors.forename: F
authors.initials: F
authors.lastname: Eckstein
authors.affiliation: Institute of Anatomy, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Chondrometrics Gmbh, Ainring, Germany. Electronic address: dr-susannemaschek@web.de.
authors.forename: S
authors.initials: S
authors.lastname: Maschek
authors.affiliation: Dept of Orthopedics, UMC Utrecht, The Netherlands. Electronic address: p.m.vanroermund@umcutrecht.nl.
authors.forename: P M
authors.initials: PM
authors.lastname: van Roermund
authors.affiliation: Dept of Orthopedics, UMC Utrecht, The Netherlands. Electronic address: r.j.h.custers@umcutrecht.nl.
authors.forename: R J H
authors.initials: RJ
authors.lastname: Custers
authors.affiliation: Rheumatology & Clinical Immunology, UMC Utrecht, The Netherlands. Electronic address: w.e.vanspil@umcutrecht.nl.
authors.forename: W E
authors.initials: WE
authors.lastname: van Spil
authors.affiliation: Rheumatology & Clinical Immunology, UMC Utrecht, The Netherlands. Electronic address: s.mastbergen@umcutrecht.nl.
authors.forename: S C
authors.initials: SC
authors.lastname: Mastbergen
authors.affiliation: Rheumatology & Clinical Immunology, UMC Utrecht, The Netherlands. Electronic address: f.lafeber@umcutrecht.nl.
authors.forename: F P J G
authors.initials: FP
authors.lastname: Lafeber
mesh_terms: D002358:Cartilage, Articular / Q000601:surgery*; D015331:Cohort Studies; D016267:External Fixators; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D019857:Osteogenesis, Distraction / Q000379:methods*; D014143:Traction; D014945:Wound Healing
keywords: Cartilaginous tissue repair; Joint distraction; Knee; Osteoarthritis; Treatment