title: Tissue structure modification in knee osteoarthritis by use of joint distraction: an open 1-year pilot study.
abstract: BACKGROUND
  Modification of joint tissue damage is challenging in late-stage osteoarthritis (OA). Few options are available for treating end-stage knee OA other than joint replacement.
  
  
  OBJECTIVE
  To examine whether joint distraction can effectively modify knee joint tissue damage and has the potential to delay prosthesis surgery.
  
  
  METHODS
  20 patients (<60 years) with tibiofemoral OA were treated surgically using joint distraction. Distraction (~5 mm) was applied for 2 months using an external fixation frame. Tissue structure modification at 1 year of follow-up was evaluated radiographically (joint space width (JSW)), by MRI (segmentation of cartilage morphology) and by biochemical markers of collagen type II turnover, with operators blinded to time points. Clinical improvement was evaluated by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Visual Analogue Scale (VAS) pain score.
  
  
  RESULTS
  Radiography demonstrated an increase in mean and minimum JSW (2.7 to 3.6 mm and 1.0 to 1.9 mm; p<0.05 and <0.01). MRI revealed an increase in cartilage thickness (2.4 to 3.0 mm; p<0.001) and a decrease of denuded bone areas (22% to 5%; p<0.001). Collagen type II levels showed a trend towards increased synthesis (+103%; p<0.06) and decreased breakdown (-11%; p<0.08). The WOMAC index increased from 45 to 77 points, and VAS pain decreased from 73 to 31 mm (both p<0.001).
  
  
  CONCLUSIONS
  Joint distraction can induce tissue structure modification in knee OA and could result in clinical benefit. No current treatment is able to induce such changes. Larger, longer and randomised studies on joint distraction are warranted.
authors.affiliation: Rheumatology and Clinical Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Femke
authors.initials: F
authors.lastname: Intema
authors.forename: Peter M
authors.initials: PM
authors.lastname: Van Roermund
authors.forename: Anne C A
authors.initials: AC
authors.lastname: Marijnissen
authors.forename: Sebastian
authors.initials: S
authors.lastname: Cotofana
authors.forename: Felix
authors.initials: F
authors.lastname: Eckstein
authors.forename: Rene M
authors.initials: RM
authors.lastname: Castelein
authors.forename: Johannes W J
authors.initials: JW
authors.lastname: Bijlsma
authors.forename: Simon C
authors.initials: SC
authors.lastname: Mastbergen
authors.forename: Floris P J G
authors.initials: FP
authors.lastname: Lafeber
mesh_terms: D000328:Adult; D019645:Arthroplasty, Replacement, Knee; D015415:Biomarkers / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D000075202:Contraindications; D004812:Epidemiologic Methods; D016267:External Fixators; D005260:Female; D005269:Femur / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D019857:Osteogenesis, Distraction / Q000009:adverse effects / Q000379:methods*; D010865:Pilot Projects; D011859:Radiography; D013977:Tibia / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D024043:Collagen Type II