title: Joint distraction attenuates osteoarthritis by reducing secondary inflammation, cartilage degeneration and subchondral bone aberrant change.
abstract: OBJECTIVE
  Osteoarthritis (OA) is a progressive joint disorder. To date, there is not effective medical therapy. Joint distraction has given us hope for slowing down the OA progression. In this study, we investigated the benefits of joint distraction in OA rat model and the probable underlying mechanisms.
  
  
  METHODS
  OA was induced in the right knee joint of rats through anterior cruciate ligament transaction (ACLT) plus medial meniscus resection. The animals were randomized into three groups: two groups were treated with an external fixator for a subsequent 3 weeks, one with and one without joint distraction; and one group without external fixator as OA control. Serum interleukin-1β level was evaluated by ELISA; cartilage quality was assessed by histology examinations (gross appearance, Safranin-O/Fast green stain) and immunohistochemistry examinations (MMP13, Col X); subchondral bone aberrant changes was analyzed by micro-CT and immunohistochemistry (Nestin, Osterix) examinations.
  
  
  RESULTS
  Characters of OA were present in the OA group, contrary to in general less severe damage after distraction treatment: firstly, IL-1β level was significantly decreased; secondly, cartilage degeneration was attenuated with lower histologic damage scores and the lower percentage of MMP13 or Col X positive chondrocytes; finally, subchondral bone abnormal change was attenuated, with reduced bone mineral density (BMD) and bone volume/total tissue volume (BV/TV) and the number of Nestin or Osterix positive cells in the subchondral bone.
  
  
  CONCLUSIONS
  In the present study, we demonstrated that joint distraction reduced the level of secondary inflammation, cartilage degeneration and subchondral bone aberrant change, joint distraction may be a strategy for slowing OA progression.
authors.affiliation: Department of Orthopaedics & Traumatology, Li Ka Shing Institute of Health Sciences and Lui Che Woo Institute of Innovative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, PR China; The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, PR China.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics & Traumatology, Li Ka Shing Institute of Health Sciences and Lui Che Woo Institute of Innovative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, PR China; The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, PR China.
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Orthopaedics and Traumatology, Bao-An District People's Hospital, Shenzhen, PR China.
authors.forename: X
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Orthopaedics & Traumatology, Li Ka Shing Institute of Health Sciences and Lui Che Woo Institute of Innovative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, PR China; The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, PR China. Electronic address: kevinho@cuhk.edu.hk.
authors.forename: K
authors.initials: K
authors.lastname: Ho
authors.affiliation: Department of Orthopaedics & Traumatology, Li Ka Shing Institute of Health Sciences and Lui Che Woo Institute of Innovative Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, PR China; The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, PR China; Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, PR China. Electronic address: gangli@cuhk.edu.hk.
authors.forename: G
authors.initials: G
authors.lastname: Li
mesh_terms: D000818:Animals; D000070598:Anterior Cruciate Ligament Injuries; D016723:Bone Remodeling; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D019902:Chondrocytes / Q000378:metabolism*; D024121:Collagen Type X / Q000378:metabolism; D004195:Disease Models, Animal; D016267:External Fixators; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism / Q000601:surgery*; D007150:Immunohistochemistry; D007249:Inflammation; D053583:Interleukin-1beta / Q000378:metabolism; D007719:Knee Joint / Q000601:surgery*; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D051381:Rats; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D000070600:Tibial Meniscus Injuries; D055114:X-Ray Microtomography
chemical_list: D024121:Collagen Type X; D053583:Interleukin-1beta; D053509:Matrix Metalloproteinase 13
keywords: Cartilage; Joint distraction; Osteoarthritis; Subchondral bone