title: Extracorporeal shockwave therapy in osteoporotic osteoarthritis of the knee in rats: an experiment in animals.
abstract: BACKGROUND
  This study investigated the effectiveness of extracorporeal shockwave therapy (ESWT) in osteoporotic (OP) osteoarthritis (OA) of rat knee.
  
  
  METHODS
  Fifty-six rats were divided into seven groups including sham, OA, OP, OA + OP, OA + ESWT, OP + ESWT, and OA + OP + ESWT groups. The evaluations included gross pathology, bone mineral density (BMD), micro-computed tomography (micro-CT) scan, bone-strength test, histopathologic examination, and immunohistochemical analysis.
  
  
  RESULTS
  On gross pathology, group OA + OP showed larger areas of osteoarthritic changes than did groups OA and OP, as compared with the sham group. BMD and bone strength significantly decreased in groups OA, OP, and OA + OP relative to the sham group, and ESWT significantly improved BMD and bone-strength changes. On micro-CT scan, the subchondral plate thickness significantly decreased, and the bone porosity increased in groups OA, OP, and OA + OP, and ESWT significantly improved the changes in subchondral-plate thickness and bone porosity. In histopathologic examination, Mankin score and safranin O score significantly increased in groups OA and group OA + OP, but not in group OP relative to the sham group, and ESWT significantly improved the changes. In immunohistochemical analysis, Dickkopf-1 (DKK-1) significantly increased, but vessel endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), and bone morphogenetic protein 2 (BMP-2) decreased in groups OA, OP, and OA + OP relative to the sham group, and ESWT significantly reversed the changes.
  
  
  CONCLUSIONS
  Osteoporosis increased the severity of cartilage damage in osteoarthritis of the knee. ESWT showed effectiveness in the reduction of osteoporotic osteoarthritis of the knee in rats.
authors.forename: Ching-Jen
authors.initials: CJ
authors.lastname: Wang
authors.forename: Chien-Yiu
authors.initials: CY
authors.lastname: Huang
authors.forename: Shan-Ling
authors.initials: SL
authors.lastname: Hsu
authors.forename: Jen-Hung
authors.initials: JH
authors.lastname: Chen
authors.forename: Jai-Hong
authors.initials: JH
authors.lastname: Cheng
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D007150:Immunohistochemistry; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000473:pathology / Q000628:therapy*; D010024:Osteoporosis / Q000150:complications* / Q000473:pathology; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography