title: Meniscectomy leads to early changes in the mineralization distribution of subchondral bone plate.
abstract: OBJECTIVE
  It is generally recognized that the subchondral bone plate (SBP) is involved in development of osteoarthritis (OA). However, the pathophysiological significance is not yet clear. The goal of this study is to investigate the extent of the changes that occur in SBP of the tibial plateau in the early stages of experimental OA.
  
  
  METHODS
  Forty-three female rabbits were assigned to 5 experimental (n = 8 each group) and one sham group (n = 3). OA was induced by medial meniscectomy in the right knee, the left knee served as control. 2, 4, 8, 12, and 24 weeks after meniscectomy, cartilage damage was evaluated, and bone mineral density (BMD) and mineralization distribution of the SBP was measured by computed tomography osteoabsorptiometry (CT-OAM).
  
  
  RESULTS
  Cartilage damage started 2 weeks after meniscectomy with surface roughening. Cartilage defects increased over time. 24 weeks postoperatively, subchondral bone was exposed. As early as 2 weeks after meniscectomy, BMD in the medial tibial plateau decreased significantly. BMD increased again and reached the values of the non-operated knee 12 weeks postoperatively. In addition, already 4 weeks after meniscectomy a significant shift of the density maximum on the medial tibial plateau, which is normally centrally located toward the margin was observed.
  
  
  CONCLUSIONS
  In conclusion, the results of this study contribute to the concept of early involvement of the SBP in the development of OA. The hypothesis that changes in the SBP occur simultaneously to cartilage damage was confirmed.
authors.affiliation: Orthopädische Gemeinschaftspraxis am OEZ, Hanauerstr. 65, 80993, Munich, Germany, dr.anetzberger@orthospezial.de.
authors.forename: Hermann
authors.initials: H
authors.lastname: Anetzberger
authors.forename: Alexandra
authors.initials: A
authors.lastname: Mayer
authors.forename: Christian
authors.initials: C
authors.lastname: Glaser
authors.forename: Stephan
authors.initials: S
authors.lastname: Lorenz
authors.forename: Christof
authors.initials: C
authors.lastname: Birkenmaier
authors.forename: Magdalena
authors.initials: M
authors.lastname: Müller-Gerbl
mesh_terms: D000818:Animals; D015519:Bone Density; D002114:Calcinosis / Q000209:etiology / Q000503:physiopathology*; D002358:Cartilage, Articular / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D008592:Menisci, Tibial / Q000601:surgery*; D019637:Orthopedic Procedures / Q000009:adverse effects; D010003:Osteoarthritis / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D011817:Rabbits; D013314:Stress, Mechanical; D016474:Weight-Bearing