title: Microstructural alterations of femoral head articular cartilage and subchondral bone in osteoarthritis and osteoporosis.
abstract: OBJECTIVE
  Explore whether osteoporosis (OP) in humans influences the morphological status of the articular cartilage and the subchondral bone. Explore the relationship between the macroscopic aspect of the articular surface and the rate of microscopic changes of both the cartilage and the subchondral bone in OP and osteoarthritis (OA).
  
  
  METHODS
  Femoral heads after total hip replacement were obtained from patients with OP or hip OA (OP, n = 56; OA, n = 12). Cartilage degeneration was assessed using the Mankin grading system whereas subchondral bone was evaluated using histomorphometry and Micro-computed Tomography (μCT) scanning system. Thickness of the cartilage layers and subchondral cortical bone (SCB) was measured.
  
  
  RESULTS
  Samples with higher total Mankin score have significantly reduced cartilage thickness. Mankin score differed between all OP specimens. In OP samples with lower Mankin scores the thickness of SCB shows a trend of an increase caused by increased levels of bone remodeling. In OP samples with higher Mankin scores we observed thinning of SCB. Structural indices of subchondral trabecular bone (STB) were significantly lower in OP than in OA samples.
  
  
  CONCLUSIONS
  Thinning of SCB, found in OP samples with higher Mankin scores could be related with the progression of the cartilage degeneration indicating an early-stage OA. Increased levels of bone remodeling and evidently changed morphology of subchondral bone found in OP samples with lower Mankin score indicated that bony bed level must have a role in the progression of the cartilage degeneration.
authors.affiliation: Department of Anatomy, School of Medicine, University of Rijeka, Rijeka, Croatia. Electronic address: dragica.bobinac@medri.uniri.hr.
authors.forename: D
authors.initials: D
authors.lastname: Bobinac
authors.forename: M
authors.initials: M
authors.lastname: Marinovic
authors.forename: E
authors.initials: E
authors.lastname: Bazdulj
authors.forename: O
authors.initials: O
authors.lastname: Cvijanovic
authors.forename: T
authors.initials: T
authors.lastname: Celic
authors.forename: I
authors.initials: I
authors.lastname: Maric
authors.forename: J
authors.initials: J
authors.lastname: Spanjol
authors.forename: T
authors.initials: T
authors.lastname: Cicvaric
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016723:Bone Remodeling / Q000502:physiology; D002358:Cartilage, Articular / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005270:Femur Head / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000473:pathology* / Q000503:physiopathology; D010024:Osteoporosis / Q000473:pathology* / Q000503:physiopathology; D012720:Severity of Illness Index; D055114:X-Ray Microtomography / Q000379:methods
keywords: Cartilage alterations; Osteoarthritis; Osteoporosis; Subchondral cortical bone; Subchondral trabecular bone