Figure 3.

Histological effect of disuse atrophy of articular cartilage on OA progression. Time-dependent changes in the maximum OARSI score (A), summed OARSI score (B), and subchondral bone damage score (C). All scores significantly increased with time. (D) Representative histological osteoarthritic features of the tibial articular cartilage. At 2 and 4 weeks, the toluidine blue–stained area was decreased in the HS-OA group relative to that in the OA group. At 4 weeks, fibrillation and fissure were observed in the OA group and HS-OA group, and erosion was also observed in the latter. At 8 weeks, cartilage thinning, fibrillation, and fissure were observed in the OA group, and erosion and deformation of the articular surface were observed in the HS-OA group. Scale bar = 500 μm. OA, osteoarthritis; HS, hindlimb suspension; OARSI, Osteoarthritis Research Society International.