Osteoarthritis is a long-term chronic joint disease and the single most common cause of disability in older adults due to deterioration of articular cartilage. At the cellular level, it is characterized by a decreased expression of cartilage matrix proteins, an increase in cartilage-degrading enzymes and inflammatory markers and cell death. Several mouse or rat in vivo models are routinely used to study osteoarthritis such as the destabilization of the medial meniscus (DMM) model, which alters the joint mechanics. However, there are still very few in vitro tools to study mechanically-induced chondrocyte damage. Here, we used cells from the ATDC5 chondrocyte progenitor cell line and differentiated them into chondrocyte aggregates by seven days of rotation culture; after differentiation, the aggregates were dissociated and the obtained cells were seeded onto Petri dishes to form monolayers; the high chondrocyte marker gene expressions were maintained on the Petri dishes for at least three days; submitting these monolayers to high hydrostatic pressure then led to a rapid down-regulation of chondrocyte marker expression. Such an in vitro cell culture protocol may be useful to study mechanically-induced chondrocyte damage without the need for conventional animal models.