Primary: Assess the ability of a continuous treatment of celecoxib 200 mg versus placebo administered once daily (QD) for 24 months in slowing disease progression as assessed radiographically in subjects with osteoarthritis (OA) of the hipSecondary:Assess the ability of a continuous treatment of celecoxib 200 mg versus placebo administered QD for 24 months in treating disease signs and symptoms in subjects with OA of the hip.Evaluate the ability of a continuous 24-month intake of celecoxib 200 mg QD versus placebo to reduce number of subjects eligible for hip replacement according to the investigator.Evaluate the tolerability and safety of a continuous 24-month intake of celecoxib 200 mg QD versus placebo in subjects with OA of the hip.