3. Placebo to match tanezumab. The study is designed with a total (post-randomization) duration of 48 weeks and will consist of three periods: Screening (up to 37 days), Double-blind Treatment (24 weeks) and Safety Follow-up (24 weeks). The Screening Period (beginning up to 37 days prior to Randomization) includes a Washout Period (lasting a minimum of 2 days for all prohibited pain medications), if required, and an Initial Pain Assessment Period (the 7 days prior to Randomization/Baseline).