Preemptif analgesia pada total knee arthroplasty perbandingan efek pemberian dosis tunggal kombinasi celecoxib dan pregabalin dengan dosis pengulangan kombinasi celecoxib dan pregabalin uji klinis acak tersamar ganda = Preemptive analgesia in total knee arthroplasty comparison of single dose effects of combination of celecoxib and pregabalin with repeated dose combination celecoxib and pregabalin double disordered clinical test