ObjectiveThis research aimed to study the effect of early application of continuous passive motion (CPM) on the drainage volume of knee joints post total knee arthroplasty (TKA).MethodsThe drainage volume was measured 1 h before,during and after CPM on the day and next day of the operation.ResultsThere was no significant difference in the drainage volume before,during and after CPM(P >0.05).ConclusionEarly application of CPM is safe for TKA patients.``