One hundred and sixty patients, between the ages of 18 and 90 years of age, who were scheduled to undergo primary total knee arthroplasty (TKA), were randomly assigned into 1 of 3 groups to determine the effect that continuous passive motion (CPM) had on clinical outcomes following surgery. Patients either received stationary CPM as an adjunct to physiotherapy, non-stationary CPM as an adjunct to physiotherapy, or standard physiotherapy alone. Results of the study indicated that, when comparing CPM intervention to physiotherapy alone, no significant differences in range of motion (ROM), swelling, blood loss, pain scores, or active ROM existed 3 weeks after intervention.