The role of continuous passive motion following total knee arthroplasty

A retrospective review of 25 knees with postoperative continuous passive motion (CPM) treatment following total knee arthroplasty (TKA) was compared with a control group of 25 knees without postoperative CPM. The diagnoses were similar in both groups, with osteoarthritis in 43 knees, traumatic arthritis in 2 knees, rheumatoid arthritis in 2 knees, osteonecrosis in one knee, and gouty arthritis in one knee. Average knee flexion at discharge was 93.2 degrees in the CPM group and 86.5 degrees in the control group (p less than 0.01). Eighty percent of the CPM group and 64% of the control group had achieved 90 degrees of flexion before hospital discharge. The time required to achieve 90 degrees of flexion after TKA averaged 9.6 days in the CPM group and 11 days in the control group (p less than 0.01). There was no significant difference in flexion at 3 months or at 1 year postoperatively between the two groups. The duration of hospitalization was not significantly different between the two groups. One knee in the CPM group and 3 knees in the control group required manipulation. Wound hemovac drainage and transfusion requirements were not significantly different. The number of pain medication was not significantly different between the two groups. The CPM made the TKA knee achieve motion earlier with fewer complications.