Sixty primary total knee arthroplasties in 43 Chinese patients were include
d into a prospective study. Twenty-six patients who had unilateral knee art
hroplasty were randomized to receive continuous passive motion (CPM) or imm
obilization in the first week. The 2 groups of patients were comparable in
demographic data and preoperative knee range of motion (ROM). In 17 patient
s who had 1-stage sequential bilateral arthroplasties, one side had CPM and
the other side was immobilized. The active knee ROM was assessed regularly
until 1 year after the operation. For all patients, the early active knee
ROM in the CPM group was significantly better than the immobilization group
. There was no difference after 7 days, however. For patients who had 1-sta
ge bilateral total knee arthroplasties, the active knee ROM was significant
ly better on the CPM side until day 28. After 4 weeks, there was no differe
nce between the CPM group and the immobilization group. Immobilization afte
r total knee arthroplasty does not preclude good ROM.