The estimates for risk of manipulation and adverse events are very imprecise and the estimate for the risk of adverse events does not distinguish between a clinical ly important increase and decrease in risk .
There was insufficient evidence to determine the effect of CPM on participants ' global assessment of treatment effectiveness .
CPM does not have clinical ly important effects on active knee flexion ROM , pain , function or quality of life to justify its routine use .
BACKGROUND Arthritis of the knee is a common problem causing pain and disability .
If severe , knee arthritis can be surgically managed with a total knee arthroplasty .
Rehabilitation following knee arthroplasty often includes continuous passive motion ( CPM ) .
CPM is applied by a machine that passively and repeatedly moves the knee through a specified range of motion ( ROM ) .
It is believed that CPM increases recovery of knee ROM and has other therapeutic benefits .
However , it is not clear whether CPM is effective .
OBJECTIVES To assess the benefits and harms of CPM and st and ard postoperative care versus similar postoperative care , with or without additional knee exercises , in people with knee arthroplasty .
This review is an up date of a 2003 and 2010 version of the same review .
Continuous passive motion after total knee arthroplasty.
Sixty-two patients undergoing primary total knee arthroplasty were studied prospect ively . There were 42 patients in whom continuous passive motion ( CPM ) was used after surgery and 20 controls .  The two groups were comparable with respect to age , diagnosis , sex , weight , and preoperative deformity and motion . The mean length of time required for CPM patients to achieve 90 degrees of flexion ( 9.1 days ) was shorter than that for the control group ( 13.8 days ) . At the time of discharge from the hospital , however , there was no significant difference between the groups in amount of either flexion or extension .  All patients had  venograms performed after arthroplasty ; the incidence of positive studies indicating thrombophlebitis was 45 % in CPM patients and 75 % in controls . These data demonstrate that CPM after knee arthroplasty enables patients to recover motion more quickly and affords some protection against deep vein thrombosis
The estimates for risk of manipulation and adverse events are very imprecise and the estimate for the risk of adverse events does not distinguish between a clinical ly important increase and decrease in risk .
There was insufficient evidence to determine the effect of CPM on participants ' global assessment of treatment effectiveness .
CPM does not have clinical ly important effects on active knee flexion ROM , pain , function or quality of life to justify its routine use .
BACKGROUND Arthritis of the knee is a common problem causing pain and disability .
If severe , knee arthritis can be surgically managed with a total knee arthroplasty .
Rehabilitation following knee arthroplasty often includes continuous passive motion ( CPM ) .
CPM is applied by a machine that passively and repeatedly moves the knee through a specified range of motion ( ROM ) .
It is believed that CPM increases recovery of knee ROM and has other therapeutic benefits .
However , it is not clear whether CPM is effective .
OBJECTIVES To assess the benefits and harms of CPM and st and ard postoperative care versus similar postoperative care , with or without additional knee exercises , in people with knee arthroplasty .
This review is an up date of a 2003 and 2010 version of the same review .