Friday, August 15, 2014 Continuous Passive Motion Called Into Question Although definitive evidence is still lacking, available research trials do not support the value of continuous passive motion (CPM) as a way to reduce venous thromboembolism (VTE) in patients with total knee arthroplasty (TKA), according to a recently published Cochrane Systematic Review. The entire review is available through PTNow. The analysis looked at 11 studies involving 808 participants conducted between 1988 and 2010, with individual study participant size ranging from 44 to 150. Of the 11 trials, 5 studies (405 patients) looked at the incidence of deep vein thrombosis (DVT), which can lead to VTE. Combined, those studies found an 18% rate of DVT in the CPM group, compared with a 15% rate for the control group. "The results of this meta-analysis showed no evidence that CPM has an effect," authors write. The real problem, according to the review, is that there just isn't enough information available to make any determination about the effectiveness of CPM therapy in reducing VTE. "The statistical power of the included studies on PE [pulmonary embolism] prevention by CPM therapy is weak and it is obvious that there is insufficient evidence to make a conclusion on CPM therapy for preventing PE after TKA," the review states. Authors call for more "high quality, randomized controlled trials," and recommend that since DVT can develop in either leg, studies should focus on both. They write that in the currently available studies "a lot of variation exists in the application of CPM, such as the postoperative range of motion, duration of CPM per day, and duration of CPM postoperatively," and recommend that future studies "address an optimal CPM dosage to diminish bias." Research-related stories featured in PT in Motion News are intended to highlight a topic of interest only and do not constitute an endorsement by APTA. For synthesized research and evidence-based practice information, visit the association's PTNow website.