Continuous passive motion following total knee arthroplasty: a useful adjunct to early mobilisation?
Abstract Objectives: To determine the effectiveness of continuous passive motion (CPM) following total knee arthroplasty when compared to a rehabilitation protocol that permits early knee mobilisation, and to determine if an optimal CPM dosage schedule exists. Methods: An electronic database search was conducted to find relevant investigations. Strict inclusion and exclusion criteria were applied. Outcomes were summarised using a rating system consisting of four levels of scientific evidence. Data were divided into short term effects (seven days or less after surgery) and long term effects (greater than seven days after surgery) Results: Eight investigations met inclusion criteria for this review. There was strong evidence that CPM exerts no influence on short and long term knee extension, long term knee flexion, long term function, pain, complications, and length of hospital stay when compared to a rehabilitation protocol that permits early knee mobilisation. Data for short term knee flexion, quadriceps strength, and short term function were conflicting. Preliminary evidence suggests that CPM applied immediately postoperatively, at a high flexion arc of motion, and for a significant amount of time each day leads to better outcomes with regards to short term knee flexion. Conclusions: With rehabilitation protocols now permitting early knee mobilisation, the use of CPM as an adjunct should be questioned as the current body of research generally does not support its use. However, before writing off CPM as unnecessary, further clinical trials utilising more aggressive CPM parameters need to be conducted as this may provide better outcomes.