Continuous passive motion (CPM) therapy has demonstrated its efficacy in promoting tissue healing, reducing edema and hemarthrosis, and improving joint function (Brosseau et. al., 2004). It has also been associated with short-term benefits, such as early flexion improvement and reduced length of hospital stay (LOS). However, the application of CPM specifically in the context of computer-assisted total knee arthroplasty (TKA) remained largely unexplored.

The primary objective of this study was to investigate whether the utilization of CPM following computer-assisted TKA would lead to significant differences in parameters such as range of motion, edema/drainage, functional ability, and pain.

This study adopted an experimental, prospective, and randomized approach, involving patients undergoing unilateral computer-assisted TKA. Patients in the experimental group were subjected to CPM three times daily, in addition to receiving physical therapy (PT) twice daily during their hospital stay. Conversely, the control group received PT twice daily but did not undergo CPM during their hospitalization. Both groups continued to receive PT after their discharge. Data collection encompassed Knee Society scores, Western Ontario McMaster Osteoarthritis Index values, range of motion, knee circumference, and HemoVac drainage, with measurements taken at various intervals from the preoperative phase through a three-month postoperative period.

Despite the control group displaying a higher level of functionality before the surgery, no statistically significant disparities in flexion, edema or drainage, functional capacity, or pain were observed between the two groups over the three-month duration of the study.

The findings of this study indicate that the use of CPM therapy following computer-assisted TKA does not lead to substantial differences in the measured parameters compared to conventional PT alone. It is worth noting that, despite the potential benefits of CPM in other orthopedic scenarios, its application in the context of computer-assisted TKA may not yield additional advantages. These results contribute to the evolving body of knowledge concerning the optimal rehabilitation strategies following TKA and emphasize the importance of tailoring treatment plans to the specific needs of each patient population.

In conclusion, while CPM has demonstrated its utility in various orthopedic contexts, its application in computer-assisted TKA may not offer significant advantages in terms of postoperative outcomes. Further research is warranted to better understand the most effective rehabilitation strategies for this particular patient group, considering factors such as individual variability in response to treatment and evolving surgical techniques.

Reference: Alkire, M. R., & Swank, M. L. (2010). Use of inpatient continuous passive motion versus no CPM in computer-assisted total knee arthroplasty. Orthopaedic Nursing, 29(1), 36-40.