The Effects of Programmed Cryotherapy and Continuous Passive Motion in Patients after Computer-Assisted Total Knee Arthroplasty: A prospective, randomized controlled trial

Background: Cryotherapy and continuous passive motion (CPM) are commonly used for conventional total knee arthroplasty (TKA) to reduce postoperative pain and increase of the range of motion (ROM). However, this postoperative nursing intervention remains elusive for patients undergoing computer-assisted total knee arthroplasty (CAS-TKA) Methods: A prospective, randomized controlled trial with a purposive sampling method was utilized. Sixty patients scheduled for a unilateral CAS-TKA at a medical center were randomly assigned to the intervention group (n=30) and control group (n=30). The intervention group applied programed cryotherapy and CPM within one hour while returning to the ward on the day of surgery, while the control group did not. Data were analyzed using mixed models to compare numeric rating scale (NRS) for pain, ROM, and swelling at postoperative day (POD) 4. Results: There was no significant difference in the NRS score between the groups ( p = 0.168). The intervention group had significantly higher ROM than the control group (98 degrees vs. 91 degrees, p = 0.004) at POD 4. Although no significant difference in joint swelling was found between groups ( p = 0.157), the intervention group had lower mean joint swelling (32.2 cm) than the control group (33.9 cm). Conclusions: Programmed cryotherapy and continuous passive motion can improve the range of motion after CAS-TKA. It should be incorporated into the daily nursing plan for patients undergoing CAS-TKA.