The effects of immediate programmed cryotherapy and continuous passive motion in patients after computer-assisted total knee arthroplasty: a prospective, randomized controlled trial

Background: The postoperative nursing intervention with immediate cryotherapy and continuous passive motion (CPM) remains elusive regarding the postoperative pain and range of motion (ROM) 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 1 h while returning to the ward on the day of surgery, while the control group did not. Data were analyzed using mixed models to compare the 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° vs. 91°, 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: Immediate programmed cryotherapy and continuous passive motion could help to improve ROM quickly after CAS-TKA. It should be incorporated into the daily nursing plan for patients undergoing CAS-TKA.

Trial registration:, NCT04136431 . Registered 23 October 2019-retrospectively registered.

Keywords: Computer-assisted; Continuous passive motion; Cryotherapy; Postoperative nursing intervention; Total knee arthroplasty.