No long-term effect of 7-day computer-assisted cryotherapy treatment after total knee arthroplasty: A randomized controlled trial with 1-year follow-up.

Abstract

Positive effects on pain and opioid use were found in the first post-operative week, but long-term effects are unclear. Since rapid recovery studies show that short-term benefits may have positive long-term effects, the aim of this study is to investigate if there are any late effects (until 1 year post-operative) of computer-assisted cryotherapy (CAC) after total knee arthroplasty (TKA) on knee function, pain and patient satisfaction. A single-centre non-blinded randomized controlled trial was performed, comparing a cryotherapy group and a regular post-operative care group after TKA. The cryotherapy group used computer-assisted cooling, with instructions for cooling several hours per day for the first seven post-operative days. Oxford knee scores (OKS) (0-48), Knee Injury and Osteoarthritis Outcome Score-Physical function Short form (KOOS-PS) scores (0-100) and numeric rating scale (NRS) pain scores (0-10) were scored pre-operative and 6 and 12 months post-operative. Anchor questions about self-perceived changes in daily functioning and pain (7-point Likert scale) and patient satisfaction (NRS, 0-10) were obtained at both post-operative time points. A total of 102 patients were analyzed, 51 patients in both groups. OKS showed no significant difference between the cryotherapy and the regular care groups after 6 and 12 months (median 37.0 vs. 38.0 after 6 months and 40.0 for both groups after 12 months, <i>p</i> = 0.634 and <i>p</i> = 0.754). Also, no significant differences were found between groups in KOOS-PS score, NRS pain score, anchor questions and patient satisfaction. This study showed that use of CAC for 7 days post-operative after TKA has no significant late effects (until 1 year post-operative) on functioning, pain and patient satisfaction. This could imply that the clinical benefits of 7 days of cryotherapy are too short to demonstrate longer-term effects. Limitations such as non-blinding and lack of objective outcome measures might have influenced the outcomes. Therapeutic study with level of evidence I.