An investigation into the effectiveness of cryotherapy following total knee replacement
Background: Cryotherapy is commonly used during physiotherapeutic rehabilitation of patients following total knee replacement (TKR). Evidence for treatment effectiveness within the current literature is contradictory and there are no clinical guidelines to inform cryotherapy treatment within this particular patient group. This study surveys current cryotherapy treatment efficacy in the acute post-operative management of TKR patients. Methods: In total 263 senior physiotherapists completed and returned a postal questionnaire, which, using open and closed questions investigated the use of cryotherapy following TKR. Survey results were used to inform a pragmatic randomized clinical trial (RCT) involving 133 consecutive TKR patients. The RCT investigated cryotherapy treatment efficacy in the acute post-operative management of TKR patients. Patients were randomized into three groups; no cryotherapy (NC), delayed cryotherapy (DC) and immediate cryotherapy (IC). The primary outcome measure was post-operative pain with knee swelling, active range of motion (AROM), function and levels of physiotherapy input assessed as secondary outcome measures. Observations were taken pre-operatively and at 3, 7 and 42 days post-operatively. Results: The survey reported that 33% of respondents used some form of cryotherapy routinely following TKR surgery. The two main methods of cryotherapy application were Cryocuff (59%) and crushed ice (30%). Treatments were most frequently applied between 24 hrs and 48 hrs post-surgery for 20 minutes, twice a day. Chi square analysis indicated significant differences (p<0.01) in between NHS and private sites relating to a lack of cryotherapy resources and treatment time for cryotherapy in the NHS. A lack of proven efficacy was the most cited reason for not applying cryotherapy treatment, and swelling the most common treatment indicator. There was particular uncertainty regarding the cleaning and sterilization of the Cryocuff device. The RCT indicated that patients in IC group had significantly less post-operative pain than the NC and DC groups at 3 days. Mean difference (p <0.05, 95% CI) in post-operative analogue scores (VAS, scale 0-10) was -1.6 (p <0.01, CI -2.49- to -0.707) for IC and NC; and -0.922 (p= 0.044, CI -0.183 to -0.009) for IC and DC groups. At 7 and 42 days there were significant reductions in VAS scores for both cryotherapy groups compared to the NC group. There was significant improvement in knee swelling, AROM, ability to transfer and need for additional physiotherapy in both cryotherapy treatment groups although no significant reduction in opiate requirement was found. Conclusions: In current clinical practice there was little consensus regarding treatment indicators, method of application and management of cryotherapy following TKR. However, in a RCT the use of cryotherapy combined with compression, as compared to a no cryotherapy control, led to significant reductions in patient reported pain, less post-operative swelling, greater recovery of AROM, faster return of function and less reliance on OPD physiotherapy treatment. It is concluded that cryotherapy combined with compression has an important role to play in the acute rehabilitation of TKR and should be considered as part of routine management.