Highlight
- Low-certainty evidence indicates cryotherapy might decrease early postoperative blood loss and pain following total knee replacement (TKR).
- Small improvement observed in range of motion by discharge, but unclear long-term functionality benefits.
- Study quality limitations, including bias and lack of blinding, weaken certainty of results.
- Future high-quality trials are required to determine clinically meaningful benefits and patient-centered outcomes.
Background
Total knee replacement (TKR) is a widely performed orthopedic procedure aimed at alleviating pain, improving mobility, and enhancing quality of life in patients with severe osteoarthritis. While its long-term benefits are well established, the early postoperative phase typically involves significant pain, swelling, and blood loss, leading to impaired mobility and prolonged hospital stays. Cryotherapy—application of cold to the surgical site—has been promoted as a non-pharmacological method to alleviate inflammation, reduce pain, and limit bleeding. Despite its popularity, the clinical evidence supporting cryotherapy’s effectiveness after TKR has remained inconclusive, prompting systematic reviews to clarify its role.
Study Design
This review included 22 studies—20 randomized controlled trials and two controlled clinical trials—encompassing 1,839 participants aged 64 to 74 years who underwent TKR for osteoarthritis. Interventions assessed included cryotherapy with or without compression compared against no cryotherapy or compression alone. The primary endpoints were blood loss, pain, transfusion rate, range of motion, knee function, adverse events, and withdrawals due to adverse events. Secondary outcomes included analgesia use, swelling, length of stay, quality of life, activity level, and patient-reported global success.
Key Findings
Blood Loss
Low-certainty evidence from 12 trials (956 participants) suggests cryotherapy may reduce postoperative blood loss within one to thirteen days after surgery. Mean blood loss was 825 mL without cryotherapy versus 561 mL with cryotherapy (mean difference 264 mL less; 95% CI 7 mL less to 516 mL less). While statistically significant, clinical impact remains uncertain.
Pain Reduction
Low-certainty evidence from six trials (530 participants) showed cryotherapy might modestly decrease pain at 48 hours post-surgery, with mean pain scores dropping from 4.8 to 3.16 on a 0–10 visual analogue scale (mean difference 1.6 points lower; 95% CI 2.3 lower to 1.0 lower). The reduction is small and its clinical importance is debatable.
Range of Motion
Three trials (174 participants) reported greater knee flexion at discharge with cryotherapy (71.2° vs 62.9°; mean difference 8.3°, 95% CI 3.6° to 13.1°). Although statistically significant, it is unclear if this early improvement translates into better long-term outcomes.
Transfusion Rate and Function
Evidence was very low-certainty for transfusion rate, with inconsistent and imprecise findings (RR 2.13, 95% CI 0.04 to 109.63). Function scores on the WOMAC scale showed a possible—but uncertain—benefit at two weeks. The degree of improvement failed to conclusively support routine use of cryotherapy for functional recovery.
Adverse Events
Reported adverse events included discomfort, skin reactions, superficial infections, cold-induced injuries, and thrombolytic events. Evidence was insufficient to determine whether cryotherapy reduced the incidence or withdrawals due to adverse effects. Overall risk ratios were imprecise, reflecting underpowered safety analyses.
Secondary Outcomes
No significant differences emerged in analgesia use, length of hospital stay, activity level, or quality of life. Cryotherapy appeared to reduce localized swelling within the first week post-surgery but not at later follow-ups.
Expert Commentary
The review emphasizes methodological weaknesses across many included studies—chiefly lack of blinding and high performance bias. While the physiological rationale for cryotherapy is sound (via reduced local metabolic activity and vasoconstriction), the measured benefits here are small and inconsistently reported. Clinicians should weigh the modest improvements against potential costs and logistical challenges of implementation.
Given the heterogeneity in device types, cooling duration, and patient characteristics, standardizing protocols may improve clarity in future trials. In line with these findings, current clinical practice may reserve cryotherapy for patients with particular risk profiles—such as high postoperative swelling—rather than universally applying it after TKR.
Conclusion
Cryotherapy after total knee replacement yields small improvements in early pain, swelling, and range of motion, with uncertain effects on clinically critical outcomes such as transfusion rates or long-term function. Low and very low certainty of evidence underscores the need for robust randomized controlled trials focusing on patient-reported outcomes, standardization of cryotherapy protocols, and cost-effectiveness analyses.
Funding and Clinical Trials
Review registered under Aggarwal A, Adie S, Harris IA, Naylor J. Cochrane Database Syst Rev. 2025 Oct 30;10(10):CD007911. No specific funding details reported. Trials were sourced from CENTRAL, MEDLINE, Embase, and multiple trial registries.
References
Aggarwal A, Adie S, Harris IA, Naylor J. Cryotherapy following total knee replacement. Cochrane Database Syst Rev. 2025 Oct 30;10(10):CD007911. doi: 10.1002/14651858.CD007911.pub4. PMID: 41165130; PMCID: PMC12574497.
