Ankle fractures are common injuries and cryotherapy is routinely used to reduce pain, swelling and local skin complications, both before and after surgery. However, the results on ankle surgery are contradictory. Despite the benefits of cryotherapy in the pre- and postoperative care of ankle surgery, lack of standardized protocols and few level-1 studies make difficult to appreciate the effectiveness. In addition, there's scarce evidence on the benefits from the preoperative use of cryotherapy.

The aim of this study is to report the results with the use of third generation cryotherapy in the preoperative treatment of ankle fractures. Third generation devices use computed cryotherapy to deliver gradual changes in pressure and temperature. The software produces a progressive drop in temperature and a controlled slow return to room temperature environment, avoiding reactive vasodilation. Time to surgery, pain, opioids intake, and local skin complications have been investigated.

Methods 169 patients with ankle fracture were randomized in two groups, the cryotherapy group (89 patients) and the control group (C: 80 patients). The time-to- surgery, Visual Analogue Scale (VAS) and the analgesic drug demand (including morphine or acetaminophen) were recorded. The development of skin complications was assessed daily. BMI and number of cigarettes smoked were also recorded.

The aim of this study is to assess the effects of third generation cryotherapy on time to surgery, pain, opioids intake, and local skin complications. Although the use of cryotherapy is traditionally believed to reduce pain, swelling, local skin complications and the need of analgesia, the results on ankle surgery are not well reported and still contradictory. The working hypothesis is that third generation cryotherapy is a safe, reduces time to surgery and is useful in the surgical management of ankle fractures The investigators analyzed the prospectively collected data of 169 patients with ankle fracture, treated with open reduction and internal fixation (ORIF). Patients were randomized in two groups at the time of the diagnosis in the emergency department. The treatment group (T: 89 patients) were treated with a third-generation cryotherapy device (Z- One®, Zamar) which was applied daily for 2 hours two times a day up to the day of surgery. The leg was immobilized in a walking boot which was removed when the cryotherapy device was applied. The control group (C: 80 patients) did not use cryotherapy before surgery, the leg was immobilized into a half cats and elevation of the injured limb was indicated. Patients were collected in two different hospitals (Azienda Ospedaliera San Camillo Forlanini -Roma and Ospedale San Paolo - Civitavecchia) between 2021 and 2023. All patients had signed a written consent, and the study was approved by the local ethic committee.

After the diagnosis was made and surgical treatment was indicated, the patient was hospitalized in the department of orthopedic and trauma surgery.

A power analysis was performed to evaluate the sample size necessary to guarantee a power of at least 0.9 with a significance level of 0.05 using preliminary data on time to surgery.

Univariate descriptive analysis of the variables under study was carried out by calculating the centrality and variability indices for the quantitative variables and frequency tables for the variables.

The homogeneity of the control group and the treatment group for the variables sex, age, type of fracture, diabetes, hypercholesterolemia, venous insufficiency, and BMI class were checked. Depending on the nature of the variables, a t-test or a chi-square test was used.

Any significant differences between the treatment and control groups were assessed using independent samples t-tests for quantitative variables and chi-square tests for qualitative variables. Where the sample size was not sufficient, the non-parametric Mann-Whitney test for independent samples was used.

An alpha significance level of 0.05 was used in all analyses mentioned. For the statistical analysis of data, IBM SPSS Statistics software version 28 was used

Inclusion Criteria:

• Patients admitted to the emergency department with an ankle fracture

Exclusion Criteria:

• Open fractures
• Fracture-dislocations which required external fixation
• Patients with one or more associated fractures
• Patients with a diagnose of major trauma
• Patients who were not able to complain with the pre- and post-surgical indications

all IPD collected throughout the trial

the will be available with the published manuscript, or by asking to the corresponding author under reasonable request with no time restriction

contacting the corresponding author (Alessio Giai Via) by e-mail