Evaluation of Ropivacaine Concentrations on Sensory Block Duration in Ultrasound-Guided Ankle Blocks for Hallux Valgus Surgery

The primary objective of this study is to compare the **duration** of the sensory block in patients undergoing hallux valgus repair surgery under an ankle block with 0.25%, 0.5%, and 1% ropivacaine over a 48-hour period. This is clinically relevant as it aims to determine the most effective concentration of ropivacaine for prolonged sensory block, which can enhance postoperative pain management and patient comfort.

Secondary objectives include:

• Comparing the differential effects of 0.25%, 0.5%, and 1% ropivacaine on the onset time of a sensory block over a 30-minute period.
• Assessing the impact of these concentrations on motor function over a 48-hour period.
• Evaluating postoperative pain scores using a numeric rating scale (NRS) over a 48-hour period.
• Analyzing postoperative opioid consumption over a 48-hour period.

The clinical trial involves participants diagnosed with **hallux valgus** who are scheduled for elective forefoot surgery. The study population includes both male and female subjects, aged between 18 and 75 years, with an **American Society of Anesthesiologists (ASA)** physical status classification of I to III. Participants are required to be able to ambulate independently and perform sensory and motor assessments at home postoperatively. The trial does not include vulnerable populations. The sponsor has not provided information regarding the total number of participants. Selection criteria include the ability to provide informed consent and the capacity to learn and perform specific sensory assessments. Lifestyle factors such as diet and physical activity are not specified as considerations for this study.

The clinical trial is designed to evaluate the effects of various concentrations of **ropivacaine** on the onset and duration of ultrasound-guided ankle blocks in patients undergoing hallux valgus repair surgery. This study is a randomized, double-blind, parallel-group interventional trial. The primary objective is to compare the duration of the sensory block in patients receiving 0.25%, 0.5%, and 1% ropivacaine over a 48-hour period. The trial is expected to commence recruitment on February 1, 2024, and conclude by February 1, 2026.

Participants will be involved in the study for a maximum of 48 hours, with the possibility of early termination if they do not meet the inclusion criteria or if adverse events occur. The inclusion criteria require participants to be aged 18 to 75 years, scheduled for elective forefoot surgery for hallux valgus repair under unilateral ankle block, and classified as American Society of Anesthesiologists (ASA) physical status I-II-III. Participants must also be able to ambulate independently and perform sensory and motor assessments at home postoperatively.

The sequence of study visits includes an initial screening visit to confirm eligibility, followed by the administration of the intervention during the surgical procedure. Follow-up visits will occur postoperatively to assess the primary and secondary endpoints, which include the duration and onset time of the sensory block, motor function, postoperative pain scores, and opioid consumption. The end-of-study visit will mark the completion of the participant's involvement in the trial.

Throughout the trial, the use of **ropivacaine** as a local anesthetic will be monitored, with a maximum daily dose of 3 mg/kg. The study is categorized as low intervention, as it aligns with the standard of care and therapeutic use of the market authorization. The trial's design ensures that the data collected will provide valuable insights into the efficacy and safety of different concentrations of ropivacaine in the specified surgical context.

The clinical trial involves the use of **Ropivacaine**, a local anesthetic classified as a sodium channel blocker. The pharmaceutical form of Ropivacaine used in this study is a **solution for injection**. The active substance, Ropivacaine, is of chemical origin. The trial aims to evaluate the effects of different concentrations of Ropivacaine (0.25%, 0.5%, and 1%) on the onset and duration of ultrasound-guided ankle blocks in patients undergoing hallux valgus repair surgery. The administration route for Ropivacaine is **perineural use**, which involves injecting the solution near a nerve to block sensation in a specific area of the body.

The dosing regimen for Ropivacaine in this study is specified as a maximum daily dose of 3 mg/kg, with the same maximum total dose amount of 3 mg/kg. The treatment period is limited to a maximum of one day. The study is designed as a randomized, double-blinded, parallel-group interventional study, ensuring that neither the participants nor the investigators know which concentration of Ropivacaine is being administered to each participant. This design helps to eliminate bias and allows for a more accurate assessment of the drug's efficacy and safety.

In addition to the experimental treatment with Ropivacaine, the study may involve the use of standard-of-care therapies as deemed necessary by the clinical investigators. However, no specific non-experimental treatments, such as a placebo or comparator treatment, are explicitly mentioned in the trial data. Participant compliance with the dosing schedule and administration protocol will be monitored throughout the study to ensure adherence to the trial's guidelines and to accurately assess the outcomes related to the use of Ropivacaine in this clinical setting.

Efficacy in this clinical trial will be assessed by evaluating the duration and onset of the sensory block in patients undergoing hallux valgus repair surgery with different concentrations of **ropivacaine**. The primary endpoint is the difference in the duration of the sensory blocks. Secondary endpoints include the difference in onset time of the sensory block, motor function, postoperative pain scores, and opioid consumption. These parameters will be measured over a 48-hour period following the administration of the anesthetic.

Patients will perform sensory and motor assessments at home on postoperative days 0 to 2, using tests for sensitivity to pinprick, cold, and light touch. The data collected will be analyzed to determine the efficacy of the different concentrations of ropivacaine in achieving the desired anesthetic effects. The trial is designed as a randomized, double-blinded, parallel-group interventional study, ensuring that the results are scientifically robust and reliable.