Evaluation of Pericapsular Nerve Group Block with Ropivacaine Hydrochloride Versus Placebo for Postoperative Pain Management in Periacetabular Osteotomy

The primary objective of this study is to evaluate whether the **pericapsular nerve group (PENG) block** is superior to placebo in reducing immediate postoperative pain and other complications following **periacetabular osteotomy (PAO)**. This is clinically relevant as effective pain management can significantly enhance postoperative recovery and patient outcomes in individuals undergoing PAO.

Secondary objectives include:

• Assessing the occurrence of moderate to severe pain, defined as a score greater than 3 on a numeric rating scale (NRS) from 0 to 10, at any point in the immediate postoperative phase upon arrival at the postoperative anesthetic care unit.
• Evaluating pain during mobilization, specifically from laying down in bed to standing and walking 5 meters, assessed on an NRS five hours after extubation.
• Monitoring opioid use from tracheal extubation until 24 hours postoperatively.

The clinical trial focuses on patients undergoing **periacetabular osteotomy** and aims to evaluate the efficacy of the pericapsular nerve group (PENG) block in reducing immediate postoperative pain and complications. The study population includes both male and female participants aged 18 years and older, who are scheduled for the procedure under general anesthesia with intubation. Participants are required to have an American Society of Anesthesiologists (ASA) physical status classification of I to III and must be able to read and understand Danish. The trial does not involve a vulnerable population. The sponsor has not provided information regarding the total number of participants. Lifestyle factors such as diet, physical activity, or habits are not specified in the available data.

The clinical trial is designed to evaluate the efficacy of a **pericapsular nerve group (PENG) block** in reducing postoperative pain following **periacetabular osteotomy**. This study is a randomized, double-blind, controlled trial comparing the effects of **ropivacaine hydrochloride** to a placebo, **saline**, both administered as a **solution for injection** via perineural use. The trial aims to determine if the PENG block is superior to placebo in decreasing immediate postoperative pain and other complications. The primary endpoint is the area under the curve (AUC) of pain reported on a numeric rating scale (NRS) from 0 to 10 during the first 24 hours postoperatively. Secondary endpoints include the number of patients reporting moderate to severe pain at rest, pain during mobilization, and opioid use from tracheal extubation until 24 hours postoperatively.

The trial is expected to commence recruitment on June 1, 2024, and conclude by December 1, 2025. Participants will be involved in the study for a maximum treatment period of one day. The inclusion criteria require participants to be 18 years or older, provide informed consent, be scheduled for periacetabular osteotomy under general anesthesia with intubation, have an American Society of Anesthesiologists (ASA) physical status classification of I to III, and be able to read and understand Danish. There are no specified exclusion criteria. Study visits will include an initial screening visit to confirm eligibility, followed by the administration of the intervention or placebo during the surgical procedure. Postoperative follow-up visits will assess pain levels and opioid consumption, with the final visit marking the end of the study period. Participants may be terminated early from the study if they withdraw consent or if any adverse events necessitate discontinuation of the intervention.

The clinical trial involves the administration of **Ropivacaine Kabi 5 mg/ml solution for injection**, which contains the active substance **ropivacaine hydrochloride**. This experimental medication is provided in the form of a solution for injection and is intended for **perineural use**. The maximum daily dose is 100 mg, with a total dose not exceeding 100 mg over a treatment period of one day. The pharmaceutical product is manufactured by Fresenius Kabi Italia S.R.L. and is classified under the ATC code N01BB09, indicating its use as a local anesthetic. The administration of the drug is monitored to ensure compliance with the dosing schedule and to assess the efficacy and safety of the treatment.

In addition to the experimental medication, the study utilizes **saline** as a placebo comparator. The saline solution is also provided in the form of a solution for injection and is administered via the same **perineural route**. The maximum daily and total dose for saline is 20 ml, administered over a one-day treatment period. The use of saline serves as a control to evaluate the effectiveness of the **Ropivacaine Kabi** in reducing postoperative pain following periacetabular osteotomy. Compliance with the administration of the placebo is similarly monitored to ensure the integrity of the trial results.

Efficacy in this clinical trial will be assessed using both primary and secondary endpoints. The primary endpoint is the area under the curve (AUC) of pain reported on a numeric rating scale (NRS) from 0 to 10 during the first 24 hours postoperatively. This will provide a comprehensive measure of pain intensity over time. Secondary endpoints include the number of patients reporting moderate to severe pain at rest, defined as a score greater than 3 out of 10 on the NRS, at any point in the immediate postoperative phase. This will be assessed upon arrival at the post-anesthesia care unit (PACU) and every 30 minutes thereafter until transfer to the ward. Additionally, pain during mobilization, from laying down in bed to standing on the floor, will be assessed on the NRS at 5 hours after extubation. Opioid use from tracheal extubation until 24 hours postoperatively will also be recorded as a secondary endpoint.