Determination of the Optimal Volume of Liposomal Bupivacaine in Adductor Canal Block for Knee Joint Surgery

Nanjing Medical University

Status and phase: Enrolling; Phase 4

Conditions: Optimal Volume of Liposomal Bupivacaine

Treatments: Drug: Perform adductor canal block with liposomal bupivacaine.

Study type: Interventional

Funder types: Other

Identifiers

NCT06942689

KY20250327-13

Details and patient eligibility

About

Building on Bayesian design methodologies from volume optimization studies of ropivacaine in shoulder surgery, this study pioneers the application of a seamless dose-finding strategy in knee ACB. Utilizing advanced statistical models (BOIN/BOP2 design), we aim to systematically evaluate the volume-effect relationship of liposomal bupivacaine, providing precise dosing recommendations to advance personalized and optimized analgesic protocols for knee surgery.

Enrollment: 63 estimated patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients undergoing elective general anesthesia for unilateral knee joint surgery.
• Patients who provide informed consent.
• Aged between 18 and 65 years old, regardless of gender.
• American Society of Anesthesiologists (ASA) physical status classification of Ⅰ to Ⅲ
• Body mass index (BMI) ≤ 35 kg/m².

Exclusion criteria

• Femoral neuropathy.
• Coagulation dysfunction.
• Allergy to local anesthetics.
• Infection at the puncture site.
• History of chronic pain or opioid use.
• Pregnancy.
• Diabetes mellitus and peripheral neuropathy.

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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63 participants in 1 patient group

Adductor Canal Block

Experimental group

Description:

Phase I: The Bayesian Optimal Interval (BOIN) design is adopted to evaluate the volume escalation of liposomal bupivacaine (10, 15, 20, 25, 30, 35, 40 mL). There are 3 cases in each group, with an initial volume of 20 mL (referring to previous ACB studies d). The target incidence of adverse events (quadriceps femoris muscle strength decline ≥ 25%) is set at 10%, and the maximum volume is limited to 40 mL to avoid local anesthetic toxicity. Phase II: Cohort expansion is carried out at volume levels lower than the MTV. The Bayesian Optimal Phase II (BOP2) design is adopted, with each group expanded to 12 cases to evaluate the balance point between block success rate and motor function preservation.

Treatment:

Drug: Perform adductor canal block with liposomal bupivacaine.