Effect of Bupivacaine Liposome Injection on Muscle Strength After Total Knee Arthroplasty (TKA)

Effect of Bupivacaine Liposome Adductor Canal Block on Muscle Strength After Total Knee Arthroplasty.

This study employs a randomized controlled trial to investigate whether bupivacaine liposome injection for adductor canal block can effectively improve lower limb muscle strength after total knee arthroplasty.

Study Overview

• Status: Not yet recruiting
• Conditions: Muscle Strength; TKA
• Intervention / Treatment: Procedure: a single-injection adductor canal block; Procedure: continuous femoral nerve block

Detailed Description

Total knee arthroplasty (TKA) involves significant trauma, and postoperative patients often experience moderate to severe pain, which limits early knee joint functional exercise and affects functional recovery. Peripheral nerve blocks can effectively relieve pain, but while providing adequate analgesia, they may also affect the motor nerves of the lower limbs, increasing the risk of falls when patients begin ambulation. Some studies have found that the incidence of falls in patients using nerve blocks during the early postoperative period, especially during hospitalization, can be as high as 2% . The actual incidence in clinical practice may be even higher. The period of highest risk is when the nerve block effect has not completely subsided and patients begin attempting to ambulate, typically within 24 to 48 hours after surgery. The loss of muscle strength caused by motor nerve blockade is the most direct cause of postoperative falls, primarily due to severe weakness in key stabilizing muscle groups such as the quadriceps.The adductor canal block has clear advantages. However, traditional local anesthetics, represented by ropivacaine or bupivacaine, typically provide effective analgesia for only 12-24 hours after a single injection, making it difficult to fully cover the peak pain period of 48-72 hours postoperatively. Continuous femoral nerve block with ropivacaine can provide prolonged analgesia. When combined with a sciatic nerve block, it can achieve nearly complete analgesia coverage for the knee. Its drawback is its association with quadriceps impairment, which may increase the risk of falls. Continuous adductor canal block also provides prolonged analgesia and has a lesser impact on postoperative muscle strength, but it faces challenges such as catheter placement difficulty and inconvenience for postoperative mobility. In contrast, bupivacaine liposome can provide analgesia for up to 72 hours. If, while offering high-quality analgesia, bupivacaine liposome indeed causes significant weakening of quadriceps strength during the critical first 2-3 days after surgery, the safety and effectiveness of early patient ambulation would be greatly compromised, potentially even increasing the risk of falls. This would contradict the original intent of using the adductor canal block to preserve muscle strength. Conversely, if it is proven to have a lesser impact on muscle strength compared to continuous femoral nerve block, it could become an almost ideal analgesic option.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Xin li Ni, MD; Phone Number: 13909586966; Email: xinlii6@nyfy.com.cn
• Study Contact Backup: Name: Qiaojiang Shen; Phone Number: 17829917323; Email: 2832394521@qq.com

Study Locations

• China
  • Ningxia
    • Yinchuan, Ningxia, China
      • General Hospital of Ningxia Medical University
      • Contact: Xinli Ni, MD; Phone Number: 86-0951-6743252; Email: xinlini6@nyfy.com.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Patients aged 60-75 years scheduled for elective TKA;
2. ASA physical status classification II-III;
3. BMI 18-30 kg/m²;
4. Agreement to participate in this study and provision of signed informed consent.

Exclusion Criteria:

1. Individuals with communication barriers such as language or hearing impairments;
2. Patients with contraindications to nerve blocks;
3. Severe systemic diseases, such as severe renal disease (estimated glomerular filtration rate below 50 mL/min), cardiac disease (congestive heart failure New York Heart Association Class III to IV), or severe hepatic disease defined as a current or past diagnosis of acute/subacute hepatic necrosis, acute liver failure, chronic liver disease, liver abscess, hepatic coma, or hepatorenal syndrome;
4. History of long-term opioid use (defined as daily or nearly daily opioid use within the past 3 months).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: a single-injection adductor canal block; An ultrasound-guided adductor canal block is performed via the conventional adductor canal approach. Under ultrasound guidance, 20 milliliters of 1.33% bupivacaine liposome is injected into the adductor canal.	Procedure: a single-injection adductor canal block; An ultrasound-guided adductor canal block is performed via the conventional adductor canal approach. Under ultrasound guidance, 20 milliliters of 1.33% bupivacaine liposome is injected into the adductor canal.
Active Comparator: continuous femoral nerve block; An ultrasound-guided perineural sheath block of the femoral nerve is performed via the conventional femoral nerve approach. A femoral nerve catheter is then placed and connected to an analgesia pump containing 150 milliliters of 0.20% ropivacaine.	Procedure: continuous femoral nerve block; An ultrasound-guided perineural sheath block of the femoral nerve is performed via the conventional femoral nerve approach. A femoral nerve catheter is then placed and connected to an analgesia pump containing 150 milliliters of 0.20% ropivacaine.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quadriceps Muscle Strength	The Maximum Voluntary Isometric Contraction (MVIC) test is used to assess quadriceps strength. The tester holds a handheld dynamometer. The patient sits on the bed with legs hanging naturally, and the knee is flexed to 60°. The patient is instructed to slowly exert force to extend the knee forward. As the patient exerts force, the tester applies an equal and opposite counterforce with the dynamometer to maintain the position and angle of the lower leg. The patient sustains maximum effort for 3-5 seconds, and the peak value displayed on the dynamometer is recorded as the result for that trial. Each leg is tested 2-3 times, with a 60-90 second rest between trials to prevent muscle fatigue from affecting the results. The average value is recorded as the final outcome. The unit of measurement is Newtons (N).	24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quadriceps muscle strength at other time points	The Maximum Voluntary Isometric Contraction (MVIC) test is used to assess quadriceps strength. The tester holds a handheld dynamometer. The patient sits on the bed with legs hanging naturally, and the knee is flexed to 60°. The patient is instructed to slowly exert force to extend the knee forward. As the patient exerts force, the tester applies an equal and opposite counterforce with the dynamometer to maintain the position and angle of the lower leg. The patient sustains maximum effort for 3-5 seconds, and the peak value displayed on the dynamometer is recorded as the result for that trial. Each leg is tested 2-3 times, with a 60-90 second rest between trials to prevent muscle fatigue from affecting the results. The average value is recorded as the final outcome. The unit of measurement is Newtons (N).	48 hours after surgery
Numeric Rating Scale (NRS) Score	Using a scale from 0 to 10 to indicate pain intensity, where 0 represents no pain and 10 represents the worst possible pain.	24 and 48 hours after surgery
Quadriceps muscle strength grade	Perform a Manual Muscle Test (MMT). The patient is placed in the supine position, with a soft pillow under the knee to provide slight flexion, or sits on the edge of the bed with legs hanging naturally. The examiner stabilizes the patient's thigh with one hand to prevent hip compensation and applies downward resistance with the other hand just above the patient's ankle. Instruct the patient to forcefully extend the knee against the resistance. Observe muscle contraction and joint range of motion, and assess according to the 0-5 grade muscle strength scale.	24 and 48 hours after surgery
Knee Joint Range of Motion	Using a goniometer, accurately measure the patient's knee joint flexion and extension range of motion. During measurement, the patient is in the supine position. The axis of the goniometer is aligned with the lateral femoral condyle, the stationary arm is parallel to the long axis of the femur, and the movable arm is parallel to the long axis of the tibia. Record the angles at full knee extension (0°) and maximum flexion separately.	24 and 48 hours after surgery
Total Opioid Consumption	Total postoperative consumption of opioids.	From the end of the surgery until 72 hours postoperatively
Postoperative Adverse Reactions	Including nausea and vomiting, urinary retention, constipation, puncture site ecchymosis and infection, as well as local anesthetic systemic toxicity.	From the end of the surgery until 72 hours postoperatively

Collaborators and Investigators

• Sponsor: General Hospital of Ningxia Medical University
• Investigators: Study Chair: Xinli Ni, General Hospital of Ningxia Medical University

Study record dates

Study Major Dates

• Study Start (Estimated): June 10, 2026
• Primary Completion (Estimated): October 30, 2026
• Study Completion (Estimated): November 3, 2026

Study Registration Dates

• First Submitted: March 27, 2026
• First Submitted That Met QC Criteria: May 26, 2026
• First Posted (Actual): May 29, 2026

Study Record Updates

• Last Update Posted (Actual): May 29, 2026
• Last Update Submitted That Met QC Criteria: May 26, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Muscle Strength; Adductor Canal Block; TKA; Bupivacaine Liposome
• Other Study ID Numbers: Qiaojiang Shen-2026-03

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No