Ultrasonographic Predictors of Adductor Canal Block Effectiveness in Total Knee Arthroplasty

NCT07730216 | Not Yet Recruiting

• 1 other identifier: 2026/235
• Study Type: observational
• Target: 623
• Locations: 1 country
• Sites: 1

Brief Summary

Total knee arthroplasty (TKA) is associated with substantial postoperative pain and opioid requirements, making effective multimodal analgesia essential for early mobilization, functional recovery, and reduction of opioid-related adverse events \[1,2\]. Adductor canal block (ACB) has become a key component of enhanced recovery after surgery (ERAS) protocols because it provides effective anterior knee analgesia while largely preserving quadriceps muscle strength \[2-4\]. However, analgesic efficacy after ACB remains variable, and some patients require rescue opioid analgesia despite technically successful block placement \[5\]. Although ultrasound guidance improves block accuracy, factors such as tissue depth, anatomical variations, saphenous nerve visibility, and injectate spread pattern may influence clinical outcomes \[6,7\]. Prospective evidence regarding the predictive value of these ultrasound-derived parameters for ACB analgesic failure remains limited. Therefore, this study aims to evaluate whether preoperative ultrasound-derived tissue and target parameters-including skin-to-target depth, subcutaneous fat thickness, muscle thickness, saphenous nerve visibility, and injectate spread pattern-can predict ACB analgesic failure and early postoperative analgesic outcomes following TKA.

Conditions

Arthroplasty, Replacement, Knee; Nerve Block Assessment; Pain, Postoperative Arthroscopy

Keywords

Adductor Canal Block; Total Knee Arthroplasty; Ultrasound; Postoperative Analgesia

Outcome Measures

Primary Outcomes (1)

• ACB Failure

  ACB analgesic failure will be defined as the requirement for rescue analgesia during the first 24 hours after block administration, with intravenous tramadol (1 mg/kg) administered to patients with an NRS pain score ≥4.

  0-24 hours

Secondary Outcomes (2)

• Secondary outcome

  0-24 hour

• Tramadol Consumption

  0-24 Hours

Interventions

Adductor Canal Block (ACB) Only PROCEDURE

The adductor canal block (ACB) will be performed in the post-anesthesia care unit (PACU) after regression of spinal anesthesia.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Scheduled for elective primary unilateral total knee arthroplasty under spinal anesthesia

You may qualify if:

• Age ≥18 years
• Scheduled for elective primary unilateral total knee arthroplasty under spinal anesthesia
• American Society of Anesthesiologists (ASA) physical status I-III

You may not qualify if:

• Daily opioid use or chronic pain syndrome
• Diabetic or other clinically diagnosed peripheral neuropathy
• Coagulopathy
• Infection at the injection site
• Known allergy or hypersensitivity to local anesthetics
• Revision total knee arthroplasty
• Conversion from spinal anesthesia to general anesthesia during surgery
• General anesthesia as the planned anesthetic technique

Sponsors & Collaborators

• Konya City Hospital: lead

Study Sites (1)

Konya City Hospital

Konya, Konya, 42090, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Pain

Interventions

Single Person

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Marital Status; Family Characteristics; Demography; Population Characteristics; Socioeconomic Factors

Central Study Contacts

Ömer Keklicek, Principal Investigator

CONTACT

+905399291702; drokeklicek@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 12 Months
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: principal investigator

Study Record Dates

• First Submitted: July 13, 2026
• First Posted: July 28, 2026
• Study Start: July 13, 2026
• Primary Completion (Estimated): July 13, 2027
• Study Completion (Estimated): July 13, 2027
• Last Updated: July 28, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)