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Ultrasonographic Predictors of Adductor Canal Block Effectiveness in Total Knee Arthroplasty

Ultrasonographic Predictors of Adductor Canal Block Effectiveness in Total Knee Arthroplasty

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07730216
Enrollment
623
Registered
2026-07-28
Start date
2026-08-09
Completion date
2027-07-13
Last updated
2026-08-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

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

Keywords

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

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.

Interventions

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

Sponsors

Konya City Hospital
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

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

Exclusion criteria

* 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

Design outcomes

Primary

MeasureTime frameDescription
ACB Failure0-24 hoursACB 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.

Secondary

MeasureTime frameDescription
Secondary outcome0-24 hour1\. Numeric Rating Scale (NRS) Pain Scores NRS pain scores at rest and during a standardized movement (active 90° knee flexion) will be recorded at postoperative 1, 6, 12, and 24 hours.
Tramadol Consumption0-24 Hours2\. Total Tramadol Consumption Total tramadol consumption (mg) during the first 24 hours following ACB administration will be recorded.

Countries

Turkey (Türkiye)

Contacts

CONTACTÖmer Keklicek, Principal Investigator
drokeklicek@gmail.com+905399291702

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 13, 2026