Ultrasonographic Predictors of Adductor Canal Block Effectiveness in Total Knee Arthroplasty
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Adductor Canal Block (ACB) Only.
- Who it may be relevant to
- Registry conditions: Arthroplasty, Replacement, Knee, Nerve Block Assessment, Pain, Postoperative Arthroscopy. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Turkey (Türkiye)
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
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
- Procedure Adductor Canal Block (ACB) Only
The adductor canal block (ACB) will be performed in the post-anesthesia care unit (PACU) after regression of spinal anesthesia.
Primary outcome measures
- ACB Failure [Time frame: 0-24 hours]
Secondary outcome measures (2)
- Secondary outcome [Time frame: 0-24 hour]
- Tramadol Consumption [Time frame: 0-24 Hours]
Eligibility criteria
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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Turkey (Türkiye) · 1 center
- Konya City Hospital — Konya
Identifiers
NCT: NCT07730216 · 2026/235