Proximal Spread in Adductor Canal Block(ACB)

This prospective, randomized clinical study is designed to evaluate the effects of two different injection levels of adductor canal block (ACB) on the proximal spread of local anesthetic and clinical outcomes in patients undergoing total knee arthroplasty. The study will be conducted at Ankara Etlik City Hospital and will include a total of 68 patients. All cases are limited to unilateral elective knee replacement surgeries performed under spinal anesthesia. In this study, the comparison will be based on the application of adductor canal block at two distinct injection levels. In both groups, blocks will be performed under ultrasound (USG) guidance using the same technical principles and standardized conditions; in the first group, the block will be administered at the level where the vasto-adductor membrane is first visualized, while in the second group, it will be performed at the level where the adductor longus ends. The type, concentration, and volume of local anesthetic used in both groups will be standardized as 20 mL of 0.25% bupivacaine. The groups will be compared in terms of the proximal spread of the local anesthetic based on the injection level, the area of spread at the apex of the iliopectineal fossa, the involvement of the femoral nerve, the incidence of postoperative falls, and analgesic consumption.

NCT Number	NCT07595471
Lead Sponsor	Ankara Etlik City Hospital
Conditions	Total Knee Anthroplasty, Postoperative Pain
Enrollment	68 participants
Start Date	2026-04-07
Primary Completion	2026-05-30 (estimated)
Study Completion	2026-06-01 (estimated)
Updated on ClinicalTrials.gov	2026-05-19