Consistency of ASIS Line vs. Tuffier's Line for Lumbar Level Identification

N/ANot Yet RecruitingNCT07396961

Kangbuk Samsung Hospital140 enrolled

Overview

Tuffier's line is commonly used as a landmark for estimating lumbar vertebral levels during spinal anesthesia. However, its accuracy can vary depending on factors such as age, sex, BMI, and posture. This study evaluates the consistency of an alternative landmark, the "ASIS line" (a line connecting both Anterior Superior Iliac Spines), for identifying lumbar levels in the lateral decubitus position. Researchers will mark both the ASIS line and Tuffier's line on participants and use ultrasound to verify the exact vertebral level where each line crosses the spine. The goal is to determine if the ASIS line provides a more consistent and reliable estimation of lumbar levels compared to Tuffier's line.

Study Type

OBSERVATIONAL

Enrollment

140

Conditions

Spinal Anesthesia Evaluation Lumbar Vertebrae

Interventions

Lumbar Ultrasound & PalpationDIAGNOSTIC_TEST

Identification of vertebral levels using Tuffier's line (palpation) and ASIS line, followed by ultrasound verification.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 85 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adults aged 18 to 85 years * Patients scheduled for spinal anesthesia or lumbar ultrasound * Participants who voluntarily agreed to participate and provided written informed consent Exclusion Criteria: * History of spinal surgery or spinal deformity * Infection or wounds at the puncture site * Inability to maintain the lateral decubitus position * Congenital lumbosacral transitional vertebrae (e.g., sacralized L5 or lumbarized S1) * Any other condition deemed unsuitable for the study by the investigator

Locations (2)

St. Vincent's Hospital

Suwon, North Carolina, South Korea

Kangbuk Samsung Hospital

Seoul, South Korea

Outcomes

Primary Outcomes

Consistency of Vertebral Level Identification (Standard Deviation)

The specific vertebral level where the ASIS line and Tuffier's line intersect the spine will be identified using ultrasound. The lumbar spine (from L2 upper to S1 upper) is divided into segments (e.g., L2=2, L3=3, L4=4, L5=5, S1=6). The consistency of each method is evaluated by calculating and comparing the standard deviation (SD) of the identified vertebral levels.

Time frame: Day 1 (Immediately during the ultrasound examination)

Secondary Outcomes

Difference in Mean Intersection Level

Comparison of the mean vertebral levels identified by the ASIS line versus Tuffier's line to determine if there is a significant difference in the average level indicated.

Time frame: Day 1

Rate of Identification within L4-L5 Interspace

The percentage of cases where the identified line falls within the target L4-L5 interspace (or within ±1 interspace range).