The effect of three different position to interspinousis opening in volunteers

Aim and Scope: We aimed to assess the effects of three different positions on interspinous opening based on ultrasound examination and to determine the position related with the widest interspinous space. Material and method: A total of 108 volunteers older than 18 years were included in this prospective study. Patients with pregnancy, osteoarthritis, rheumatoid arthritis, orthopaedic disease, orthopaedic dysfunction, spinal and lumbar spinal surgery, lumbar spinal disease, back pain, spinal deformities, patients incapable of maintaining the clinical position and under 18 years old were excluded from the study. The ultrasound-guided measurements were performed in three different positions as lateral decubitus position, sitting position while the legs are hanging down from the table and sitting position while the legs are on the table. The distance between the most prominent point of spinous process, interspinous space, the length of ligamentum flavum and, the distance between the skin and ligamentum flavum were measured and recorded. Findings: The distance between L3-4 and L4-5 interspinous spaces and the distance between the most prominent point of spinous processes were found as higher in all cases in the lateral decubitus and sitting position while the legs are on the table (p <0.001, p = 0.004). The interspinous space at the between of L3-4 and L4-5 were found to be higher in lateral decubitus and sitting position while the legs are on the table in the BMI <24.9 and BMI 25-29.9 patients. In patients with a BMI>30; the interspinous space was similar in all positions at the level of L3-4 while the largest space was measured at lateral decubitus position. The distance between skin and ligamentum flavum was measured as 48 mm (41.1-53.7) and 48.5 mm (42.4-54.8) at the levels of L3-4 and L4-5 (respectively). In BMI> 30 patients the distance was measured as 55 mm (49.8-60.1) and 55 mm (50.2-60.1) at the levels of L3-4 and L4-5 (respectively).The length of the ligament flavum was measured in between 10.4-14.1 mm. Discussion and Conclusion: We determined that the lateral decubitus position and sitting position while the legs are on the table were superior based on the ultrasonographic evaluation of interspinous space in 3 different positions (p <0.001). The position may have an effect on blockage attempt in patients with different BMI. The distance between the skin and ligamentum flavum is related to BMI and the distance between skin and ligamentum flavum was found to be increasing as the BMI increases. USG imaging may allow a more reliable and accurate prediction of epidural and intrathecal distance and a more accurate identification of the intervertebral levels. The use of ultrasound in difficult neuraxial block patients can be an effective method. Keywords: Anesthesia, Spinal, Epidural, Ultrasonography, Body Mass Index, Obesity Contact address: eksi.0.drc@gmail.com