Korean J Pain 2012 April; Vol. 25, No. 2: 116-120 pISSN 2005-9159 eISSN 2093-0569 http://dx.doi.org/10.3344/kjp.2012.25.2.116 | Case Report | Psoas Compartment Blockade in a Laterally Herniated Disc Compressing the Psoas Muscle -A Case Report- Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Seongnam, *Seoul National University Hospital, Seoul, †Jeju National University Hospital, Jeju, Korea Hye Young Kim, MD, Jin Woo Park, MD*, Soo Young Park, MD*, Jee Youn Moon, MD*, Jae Hyuck Shin, MD*, and Sang Hyun Park, MD† A psoas compartment block has been used to provide anesthesia for orthopedic surgical procedures and analgesia for post-operative pain. Currently, this block is advocated for relieving pain in the lower extremity and pelvic area resulting from various origins. We report a case of a 69-year-old male patient who had gait abnormality with posterior pelvic and hip pain, which were both aggravated by hip extension. From the magnetic resonance image, the patient was found to have a laterally herniated intervertebral disc at the L2/3 level, which compressed the right psoas muscle. This was thought to be the origin of the pain, so a psoas compartment block was performed using 0.25% chirocaine with triamcinolone 5mg, and the pain in both the pelvis and hip were relieved. (Korean J Pain 2012; 25: 116-120) Key Words: gait, intervertebral disk displacement, pain, psoas muscles. The psoas muscle is involved with the curvature of the pelvis and spine, which starts at the thoracic vertebrae to connect with the lower vertebral body and transverse process. It proceeds past the pelvis to extend up to the lesser trochanter [1]. The psoas muscle plays a most im- portant role when walking, as it pulls the spine forward while standing, and balances the body when sitting. Therefore, when the psoas muscle continuously contracts due to injury or stress, the vital dynamics of the pelvis, lumbar, and even the cervical vertebrae, can be disturbed. This incongruity can be the cause of pain in the lower back, pelvis, buttocks, and the femoral region. It can trig- ger a distinctive psoas gait, where the patient drags their leg while walking since the leg is not strongly pushed for- ward [2]. The psoas compartment block is performed on parts of the lumbar plexus and the sacral plexus for pain in the front thigh and inner, lower leg [3]. Since Chayen et al. first reported its use in the pelvic joint and lower thigh surgery in 1976 [4], it has also been performed in the open Received November 28, 2011. Revised December 14, 2011. Accepted December 26, 2011. Correspondence to: Soo Young Park, MD Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, 101, Daehang-ro, Jongno-gu, Seoul 110-744, Korea Tel: ＋82-2-2072-2952, Fax: ＋82-2-763-9390, E-mail: soo02@snu.ac.kr This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright ⓒ The Korean Pain Society, 2012