Pain Physician 2015; 18:E1111-E1117 • ISSN 2150-1149 Cadaveric Study Ultrasound-Guided Injection of the Adductor Longus and Pectineus in a Cadaver Model Dong-wook Rha, MD, PhD1, Sang-Hee Lee, DDS2, Hyung-Jin Lee2, You-Jin Choi, BSDH2, Hee-Jin Kim, DDS, PhD2, and Sang Chul Lee, MD, PhD1 From: 1Department and Research Background: The close anatomic and functional relationship between the proximal parts of Institute of Rehabilitation Medicine, the adductor longus and pectineus muscles produce considerable overlap in symptoms and Yonsei University College of Medicine, signs in the inguinal region. To our knowledge, there have been no publications of ultrasound South Korea; 2Division in Anatomy and Developmental Biology, Department (US)-guided injection techniques into the 2 muscles. of Oral Biology, Human Identification Research Center, Yonsei University Objective: This study sought to describe US-guided injection techniques in the proximal College of Dentistry, South Korea. part of the adductor longus and pectineus muscles and to validate whether these techniques Address Correspondence: deliver injections appropriately to their target muscles in unembalmed cadavers. Sang Chul Lee, MD, PhD, Department and Research Institute of Study Design: Cadaveric study. Rehabilitation Medicine Yonsei University College of Medicine Methods: A preliminary trial with 2 unembalmed cadavers provided information on the 50-1 Yonsei-ro, Seodaemun-gu, Seoul target sonographic structures of proximal adductor longus and pectineus muscles. Bilateral 120-752, South Korea US-guided intramuscular injections in the proximal adductor longus and pectineus were E-mail: performed using the remaining 5 unembalmed male cadavers. To avoid confusion of dye [email protected] location, we did not inject into both the adductor longus and pectineus muscle in the same Disclaimer: There was no external side. After injections, each specimen was dissected to evaluate the accuracy of injection. funding in the preparation of this manuscript. Results: Ten injections (5 for the adductor longus muscle and 5 for the pectineus muscle) Conflict of interest: Each author were performed targeting the proximal parts of muscles in 5 cadaveric specimens. All injections certifies that he or she, or a member of his or her immediate family, has were successful and blue dye was injected accurately at the target area within the adductor no commercial association (i.e., longus and the pectineus muscles. No other muscles were injected unintentionally. There were consultancies, stock ownership, no accidental penetrations and/or injuries at adjacent neurovascular structures as well. equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with Limitation: Despite successful injection of the proximal parts of adductor longus and the submitted manuscript. pectineus, this study did not verify the usefulness of this technique in clinical practice. Manuscript received: 02-28-2015 Conclusions: The results of this study may play a role in the diagnosis and management of Revised manuscript received: 04-20-2015 patients presenting with chronic pelvic pain syndrome and sports hernia. Accepted for publication: 04-27-2015 Key words: Inguinal, injections, ultrasonography, pain, cadaver, pectineus, adductor, pelvis Free full manuscript: Pain Physician 2015; 18:E1111-E1117 www.painphysicianjournal.com nguinal pain can present a difficult therapeutic neuromuscular problems (1). No biomarkers have been and diagnostic dilemma. The sources of pain in validated to help guide classification and treatment Ithe inguinal region range from urologic problems for CPPS (2). For most men with CPPS referred to to musculoskeletal abnormalities. Chronic pelvic pain urologists, traditional therapeutic modalities like syndrome (CPPS) or National Institutes of Health (NIH) antibiotics, analgesics, and alpha-blockers fail category III prostatitis (nonbacterial prostatitis) is a to relieve symptoms, and only 17% of patients common clinical syndrome with multiple potential reported significantly improved symptoms (3). Some etiologies including infection, autoimmunity, and investigators have evaluated and attempted to treat www.painphysicianjournal.com Pain Physician: November/December 2015; 18: E1111-E1117 the associated muscular tenderness of CPPS, particularly tion is needed to avoid neurovascular injury. The large painful myofascial trigger points (MTrPs) (4). Zermann et femoral neurovascular structures, superficial and deep al (5) found that 88% of men with CPPS had tenderness branches of obturator nerve, and long and accessory in the myofascial area on palpation. saphenous vein run immediately adjacent to the adduc- While MTrPs are considered one of the possible tor longus and pectineus muscles. Even for trigger point causes for CPPS, most previous studies focused on the injection, the needle is inserted several times in various pelvic floor muscles, such as the levator ani (6,7). How- directions to provoke local twitch responses. Therefore, ever, Anderson et al (4) reported that the most preva- there are risks of injection-related vascular and neural lent pain sites were the penis (91.7% of men with CPPS) injuries. In addition, most patients are afraid of getting and the inguinal area (47.2% of men with CPPS); the an injection around their inguinal area and most phy- pain may have originated from the abdominal and hip sicians are reluctant to do an injection near patients’ adductor muscles. Based on the anatomical proximity external genitalia. and our clinical experience, direct tenderness and asso- Ultrasound (US) guidance has gained popularity as ciated inguinal pain might originate from the proximal an effective technique to perform a variety of diagnos- parts of the adductor longus and/or pectineus muscles tic and therapeutic injections throughout the musculo- (Fig. 1). skeletal system due to exquisite soft tissue resolution, The adductor longus muscle attaches proximally availability, and lack of ionizing radiation (10,11). Based to the relatively small spot on the outer surface of the on potential hazards of inserting a needle into the in- pelvis between the symphysis pubis and obturator fo- guinal region, the use of US-guidance appears warrant- ramen through a narrow flat tendon (2). MTrPs at the ed. To our knowledge, there have been no publications adductor longus, especially its proximal portion, may be of US-guided injection techniques into the proximal the most common cause of inguinal pain (8). MTrPs in part of the adductor longus and pectineus muscles. the adductor longus may result from sitting in a fixed Therefore, the purposes of this study were to describe position while on a prolonged driving trip, sitting for US-guided injection techniques into the proximal part long periods in a chair with the hips acutely flexed, sit- of the adductor longus and pectineus muscles, and to ting with one thigh or leg crossed over the other knee, validate whether these techniques deliver injections ap- as well as sports activity (2). propriately to their target muscles using unembalmed The pectineus muscle attaches proximally to the cadavers. superior ramus of the pubic bone beside the pubic tu- METHODS bercle. The attachment site is caudal and deep to the inguinal ligament, and medial to the pubic tubercle (9). The MTrPs in the pectineus muscle are mostly located Preparation of Cadavers just distal to the superior ramus of the pubis, and re- Seven unembalmed male cadaveric specimens ferred pain projects over the pectineus muscle just be- were used for this investigation. The average age ± SD low the inguinal ligament and extends deep into the at death was 68.8 ± 6.9 years (range, 59 – 80 years). inguinal area (2). The average ± SD body mass index (BMI) was 23.9 ± 2.0 Because of the close anatomic and functional re- kg/m2 (range, 20.8 – 27.6). There was no evidence of lationship between the proximal parts of the adduc- previous injury or surgical procedure around the pelvis. tor longus and pectineus muscles, symptoms and signs None of the recorded causes of death were deemed to from these 2 muscles’ pathology considerably overlap have affected the results of this study with regard to in the inguinal region. Trigger point injection or diag- needle placement or dissection. nostic local anesthetic block can assist in the accurate diagnosis of muscle-related pathology and also relieve Preliminary Injection and Dissection the symptoms in affected patients. Sometimes, precise B-mode, real-time ultrasonography at 5 – 12 MHz diagnostic intra-muscular injections are more impor- was performed using the UGEO HM70A system (Sam- tant since the physical examinations lack specificity sung Medison, Seoul, South Korea) interfaced with a for identifying these muscles-related pains and MTrPs linear array transducer. An investigator (SCL) with more usually appear normal even by an advanced imaging than 7 years experience in musculoskeletal ultrasonog- technique like magnetic resonance imaging. When raphy carried out these procedures. All photographs preforming the injection at the inguinal area, atten- and diagrams in this article are of structures viewed E1112 www.painphysicianjournal.com Ultrasound-Guided Injection of the Adductor Longus and Pectineus in a Cadaver Model from the left side of the specimen. Based on our clinical experience, the proximal parts of the adductor longus and pectineus muscles where we frequently observed the tenderness in patients were targeted (Fig. 1). First,