Magnetic resonance imaging study of the sciatic nerve variation in the pediatric gluteal region: Implications for the posterior approach of the sciatic nerve blockade.

INTRODUCTION: In pediatric patients, the sciatic nerve is one of the most commonly blocked peripheral nerves during orthopedic procedures of the lower limb. Ultrasound guidance is the current standard for a successful localization of the sciatic nerve in the gluteal region. Relevant anatomical landmarks are also used to determine the nerve location when ultrasound is not available or inadequate. However, reports have demonstrated paucity of information regarding the sciatic nerve location and variation in the hip throughout pediatric development. This imaging study aimed to document and analyze the relative morphometric relationship of the sciatic nerve in the pediatric gluteal region throughout development. METHODS: The location of the sciatic nerve in relation to bony landmarks was measured in 84 pediatric magnetic resonance imaging of patients aged 0.7-15.8 years. RESULTS: The sciatic nerve was identified medial to the most lateral point of greater trochanter at the level of ischial spine and the tip of coccyx. The strong positive correlation between sciatic nerve to landmark distances and age and stature demonstrated linear variation between sciatic nerve location with age and growth of children. To predict the nerve location in the gluteal region, regression equations using patient age were created, having implications for the posterior approach of the sciatic nerve blockade in children. Clinically significant differences were found between sexes, specifically in the older age group. CONCLUSION: Despite the small sample size of younger age group, this study is the first to document the morphometric changes of the sciatic nerve in the gluteal region across pediatric development and may be useful for providing confirmatory guidelines for nerve location when ultrasound is not accessible or cannot be utilized for practice.

Pediatric regional anesthesia: A review of the relevance of surface anatomy and landmarks used for peripheral nerve blockades in infants and children.

In regional anesthesia, accurate knowledge of surface anatomy and landmarks are essential for successful nerve blockades with least possible complications. The long-established anatomical landmarks used for peripheral nerve blockades in adult patients have also gained a place in pediatric anesthesia. Despite the continuing benefits and need for more effective peripheral techniques in pediatrics, there is a paucity of data on pediatric landmarks, and hence the absence of more appropriate techniques for the different age groups of children. Recent advancement in imaging has shown that there is a greater awareness for the different surface projections at various stages of postnatal development, as compared with that of adults. Thus, if adult landmarks are not appropriately adapted for use in children, complication rates may rise due to injuries to anatomical structures. This review evaluated the existing evidence of the pediatric nerve block landmarks in the reported literature, in order to highlight the limitations in our current understanding of pediatric surface anatomy and landmarks. A literature search was done using five databases to obtain 141 references. Only a few of these studies provided detailed reports of the relations of relevant nerves to anatomical landmarks. A few clinical imaging studies have provided new anatomical landmarks in children with reference to their age-related growth and anatomy. Most landmarks need to be standardized in children of various ages, and furthermore, inconsistencies in the current descriptions of the surface landmarks need to be validated and standardized for use in pediatric clinical practice. Clin. Anat. 32:803-823, 2019. © 2019 Wiley Periodicals, Inc.

A computed tomography and magnetic resonance imaging study of the variations of the sciatic nerve branches of the pediatric knee: Implications for peripheral nerve blockade.

In pediatric patients, peripheral anesthetic blockade of the sciatic nerve is useful for postoperative pain relief after orthopedic procedures of the lower limb. The identification of the sciatic and its branches relative to the surrounding anatomical structures of the knee significantly contribute to the successful nerve blockade. However, reports have demonstrated complications arising from the inadequate and inconsistent understanding of the anatomy of the nerves in the knee region. In addition, the paucity of information regarding the location of the nerves of the knee throughout the pediatric development needs to be addressed in order for peripheral nerve blockades to become more readily used among the pediatric population. This clinical imaging study therefore aimed to document and analyze the relative morphometric relationship of the nerves in the knee region throughout the different stages of pediatric development. The locations of the sciatic, tibial, and common fibular nerves were measured in relation to relevant anatomical structures in 142 pediatric magnetic resonance imaging and computed tomography. A strong correlation was found between age and the distance from the common fibular nerve to the semitendinosus muscle, and thus can be used to predict stature. Significant differences were found between males and females, specifically after puberty, suggesting that sexual dimorphism emerges more distinctively at puberty. In order to predict the location of the nerves at the popliteal fossa, a regression formula using the patient's age and bicondylar width was created. These finding may have significant implications for popliteal approach of the sciatic nerve blockade in pediatric patients. Clin. Anat. 32:836-850, 2019. © 2019 Wiley Periodicals, Inc.