Vertebral levels of key landmarks in the neck

Abstract

Vertebral levels of key landmarks in the neck are well documented in anatomy texts but are they accurate? This study aimed to investigate the vertebral levels of the hard palate, hyoid bone, thyroid cartilage, cricoid cartilage, and bifurcation of the common carotid artery (CCA) using computed tomography (CT). After excluding patients with distorting pathology, 52 CT scans of the neck from supine adults with a standardized head position (mean age 63 ± 17 years, range 30-94 years; 21 female) were available for analysis by dual consensus reporting. Only the vertebral level of the hard palate (C1) was consistent with contemporary descriptions. Other landmarks were located most frequently at the following vertebral levels: the center of the body of the hyoid bone at C4 (54% of cases); the superior limit of the laminae of the thyroid cartilage at C4 in women (60%) and C5 in men (52%) (P = 0.02); the inferior border of the cricoid cartilage in the midline anteriorly at C6 in women (37%) and C7 in men (47%) (P = 0.008); and the bifurcation of the left and right common carotid arteries at C3 (left 56%, right 62%). The bifurcation of the CCA was a mean of 1.6 ± 1.2 cm above the superior border of the thyroid laminae. Vertebral levels of key bony/cartilaginous structures in the neck differ from standard descriptions but in the absence of a standardized cervical axial plane have limited value and clinical utility.

Intrinsic Vertebral Markers for Spinal Level Localization in Anterior Cervical Spine Surgery: A Preliminary Report

“…The use of surface landmarks, such as the mandibular angle, hyoid bone, thyroid cartilage, first cricoid ring, and C6 carotid tubercle, as general reference points for SLL has been reported in the literature; however, these landmarks do not correspond to the exact cervical spine levels [91026]. Although these landmarks can facilitate skin incision placement, definitive SLL cannot be based on these landmarks alone.…”

“…Except for the C6 tubercle, positions of all these surface landmarks are likely to change with respect to shifts in the vertebral body positions caused by head and neck movements [10]. Despite various reports on these landmarks, observations vary significantly depending on the patients' age, sex, and somatometric measurements [91026]. However, none of these factors affect intrinsic markers, which are located directly on the vertebral body.…”

“…However, many hospitals and institutes, particularly those located in peripheral regions of developing countries, do not have access to the aforementioned radiographic localization equipment [8]. Although various cervical landmarks have been reported, including the mandibular angle, hyoid bone, thyroid cartilage, and first cricoid ring, the C6 carotid tubercle is the only spinal/vertebral landmark that has been studied with respect to SLL [9]. In other words, none of the studied anterior vertebral/intervertebral surface landmarks, except the C6 carotid tubercle, have been used for SLL [10].…”

Perhaps we don’t know what we thought we knew: Why clinicians need to re-visit and re-engage with clinical anatomy

“…1 The topic of surface landmarks, popular with clinicians, have been given a special section in a recent edition of the journal Clinical Anatomy. [2][3][4][5][6][7][8] This section was dedicated to recent findings that challenge the existing anatomical dogma and guidelines by examining the evidence for the current data. Many original research articles in this issue provide evidence that is contrary to the commonly held beliefs that have been passed from generation to generation of both textbook and clinician.…”

Use of Clinical Anatomy Resources by Musculoskeletal Outpatient Physiotherapists in Australian Public Hospitals: A Cross-Sectional Study

“…14,15 Clinical anatomy resources are important in that they provide information pertinent to patient management. Yet despite the importance of clinical resources, 5,7 the rise of online and mobile education and information, 11,16 and the importance of clinical anatomy in diagnosis and clinical decision making, 17,18 the use of clinical anatomy resources by physiotherapists has remained unexplored. Our study investigated how hospital-based musculoskeletal outpatient physiotherapists perceive and interact with clinical anatomy resources.…”