Exploring the Safety Range via the Transoral Approach to the Craniovertebral Junction

Abstract

Surgeries via the transoral approach are widely used to deal with lesions near the craniovertebral junction. For this approach, the pharyngeal tubercle is an important landmark to identify the midline. The foramen lacerum, another important anatomic area where some crucial structures pass, is close to the pharyngeal tubercle. In the current study, we measured relevant distances and angles on 120 adults without brain diseases to estimate the safety range of the transoral approach. Distances between the pharyngeal tubercle and the foramen lacerum were expressed as mean (SD) and 95% confidence interval. Angles between the straight lines, which pass through the pharyngeal tubercle and the foramen lacerum, and the sagittal plane, as well as the horizontal plane, were also presented as mean (SD) and 95% confidence interval. As regards the 95% confidence intervals of the angles and the distances, which were used to define the safety range, no differences were observed between the right side and the left side. During such surgeries, if the midline is defined as a datum line, it is less likely for surgeons to destroy adjacent structures when moving within 36.30 degrees on the sagittal plane and 45.00 degrees on the horizontal plane once they find the pharyngeal tubercle. It is also safe to move within 16.20 mm from the pharyngeal tubercle. With these data, we have successfully defined the safety range of the surgery, which may help operators choose proper instruments in surgery and avoid injuries to important structures. Moreover, operators may use these data to position the pharyngeal tubercle so as not to deviate from the midline.

Congenital Osseous Torticollis that Mimics Congenital Muscular Torticollis: A Retrospective Observational Study

“…From the above process, patients with congenital torticollis were divided into the following four groups: ocular torticollis, defined as torticollis caused by ophthalmic conditions, such as disorders of ocular movement and nystagmus [ 10 , 11 ]; neurogenic torticollis, defined as abnormal head and neck posture due to associated neurologic abnormalities that weakens the neural connections required for proper head and neck positioning (e.g., cerebral palsy) [ 11 , 12 ]; osseous torticollis, defined as torticollis associated with congenital malformation of the spine such as vertebral segmentation defects [ 11 , 13 , 14 , 15 ]; and CMT, diagnosed by evidence of shortening of the SCM muscle via physical examination and/or enlarged thickness, heterogeneous echogenicity, fibromatous lesion, or asymmetry of the SCM muscle on sonographic findings. The diagnosis of CMT included tumor, muscular, and postural types [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

The rise and fall of the craniocervical junction relative to the hard palate: a lifetime story

“…8,17,18 Although each respective corridor has been partially evaluated in cadaveric and radiographic studies of small case series, 2,8,18,23,29,31 the extent to which age causes these corridors to vary has not been adequately addressed. Banu and colleagues found both the working angle and distance of the EN corridor differed with age in a pediatric population.…”