Related Experiment Video
Updated: Aug 27, 2026

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Anatomical considerations regarding the "bare spot" of the glenoid cavity
F Aigner1, S Longato, H Fritsch
1Institute of Anatomy, Histology and Embryology, Department of Clinical and Functional Anatomy, Medical University Innsbruck, Muellerstrasse 59, 6010, Innsbruck, Austria. felix.aigner@uibk.ac.at
Abstract:
The "bare spot" of the glenoid cavity has recently been described as a constant reference point to quantify the amount of bone loss from the inferior portion of the glenoid cavity. In shoulder surgery this spot should help the surgeon to determine the width of the inferior portion of the glenoid cavity arthroscopically. The aim of this study was to determine the localization of the bare spot within the glenoid cavity and to prove its usefulness in shoulder surgery by means of a macroscopic study using embalmed glenohumeral joints ( n=20; 12 left, 8 right). Each glenoid cavity was photographed and transferred to a commercial AutoCAD software program. The bare spot was marked and the mean distances between the center of the bare spot and the inferior ( a), anterior ( b(1)) and posterior ( b(2)) inner margins of the glenoid labrum as well as its relationship ( c) to the mid-point of a virtual circle formed by the inferior portion of the glenoid cavity were measured (mean values : a=9.70, b(1)=10.88, b(2)=13.71, c=3.2 mm). In most cases, the bare spot showed a significantly excentric position within the inferior part of the glenoid cavity ( p<0.05). Due to the great variability in the shape of the glenoid cavity, an inferior circle according to previous descriptions could only be observed in half the specimens. From the results of our study the bare spot seems to be an unreliable landmark for the determination of the center of the inferior portion of the glenoid cavity, although it has a constant appearance and is probably expressed as the result of cartilaginous distribution due to dynamic shoulder activity.
Related Concept Videos
Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
Bones of the Upper Limb: Humerus
Cranial Bones: Superior and Posterior View
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
Anatomical Positions
The body is upright, facing forward, and standing erect.
The feet are parallel and flat on the floor.
The arms are hanging by the...
Bone Markings
Articulating Projections
Articulating projections are found where two bones meet to form a joint. These structures are usually found at the ends of bones. The largest articulation is a rounded projection called the head, supported by a narrow neck at the ends of...
Bones of the Lower Limb: Femur and Patella
