Related Experiment Video
Updated: Dec 29, 2025

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
The V-Sign: A Simple Radiographic Sign of Shoulder Subluxation
Bradley Schoch1, Adam Smitherman2, Mary Beth Horodyski3
1Orthopaedic Surgery, Mayo Clinic, Jacksonville, USA.
Abstract:
Introduction Shoulder subluxation is a common finding associated with orthopedic pathology. This study assesses the inter- and intra-observer reliability of a new radiographic sign used to identify glenohumeral subluxation. Methods Shoulders of 55 consecutive patients presenting with shoulder pain were reviewed for the presence of a "V-sign". Three shoulder surgeons reviewed all radiographs at three separate time periods in a randomized fashion. Inter- and intra-observer reliabilities were calculated. Results The V-sign was identified in 26 (47%) shoulders. Intra-rater reliability was satisfactory for all the three surgeons, with kappa values of 0.85, 0.78, and 0.77, respectively. Inter-rater reliability was similarly satisfactory, with a value of 0.71. The surgeons demonstrated 100% agreement on the direction of subluxation when a V-sign was documented. Discussion The V-sign is a reproducible radiographic sign that can be used to detect glenohumeral subluxation in patients presenting with shoulder pain.
Related Concept Videos
Muscles of the Shoulder
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...
Articulations of the Vertebral Column
Muscles that Move the Arm
The pectoralis major has two origins. Its clavicular head originates on the medial half of the clavicle. In contrast, the sternocostal head originates on the costal cartilages of ribs 1-6, the sternum, and the aponeurosis of the external oblique of the...
Radiological Investigation II: MRI and Ventilation Perfusion Scan
Magnetic Resonance Imaging (MRI) and Ventilation Perfusion Scans are two radiological investigations that offer detailed diagnostic images of the body, particularly lung structures.
MRI
MRI uses magnetic fields and radiofrequency signals to distinguish between normal and abnormal tissues. This technology provides a more detailed diagnostic image than CT scans, enabling it to characterize pulmonary nodules, stage bronchogenic carcinoma, and evaluate inflammatory activity in...
Bones of the Upper Limb: Radius
The radius has a nail-shaped head, and a...
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...

