Original article
Determination of in vivo glenohumeral translation using fluoroscopy and shape-matching techniques

https://doi.org/10.1016/j.jse.2007.05.018Get rights and content

The purpose of this study was to investigate glenohumeral translation in-vivo during active shoulder abduction in the scapular plane. Three-dimensional (3D) models of 9 shoulders were created from CT scans. Fluoroscopic views aligned to the plane of the scapula were recorded during active arm abduction with neutral rotation. 3D motions were determined using model-based 3D-to-two-dimensional (2D) registration. Humeral translation was referenced to the glenoid center in the superior/inferior direction. The humerus moved an average of 1.7 mm superior with arm abduction, from an inferior location to the glenoid center. The humeral head was centered within 1 mm from the glenoid center above 80° abduction. Variability in glenohumeral translation between shoulders decreased significantly from initial to final arm abduction. Our findings agree with some authors' observations of inferior-to-central translation of the humerus and behavior as a congruent ball and socket. We believe this information will help improve the understanding of shoulder function.

Section snippets

Materials and methods

Nine shoulders in 9 subjects (8 males, 1 female; average 31 years, 27-38 years) were studied. All shoulders were asymptomatic and had no history of injury and no clinical or radiographic sign of pathology. All subjects provided informed consent to participate in this study. CT scans (LightSpeed Plus, GE Yokokawa Medical System) of each shoulder were acquired at 0.5 mm intervals, and 3D models of the scapula and proximal humerus were created (Tomovision, SliceOmatic and Raindrop Geomagic

Results

The humerus moved an average of 1.7 mm, from inferior to the glenoid center, during arm active abduction (Fig 3). The humeral head was centered within 1 mm from the glenoid center above 80° abduction. All 9 shoulders exhibited the same pattern of motion, with most variability in the data appearing to result from the definition of the glenoid center. Variation in the defined glenoid center point resulted in an offset of each shoulder's data from a consistent point on the glenoid. The variability

Discussion

A variety of methods have been used in previous studies to describe humeral head translation relative to the glenoid. These reports have provided few consistent findings. Poppen and Walker observed on radiographs that the humeral head moved upward relative to the glenoid between 0°and 30° abduction, with little additional translation thereafter. Other in vivo studies have suggested that the glenohumeral joint behaves as a perfectly congruent ball and socket joint.9, 19, 20 Cadaver studies have

References (21)

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  • The influence of three-dimensional scapular kinematics on arm elevation angle in healthy subjects

    2023, Journal of Orthopaedic Science
    Citation Excerpt :

    The scapula has complicated 3D motions that researchers have investigated using X-ray, fluoroscopic [16,17], CT, and MR imaging [18,19]. 3D electromagnetic or optical tracking devices [4,12,20] and 2D/3D image registration [7–11] have been widely used for 3D kinematic analysis of the shoulder. Previous reports analyzing scapular motion using 3D electromagnetic devices showed 40–60° of upward rotation and 20–30° of posterior tilting during flexion, scaption, and abduction [4,12,20].

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