CT imaging and three-dimensional reconstructions of shoulders with anterior glenohumeral instability

Abstract

Glenohumeral instability is a common occurrence following anterior dislocation of the shoulder joint, particularly in young men. The bony abnormalities encountered in patients with glenohumeral instability can be difficult to detect with conventional radiography, even with special views. The aim of our study was to evaluate the bony abnormalities associated with glenohumeral instability using CT imaging with 3‐D reconstruction images. We scanned 11 patients with glenohumeral instability, one with bilateral symptoms; 10 were male, one female, and their ages ranged from 18–66 years. Contiguous 3 mm axial slices of the glenohumeral joint were taken at 2 mm intervals using a Siemens Somatom CT scanner. In the 12 shoulders imaged, we identified four main abnormalities. A humeral‐head defect or Hill‐Sachs deformity was seen in 83% cases, fractures of the anterior glenoid rim in 50%, periosteal new bone formation secondary to capsular stripping in 42%, and loose bone fragments in 25%. Manipulation of the 3‐D images enabled the abnormalities to be well seen in all cases, giving a graphic visualization of the joint, and only two 3‐D images were needed to demonstrate all the necessary information. We feel that CT is the imaging modality most likely to show all the bone abnormalities associated with glenohumeral instability. These bony changes may lead to the correct inference of soft tissue abnormalities making more invasive examinations such as arthrography unnecessary. Clin. Anat. 12:326–336, 1999. © 1999 Wiley‐Liss, Inc.

Comparisons of glenoid bony defects between normal cadaveric specimens and patients with recurrent shoulder dislocation: an anatomic study

“…19 Other studies have confirmed the usefulness of CT scanning for evaluating the bony defects associated with glenohumeral instability. 20 Currently, precise en face 3D CT views are preferred for the evaluation of a glenoid bony defect. 15 However, 3D CT imaging has several disadvantages, including higher cost compared with standard X-ray imaging, the need for further magnetic resonance imaging evaluation for capsulolabral pathologies, and the relatively high radiation dose resulting from the CT exposure.…”

“…15 However, 3D CT imaging has several disadvantages, including higher cost compared with standard X-ray imaging, the need for further magnetic resonance imaging evaluation for capsulolabral pathologies, and the relatively high radiation dose resulting from the CT exposure. 20 Saito et al 18 reported that the mean orientation of the defect was pointing toward the 3:00 o'clock position of the glenoid and that these defects continued from the anterosuperior glenoid rim to the inferior glenoid rim. In our study, we evaluated the en face 3D CT view of the cadaveric glenoid and the glenoid of patients with instability, the length was standardized and compared with the bone defect, and the greatest size difference was detected at the 3:20 o'clock position.…”

“…CT scanning is helpful in the preoperative and postoperative assessment of these patients with shoulder dislocation, and many consider CT is the best imaging modality for the assessment of glenoid bone defects. 19,20 CT scanning is helpful in quantifying the amount of glenoid bone loss, but no studies have described how to quantify that bone loss. Lo et al 16 validated CT scanning for this purpose using a cadaveric model and found that the CT measurements reliably reproduced the bone loss measured in the cadaver scapulas.…”

Comparison between 2D and 3D computed tomography evaluation of glenoid bone defect in unilateral anterior gleno-humeral instability

“…In particolare, molti autori hanno riportato l'uso della tomografia computerizzata (TC) al fine di stabilire dimensioni, sede e tipo (frattura o erosione) del difetto glenoideo associato con l'instabilità gleno-omerale utilizzando ricostruzioni tridimensionali (3D) volume rendering technique (VRT) [15,[19][20][21][22][23], o bidimensionali (2D) multi-planar reconstruction (MPR) [14,[24][25][26][27]. La porzione mancante della glena misurata sulle acquisizioni TC può essere calcolata come percentuale dell'area della glena inferiore (metodo del cerchio) [15,19,24], o percentuale dell'ampiezza massima della glena [14,21,25,26].…”

Quantification of a glenoid defect with three-dimensional computed tomography and magnetic resonance imaging: A cadaveric study

“…3,4,8,12,27,29,30,32 Laboratory and clinical studies have shown that these defects can influence the outcome of treatment for recurrent anterior glenohumeral instability and changes the biomechanics of the glenohumeral joint. 3,4,10,11,16,19,22,31,33 However, there is no consensus regarding the exact role of a glenoid defect in glenohumeral instability.…”