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

doi:10.1016/j.jse.2007.02.115

Journal of Shoulder and Elbow Surgery

Volume 16, Issue 6, November–December 2007, Pages 803-809

https://doi.org/10.1016/j.jse.2007.02.115 Get rights and content

Bone loss of the glenoid is a common finding in anterior glenohumeral instability. Several methods to measure the size of a glenoid defect have been described but have not been validated. In this study, 14 cadaver glenoids with a randomly created anteroinferior glenoid defect were used for validation of the so-called circle method. Measurements were done by 2 researchers on digital photographs, 3-dimensional (3D) computed tomography (CT) scans, and magnetic resonance images (MRI). The correlation coefficient (r²) for comparing measurements from the digital photographs with the CT scans was 0.97 for researcher 1 and 0.90 for researcher 2. When they compared digital images with MRI, the r² was 0.93 for researcher 1 and 0.92 for researcher 2. No statistical differences were found between the 2 researchers. The circle method is a simple method for preoperative quantification of a glenoid defect. Measurements can be done with 3D CT scans as well as MRI.

Section snippets

Materials and methods

This study used 8 formaldehyde-preserved scapulae and 6 fresh-frozen scapulae from skeletally mature individuals. Scapulae with a bony defect or erosion of the glenoid were excluded.

A 3D CT scan (AVE 1 Philips Tomoscan, 125 mA, 120 kV, 1 second; field of view, 120 mm; filter, 1H; slice, 1 mm; table speed, 1 mm/s; reconstruction index, 1 mm; Philips Medical Systems, Best, The Netherlands) and an MRI scan (3D T1-weighted, fast field echo, echo planer imaging, Matrix 256*256, 0.5 mm slice

Results

The MRI and CT images showed no difference in quality or appearance between the fresh and embalmed scapulae. All specimens had an exact circle-shaped inferior glenoid on the digital photograph and CT and MRI scans before the defect was created.

The measurements of the size of the glenoid defect taken from the different imaging modalities by the 2 researchers were analyzed. Figures 4, A and B show Bland-Altman plots for the comparison of the measurements taken from the digital photograph and the

Discussion

Although it is well known that a defect or erosion from the anteroinferior glenoid rim is a common finding in glenohumeral instability,3, 4, 8, 12, 17, 24, 27, 29, 32 the exact role of this finding is still being discussed. Some authors found a relationship between the presence and size of a glenoid defect and redislocation after Bankart repair,3, 4, 16, 22, 23, 31, 33 but others could not confirm this relationship.13, 20, 24 Future prospective studies are needed to investigate this particular

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Cited by (147)

The Perfect Circle Technique Shows Poor Inter-rater Reliability in Measuring Anterior Glenoid Bone Loss on Magnetic Resonance Imaging
2024, Arthroscopy, Sports Medicine, and Rehabilitation
To evaluate the reliability of the perfect circle methodology for measurement of glenoid bone loss in patients with anterior glenohumeral instability.
We performed a chart review of retrospectively collected patients who underwent isolated arthroscopic anterior labral repair between January 1 and June 30, 2021, using our institution’s electronic medical records. The inclusion criteria included isolated anterior shoulder instability with anterior labral repair and corroborated tears on magnetic resonance imaging. A total of 9 raters, either sports or shoulder and elbow fellowship-trained orthopaedic surgeons, each evaluated the affected shoulder magnetic resonance imaging scans twice, with a minimum of 2 weeks between measurements. Measurements followed the “perfect circle” technique and included projected anterior-to-posterior glenoid diameter, amount of posterior bone loss, and percentage of posterior bone loss. Intrarater reliability and inter-rater reliability were then determined by calculating intraclass correlation coefficients (ICCs).
Ten consecutive patients meeting the selection criteria were chosen for inclusion in this analysis. Average estimated bone loss for the cohort was 2.45 mm, and the mean estimated glenoid diameter of the involved shoulder was 28.82 mm. The average percentage of bone loss measured 8.54%. The ICC for interobserver reliability was 0.55 for the perfect circle diameter and 0.17 for the anterior bone loss measurement (poorly to moderately reliable). The ICC for intraobserver reliability was 0.69 for the perfect circle diameter and 0.71 for anterior bone loss (moderately reliable).
The perfect circle technique for estimating anterior glenoid bone loss on magnetic resonance imaging was found to have moderate intrarater reliability; however, reliability between observers was found to be moderate to poor.
Level IV, diagnostic case series.
The Perfect-Circle Technique Demonstrates Poor Inter-Rater Reliability in Measuring Posterior Glenoid Bone Loss on Magnetic Resonance Imaging
2024, Arthroscopy, Sports Medicine, and Rehabilitation
To evaluate the reliability of the “perfect-circle” methodology for measurement of glenoid bone loss with magnetic resonance imaging (MRI) in patients with posterior glenohumeral instability.
A prospective chart review was performed on patients who underwent isolated arthroscopic posterior labral repairs in our institution’s electronic medical records between January 1, 2021, and June 30, 2021. Inclusion criteria included isolated posterior shoulder instability with posterior labral repair and corroborated tears on MRI. A total of 9 raters, either sports or shoulder and elbow fellowship-trained orthopaedic surgeons, each evaluated the affected shoulder MRI scans twice, at over 2 weeks apart. Measurements followed the “perfect-circle” technique and included projected anterior-to-posterior (AP) glenoid diameter, amount of posterior bone loss, and percentage of posterior bone loss.
Ten consecutive patients between the ages of 17 and 46 years with diagnosed posterior glenohumeral instability were selected. The average age was 28 ± 10 years, and 60% of patients were male. The patient’s dominant arm was affected in 40%, and 50% of cases involved the right shoulder. The average glenoid diameter was 29.62 ± 3.69 mm, and the average measured bone loss was 2.8 ± 1.74 mm. The average percent posterior glenoid bone loss was 9.41 ± 5.78%. The inter-rater reliability was poor for the AP diameter and for the posterior glenoid bone loss with intraclass correlation coefficients at 0.30 (0.12-0.62) and 0.22 (0.07-0.54) respectively. The intrarater reliability was poor for AP diameter and moderate for posterior glenoid bone loss, with intraclass correlation coefficients at 0.41 (0.22-0.57) and 0.50 (0.33-0.64), respectively.
Using the “perfect-circle” technique for evaluating posterior glenohumeral bone loss has poor-to-moderate inter- and intrarater reliability from MRI.
Level IV, prospective diagnostic study.
Magnetic Resonance Imaging Analysis Demonstrates Improved Reliability in Measuring Shoulder Glenoid Bone Loss Using a Two-Thirds Glenoid Height Technique Compared to the “Best-fit Circle”
2024, Arthroscopy - Journal of Arthroscopic and Related Surgery
To evaluate the superior to inferior glenoid height as a reliable reference in best-fit circle creation for glenoid anatomy.
The morphology of the native glenoid was evaluated using magnetic resonance imaging (MRI) in patients without shoulder instability. Using T1 sagittal MRI images, 2 reviewers independently estimated glenoid size using the two-thirds technique and the “best-fit circle” technique at 2 different times. A Student t-test was used to determine significant difference between the two methodologies. Inter- and intra-rater reliability were calculated using interclass and intraclass coefficients.
This study included 112 patients. Using the results of glenoid height and “best-fit circle” diameter, the diameter of the “best-fit circle” was found to intersect the glenoid line at 67.8% of the glenoid height on average. We found no significant difference between the 2 measures of glenoid diameter (27.6 vs 27.9, P = .456). The interclass and intraclass coefficients for the two-third method were 0.85 and 0.88, respectively. The interclass and intraclass coefficients for the perfect circle methods were 0.84 and 0.73, respectively.
We determined that the diameter of a circle placed on the inferior glenoid using the “best-fit circle” technique corresponds to 67.8% of the glenoid height. Additionally, we found that constructing a perfect circle using a diameter equal to two-thirds the height of the glenoid may improve intraclass reliability.
Level IV, retrospective cohort study.
Three-Dimensional Magnetic Resonance Imaging FRACTURE (Fast Field Echo Resembling A CT Using Restricted Echo-Spacing) Sequence Is Equivalent to Three-Dimensional Computed Tomography in Quantifying Bone Loss and Measuring Shoulder Morphology in Patients With Shoulder Dislocation
2024, Arthroscopy - Journal of Arthroscopic and Related Surgery
To evaluate the equivalence of 3-dimensional (3D) magnetic resonance imaging (MRI) (FRACTURE [Fast field echo Resembling A CT Using Restricted Echo-spacing]) and 3D computed tomography (CT) in quantifying bone loss in patients with shoulder dislocation and measuring morphologic parameters of the shoulder.
From July 2022 to June 2023, patients with anterior shoulder dislocation who were aged 18 years or older and underwent both MRI and CT within 1 week were included in the study. The MRI protocol included an additional FRACTURE sequence. Three-dimensional reconstructions of MRI (FRACTURE) and CT were completed by 2 independent observers using Mimics software (version 21.0) through simple threshold-based segmentation. For bone defect cases, 2 independent observers evaluated glenoid defect, percentage of glenoid defect, glenoid track, Hill-Sachs interval, and on-track/off-track. For all cases, glenoid width, glenoid height, humeral head–fitting sphere radius, critical shoulder angle, glenoid version, vault depth, and post-processing time were assessed. The paired t test was used to assess the differences between 3D CT and 3D MRI (FRACTURE). Bland-Altman plots were constructed to evaluate the consistency between 3D CT and 3D MRI (FRACTURE). Interobserver and intraobserver agreement was evaluated with the interclass correlation coefficient. The paired χ² test and Cohen κ statistic were used for binary variables (on-track/off-track).
A total of 56 patients (16 with bipolar bone defect, 5 with only Hill-Sachs lesion, and 35 without bone defect) were ultimately enrolled in the study. The measurements of 21 bone defect cases showed no statistically significant differences between 3D CT and 3D MRI: glenoid defect, 4.05 ± 1.44 mm with 3D CT versus 4.16 ± 1.39 mm with 3D MRI (P = .208); percentage of glenoid defect, 16.21% ± 5.95% versus 16.61% ± 5.66% (P = .199); glenoid track, 18.02 ± 2.97 mm versus 18.08 ± 2.98 mm (P = .659); and Hill-Sachs interval, 14.29 ± 1.93 mm versus 14.35 ± 2.07 mm (P = .668). No significant difference was found between 3D CT and 3D MRI in the diagnosis of on-track/off-track (P > .999), and diagnostic agreement was perfect (κ = 1.00, P < .001). There were no statistically significant differences between the 2 examination methods in the measurements of all 56 cases, except that the post-processing time of 3D MRI was significantly longer than that of 3D CT: glenoid height, 34.56 ± 1.98 mm with 3D CT versus 34.67 ± 2.01 mm with 3D MRI (P = .139); glenoid width, 25.32 ± 1.48 mm versus 25.45 ± 1.47 mm (P = .113); humeral head–fitting sphere radius, 22.91 ± 1.70 mm versus 23.00 ± 1.76 mm (P = .211); critical shoulder angle, 33.49° ± 2.55° versus 33.57° ± 2.51° (P = .328); glenoid version, –3.25° ± 2.57° versus –3.18° ± 2.57° (P = .322); vault depth, 37.43 ± 1.68 mm versus 37.58 ± 1.75 mm (P = .164); and post-processing time, 89.66 ± 10.20 seconds versus 360.93 ± 26.76 seconds (P < .001). For all assessments, the Bland-Altman plots showed excellent consistency between the 2 examination methods, and the interclass correlation coefficients revealed excellent interobserver and intraobserver agreement.
Three-dimensional MRI (FRACTURE) is equivalent to 3D CT in quantifying bone loss in patients with shoulder dislocation and measuring shoulder morphologic parameters.
Level II, development of diagnostic criteria (consecutive patients with consistently applied reference standard and blinding).
Glenoid segmentation from computed tomography scans based on a 2-stage deep learning model for glenoid bone loss evaluation
2023, Journal of Shoulder and Elbow Surgery
The best-fitting circle drawn by computed tomography (CT) reconstruction of the en face view of the glenoid bone to measure the bone defect is widely used in clinical application. However, there are still some limitations in practical application, which can prevent the achievement of accurate measurements. This study aimed to accurately and automatically segment the glenoid from CT scans based on a 2-stage deep learning model and to quantitatively measure the glenoid bone defect.
Patients who were referred to our institution between June 2018 and February 2022 were retrospectively reviewed. The dislocation group consisted of 237 patients with a history of ≥2 unilateral shoulder dislocations within 2 years. The control group consisted of 248 individuals with no history of shoulder dislocation, shoulder developmental deformity, or other disease that may lead to abnormal morphology of the glenoid. All patients underwent CT examination with a 1-mm slice thickness and a 1-mm increment, including complete imaging of the bilateral glenoid. A residual neural network (ResNet) location model and a U-Net bone segmentation model were constructed to develop an automated segmentation model for the glenoid from CT scans. The data set was randomly divided into training (201 of 248) and test (47 of 248) data sets of control-group data and training (190 of 237) and test (47 of 237) data sets of dislocation-group data. The accuracy of the stage 1 (glenoid location) model, the mean intersection-over-union value of the stage 2 (glenoid segmentation) model, and the glenoid volume error were used to assess the performance of the model. The R² value and Lin concordance correlation coefficient were used to assess the correlation between the prediction and the gold standard.
A total of 73,805 images were obtained after the labeling process, and each image was composed of CT images of the glenoid and its corresponding mask. The average overall accuracy of stage 1 was 99.28%; the average mean intersection-over-union value of stage 2 was 0.96. The average glenoid volume error between the predicted and true values was 9.33%. The R² values of the predicted and true values of glenoid volume and glenoid bone loss (GBL) were 0.87 and 0.91, respectively. The Lin concordance correlation coefficient value of the predicted and true values of glenoid volume and GBL were 0.93 and 0.95, respectively.
The 2-stage model in this study showed a good performance in glenoid bone segmentation from CT scans and could quantitatively measure GBL, providing a data reference for subsequent clinical treatment.
Does glenoid bone loss accompany posterior shoulder instability with only labral tear? A magnetic resonance imaging–based study
2023, Journal of Shoulder and Elbow Surgery
The primary aim of this study was to investigate bone loss in the glenoid with magnetic resonance imaging in posterior shoulder instability with only a labral tear.
A total of 76 patients operated on because of posterior and anteroposterior shoulder instability only with a labral tear between 2006 and 2019 (n = 40 and n = 36, respectively) were included in this study. The instability type, a presence of an additional superior labrum anteroposterior (SLAP) lesion, the number of dislocations, and the magnetic resonance imaging–based measurements (the glenoid diameter and the bone defect size in the glenoid, the Hill-Sachs lesion [HSL] and the reverse HSL [rHSL] length, the angle and the arc length of HSL and rHSL, and the humerus head diameter and its area) were analyzed.
The size of the anterior glenoid defect, the rHSL measurements (length, angle, and arc length), and the ratio of the anterior glenoid defect size to the glenoid diameter were significantly higher for anteroposterior instability (P < .01) cases. There was no significant difference (P = .49, .64, and .82, respectively) for the presence of an additional SLAP pathology, the glenoid diameter, the posterior glenoid defect, and the ratio of the posterior glenoid defect size to the glenoid diameter in posterior and anteroposterior instability groups. The increased number of dislocations was associated with increased rHSL length and total arc length (P = .04 and .03, respectively). An additional SLAP lesion in posterior shoulder instabilities was not associated with the bone defect size (P = .29).
Although the posterior shoulder instability with only a labral tear is likely to cause a bone defect, we have shown that the instability is not expected to be caused by the bone defect. Therefore, this study points out that only soft tissue repair without considering the bone defect could be promising in this patient group.

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

Section snippets

Materials and methods

Results

Discussion

Arthroscopy

Arthroscopy

Arthroscopy

J Shoulder Elbow Surg

J Shoulder Elbow Surg

Arthroscopy

Radiol Clin North Am

J Shoulder Elbow Surg

J Shoulder Elbow Surg

MR arthrography of the shoulder: variants and pitfalls

Radiographics

Glenohumeral instability: evaluation with MR arthrography

Radiographics

Glenoid rim lesions associated with recurrent anterior dislocation of the shoulder

Am J Sports Med

Glenohumeral ligaments and shoulder capsular mechanism: evaluation with MR arthrography

Radiology

Glenoid labral tears: prospective evaluation with MRI imaging, MR arthrography, and CT arthrography

AJR Am J Roentgenol

Glenoid labrum: evaluation with MR imaging

Radiology

Classification of glenohumeral joint instability

Clin Orthop

Anterior shoulder dislocation: quantification of glenoid bone loss with CT

AJR Am J Roentgenol

Arthroscopic versus open reconstruction of the shoulder in patients with isolated Bankart lesions

Am J Sports Med

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