Measuring glenoid and humeral bone loss in shoulder dislocation

The Latarjet Procedure for Recurrent Anterior Shoulder Instability in the Contact Athlete

In young athletes, anterior shoulder instability is a prevalent condition. Because of high-energy traumas, contact athletes often suffer recurrent instability, bone loss and postoperative recurrences. Patients younger than 20 years, symptomatic for more than 6 months, with ≥ 2 dislocations, with off-track Hill-Sachs lesion, glenoid bone loss, ALPSA lesion, Instability Severity Index Score > 3, and Glenoid Track Instability Management Score > 3 are at higher risk of failure. In cases of multiple dislocations with critical or subcritical glenoid bone loss, notably in collision and contact athletes, the Latarjet procedure is widely recognized as the treatment of choice.

Promising clinical effect of arthroscopic autologous iliac bone grafting with suture anchor binding fixation for recurrent anterior shoulder instability

Background

To evaluate the clinical efficacy of arthroscopic autologous iliac bone grafting with suture anchor binding fixation combined with a Bankart repair for recurrent anterior shoulder dislocation with a significant anterior glenoid defect.

Methods

Patients with recurrent anterior shoulder dislocation with an anterior glenoid defect area greater than 20% admitted to our department from March 2019 to March 2022 were prospectively enrolled. Arthroscopic autologous iliac bone grafting with suture anchor binding fixation combined with a Bankart repair was performed. Computed tomography (CT) images were captured preoperatively, immediately after surgery, and at 3, 6, and 12 months postoperatively to evaluate the glenoid defect area, graft area, and graft healing. Shoulder function was assessed using the Instability Severity Index, Oxford Shoulder Instability, and Rowe scores recorded preoperatively and at the final follow-up. The shoulder range of motion, shoulder stability test, surgery-related complications, subluxation/dislocation, and revision surgery were also evaluated.

Results

A total of 32 patients were included in the study, with an average follow-up time of 18.3 ± 6.3 months, when the graft healing rate was shown to be 100%. The area ratio of the graft to the glenoid was 37.6% ± 10.5% (range, 23.5%-44.1%) determined by an enface-view three-dimensional CT performed immediately after surgery, and 29.2 ± 8.2% (range, 19.6%-38.7%) at 12 months postoperatively. At the final follow-up, the glenoid defect had improved from 28.7 ± 6.4% (range, 20.5%-40.6%) before surgery to -10.2 ± 4.7% (range, -13.8% to 6.1%). The preoperative Rowe and Oxford scores were 56.4 ± 8.5 and 34.7 ± 7.1 respectively, which improved to 94.3 ± 6.7 and 15.3 ± 3.2 at the final follow-up (p < .001). All patients had no limited shoulder joint activity, no re-dislocation or revision surgery, and no neurovascular injury.

Conclusions

For recurrent anterior shoulder dislocation with an anterior glenoid defect area greater than 20%, arthroscopic autologous iliac bone grafting with suture anchor fixation combined with a Bankart repair produced a promising clinical effect. A significant shoulder function score was achieved, as was a 100% bone healing rate and ideal glenoid reconstruction without major complications. Thus, this technique may be considered an alternative to the classic Latarjet approach to treat recurrent anterior shoulder dislocation with an anterior glenoid defect area greater than 20%.

Level of Evidence

IV.

Longer peripheral-track lesions are associated with instability after arthroscopic Bankart repair

BACKGROUND

The glenoid track concept has enabled the categorization of Hill-Sachs lesions (HSLs) into on-track lesions and off-track lesions. Furthermore, among the on-track lesions, further categorization has been established based on the distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track, into peripheral-track lesions and central-track lesions. Recent studies on peripheral-track lesions and central-track lesions within the glenoid track have shown inconsistencies in failure rates, which deserves further investigation.

METHODS

A retrospective cohort comparison of patients who underwent arthroscopic Bankart repair between 2015 and 2020 was performed. 102 patients with peripheral-track HSLs were included. The patients were divided into 2 groups based on the results of the postoperative apprehension test: the apprehension positive group (n = 30), and the apprehension negative group (n = 72). Using preoperative computed tomography (CT) and an image reconstruction program, 3-dimensional (3D) images were segmented to calculate the length, width, depth, and distance of the HSLs. A multivariate logistic regression was used to determine the risk factors of recurrence, for which odds ratio (OR) and 95% confidence interval (CI) were provided.

RESULTS

A multivariate logistic regression analysis revealed that the length of the peripheral-track HSLs was a significant independent predictor of failure in this study. (OR 1.380; 95% CI 1.170-1.627; P < .001). The receiver operating characteristics curve (ROC) demonstrated a predictive power (area under the curve = 0.841) and a threshold value of 14.2 mm.

CONCLUSION

Length was the only risk factor for the recurrent instability of peripheral-track HSLs after ABR. In the context of surgical decision-making, utilizing the glenoid track concept, medical practitioners may need to evaluate instability by considering the length as a continuous factor, while differentiating between peripheral-track and central-track classifications.

Similar outcomes in collision athletes with subcritical glenoid bone loss and on-Track Hill Sachs lesion versus off-track Hill Sachs lesion managed with open Bankart repair plus inferior capsular shift

INTRODUCTION

Open Bankart repair plus inferior capsular shift has not yet been tested under the concept of glenoid track as a predictor of failure. The aim of this study was to compare the subjective and objective outcomes in collision athletes with subcritical glenoid bone loss and on-track Hill Sachs lesions versus those with off-track Hill Sachs lesions, all treated with open Bankart repair.

METHODS

Two study groups were created: 50 patients had on-track Hill Sachs lesions, while 38 had off-track lesions. The subcritical glenoid bone loss was ≤ 10%. A minimum follow-up period of 3 years was established. Preoperative and postoperative evaluation of each group and between them was performed. The Western Ontario Shoulder Instability Index score and the American Shoulder and Elbow Surgeons scale were used to assess subjective outcomes. Recurrence rate, range of motion and return to sport were evaluated as objective outcomes.

RESULTS

Significant differences were reported in the WOSI and ASES scores between preoperative and postoperative values in each group. There were no significant differences between the two groups (p-value = 0.36 and 0.71). Three dislocations (6%) in the on-track group and 3 (7.8%) in the off-track group were recorded, showing no differences between the two groups (p-value = 0.83). There were no differences in ROM between pre- and post-operatively in each group or when comparing the two groups.

CONCLUSIONS

We found no differences between the outcomes of the two groups. According to the surgeon's preference, we recommend performing open Bankart repair plus inferior capsular shift as a treatment alternative in collision athletes with SGBL ≤ 10% independently of the type of Hill Sachs lesion.

Shoulder MRI parameters in anticipating anterior shoulder dislocation: Are they a reliable and reproducible tool in clinical practice?

BACKGROUND

Anterior shoulder dislocation (ASD) is a frequently observed musculoskeletal injury that is often encountered in the context of sports activities or as a result of trauma. Several magnetic resonance imaging (MRI) parameters have been previously investigated for the purpose of characterizing the anatomical features, which could potentially be responsible for the episodes of instability. These measurements have the potential to identify patients who are susceptible to dislocation. Consequently, ensuring the reliability and consistency of these measurements is crucial in the diagnosis and the management of athletic or traumatic shoulder injuries.

METHODS

A group of four students, who had no previous experience in reading MRI series, were selected to perform radiographic measurements on specific parameters of MRI scans. These parameters were glenoid version, glenoid depth, glenoid width, humeral head diameter, humeral containing angle, and the ratio of humeral head diameter to glenoid diameter. The four participants conducted two distinct readings on a total of 28 sets of shoulder MRI scans. Simultaneously, the aforementioned measures were assessed by a consultant shoulder surgeon.

RESULTS

A total of 1512 measurements were categorized into nine sets: eight from students' measurements (two per student) and one from the consultant. Intra-rater reliability assessed by the intra-class correlation (ICC) test indicated excellent or good reliability for all parameters (p < 0.05), with glenoid depth showing the highest (0.925) and humeral-containing angles the lowest (0.675) ICC value. Inter-rater correlation, also evaluated using ICC, demonstrated strong correlation (p < 0.05), with glenoid diameter having the highest ICC score (0.935) and glenoid depth the lowest (0.849). Agreement analysis, expressed by Cohen's Kappa test, revealed substantial agreement (p < 0.05) for all parameters, with humeral head diameter having the highest agreement (0.90) and humeral-containing angle the lowest (0.73).

CONCLUSION

In this study, intra- and inter-rater MRI parameters are substantially concordant. Credibility comes from these reliability and agreement analyses' statistical significance. Glenoid diameter and depth are the most reliable intrarater and interrater, respectively. Best agreement was with the humeral-containing angle. These data demonstrate repeatability and clinical relevance.

LEVEL OF EVIDENCE

Level IV.

Objective calculation of glenoid bone loss in anterior shoulder instability based on the contour of the posteroinferior quadrant using the best-fit circle method: an accurate and reproducible evaluation

BACKGROUND

Glenoid bone loss is proposed to be an important risk factor for recurrent anterior shoulder instability. The purpose of the present study was to develop an accurate and reproducible method for quantifying a bone loss in patients with anterior shoulder instability.

METHODS

A total of 66 sets of computed tomography images of the glenoid were acquired and en face view was established. Based on the contour of the inferior half and posteroinferior quadrant of the glenoid, the best-fit circle was drawn using the least-squares method with a comparison of the radii. A bone loss was created via a simulated osteotomy, and a method for estimating the bone loss based on the contour of the posteroinferior quadrant was developed.

RESULTS

The radii of the best-fit circle were 29.30 ± 1.84 mm and 33.76 ± 2.04 mm, based on the inferior half and posteroinferior quadrant of the glenoid, respectively (P < .01). Bone loss quantification using the contour of the inferior half or posteroinferior quadrant with simulated osteotomy showed a significant difference (P < .01). For a 25% of glenoid bone loss, the estimated value using the traditional method on the contour of the posteroinferior quadrant was 34%. A new method for accurate bone loss quantification was developed based on the contour of the posteroinferior quadrant of the glenoid.

CONCLUSION

Estimation of the glenoid bone loss based on the rim of the posteroinferior quadrant may overestimate the glenoid bone loss due to the difference in the radius of the curvature of the inferior half and posteroinferior quadrant. A mathematical method developed to correct this error and may aid in more accurately, measuring the glenoid bone loss using the contour of the posteroinferior quadrant in patients with anterior shoulder instability.

Reconstruction of recurrent shoulder dislocation with glenoid bone defect with 3D-printed titanium alloy pad: outcomes at 2-year minimum follow-up

BACKGROUND

To evaluate the outcome of shoulder arthroscopy-assisted implantation of three-dimensional (3D)-printed titanium pads for recurrent shoulder dislocation with glenoid bone defects.

METHODS

From June 2019 to May 2020, the clinical efficacy of 3D printed titanium pad implantation assisted by shoulder arthroscopy, for the treatment of recurrent shoulder dislocations with shoulder glenoid defects was retrospectively analyzed. The American Shoulder and Elbow Surgeons (ASES) shoulder, Rowe, and Constant scores were recorded before surgery and at 3 months, 6 months, 1 year, and 2 years after surgery. 3D computed tomography (CT) and magnetic resonance imaging were used to evaluate the location of the glenoid pad, bone ingrowth, joint degeneration, and osteochondral damage.

RESULTS

The mean age of the 12 patients was 21.4 (19-24) years and the mean follow-up time was 27.6 (24-35) months. The Visual Analog Scale score significantly improved from 5.67 ± 1.98 preoperatively to 0.83 ± 0.58 postoperatively (p = 0.012). The postoperative ASES score was significantly increased to 87.91 ± 3.47 compared with preoperative ASES score (46.79 ± 6.45) (p < 0.01). Rowe and Constant scores also improved from 22.5 ± 12.34 and 56.58 ± 7.59 preoperatively to 90.83 ± 4.69 and 90.17 ± 1.89 at 2 years postoperatively, respectively. CT performed 2 years after surgery showed that the pad perfectly replenished the bone-defective part of the shoulder glenoid and restored the articular surface curvature of the shoulder glenoid in the anterior-posterior direction, and the bone around the central riser of the pad was tightly united. Magnetic resonance imaging 2 years after surgery showed that the humeral head osteochondral bone was intact, and there was no obvious osteochondral damage.

CONCLUSIONS

3D printed titanium pads are a reliable, safe, and effective surgical procedure for treating recurrent shoulder dislocations with glenoid bone defects.

Defining Critical Humeral Bone Loss: Inferior Craniocaudal Hill-Sachs Extension as Predictor of Recurrent Instability After Primary Arthroscopic Bankart Repair

BACKGROUND

The glenoid track concept for shoulder instability primarily describes the medial-lateral relationship between a Hill-Sachs lesion and the glenoid. However, the Hill-Sachs position in the craniocaudal dimension has not been thoroughly studied.

HYPOTHESIS

Hill-Sachs lesions with greater inferior extension are associated with increased risk of recurrent instability after primary arthroscopic Bankart repair.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The authors performed a retrospective analysis of patients with on-track Hill-Sachs lesions who underwent primary arthroscopic Bankart repair (without remplissage) between 2007 and 2019 and had a minimum 2-year follow-up. Recurrent instability was defined as recurrent dislocation or subluxation after the index procedure. The craniocaudal position of the Hill-Sachs lesion was measured against the midhumeral axis on sagittal magnetic resonance imaging (MRI) using either a Hill-Sachs bisecting line through the humeral head center (sagittal midpoint angle [SMA], a measure of Hill-Sachs craniocaudal position) or a line tangent to the inferior Hill-Sachs edge (lower-edge angle [LEA], a measure of Hill-Sachs caudal extension). Univariate and multivariate regression were used to determine the predictive value of both SMA and LEA for recurrent instability.

RESULTS

In total, 176 patients were included with a mean age of 20.6 years, mean follow-up of 5.9 years, and contact sport participation of 69.3%. Of these patients, 42 (23.9%) experienced recurrent instability (30 dislocations, 12 subluxations) at a mean time of 1.7 years after surgery. Recurrent instability was found to be significantly associated with LEA >90° (ie, Hill-Sachs lesions extending below the humeral head equator), with an OR of 3.29 (P = .022). SMA predicted recurrent instability to a lesser degree (OR, 2.22; P = .052). Post hoc evaluation demonstrated that LEA >90° predicted recurrent dislocations (subset of recurrent instability) with an OR of 4.80 (P = .003). LEA and SMA were found to be collinear with Hill-Sachs interval and distance to dislocation, suggesting that greater LEA and SMA proportionally reflect lesion severity in both the craniocaudal and medial-lateral dimensions.

CONCLUSION

Inferior extension of an otherwise on-track Hill-Sachs lesion is a highly predictive risk factor for recurrent instability after primary arthroscopic Bankart repair. Evaluation of Hill-Sachs extension below the humeral equator (inferior equatorial extension) on sagittal MRI is a clinically facile screening tool for higher-risk lesions with subcritical glenoid bone loss. This threshold for critical humeral bone loss may inform surgical stratification for procedures such as remplissage or other approaches for at-risk on-track lesions.

Glenoid segmentation from computed tomography scans based on a 2-stage deep learning model for glenoid bone loss evaluation

BACKGROUND

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

[A study of the correlation between glenohumeral joint congruence and stability in recurrent shoulder dislocations]

Objective

To investigate the correlation between glenohumeral joint congruence and stability in recurrent shoulder dislocations.

Methods

Eighty-nine patients (89 sides) with recurrent shoulder dislocation admitted between June 2022 and June 2023 and met the selection criteria were included as study subjects. There were 36 males and 53 females with an average age of 44 years (range, 20-79 years). There were 40 cases of left shoulder and 49 cases of right shoulder. The shoulder joints dislocated 2-6 times, with an average of 3 times. The three-dimensional models of the humeral head and scapular glenoid were reconstructed using Mimics 20.0 software based on CT scanning images. The glenoid track (GT), inclusion index, chimerism index, fit index, and Hill-Sachs interval (HSI) were measured, and the degree of on/off track was judged (K value, the difference between HSI and GT). Multiple linear regression was used to analyze the correlation between the degree of on/off track (K value) and inclusion index, chimerism index, and fit index.

Results

Multiple linear regression analysis showed that the K value had no correlation with the inclusion index ( P>0.05), and was positively correlated with the chimerism index and the fit index ( P<0.05). Regression equation was K=-24.898+35.982×inclusion index+8.280×fit index, R 2=0.084.

Conclusion

Humeral head and scapular glenoid bony area and curvature are associated with shoulder joint stability in recurrent shoulder dislocations. Increased humeral head bony area, decreased scapular glenoid bony area, increased humeral head curvature, and decreased scapular glenoid curvature are risk factors for glenohumeral joint stability.

Novel anterior coracoglenoid line utilizing magnetic resonance imaging (MRI) corresponds with critical glenoid bone loss

OBJECTIVE

Glenoid bone loss is estimated using a best-fit circle method and requires software tools that may not be available. Our hypothesis is that a vertical reference line drawn parallel to the long axis of the glenoid and passing through the inflection point of the coracoid and glenoid will represent a demarcation line of approximately 20% of the glenoid. Our aim is to establish a more efficient method to estimate a surgical threshold for glenoid insufficiency.

METHODS

Fifty patients with normal glenoid anatomy were randomly chosen from an orthopedic surgeon's database. Two orthopedic surgeons utilized T1-weighted sagittal MRIs and the coracoglenoid line technique to determine the percentage of bony glenoid anterior to vertical line. Two musculoskeletal radiologists measured the same 50 glenoids using the circle technique. Differences were determined using dependent t test. Reliability was compared using interclass correlation coefficient and Kappa. Validity was compared using Pearson correlation coefficient.

RESULTS

Mean surface area of the glenoid anterior to the vertical line was on average 21.69% ± 3.12%. Surface area of the glenoid using the circle method was on average 20.86% ± 2.29%. Inter-rater reliability of the circle method was 0.553 (fair). Inter-rater reliability of the vertical line technique was 0.83 (excellent). There was a linear relationship between circle and vertical line measurements, r = 0.704 (moderate to high).

CONCLUSION

The coracoglenoid line appears to represent a line of demarcation of approximately 21% of glenoid bone anterior to the coracoglenoid line. Our technique was found to be reliable, valid, and accurate.

How to Report: Shoulder MRI

Magnetic resonance imaging of the shoulder is a commonly performed investigation. This article discusses the common shoulder pathologies encountered, emphasizes the key features to report, and provides examples of terminology used to describe these pathologies.

Is Revision Bankart Repair with Remplissage a Viable Option for Failed Bankart Repair in Non-contact Sports Person Aiming to Return to Sports?

PURPOSE

Failure of a well-executed Bankart repair in non-contact athletes is difficult to predict and its management is a lesser investigated area with uncertain outcome in terms of return to sports (RTS). This study analyses effectiveness of revision Bankart repair with remplissage for failed Bankart repair in non-contact athletes, focusing on time and level of RTS.

MATERIALS AND METHODS

Fifty-five consecutive non-contact athletes with evidence of instability after primary arthroscopic Bankart repair having glenoid loss < 25% and off-track Hill-Sachs lesion were included in the study according to algorithm mentioned. All cases underwent revision arthroscopic Bankart repair with remplissage and followed-up for 24 months. Rowe, UCLA, WOSI and Quick-DASH scores were recorded preoperative and at 24 months. RTS was allowed after unilateral seated shot-put test.

RESULTS

Out of 55 cases, 6 were excluded because of poor tissue quality, 7 were lost to follow-up. Forty-two cases with a mean age of 28.2 ± 5.2 years were included. Mean duration between primary surgery and failure was 7.3 ± 1.4 months with a mean 1.9 redislocations. The mean Rowe, WOSI, UCLA, Quick-DASH scores improved from 37 to 89, 39.3 to 83.7%, 18.4 to 30.5, 45.3 to 18.7 at 24 months. Thirty-five cases could RTS in a mean time 15.4 ± 1.4 months. Out of seven cases who could not RTS, four had instability, one had pain and two voluntarily quit sports.

CONCLUSION

Revision Bankart repair with remplissage is a feasible option for failed primary Bankart repair in non-contact athletes who have glenoid bone loss < 25% with off-track Hill-Sachs.

LEVEL OF EVIDENCE

Level IV.