Interobserver and intraobserver variability of glenoid track measurements

The Global Track Concept for Assessment of Engaging Hill-Sachs Defects in Anterior Shoulder Instability

BACKGROUND

The glenoid track concept is used to determine preoperatively whether a Hill-Sachs defect is engaging or not. Currently, the glenoid track concept relies on measurements of bony structures as well as on the confines and elasticity of the rotator cuff as a reference point, which varies extensively among individuals and therefore limits the reliability and accuracy of this concept.

PURPOSE

To evaluate the reliability of the global track concept, which determines the angular distance of the Hill-Sachs defect from the center of the articular surface of the humeral head as a new reference point with the help of an automated image analysis software and 3-dimensional analysis of the humeral head.

STUDY DESIGN

Controlled laboratory study.

METHODS

Computed tomography scans of 100 patients treated for anterior shoulder instability with different sizes of Hill-Sachs defects were evaluated manually by 2 orthopaedic surgeons independently using the software OsiriX as well as automatically by using a dedicated prototype software (ImFusion). Obtained manual and automated measurements included the Hill-Sachs length, Hill-Sachs width, and Hill-Sachs depth of the defect; the Hill-Sachs interval (HSI); and the glenoid width for the glenoid track concept, as well as the angular distance of the Hill-Sachs defect from the center of the articular surface of the humeral head (global track concept). The reliability of the different measurement techniques was compared by calculating intraclass correlation coefficients (ICCs).

RESULTS

There was a significant difference for all obtained parameters comparing manual and automatic measurements. For manually obtained parameters, measurements referring to bony boundaries (glenoid width, Hill-Sachs length, and Hill-Sachs width) showed good to excellent agreement (ICC, 0.86, 0.82, and 0.62, respectively), while measurements referring to soft tissue boundaries (HSI and glenoid track; ICC, 0.56 and 0.53, respectively) or not directly identifiable reference points (center of articular surface and global track) only showed fair reliability (ICC middle excursion, 0.42). When the same parameters were measured with the help of an automated software, good reliability for the glenoid track concept and excellent reliability for the global track concept in the middle excursion were achieved.

CONCLUSION

The present study showed that the more complex global track measurements of humeral defects are more reliable than the current standard HSI and glenoid track measurements. However, this is only true when automated software is used to perform the measurements.

CLINICAL RELEVANCE

Future studies using the new proposed method in combination with an automated software need to be conducted to determine critical threshold values for defects prone to engagement.

Validating the Glenoid Track Concept Using Dynamic Arthroscopic Assessment

Background

Failure after isolated Bankart repair has led surgeons to consider when to address the Hill-Sachs lesion, which is thought to be a contributor to recurrent instability. One approach utilizes the glenoid track concept to determine whether a Hill-Sachs lesion is classified as "off-track," suggesting that the addition of a remplissage procedure may aid stability. However, the accuracy and reliability of using this approach require validation using an appropriate reference.

Purpose

To determine the accuracy and reliability of using the glenoid track concept against dynamic arthroscopic assessment of Hill-Sachs lesion engagement.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

A total of 49 patients undergoing arthroscopic Bankart repair surgery for recurrent traumatic anterior shoulder instability were enrolled in this diagnostic validation study. Shoulders were classified as on-track or off-track using 3-dimensional computed tomography (3DCT) and static arthroscopic measurements. These classifications were compared with dynamic arthroscopic assessment (engagement of the Hill-Sachs lesion on the anterior glenoid rim in the 'athletic position') to determine their accuracy and reliability.

Results

The 3DCT-based measurements to determine glenoid track status had a higher positive predictive value (66% vs 42%), higher specificity (47% vs 42%), and higher accuracy (65% vs 59%) compared with static arthroscopic measurements. Static arthroscopic measurements to determine glenoid track status had a higher negative predictive value (96% vs 64%) and higher sensitivity (96% vs 81%) compared with 3DCT-based measurements. Interrater reliability (Krippendorff α) was 'fair' for determining the glenoid track status using 3DCT (0.368; 95% CI, 0.217-0.519) and 'moderate' for static arthroscopic measurements (0.523; 95% CI, 0.364-0.666). Intrarater reliability (intraclass correlation coefficient [ICC] 3,k) was 'moderate' for 3DCT measurements (0.660; 95% CI, 0.444-0.798) and 'good' for static arthroscopic measurements (0.769; 95% CI, 0.629-0.862).

Conclusion

Determining glenoid track status using either 3DCT or static arthroscopic measurements yielded moderate accuracy and reliability. Surgeons using the glenoid track concept to aid surgical decision-making in traumatic recurrent anterior shoulder instability should utilize 3DCT or static arthroscopic measurements with caution.

How does dynamic arthroscopic tracking compare with radiologic glenoid track for identification of on- and off-track lesions in anterior shoulder instability?

BACKGROUND

Current treatment paradigms for anterior shoulder instability are based on radiologic measurements of glenohumeral bone defects, and mathematical calculation of the glenoid track (GT) is used to classify lesions into on-track and off-track morphology. However, radiologic measurements have shown high variability, and GT widths under dynamic conditions have been reported to be significantly smaller than those under static radiologic conditions. The purpose of this study was to assess the reliability, reproducibility, and diagnostic validity of dynamic arthroscopic standardized tracking (DAST) in comparison to the gold-standard radiologic track measurement method for the identification of on- and off-track bony lesions in patients with anteroinferior shoulder instability.

METHODS

Between January 2018 and August 2022, 114 patients with traumatic anterior shoulder instability were evaluated using 3-T magnetic resonance imaging or computed tomography scans; glenoid bone loss, Hill-Sachs interval, GT, and Hill-Sachs occupancy ratio (HSO) were measured, and defects were classified as on-track or off-track defects and peripheral-track defects (based on HSO percentage) by 2 independent researchers. During arthroscopy, a standardized method (DAST method) was used by 2 independent observers to classify defects into on-track defects (central and peripheral) and off-track defects. Interobserver reliability of the DAST and radiologic methods was calculated using the κ statistic and reported as percentage agreement. Diagnostic validity (sensitivity, specificity, positive predictive value, and negative predictive value) of the DAST method was calculated using the radiologic track (HSO percentage) as the gold standard.

RESULTS

The radiologically measured mean glenoid bone loss percentage, Hill-Sachs interval, and HSO in off-track lesions were lower with the arthroscopic method (DAST) as compared with the radiologic method. The DAST method showed nearly perfect agreement between the 2 observers for the on-track/off-track classification (κ = 0.96, P < .001) and the on-track central or peripheral /off-track classification (κ = 0.88, P < .001). The radiologic method showed greater interobserver variability (κ = 0.31 and κ = 0.24, respectively) with only fair agreement for both classifications. Inter-method agreement varied between 71% and 79% (95% confidence interval, 62%-86%) between the 2 observers, and reliability was assessed as slight (κ = 0.16) to fair (κ = 0.38). Overall, for identification of an off-track lesion, the DAST method showed maximum specificity (81% and 78%) when radiologic peripheral-track lesions (HSO percentage of 75%-100%) were considered off-track and showed maximum sensitivity when arthroscopic peripheral-track lesions were classified as off-track.

CONCLUSION

Although inter-method agreement was low, a standardized arthroscopic tracking method (DAST method) showed superior interobserver agreement and reliability for lesion classification in comparison to the radiologic track method. Incorporating DAST into current algorithms may help reduce variability in surgical decision making.

The size of the Hill Sachs defect increases during reduction of a first time shoulder dislocation in older adults: a pilot study in 20 cases

PURPOSE

To evaluate if the size of Humeral Hill-Sachs Defects (HSDs) increases during reduction in the emergency department (ED) in subjects that have a first-time anterior shoulder dislocation.

METHODS

Subjects more than 18 years old presenting to the ED a first-time anterior shoulder dislocation were included. A computed tomography was performed prior to any reduction attempt (Pre-CT). The shoulder was reduced in the emergency room with intraarticular lidocaine; if two attempts failed, the shoulder was reduced under anaesthesia. A second CT was performed after reduction of the shoulder (Post-CT). CT were evaluated using the Osirix software. A 3-dimensional reconstruction of the humeral head was performed and the maximum width of the humeral defect, maximum depth of the humeral defect and total volume of the humeral defect were measured. The relative increase in size was calculated.

RESULTS

Twenty subjects were included in the study. All subjects presented HSDs in the Pre-CT that had a width of a median of 9.9(interquartile range:2.9)mm, a depth of 7.0(3.0]mm and a volume of 355(333)mm2. The HSD in the Post-CT had a width of 10.9(3.0)mm (an increase of 7.23[8.5]%, significant differences, p = 0.0001) a depth of 7.2(2.7)mm (an increase of 9.93[20.7]%, significant differences, p < 0.0001) and a volume of 469(271) mm2 (an increase of 27.5[26.9]%, significant differences, p < 0.0001). There were size increases larger than 25% in 15/20 (75%) of subjects.

CONCLUSION

Standard reduction manoeuvres performed in a first-time anterior shoulder dislocation increase the size of the HSD. This increase in size is larger than 25% in four out of five cases.

LEVEL OF EVIDENCE

IV, prospective cases series study.

Variability in quantifying the Hill-Sachs lesion: A scoping review

Background

Currently, is there no consensus on a widely accepted measurement technique for calculating the Hill-Sachs lesion (HSL). The purpose of this review is to provide an overview of the techniques and imaging modalities to assess the HSL pre-operatively.

Methods

Four online databases (PubMed, Embase, MEDLINE, and COCHRANE) were searched for literature on the various modalities and measurement techniques used for quantifying HSLs, from data inception to 20 November 2021. The Methodological Index for Non-Randomized Studies tool was used to assess study quality.

Results

Forty-five studies encompassing 3413 patients were included in this review. MRA and MRI showed the highest sensitivity, specificity, and accuracy values. Intrarater and interrater agreement was shown to be the highest amongst MRA. The most common reference tests for measuring the HSL were arthroscopy, radiography, arthro-CT, and surgical techniques.

Conclusion

MRA and MRI are reliable imaging modalities with good test diagnostic properties for assessment of HSLs. There is a wide variety of measurement techniques and imaging modalities for HSL assessment, however a lack of comparative studies exists. Thus, it is not possible to comment on the superiority of one technique over another. Future studies comparing imaging modalities and measurement techniques are needed that incorporate a cost-benefit analysis.

Current Concepts in the Measurement of Glenohumeral Bone Loss

PURPOSE

The extent of glenohumeral bone loss seen in anterior shoulder dislocations plays a major role in guiding surgical management of these patients. The need for accurate and reliable preoperative assessment of bone loss on imaging studies is therefore of paramount importance to orthopedic surgeons. This article will focus on the tools that are available to clinicians for quantifying glenoid bone loss with a focus on emerging trends and research in order to describe current practices.

RECENT FINDINGS

Recent evidence supports the use of 3D CT as the most optimal method for quantifying bone loss on the glenoid and humerus. New trends in the use of 3D and ZTE MRI represent exciting alternatives to CT imaging, although they are not widely used and require further investigation. Contemporary thinking surrounding the glenoid track concept and the symbiotic relationship between glenoid and humeral bone loss on shoulder stability has transformed our understanding of these lesions and has inspired a new focus of study for radiologists and orthopedist alike. Although a number of different advanced imaging modalities are utilized to detect and quantify glenohumeral bone loss in practice, the current literature supports 3D CT imaging to provide the most reliable and accurate assessments. The emergence of the glenoid track concept for glenoid and humeral head bone loss has inspired a new area of study for researchers that presents exciting opportunities for the development of a deeper understanding of glenohumeral instability in the future. Ultimately, however, the heterogeneity of literature, which speaks to the diverse practices that exist across the world, limits any firm conclusions from being drawn.

Glenoid Track Assessment at Imaging in Anterior Shoulder Instability: Rationale and Step-by-Step Guide

Anterior shoulder dislocation is the most common form of joint instability in humans, usually resulting in soft-tissue injury to the glenohumeral capsuloligamentous and labral structures. Bipolar bone lesions in the form of fractures of the anterior glenoid rim and posterolateral humeral head are often associated with anterior shoulder dislocation and can be a cause or result of recurrent dislocations. Glenoid track assessment is an evolving concept that incorporates the pathomechanics of anterior shoulder instability into its management. Currently widely endorsed by orthopedic surgeons, this concept has ramifications for prognostication, treatment planning, and outcome assessment of anterior shoulder dislocation. The glenoid track is the contact zone between the humeral head and glenoid during shoulder motion from the neutral position to abduction and external rotation. Two key determinants of on-track or off-track status of a Hill-Sachs lesion (HSL) are the glenoid track width (GTW) and Hill-Sachs interval (HSI). If the GTW is less than the HSI, an HSL is off track. If the GTW is greater than the HSI, an HSL is on track. The authors focus on the rationale behind the glenoid track concept and explain stepwise assessment of the glenoid track at CT or MRI. Off-track to on-track conversion is a primary goal in stabilizing the shoulder with anterior instability. The key role that imaging plays in glenoid track assessment warrants radiologists' recognition of this concept along with its challenges and pitfalls and the production of relevant and actionable radiology reports for orthopedic surgeons-to the ultimate benefit of patients. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Anatomic risk factors for arthroscopic Bankart repair failure: A case-control study comparing failure and non-failure groups in an Asian population

Introduction

Post-arthroscopic Bankart repair failure/re-dislocation rates are influenced by several risk factors, including anatomic defects. There is limited evidence on the role of anatomic defects, especially for Hill-Sachs size in on-track lesions. This study aimed to assess glenoid bone loss, Hill-Sachs lesion and labral tear size and evaluate their contribution to post-operative instability after a primary repair.

Material and methods

Across 169 patients with on-track Bankart lesions who underwent primary arthroscopic Bankart repair from 2010 to 2015, this study matched 14 failure with 14 non-failure cases based on age/gender. Patient demographics, pre-operative radiological parameters (including size of glenoid bone loss and Hill-Sachs lesion) and labral tear size were compared between the failure and non-failure groups.

Result

All patients were male with a mean age of 21.01 ± 4.97. Significantly greater glenoid bone loss (p = 0.024) and labral tear size (p = 0.039) were found in the failure group. However, there was no significant difference in mean volume of Hill-Sachs lesion between the two groups (p = 0.739).

Conclusion

Extensive glenoid bone loss and labral tears are risk factors for post-arthroscopic Bankart failure. However, the size of Hill-Sachs lesion is not a risk factor for failure, in a specific group of on-track Hill-Sachs lesions.

Level of evidence

Retrospective Study, Level IV.

"Nearly off-track lesions" or a short distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track does not seem to be accurate in predicting recurrence after an arthroscopic Bankart repair in a military population: a case-control study

BACKGROUND

On-track lesions with a short distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track (nearly off-track) may predispose recurrence after arthroscopic Bankart repair (ABR) in the general population. The aim of this study was to determine if a shorter distance between the medial edge of the Hill-Sachs lesion and the medial edge of the glenoid track could accurately predict recurrence after an ABR in a high-demand military population. It was hypothesized that a shorter distance would not accurately predict recurrence.

MATERIALS AND METHODS

A retrospective monocenter case-control study was performed at the Dutch Central Military Hospital. Patients with an on-track Hill-Sachs lesion who underwent a primary ABR between 2014 and 2019 with a minimal follow-up of 2 years and a preoperative magnetic resonance imaging (MRI) assessment received a questionnaire. The primary outcome was recurrence, defined as a complete dislocation or subluxation. Glenoid bone loss was assessed using a linear-based method on MRI. The distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track was defined as the distance to dislocation (DTD). A receiver operating characteristic curve was created to determine the predictive value of the DTD for recurrence. Logistic regression was used to determine preoperative risk factors that predispose recurrence. Covariates were selected based on univariable analysis and included gender, body mass index, age at surgery and first dislocation, laterality, smoking habits, overhead shoulder activity during work, preoperative dislocations, sports type and level, bony or labral lesions on MRI, and DTD.

RESULTS

In total, 80 patients with an average follow-up of 4.8 ± 1.9 years completed the questionnaire and were included in the analyses. Seventeen patients (21%) experienced recurrence at the final follow-up. No difference in DTD was observed among patients who experienced recurrence (9 ± 4 mm) compared with patients who did not (9 ± 5 mm; P = .81). The receiver operating characteristic curve demonstrated no predictive power of DTD for recurrence (area under the curve = 0.49). Smoking at the time of surgery (odds ratio: 3.9; confidence interval: 1.2-12.7; P = .02) and overhead shoulder movement during work (odds ratio: 9.3; confidence interval: 1.1-78.0; P = .04) were associated with recurrence according to the logistic regression analysis.

CONCLUSION

A shorter DTD demonstrated no accuracy in predicting recurrence in a military population. Smoking at the time of surgery and overhead shoulder activity during work were associated with recurrence; however, these analyses were underpowered to draw valid conclusions.

Clinical outcomes and recurrence rate of 4 procedures for recurrent anterior shoulder instability: ASA, remplissage, open, and arthroscopic Latarjet: a multicenter study

BACKGROUND

The aim of the present study was to compare the clinical outcomes of 4 surgical techniques in patients with recurrent anterior shoulder dislocation, glenoid bone loss (GBL) <15% and Instability Severity Index (ISI) score >3.

METHODS

A retrospective multicenter study was conducted on 226 patients who underwent 1 of 4 different techniques (Bankart plus arthroscopic subscapularis augmentation (ASA), Bankart plus remplissage, Latarjet, Arthro-Latarjet). The inclusion criteria were: recurrent dislocation, GBL <15%, and ISI score >3. The exclusion criteria were: GBL >15%, voluntary instability, multidirectional instability, preexisting osteoarthritis, throwing athletes' first dislocation, and ISI score<3. Follow-up ranged from 24 months to 6 years. Hyperlaxity was clinically evaluated according to Neer and Coudane-Walch tests. Clinical outcomes were assessed using the Rowe score and the Western Ontario Shoulder Instability Index (WOSI) for each technique. Before surgery, all patients underwent magnetic resonance imaging and computed tomography scanning. The Pico area method was used to assess the percentage of GBL. The operations were performed by 10 experienced surgeons; the functional outcomes were evaluated by 2 independent observers.

RESULTS

A total of 226 patients who met the inclusion criteria were included in the present series. A total of 89.2% of patients in the ASA group reported an excellent Rowe score at the final follow-up, and their scores on the WOSI scale, improved from 838 to 235 points. A total of 79.9% of patients in remplissage (R) group reported an excellent Rowe score at the final follow-up, and their scores on the WOSI scale improved from 1146 to 465 points. A total of 98.5% of patients in the Latarjet (L) group reported an excellent Rowe score at the final follow-up, and their scores on the WOSI scale improved from 1456 to 319 points. A total of 81.6% of patients in the Arthro-Latarjet (AL) group reported an excellent Rowe score at the final follow-up, and their scores on the WOSI scale improved from 1250 to 221 points. The recurrence rates were as follows: ASA group (7%), remplissage group (6.1%), L group (1.5%), Arthro-Latarjet group (0%). Patients in the open L group had 15.5% (10/66) more complications.

CONCLUSION

The use of ASA and remplissage to augment the Bankart repair have been demonstrated to be effective for restoring joint stability, yielding good clinical outcomes similar to the L procedure in patients affected by recurrent anterior dislocation with GBL <15% and an ISI score score >3. Soft tissues augmentations of the Bankart repair have been demonstrated to be effective for addressing anterior soft tissue deficiency dysfunction and critical Hill-Sachs lesions.

Glenoid Track Width Is Smaller Under Dynamic Conditions: An In Vivo Dual-Fluoroscopy Imaging Study

BACKGROUND

The glenoid track concept has been widely used to assess the risk of instability due to bipolar bone loss. The glenoid track width was commonly used as 83% of the glenoid width to determine if a lesion was on-track or off-track. However, the value was obtained under static conditions, and it may not be able to reflect the actual mechanism of traumatic dislocation during motion.

PURPOSE

To compare the glenoid track width under dynamic and static conditions using a dual-fluoroscopic imaging system.

STUDY DESIGN

Controlled laboratory study.

METHODS

In total, 40 shoulders of 20 healthy volunteers were examined for both dynamic and static tests within a dual-fluoroscopic imaging system at 5 different arm positions: 30°, 60°, 90°, 120°, and 150° of abduction, keeping the shoulder at 90° of external rotation. The participants performed a fast horizontal arm backswing for dynamic tests while keeping their arm in maximum horizontal extension for static tests. Computed tomography scans were used to create 3-dimensional models of the humerus and scapula for 2-dimensional to 3-dimensional image registration. Magnetic resonance imaging scans were obtained to delineate the medial margin of the rotator cuff insertion. The glenoid track width was measured as the distance from the anterior rim of the glenoid to the medial margin of the rotator cuff insertion and compared between static and dynamic conditions.

RESULTS

The mean glenoid track widths at 30°, 60°, 90°, 120°, and 150° of abduction were significantly smaller under dynamic conditions (88%, 81%, 72%, 69%, and 68% of the glenoid width) than those under static conditions (101%, 92%, 84%, 78%, and 77% of the glenoid width) (all P < .001). The glenoid track width significantly decreased with the increasing abduction angles in the range of 30° to 120° under static conditions (all P < .003) and 30° to 90° under dynamic conditions (all P < .001).

CONCLUSION

A smaller dynamic-based value should be considered for the glenoid track width when distinguishing on-track/off-track lesions. Clinical evidence is needed to establish the superiority of the dynamic-based value over the static-based value as an indicator for augmentation procedures.

CLINICAL RELEVANCE

Some off-track lesions might be misclassified as on-track lesions when the original commonly used static-based value of 83% is used as the glenoid track width.

Assessing Bone Loss in the Unstable Shoulder: a Scoping Review

PURPOSE OF REVIEW

The aim of this scoping review is to identify and summarize findings published in the literature over the past 5 years related to methods for assessment of bone loss in anterior shoulder instability.

RECENT FINDINGS

Of the 113 clinical studies included in this review, 76 reported a cutoff for glenoid bone loss when determining the patients indicated for one of the many stabilization procedures investigated. Bone loss on the glenoid side was evaluated most commonly with three-dimensional computed tomography (3D CT), and either linear or surface area-based methods were employed with the use of a best-fit circle. When combined with plain CT, the two methods comprise up to 70% of the reported measurement techniques for glenoid bone loss (79 of 113 studies). On the humeral side, Hill-Sachs lesions were assessed more heterogeneously, though plain CT or 3D CT remained the methods of choice in the majority of studies (43 of 68, 63.2%). Lastly, the glenoid track was assessed by 27 of 113 studies (23.9%), again most commonly with 3D CT (13 studies) and plain CT (seven studies). The assessment of glenoid and humeral bone loss is essential to treatment decisions for patient with recurrent anterior shoulder instability. Glenoid bone loss is most commonly assessed using cross-sectional imaging, most often 3D CT, and some variation of a best-fit circle applied to the inferior portion of the glenoid. Hill-Sachs lesion assessment was also commonly done using three-dimensional imaging; however, there was more variability in assessment methods across studies and there is an obvious need to unify the approach to humeral bone loss assessment for the purposes of improving treatment decisions and to better assess on-track and off-track lesions.

Validação clínica do conceito de glenoid track na instabilidade glenoumeral anterior

Objective  To evaluate the correlation of the glenoid track and glenoidal bone loss with the recurrence dislocation rate and the Rowe score.

Methods  Retrospective study that assessed the glenoid track and glenoidal bone loss through preoperative magnetic resonance imaging. Patients undergoing primary arthroscopic repair of anterior Bankart were included. Patients with glenoidal bone loss greater than 21%, rotator cuff tear, scapular waist fracture, and posterior or multidirectional instability were not included. Rowe score were the primary outcome, and the recurrence rate was the secondary outcome.

Results  One hundred and two patients were included. Postoperative recurrent instability was reported by 8 patients (7.8%). Four patients (50%) in the group with recurrence presented glenoidal bone loss greater than 13.5% against 24 (25.5%) in the group without recurrence ( p  = 0.210), with a negative predictive value of 94.6%. Three patients (37.5%) in the recurrence group were considered off-track, against 13 (13.8%) in the group without recurrence ( p  = 0.109), with a negative predictive value of 94.2%. Patients with absolute glenoid track value ≤ 1.5 mm had worse results in relation to the recurrence group, with 6 patients (75%) presenting recurrence ( p  = 0.003).

Conclusion  Off-track injury and glenoidal bone loss greater than the subcritical are not related to the recurrence rate and Rowe score, despite the high negative predictive value. The cut of the absolute value of the glenoid track at 1.5 mm had a significant relationship with the recurrence rate.

Recurrence in traumatic anterior shoulder dislocations increases the prevalence of Hill-Sachs and Bankart lesions: a systematic review and meta-analysis

PURPOSE

The extent of shoulder instability and the indication for surgery may be determined by the prevalence or size of associated lesions. However, a varying prevalence is reported and the actual values are therefore unclear. In addition, it is unclear whether these lesions are present after the first dislocation and whether or not these lesions increase in size after recurrence. The aim of this systematic review was (1) to determine the prevalence of lesions associated with traumatic anterior shoulder dislocations, (2) to determine if the prevalence is higher following recurrent dislocations compared to first-time dislocations and (3) to determine if the prevalence is higher following complete dislocations compared to subluxations.

METHODS

PubMed, EMBASE, Cochrane and Web of Science were searched. Studies examining shoulders after traumatic anterior dislocations during arthroscopy or with MRI/MRA or CT published after 1999 were included. A total of 22 studies (1920 shoulders) were included.

RESULTS

The proportion of Hill-Sachs and Bankart lesions was higher in recurrent dislocations (85%; 66%) compared to first-time dislocations (71%; 59%) and this was statistically significant (P < 0.01; P = 0.05). No significant difference between recurrent and first-time dislocations was observed for SLAP lesions, rotator-cuff tears, bony Bankart lesions, HAGL lesions and ALPSA lesions. The proportion of Hill-Sachs lesions was significantly higher in complete dislocations (82%) compared to subluxations (54%; P < 0.01).

CONCLUSION

Higher proportions of Hill-Sachs and Bankart were observed in recurrent dislocations compared to first-time dislocations. No difference was observed for bony Bankart, HAGL, SLAP, rotator-cuff tear and ALPSA. Especially when a Hill-Sachs or Bankart is present after first-time dislocation, early surgical stabilization may need to be considered as other lesions may not be expected after recurrence and to limit lesion growth. However, results should be interpreted with caution due to substantial heterogeneity and large variance.

LEVEL OF EVIDENCE

IV.

Imaging Modalities for the Glenoid Track in Recurrent Shoulder Instability: A Systematic Review

Background:

The glenoid track (GT) concept illustrates how the degree of glenoid bone loss and humeral bone loss in the glenohumeral joint can guide further treatment in a patient with anterior instability. The importance of determining which lesions are at risk for recurrent instability involves imaging of the glenohumeral joint, but no studies have determined which type of imaging is the most appropriate.

Purpose/Hypothesis:

The purpose of this study was to determine the validity and accuracy of different imaging modalities for measuring the GT in shoulders with recurrent anterior instability. We hypothesized that 3-dimensional computed tomography (3D-CT) would be the most accurate imaging technique.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using PubMed, Scopus, Medline, and Cochrane libraries between database inception and July 2019. We included all clinical trials or cadaveric studies that evaluated imaging modalities for assessing the GT.

Results:

A total of 13 studies were included in this review: 1 study using 2-dimensional CT, 6 studies using 3D-CT, 4 studies using magnetic resonance imaging (MRI), 1 study using magnetic resonance arthrography (MRA)/MRI, and 1 study combining CT and MRI. The mean sensitivity, specificity, and accuracy for 2D-CT was 92%, 100%, and 96%, respectively. For MRI, the means were 72.2%, 87.9%, and 84.2%, respectively. No papers included 3D-CT metrics. The mean intraclass correlation coefficients (ICCs) for intraobserver reliability were 0.9046 for 3D-CT and 0.867 for MRI. ICCs for interobserver reliability were 0.8164, 0.8845, and 0.43 for 3D-CT, MRI, and MRA/MRI, respectively.

Conclusion:

There is evidence to support the use of both CT and MRI imaging modalities in assessing the GT. In addition, few studies have compared radiographic measurements with a gold standard, and even fewer have looked at the GT concept as a predictor of outcomes. Thus, future studies are needed to further evaluate which imaging modality is the most accurate to assess the GT.

Evaluation and Management of Glenohumeral Instability With Associated Bone Loss: An Expert Consensus Statement Using the Modified Delphi Technique

PURPOSE

To establish an international expert consensus, using the modified Delphi technique, on the evaluation and management of glenohumeral instability with associated bone loss.

METHODS

A working group of 6 individuals generated a list of statements related to history and physical examination, imaging and specialized diagnostic tests, bone loss quantification and classification, treatment outcomes and complications, and rehabilitation for the management of glenohumeral instability associated with bone loss to form the basis of an initial survey for rating by a group of experts. The expert group (composed of 22 high-volume glenohumeral instability experts) was surveyed on 3 occasions to establish a consensus on the statements. Items with over 70% agreement and less than 10% disagreement achieved consensus.

RESULTS

After a total of 3 rounds, 31 statements achieved consensus. Eighty-six percent of the experts agreed that a history of multiple dislocations and failed soft-tissue surgery should raise suspicion about the possibility of an associated bone deficit. Ninety-five percent of the experts agreed that 3-dimensional (3D) computed tomography (CT) is the most accurate diagnostic method to evaluate and quantify bone loss. Eighty-six percent of the experts agreed that any of the available methods to measure glenoid bone deficiency is adequate; however, 91% of the experts thought that an en face view of the glenoid using 3D CT provides the most accurate method. Ninety-five percent of the experts agreed that Hill-Sachs lesions are poorly quantified and classified by current imaging systems. Ninety percent of the experts agreed that in cases with a glenoid bone deficit greater than 20%, glenoid bone graft reconstruction should be performed and any of the available options is valid. There was no consensus among experts on how Hill-Sachs injuries should be managed or on how postoperative rehabilitation should be carried out.

CONCLUSIONS

The essential statements on which the experts reached consensus included the following: A history of multiple dislocations and failed soft-tissue surgery should make surgeons consider the possibility of an associated bone deficit. Three-dimensional CT is the most accurate diagnostic method to evaluate and quantify bone loss. Although any of the available methods to measure glenoid bone deficiency is adequate, an en face view of the glenoid using 3D CT provides the most accurate method. Hill-Sachs lesions are poorly quantified and classified by current imaging systems. Finally, in cases with a glenoid bone deficit greater than 20%, glenoid bone graft reconstruction should be performed.

LEVEL OF EVIDENCE

Level V, consensus statement.

Arthroscopic Bankart Repair Versus Immobilization for First Episode of Anterior Shoulder Dislocation Before the Age of 25: A Randomized Controlled Trial

BACKGROUND

The risk of recurrence after the first episode of anterior shoulder dislocation is high with nonoperative treatment in younger patients.

PURPOSE/HYPOTHESIS

The aim of this study was to compare the results of arthroscopic Bankart repair and nonoperative treatment for shoulder dislocation in patients younger than 25 years, with a minimum of 2 years of follow-up. The hypothesis was that surgery would decrease the risk of recurrence.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

We included patients aged between 18 and 25 years after a first episode of anterior shoulder dislocation and divided them into 2 groups. The first group was treated surgically with an arthroscopic Bankart repair within 2 weeks after the dislocation; the second group was treated nonoperatively. Both groups were immobilized for 3 weeks in internal rotation and followed the same physical therapy protocol. Standard radiography and computed tomography were performed immediately after reduction of the dislocation, and follow-up was performed at 3, 6, 12, and 24 months. The primary outcome measure was instability recurrence, defined as another anterior shoulder dislocation requiring closed reduction by another person (the patient was unable to reduce the dislocated joint themselves), a subluxation, or a positive apprehension test. Secondary outcome measures included range of motion, return to sport, and functional scores such as the short version of the Disabilities of the Arm, Shoulder and Hand score the Walch-Duplay score, and the Western Ontario Shoulder Instability Index (WOSI).

RESULTS

A total of 20 patients were included in each group. The mean ± SD age was 21 ± 1.8 years, and there were 33 men (82.5%) and 7 women (17.5%) in the total sample. Recurrence of instability was significantly decreased in the surgical treatment group compared with the nonoperative group (2 [10%] vs 14 [70%], respectively; P = .0001). Fewer patients in the surgical treatment group versus the nonoperative group had another episode of dislocation (0 vs 6 [30%], respectively), subluxation (2 [10%] vs 13 [65%], respectively; P = .003), or a positive apprehension test (1 [5%] vs 11 [58%], respectively; P = .0005). The Walch-Duplay score (88.4 vs 70.3 points; P = .046) and WOSI (11.5 vs 17.7 points; P = .035) were significantly better in the surgical group versus the nonoperative group after a 2-year follow-up. Level of sport was the same or better in 89% of the surgical treatment group vs 53% of the nonoperative treatment group (P = .012). No surgical complication was recorded. We did not find any significant difference in range of motion.

CONCLUSION

In patients with first-time shoulder dislocations, arthroscopic labral repair (Bankart procedure) reduced the risk of secondary shoulder dislocation and improved functional outcome versus nonoperative treatment after a 2-year follow-up. Surgical treatment after a first episode of shoulder dislocation could be offered as a primary treatment option in a younger population if these results are confirmed by larger studies with a longer follow-up.

REGISTRATION

NCT03315819 (ClinicalTrials.gov identifier).

Determining On-/Off-track Lesions in Glenohumeral Dislocation Using Multiplanar Reconstruction Computed Tomography Is Easier and More Reproducible Than Using 3-dimensional Computed Tomography

BACKGROUND

The glenoid track is a useful tool to predict engagement and therefore the risk of recurrence of dislocation in the presence of Hill-Sachs and/or bony Bankart lesions. To assess the glenoid track preoperatively, only methods using 3-dimensional reconstruction (3DR) have been described, but these lack a standardized, reliable, and easy description.

PURPOSE/HYPOTHESIS

The purpose was to evaluate a new method for determining the glenoid track using computed tomography (CT) scan with multiplanar reconstruction (MPR) in comparison with using 3DR images. Our hypothesis was that the MPR method would be easier to standardize and more reproducible.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

A total of 52 patients whose arthro-CT scan revealed a Hill-Sachs lesion, whether in combination with a bony Bankart lesion or not, were included. Digital Imaging and Communications in Medicine data from the 52 CT scans were all analyzed using open source image analysis software. Glenoid width, with or without associated bony defect, and the Hill-Sachs interval (HSI) were measured on MPR as well as on 3DR images. All measurements obtained using both methods were directly compared and evaluated for intra- and interobserver reliability.

RESULTS

In absolute values, only small differences were seen between the MPR and 3DR methods, amounting to a maximal difference of 0.07 cm for the HSI and 0.04 cm for the glenoid width. For glenoid measurements, both methods were similar. For humeral measurements, the MPR method demonstrated higher inter- and intraobserver reliability than did the 3DR method.

CONCLUSION

The newly described MPR method for the assessment of the glenoid track and HSI is at least as accurate as the published 3DR method, with better intra- and interobserver reliability. Because MPRs are also easier to obtain, this method could be recommended in daily practice.

Accuracy and Reliability of Imaging Modalities for the Diagnosis and Quantification of Hill-Sachs Lesions: A Systematic Review

PURPOSE

To determine the reliability and accuracy of different imaging modalities in assessing Hill-Sachs lesions within the setting of anterior shoulder instability.

METHODS

A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines using the PubMed, Scopus, Embase, and Cochrane Library databases. The inclusion criteria were clinical trials or cadaveric studies that assessed the accuracy of humeral head bone loss imaging or reliability and English-language articles. The exclusion criteria were animal studies; imaging studies without measures of accuracy, reliability, or clinical predictive power; studies of shoulder injuries without humeral head bone loss; editorials; abstracts; reviews; case reports; and surveys. The search terms included "imaging" OR "radiographic" OR "CT" OR "MRI" AND "Hill-Sachs" OR "humeral head bone loss." Assessment of the methodologic quality of the included studies was performed using the original Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool.

RESULTS

Forty studies (2,560 shoulders) met the inclusion criteria and were assessed. For diagnosing the presence of Hill-Sachs lesions, computed tomography (CT) arthrography had the highest reported accuracy (median, 91%; range, 66%-100%). For the same assessment, CT arthrography also had the greatest reported sensitivity (median, 94%; range, 50%-100%). For the quantification of Hill-Sachs lesion parameters, reported intraobserver reliabilities were highest for 3-dimensional (3D) CT (intraclass correlation coefficient [ICC] range, 0.916-0.999), followed by 2-dimensional CT (ICC range, 0.858-0.861) and magnetic resonance imaging (MRI) (ICC range, 0.28-0.97). For the same quantification parameters, interobserver reliabilities were also reported for 3D CT (ICC range, 0.772-0.996), 2-dimensional CT (ICC range, 0.721-0.879), and MRI (κ range, 0.444-0.700). Intraobserver reliabilities for determining glenoid tracking were only reported for 3D CT (κ range, 0.730-1.00; ICC range, 0.803-0.901) and MRI (ICC range, 0.770-0.790).

CONCLUSIONS

This study shows that the current literature supports a variety of different imaging modalities that provide clinically acceptable accuracy in diagnosing and quantifying Hill-Sachs lesions, as well as determining whether they will cause persistent anterior shoulder instability. Furthermore, this systematic review justifies that further research is needed to help develop a treatment algorithm on the proper imaging modalities needed to help treat patients with anterior shoulder instability that is both reliable and financially acceptable.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I through IV studies.

Clinical and radiological examination of bony-mediated shoulder instability

The coexistence of glenoid and humeral head bone defects may increase the risk of recurrence of instability after soft tissue repair.

Revealed factors in medical history such as male gender, younger age of dislocation, an increasing number of dislocations, contact sports, and manual work or epilepsy may increase the recurrence rate of instability.

In physical examination, positive bony apprehension test, catching and crepitations in shoulder movement may suggest osseous deficiency.

Anteroposterior and axial views allow for the detection of particular bony lesions in patients with recurrent anterior shoulder instability.

Computed Tomography (CT) with multiplanar reconstruction (MPR) and various types of 3D rendering in 2D (quasi-3D-CT) and 3D (true-3D-CT) space allows not only detection of glenoid and humeral bone defects but most of all their quantification and relations (engaging/not-engaging and on-track/off-track) in the context of bipolar lesion.

Magnetic resonance imaging (MRI) is increasingly developing and can provide an equally accurate measurement tool for bone assessment, avoiding radiation exposure for the patient.

Cite this article: EFORT Open Rev 2020;5:815-827. DOI: 10.1302/2058-5241.5.200049

Evaluation of the Glenoid Track Tomographic Method in Magnetic Resonance Imaging/Arthro-MRI

Objective  To evaluate and compare the glenoid track method in 3D-reconstructed computed tomography (3D-CT) scans with magnetic resonance imaging (MRI) and/or arthro-MRI.

Methods  Forty-four shoulders with clinical and radiographic diagnosis of traumatic anterior instability were assessed using 3D-CT, MRI, and/or arthro-MRI scans. Glenoid track (GT), Hill-Sachs interval (HSI), and glenoid bone loss (GBL) were determined by a radiologist using 3D-CT images, and classified as on-track/off-track. Three surgeons, blinded to the radiologist's evaluation, performed the same determinations using MRI/arthro-MRI. Descriptive analysis, variance analysis, results disagreement analysis, and receiver operating characteristic (ROC) curves were performed.

Results  Results from the 4 examiners were fully consistent in 61.4% of the cases. Magnetic resonance imaging/arthro-MRI diagnosed off-track injuries with 35 to 65% sensitivity and on-track injuries, with 91.67 to 95.83% specificity. Accuracy ranged from 68.1 to 79.5%. The greatest data divergence occurred for off-track injuries diagnosed by MRI/arthro-MRI. The greatest data variability referred to HSI calculation. Higher HSI and GBL values were associated with greater disagreement among examiners. Hill-Sachs interval values were lower at MRI/arthro-MRI when compared to 3D-CT. Agreement between CT and MRI/arthro-MRI for the GT method was only moderate (kappa value, 0.325–0.579).

Conclusion  Magnetic resonance imaging/arthro-MRI showed low accuracy and moderate agreement for the GT method; as such, it should be used with caution by surgeons.

Outcomes of arthroscopic capsulolabral reconstruction for anterior instability with greater than 20% glenoid bone defects: are Latarjet procedures absolutely indicated for these patients?

Background

Recent studies have reported high rates of recurrence of shoulder instability in patients with glenoid bone defects greater than 20% after capsulolabral reconstruction. The purpose of the present study was to evaluate the failure rate of arthroscopic capsulolabral reconstruction for the treatment of anterior instability in the presence of glenoid bone deficits >20%.

Methods

Retrospective analyses were conducted among cases with anterior shoulder instability and glenoid bone defects of >20% that were treated by arthroscopic capsulolabral reconstruction with a minimum 2-year follow-up (30 cases). We included the following variables: age, bone defect size, instability severity index score (ISIS), on-/off-track assessment, incidence recurrent instability, and return to sports.

Results

The mean glenoid bone defect size was 25.8%±4.2% (range, 20.4%–37.2%), and 18 cases (60%) had defects of >25%. Bony Bankart lesions were identified in 11 cases (36.7%). Eleven cases (36.7%) had ISIS scores >6 points and 21 cases (70%) had off-track lesions. No cases of recurrent instability were identified over a mean follow-up of 39.9 months (range, 24–86 months), but a sense of subluxation was reported by three patients. Return to sports at the preinjury level was possible in 24 cases (80%), and the average satisfaction rating was 92%.

Conclusions

Arthroscopic soft tissue reconstruction was successful for treating anterior shoulder instability among patients with glenoid bone defects >20%, even enabling return to sports. Future studies should focus on determining the range of bone defect sizes that can be successfully managed by soft tissue repair.

A retrospective cohort analysis of arthroscopic Bankart repair with or without remplissage in patients with off-track Hill-Sachs lesion evaluated for functional outcomes, recurrent instability, and range of motion

BACKGROUND

Lone Bankart repair is associated with high rates of recurrence, especially in off-track Hill-Sachs (HS) lesion. The objective of the study was to assess the impact of remplissage in off-track HS lesion influencing the rate of redislocation and range of motion (ROM) of the shoulder.

MATERIAL AND METHOD

We retrospectively reviewed 136 patients for arthroscopic Bankart repair without remplissage (group 1, n = 77) or with remplissage (group 2, n =59) for recurrent anterior dislocation of the shoulder with glenoid bone loss of <25%. Further subgroups of on- and off-track HS lesion were based on computed tomographic assessment. At a minimum follow-up of 2 years; patients were evaluated for functional scores (Rowe, Constant-Murley, Western Ontario Shoulder Instability Index), redislocations, and ROM.

RESULTS

At a mean follow-up of 54 and 44 months in group 1 and 2, respectively, there was no difference in postoperative functional scores. There were significantly more dislocations in patients with Bankart repair with off-track lesion than in patients with Bankart repair with on-track lesion (P = .02). There were significantly fewer redislocations in patients with off-track lesion who underwent Bankart repair and remplissage than in those who did not undergo remplissage (P = .0007). Compared with group 1 patients, those in group 2 revealed a statistically significant loss of ROM.

CONCLUSIONS

Although a nonremplissaged off-track HS lesion remains an important risk factor for recurrent instability, remplissage also results in significant loss of shoulder ROM compared with those who do not undergo remplissage.

Editorial Commentary: Methodology of Measuring Bone Loss in Recurrent Shoulder Instability Surgery: Traditional Computed Tomography Scan and Magnetic Resonance Imaging Do Not Tell the Full Story

When measuring bone loss in recurrent shoulder instability, both computed tomography (CT) scan and magnetic resonance imaging (MRI) are accurate using the circle method. However, measurement of on- versus off-track lesions can be inconsistent, and measuring Hill-Sachs lesions on MRI relative to an extrapolated rotator cuff attachment is difficult. In the end, determination of on- versus off-track treatment is quite difficult, and for this determination, differences between CT scan and MRI may be clinically imperceptible. Thus, for now, we, and we believe, other surgeons will continue to stick with the circle technique when determining individual patient treatment for recurrent shoulder instability.

Does Bone Loss Imaging Modality, Measurement Methodology, and Interobserver Reliability Alter Treatment in Glenohumeral Instability?

PURPOSE

To determine, in the context of measuring bone loss in shoulder instability, whether measurement differences between magnetic resonance imaging (MRI) and computed tomography (CT), linear-based and area-based methods, and observers altered the proposed treatment when a standardized algorithm was applied.

METHODS

This was a retrospective, comparative imaging study of preoperative patients with anterior shoulder instability with both an MRI and CT scan within 1 year of one another. On parasagittal images reoriented en face to the glenoid, 2 attending orthopaedic surgeons measured glenoid width, glenoid area, glenoid defect width, and glenoid defect area. On axial images maximal Hill-Sachs width was measured. From these, linear percent glenoid bone loss (%GBL) and area %GBL were calculated, and on-versus off-track was determined. With these results, a recommended treatment was determined by applying a standardized algorithm, in which the Latarjet procedure was selected for %GBL >20%, arthroscopic labral repair and remplissage for off-track lesions with %GBL <20%, and arthroscopic labral repair on-track shoulders with %GBL <20%.

RESULTS

In total, 53 patients with mean ± standard deviation 45 ± 83 days between scans were include with a CT linear %GBL of 23.5 ± 9.6% (range 0%-47%). CT lead to larger measurements of %GBL than MRI (linear P = .008, area P = .003), and fewer shoulders being considered on-track (33.0% vs 40.5%), which would alter treatment in 25% to 34%. Linear measurements produced larger values for %GBL (CT, P < .001; MRI, P < .001), which would alter treatment in 25%. For %GBL, inter-rater reliability was good, with intraclass correlation coefficients varying from 0.727 to 0.832 and Kappa varying from 0.57 to 0.62, but these inter-rater differences would alter treatment in 31%.

CONCLUSIONS

The significant differences in bone loss measurement between imaging modality, measurement method, and observers may lead to differences in treatment in up to 34% of cases. Linear CT measurements resulted in the most aggressive treatment recommendations.

LEVEL OF EVIDENCE

Retrospective Comparative Study: Diagnostic, Level III.

Previous arthroscopic Bankart repair is an independent risk factor for an inferior outcome after Latarjet procedure

BACKGROUND

There is limited evidence that the Latarjet procedure has a worse outcome as a revision operation, after a failed stabilization surgery, compared with when it is the primary procedure for posttraumatic anteroinferior instability of the shoulder joint.

PURPOSE

To compare the results from Latarjet as a primary operation vs. revision surgery after a failed arthroscopic Bankart repair for posttraumatic anteroinferior shoulder instability. In addition, to assess the effect of preoperative bony pathology on outcome.

PATIENTS AND METHODS

Ninety-nine patients who underwent the Latarjet procedure (47 primary, 52 revision after failed Bankart repair) were analyzed after an average of 3.8 (SD 2.3, range 1-11) years of follow-up. All patients underwent either computed tomography or magnetic resonance imaging preoperatively. Glenoid and humeral bone defects were measured to assess whether the Hill-Sachs lesion was on- or off-track. Clinical outcome measures included the Western Ontario Shoulder Instability Index (WOSI), subjective shoulder value (SSV), and recurrence of instability (dislocation, subluxation, or any perception of instability).

RESULTS

There were no cases of recurrent dislocation in either group. Four patients in the primary surgery group and 13 in the revision group had at least one subluxation or perception of instability after the Latarjet procedure. Patients with a previous arthroscopic Bankart repair had worse outcomes than those undergoing primary Latarjet when assessed by the WOSI: 76 (SD 22) vs. 85 (SD 15), difference in means -9 (95% CI -17 to -1, p=0.02); SSV: 80 (SD 18) vs. 88 (SD 13), difference in means -8 (95% CI -15 to -2, p=0.01); and the recurrence percentage (25% vs. 9%, p=0.03). A multivariate linear regression model adjusted for the length of follow-up, glenoid bone defect size, Hill-Sachs lesion size, and the frequency of preoperative bipolar bone defects (on/off track Hill-Sachs lesions) further increased the difference in WOSI to -12 (95% CI -21 to -4, p=0.005).

DISCUSSION

A previous failed arthroscopic Bankart repair was a significant independent risk factor for inferior outcome. Preoperative bony pathology did not explain the worse outcome from the revision vs. primary Latarjet procedure.

LEVEL OF EVIDENCE

IV, cohort observational study.

Off-track Hill-Sachs lesions do not increase postoperative recurrent instability after arthroscopic Bankart repair with selective Remplissage procedure

PURPOSE

This study aimed to compare clinical outcomes and recurrence rates after arthroscopic Bankart repair with selective Remplissage procedure, between patients with off-track and on-track Hill-Sachs lesions.

METHODS

Patients who underwent arthroscopic Bankart repair with selective Remplissage procedure for recurrent anterior shoulder instability and were followed up for at least 2 years were included. Patients with a glenoid defect greater than 25% were excluded. According to the glenoid track concept, patients were divided into group I (off-track lesions) and group II (on-track lesions). After Bankart repair, an additional Remplissage procedure was performed selectively in patients who sustained engagement of the humeral head. The clinical outcomes and recurrence rates were evaluated.

RESULTS

A total of 193 patients (23 in group I and 170 in group II) were enrolled. No significant differences were found in clinical outcomes (n.s.) or recurrence rates (n.s.) between the two groups, despite larger glenoid defects in group I (group I:17.1 ± 6.1%, and group II:13.0 ± 6.4%, P = 0.003). In all patients, the incidence of off-track lesions was not significantly different according to the occurrence of postoperative recurrence (n.s.), whereas the glenoid defect size showed a significant difference (with recurrence: 17.9 ± 3.9%, and without recurrence: 13.2 ± 6.5%, P = 0.002).

CONCLUSIONS

The presence of an off-track lesion did not alter the clinical outcomes and recurrence rates after arthroscopic Bankart repair with selective Remplissage procedure. The glenoid defect size rather than the presence of an off-track lesion can more reliably predict postoperative recurrence. Arthroscopic Bankart repair with selective Remplissage procedure is considered one surgical option for the treatment of off-track lesions.

LEVEL OF EVIDENCE

III.

The medico-legal assessment of aesthetic damage. A correlation analysis between experts and an operative proposal

Aesthetic damage, defined as any detrimental modification of the individual morpho-functional exterior attributes, is difficult to assess, since the perception of its entity is rather subjective. This study aims to provide a medico-legal contribution to the assessment of this kind of damage. 60 photographic images, representing stabilized aesthetic damage, were collected and showed to 16 expert evaluators, who were required to exclusively quantify the objective component of the aesthetic impairment. The inter-observer agreement for the assessments was calculated using the Intraclass Correlation Coefficient (ICC). Looking into specific characteristics of both the injury and the damaged subject, the assessors were more consistent in quantifying the damage in male subjects (ICC 0.68) and in subjects aged over 50 years (ICC 0.81) as well as in assessing extensive damages (ICC 0.61) than those of mild severity (ICC 0.41). The assessment of impairments located in the facial area resulted in a high level of concordance (ICC 0.73), while damages located the head and neck regions presented the lowest concordance (ICC 0.35). The evaluators were more consistent in assessing the outcomes of burns (ICC 0.70). Regardless the various reasons underlying the different degree of concordance, these results and the high degree of the overall concordance (ICC 0.63) point out the skillfulness of medicolegal professionals to formulate a complex judgment as more objectively as possible. Finally, an operative proposal was outlined to guide medico-legal professionals or interns in evaluating the aesthetic damage as more objectively as possible.

Hill-Sachs Lesion Classification by the Glenoid Track Paradigm in Shoulder Instability: Poor Agreement Between 3-Dimensional Computed Tomographic and Arthroscopic Methods

PURPOSE

The purpose of this study was to determine the amount of agreement between preoperative 3-dimensional computed tomographic (3D-CT) and intraoperative arthroscopic classification of Hill-Sachs lesions (HSLs) according to the glenoid track (GT) paradigm.

METHODS

Records for patients treated surgically for anterior shoulder instability from a single surgeon's practice from August 2013 until March 2016 were retrospectively reviewed. Inclusion criteria were presence of an HSL, < 25% glenoid bone loss, bilateral 3D-CT, and arthroscopically recorded bone loss measurements. Records for patients with chronic dislocations or prior operations were excluded. Calculations by 3D-CT and arthroscopy were performed as follows: Hill-Sachs interval (HSI) was the distance from rotator cuff insertion to medial edge of the HSL; GT was 83% of the normal glenoid width minus any glenoid defect; on-track was HSI less than GT; off-track was HSI greater than GT.

RESULTS

Sixteen shoulders with HSL status determined as on- or off-track demonstrated agreement between the 2 methods in 10 of 16 cases (63%, Cohen's κ = 0.16). All 6 cases with disagreement were calculated as on-track by 3D-CT and off-track by arthroscopic measurement. The GT was larger as determined by 3D-CT measurement (22 ± 1 mm [21-24]) compared with arthroscopy (18 ± 1 mm [17-20], P = .002).

CONCLUSIONS

Preoperative 3D-CT showed slight agreement compared with intraoperative arthroscopic measurements in classifying HSL as on-track versus off-track in the GT paradigm; larger GT size by 3D-CT versus arthroscopy accounted for all discrepancies. Determination of off-track status based on preoperative 3D-CT versus determination with the arthroscopic method would result in fewer HSLs treated with remplissage if the GT treatment paradigm were followed. Surgeons using the GT paradigm to determine treatment of HSL by remplissage should recognize the potential for discordance between arthroscopic and radiographic measurements.

How to measure a Hill-Sachs lesion: a systematic review

Quantifying bone loss is important to decide the best treatment for patients with recurrent anterior glenohumeral instability. Currently, there is no standard method available to make a precise evaluation of the Hill–Sachs lesion and predict its engagement before the surgical procedure. This literature review was performed in order to identify existing published imaging methods quantifying humeral head bone loss in Hill–Sachs lesions.

Searches were undertaken in Scopus and PubMed databases from January 2008 until February 2018. The search terms were “Hill-Sachs” and “measurement” for the initial search and “Hill–Sachs bone loss” for the second, to be present in the keywords, abstracts and title. All articles that presented a method for quantifying measurement of Hill–Sachs lesions were analysed.

Several methods are currently available to evaluate Hill–Sachs lesions. The length, width and depth measurements on CT scans show strong inter and intra-observer correlation coefficients. Three-dimensional CT is helpful for evaluation of bony injuries; however, there were no significant differences between 3D CT and 3D MRI measurements. The on-track off-track method using MRI allows a simultaneous evaluation of the Hill–Sachs and glenoid bone loss and also predicts the engaging lesions with good accuracy.

Cite this article: EFORT Open Rev 2019;4:151-157. DOI: 10.1302/2058-5241.4.180031

Arthroscopic Remplissage for Anterior Shoulder Instability: A Systematic Review of Clinical and Biomechanical Studies

PURPOSE

To examine the clinical outcomes and biomechanical data supporting the use of the remplissage procedure.

METHODS

A query of the Embase, PubMed, Scopus, and Web of Science databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines from 2000 to 2017. Data were extracted from included studies for a qualitative review of both clinical and biomechanical outcomes.

RESULTS

After review, 18 clinical and 10 biomechanical studies were available for analysis; 10 of 18 clinical studies (55.6%) were Level IV evidence. Within the clinical studies, there were 567 patients (570 shoulders) evaluated with follow-up ranging from 6 to 180 months. Overall, 5.8% of shoulders (33 of 570) displayed recurrent instability after arthroscopic remplissage. Of the shoulders with recurrent instability, 42.4% of shoulders (14 of 33) underwent further surgical management. In all studies evaluating pre- and postoperative patient-reported outcomes, the arthroscopic remplissage procedure improved patient-reported outcomes a statistically significant amount postoperatively. Within individual clinical studies, external rotation with the arm in neutral was the most consistently limited range of motion (ROM) parameter, with deficits compared with the contralateral shoulder ranging from 9° to 14°. Biomechanical analysis appeared to corroborate the clinical results, although significant conclusions were limited by heterogeneity of reporting.

CONCLUSIONS

Arthroscopic remplissage performed in conjunction with arthroscopic Bankart repair is a safe and effective procedure for patients with engaging Hill-Sachs lesions and subcritical glenoid bone loss. Although both the included clinical and biomechanical studies would suggest minimal changes in glenohumeral ROM following the remplissage procedure, strong conclusions are limited by the heterogeneity in reporting ROM data and lack of comparative studies.

LEVEL OF EVIDENCE

IV, systematic review.

The relationship between the glenoid track and the range of shoulder motion: A cadaver study

INTRODUCTION

The concept of the glenoid track has been proposed to evaluate the risk of dislocation. The glenoid track width was demonstrated to be 84% of the glenoid width in cadaveric shoulders and 83% in live shoulders.

HYPOTHESIS

The glenoid track width seems to be affected by the range of motion.

PURPOSE

The purpose of this study was to determine the relationship between the glenoid track and the range of shoulder motion.

METHODS

Ten fresh-frozen cadaveric shoulders were used. The specimen was fixed to a shoulder-positioning device. The anterior rim of the glenoid was marked on the humeral head using a Kirschner wire with the arm in 60° of abduction. This marking was repeated with the arm in (1) horizontal flexion/extension and (2) internal/external rotations (0° to max). The distances from the Kirschner wire markings to the footprint of the rotator cuff tendon were measured.

RESULTS

The greater the angle of the horizontal extension or external rotation, the smaller the glenoid track width, whereas the greater the angle of the horizontal flexion or internal rotation, the greater the glenoid track width. There was a negative relationship between them. The horizontal flexion/extension motion was demonstrated to affect the glenoid track width more than the internal/external rotation motion.

CONCLUSION

The glenoid track width decreased with the increase of horizontal extension. We should consider the range of horizontal extension angle when applying the glenoid track concept in clinical practice.

TYPE OF STUDY

Laboratory study.

Using the "Hill-Sachs interval to glenoid track width ratio" for prediction of recurrent instability after arthroscopic Bankart repair

INTRODUCTION

The glenoid track concept was used to confirm the engaging Hill-Sachs lesion (HSL) as a risk factor for recurrent instability following arthroscopic Bankart repair (ABR). However, the post-operative condition of soft tissue in vivo was not comparable to that designed in the intact condition in vitro in the original study of the glenoid track concept. Herein, the possibility of engagement may be underestimated.

HYPOTHESIS

A threshold of the Hill-Sachs interval to glenoid track width ratio (H/G ratio) that is related to recurrent instability after ABR could be found, in order to adjust the original glenoid track concept.

PATIENTS AND METHODS

Patients who underwent ABR with minimum 24-months follow-up were reviewed retrospectively. The primary outcome was evaluated with the recurrent instability. The H/G ratio of individual patients was used to calculate the sensitivity, specificity, and a receiver operating characteristic (ROC) curve, which aimed to establish a H/G ratio threshold related to recurrent instability after ABR.

RESULTS

From June 2005 to December 2013, 160 patients with a mean age of 27.7years were enrolled. The mean follow-up period was 77.2 months. The ROC curve indicated that H/G ratio≥0.7 had the sensitivity and specificity of 0.74 and 0.71, respectively, in predicting recurrent instability. On univariate logistic regression analysis, the H/G ratio≥0.7 was a significant predictor of higher risk for recurrent instability (p<0.001).

DISCUSSION

H/G ratio seems to be a reliable parameter for predicting recurrent instability. H/G ratio≥0.7 may be considered as a positive predictor for recurrent instability after ABR.

LEVEL OF EVIDENCE

Level IV: retrospective diagnostic study.

The Incidence of Glenohumeral Bone and Cartilage Lesions at the Time of Anterior Shoulder Stabilization Surgery: A Comparison of Patients Undergoing Primary and Revision Surgery

BACKGROUND

Intra-articular glenohumeral joint changes frequently occur after shoulder instability events.

PURPOSE

(1) To compare demographic characteristics, baseline patient-reported outcomes, and intraoperative findings for patients undergoing primary or revision shoulder stabilization surgery and (2) to determine the incidence of glenohumeral bone and cartilage lesions in this population while identifying factors independently associated with these lesions.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

The Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Group shoulder instability database was used to identify all prospectively enrolled patients undergoing shoulder stabilization surgery for anterior instability between October 2012 and September 2016. Any patient who underwent surgery for posterior or multidirectional shoulder instability or concomitant rotator cuff repair surgery was excluded. Patient demographic characteristics, preoperative patient-reported outcomes, and intraoperative findings, including glenohumeral bone and cartilage lesions, were compared for patients undergoing primary and revision shoulder stabilization surgery. Additionally, patients with and without glenohumeral bone and cartilage lesions were compared and independent associations determined using multivariate analysis.

RESULTS

There were 545 patients available for analysis (461/545 [84.6%] primary; 84/545 [15.4%] revision). Patients undergoing revision surgery were older ( P = .001), were more frequently smokers ( P = .022), had a greater number of instability events before surgery ( P = .047), more frequently required reduction assistance ( P < .001), and had lower Short Form-36 (SF-36) Mental Component Summary ( P = .020) and Western Ontario Shoulder Instability Index (WOSI) ( P = .026) scores preoperatively. Additionally, patients undergoing revision surgery had a higher frequency of bone and cartilage lesions than those undergoing primary surgery (47.6% vs 18.4%, respectively; P < .001). Male sex, revision surgery, black race, increasing body mass index, increasing patient age, and lower preoperative SF-36 Physical Component Summary score were independently associated with the presence of glenohumeral bone and cartilage lesions at the time of shoulder stabilization surgery. Revision surgery was strongly associated with the presence of glenohumeral bone and cartilage lesions (odds ratio [OR], 4.381 [95% CI, 2.591-7.406]) and glenoid bone loss greater than 10% (OR, 9.643 [95% CI, 5.128-18.134]) or 20% (OR, 13.076 [95% CI, 5.113-33.438]) of the glenoid width.

CONCLUSION

Glenohumeral bone and cartilage lesions are common at the time of shoulder stabilization surgery, occurring more frequently in patients undergoing revision surgery as compared with primary surgery. On the basis of these findings, future prospective studies should aim to compare the clinical outcomes in these 2 groups.

Understanding the Hill-Sachs Lesion in Its Role in Patients with Recurrent Anterior Shoulder Instability

PURPOSE OF REVIEW

The purpose of this study is to provide an update to the orthopedic field in regard to treatment of the Hill-Sachs lesion and anterior shoulder instability. The review highlights the most current knowledge of epidemiology, clinical evaluation, and surgical methods used to treat Hill-Sachs lesions. It also details the relevant clinical and surgical findings that have been made throughout the literature in the past couple of years.

RECENT FINDINGS

The most recent literature covering the Hill-Sachs lesion has focused on the relatively new and unexplored topic of the importance of concomitant injuries while treating a humeral head defect. The glenoid track concept has been clinically validated as a method to predict engagement. 3D-CT has become the "gold standard" for Hill-Sachs imaging; however, it has been noted that 3D-MRI produces results that are not significantly different from CT. Also, it has been found that when the arm is in a position of abduction during the primary injury, there is a higher risk of engagement and subsequent dislocation. Recent studies have demonstrated successful results stemming from purely arthroscopic procedures in treating Hill-Sachs lesions. Anterior shoulder instability, specifically the Hill-Sachs lesion, is an area of orthopedic study that is highly active and constantly producing new studies in an attempt of gaining the best outcomes for patients. The past few years have yielded many excellent discoveries, but there is still much more work to be done in order to fully understand the role of the Hill-Sachs lesion in anterior shoulder instability.

The glenoid track: a review of the clinical relevance, method of calculation and current evidence behind this method

In the setting of bipolar bone injury, orthopedic surgeons are currently making use of the glenoid track method to guide surgical management. Using preoperative CT or MR imaging, this method allows the identification of patients who are more likely to fail a primary capsuloligamentous Bankart repair. As the glenoid track method becomes increasingly used in preoperative planning, it is important for the radiologist to become familiar with its concept and method of calculation. This review article aims to concisely summarize the current literature and the clinical implications of the glenoid track method.

Indication for Computed Tomography Scan in Shoulder Instability: Sensitivity and Specificity of Standard Radiographs to Predict Bone Defects After Traumatic Anterior Glenohumeral Instability

Background:

Quantifying glenohumeral bone loss is key in preoperative surgical planning for a successful Bankart repair.

Hypothesis:

Simple radiographs can accurately measure bone defects in cases of recurrent shoulder instability.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

A true anteroposterior (AP) view, alone and in combination with an axillary view, was used to evaluate the diagnostic properties of radiographs compared with computed tomography (CT) scan, the current gold standard, to predict significant bone defects in 70 patients. Sensitivity, specificity, and positive and negative predictive values were evaluated and compared.

Results:

Detection of glenoid bone loss on plain film radiographs, with and without axillary view, had a sensitivity of 86% for both views and a specificity of 73% and 64% with and without the axillary view, respectively. For detection of humeral bone loss, the sensitivity was 8% and 17% and the specificity was 98% and 91% with and without the axillary view, respectively. Regular radiographs would have missed 1 instance of significant bone loss on the glenoid side and 20 on the humeral side. Interobserver reliabilities were moderate for glenoid detection (κ = 0.473-0.503) and poor for the humeral side (κ = 0.278-0.336).

Conclusion:

Regular radiographs showed suboptimal sensitivity, specificity, and reliability. Therefore, CT scan should be considered in the treatment algorithm for accurate quantification of bone loss to prevent high rates of recurrent instability.

Applying the Glenoid Track Concept in the Management of Patients with Anterior Shoulder Instability

PURPOSE OF REVIEW

The purpose of this paper is to evaluate the recent evolution in the treatment of anterior shoulder instability and the dynamic interaction between the glenoid and Hill-Sachs lesion.

RECENT FINDINGS

Through the glenoid track concept, glenoid- and humeral-sided bone loss are evolving away from being approached as separate entities. Recent cadaveric studies have validated the glenoid track concept. Moreover, a recent clinical study has demonstrated a much higher rate of failure after arthroscopic Bankart repair for shoulders that were off track. The glenoid track concept is a useful tool in evaluating patients with anterior shoulder instability. Shoulders that are off track may require more than a simple arthroscopic Bankart, and the addition of a remplissage or bony transfer may be considered.

Bipolar Bone Loss in Patients With Anterior Shoulder Dislocation: A Comparison of Adolescents Versus Adult Patients

PURPOSE

To compare bipolar bone loss by evaluating the degree of glenoid bone loss, Hill-Sachs lesion size, and glenoid track in adolescents and adults with shoulder dislocations.

METHODS

We performed a retrospective review between 2012 and 2016 of surgical and nonsurgical patients with a history of anterior shoulder dislocations (primary or recurrent) who underwent magnetic resonance imaging of the affected shoulder. The exclusion criteria included multidirectional instability, prior surgery, and posterior dislocation. Patients were grouped into 2 groups: adolescents (aged 10-19 years) and adults (aged ≥20 years). The groups were compared regarding measures of glenoid bone loss (best-fit circle technique) and Hill-Sachs lesion size (medial margin of rotator cuff footprint to medial margin of Hill-Sachs lesion). If the medial margin of a Hill-Sachs lesion was within the glenoid track, it was defined as on track; if it was more medial than the glenoid track, it was defined as off track.

RESULTS

We identified 45 adolescents (mean age, 16.1 years) and 30 adults (mean age, 28.9 years) with anterior shoulder dislocations. There was no significant difference in percentage of bone loss between adolescents (mean, 8.4%) and adults (mean, 9.9%; P = .23). There was no significant difference in Hill-Sachs lesion size between adolescents (mean, 12.7 mm) and adults (mean, 9.9 mm; P = .12). There were 12 patients with off-track lesions. Off-track lesions were present in 11 of 45 adolescents (24.4%) and 1 of 30 adults (3.3%). Adolescents had an increased risk of having an off-track lesion (odds ratio, 9.38; 95% confidence interval, 1.14-77.1). A subgroup analysis identified multiple dislocations as an independent risk factor for an off-track lesion (odds ratio, 4.15; 95% confidence interval, 0.85-20.23).

CONCLUSIONS

This study shows that adolescence and a history of multiple dislocations are independent risk factors for a greater likelihood of glenoid off-track lesions. The findings support the use of bipolar assessment of shoulder dislocators, especially in adolescents and multiple dislocators.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.