Three-dimensional computed tomography measurement accuracy of varying Hill-Sachs lesion size

Knotless Bioabsorbable Anchors Placed on the Glenoid Face for Arthroscopic Bankart Repair

BACKGROUND

Quantitative analysis of the glenoid face knotless-type anchor placement for arthroscopic Bankart repair has not been reported.

PURPOSE

To evaluate the clinical and radiologic outcomes after arthroscopic Bankart repair using knotless bioabsorbable anchors depending on the anchor location.

STUDY DESIGN

Case series, Level of evidence, 4.

METHODS

A total of 124 patients (113 men and 11 women; age, 25.6 ± 7.5 years; follow-up time, 46.5 ± 18.2 months [range, 6.2-75.5 months]) who underwent arthroscopic Bankart repair with the bioabsorbable knotless anchor between 2017 and 2021 were included in this study. Among them, 118 patients were observed for >2 years (mean, 48.2 ± 16.8 months [range, 24-75.5 months]) and were analyzed for final clinical and radiologic outcomes. Using postoperative 6-month magnetic resonance imaging, remnant glenoid (%) and labral height were measured. Shoulder range of motion (ROM), radiographic osteoarthritic change, dislocation, apprehension test, and return to sports were recorded. Three groups were established based on the remnant glenoid, which represented the percentage of the exposed glenoid anteroposterior diameter to the original diameter using the best-fit circle method-group A: lower quartile; group B: interquartile; and group C: upper quartile-and variables were analyzed.

RESULTS

Overall, the remnant glenoid was 57% ± 6.4% (range, 41.5%-75%) after the surgery. Osteoarthritic change, dislocations, and positive apprehension tests were observed in 5 (4.2%), 4 (3.4%), and 12 (10.2%) patients, respectively. A total of 34 (28.8%) and 64 (54.2%) patients could return to sports without and with restrictions, respectively. Comparing groups A, B, and C, postoperative labral height (7 ± 1, 7 ± 2, and 7 ± 1 mm; P = .623), final osteoarthritic change (1, 4, and 0; P = .440), positive apprehension tests (5, 5, and 2; P = .387), and return to sports (complete/restricted/unable, 6/18/5, 19/29/11, 9/17/4; P = .769) were not different. All ROM were similar across the groups (all P > .054), except for external rotation (ER) at postoperative 6 months (41.3°± 12.8°; 50.2°± 18.5°; and 49.8°± 15.2°; P = .050). However, ER after 1 year was similar across the groups (all P > .544). In further analysis, patients with positive apprehension tests had lower labral height compared with others (5 [4-6] mm and 7 [6-8] mm; P < .001).

CONCLUSION

In arthroscopic Bankart repair, the placement of knotless bioabsorbable anchors on the glenoid face, combined with the remplissage procedure or rotator interval closure, resulted in a low recurrence rate and moderate return to sports. However, most patients had some restrictions in returning to sports. Moreover, this technique was not associated with postoperative arthritis and shoulder stiffness, including ER deficit, which was not affected by the position of the anchor on the glenoid face for a minimum 2-year follow-up.

Review of Burkhart and DeBeer's (2000) article on traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repair: Where have we taken the concept of glenoid bone loss in 2023?

This classic discusses the original publication by Burkhart and DeBeer "Traumatic Glenohumeral Bone Defects and Their Relationship to Failure of Arthroscopic Bankart Repair" published in 2000 in Arthroscopy. At that time, the authors sought to understand the reasons behind the failure of arthroscopic soft tissue repair. Based on their findings, the authors introduced the concept of the inverted pear glenoid and engaging Hill-Sachs lesion which is now part of the orthopedic lexicon. The importance of bony pathologic changes in anterior glenohumeral instability has become so apparent, that it now forms the basis of clinical understanding and underpins treatment algorithms. Since this publication over 20 years ago, the idea of glenohumeral bone loss has been extensively explored and refined. There is no doubt of the importance of structural bone loss yet there is still uncertainty as to the best management of those with subcritical bone loss. The purpose of revisiting this classic article is to look at where we are in understanding recurrent instability and bony deficiency while appreciating how far we have come. This review begins with a detailed summary of the classic article along with a historic perspective. Next, we look at the current evidence as it pertains to the classic article and how modern technology and innovation has advanced our ability to assess and quantify glenohumeral bone loss. We finish with expert commentary on the topic from two current surgeons with a research interest in shoulder instability to offer an insight into how modern surgeons view and address this issue. One of the original authors also reflects on the topic. The findings of this classic study changed the way we think about shoulder instability and opened the doors to an exciting body of research that is still growing today. Future research offers an opportunity for high quality evidence to guide management in the group of patients with subcritical bone loss and we eagerly await the results.

Native Glenoid Depth and Hill-Sachs Lesion Morphology in Traumatic Anterior Shoulder Instability

BACKGROUND

Although Hill-Sachs lesions (HSLs) are assumed to be influenced by glenoid characteristics in the context of bipolar bone loss, little is known about how glenoid concavity influences HSL morphology.

PURPOSE

To investigate the relationship between the native glenoid depth and HSL morphological characteristics.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Computed tomography images of bilateral shoulders from 151 consecutive patients with traumatic unilateral anterior shoulder instability were retrospectively reviewed. Patients were categorized into flat (<1 mm), moderate (1-2 mm), and deep (>2 mm) groups based on the native glenoid depth measured from the contralateral unaffected shoulder. The HSL morphological characteristics included size (depth, width, length, and volume), location (medial, superior, and inferior extent), and orientation (rim and center angle). The glenoid characteristics included diameter, depth, version, and bone loss. The patient, glenoid, and HSL morphological characteristics were compared among the 3 depth groups. Subsequently, the independent predictors of some critical HSL morphological characteristics were determined using multivariate stepwise regression.

RESULTS

After exclusion of 55 patients, a total of 96 patients were enrolled and classified into the flat group (n = 31), moderate group (n = 35), and deep group (n = 30). Compared with those in the flat group, patients in the deep group were more likely to have dislocation (38.7% vs 93.3%; P = .009) at the primary instability and had a significantly larger number of dislocations (1.1 ± 1.0 vs 2.2 ± 1.8; P = .010); moreover, patients in the deep group had significantly deeper, wider, larger volume, more medialized HSLs and higher incidences of off-track HSLs (all P≤ .025). No significant differences were detected among the 3 groups in HSL length, vertical position, and orientation (all P≥ .064). After adjustment for various radiological and patient factors in the multivariate regression model, native glenoid depth remained the strongest independent predictor for HSL depth (β = 0.346; P < .001), width (β = 0.262; P = .009), volume (β = 0.331; P = .001), and medialization (β = -0.297; P = .003).

CONCLUSION

The current study sheds light on the association between native glenoid depth and the morphology of HSLs in traumatic anterior shoulder instability. Native glenoid depth was independently and positively associated with HSL depth, width, volume, and medialization. Patients with deeper native glenoids were more likely to have off-track HSLs and thus require more attention in the process of diagnosis and treatment.

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.

ACR Appropriateness Criteria® Chronic Shoulder Pain: 2022 Update

Chronic shoulder pain is an extremely common presenting complaint. Potential pain generators include the rotator cuff tendons, biceps tendon, labrum, glenohumeral articular cartilage, acromioclavicular joint, bones, suprascapular and axillary nerves, and the joint capsule/synovium. Radiographs are typically the initial imaging study obtained in patients with chronic shoulder pain. Further imaging may often be required, with modality chosen based on patient symptoms and physical examination findings, which may lead the clinician to suspect a specific pain generator. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Open anatomical glenoid reconstruction with an iliac crest bone autograft effectively resolves off-track Hill-Sachs lesions to on-track lesions

INTRODUCTION

The purpose of this study was to determine if "off-track" Hill-Sachs lesions in patients with dynamic anteroinferior instability were transformed into "on-track" lesions using iliac bone autografts with screw fixation. The secondary purpose was to observe if postoperative bony remodeling would occur over time, resulting in recurrent "off-track" Hill-Sachs lesions with corresponding instability.

MATERIALS AND METHODS

We retrospectively reviewed clinical and CT records of 8 patients with an "off-track" Hill-Sachs lesion who underwent open anatomical glenoid reconstruction with an iliac crest bone autograft. Hill-Sachs lesions, glenoid track widths, and glenoid surface areas were measured on a preoperative and two postoperative (6 weeks, ≥ 2 years) 3D-CT models to determine graft resorption over time. All patients were available for postoperative clinical and CT final follow-up 3 years (2-4 years) postoperatively.

RESULTS

In all patients, the Hill-Sachs lesions were "on-track" 6 weeks postoperatively and remained "on-track" at final-follow-up. Compared to preoperative values, the glenoid track width and glenoid surface area both were higher 6 weeks postoperatively (p < 0.001 and p = 0.023, respectively) and at final follow-up (p < 0.001 and p = 0.023, respectively). Whereas the glenoid track width between 6 weeks and final follow-up showed no decrease (p = 0.234), glenoid surface area tended to decrease (p = 0.055). The median SSV was 93 points (85-95 points), the Rowe score 90 points (80-100 points) and the WOSI 1980 points (1783-2067 points) at final follow-up. No recurrent dislocations or subluxations were observed.

CONCLUSIONS

An open anatomical glenoid reconstruction with an iliac crest bone autograft technique using screw fixation effectively transformed "off-track" Hill-Sachs lesions to "on-track" lesions, resulting in good short-term clinical outcomes. Whereas glenoid surface area tended to be reduced by bony remodeling processes over time, the glenoid track width did not decrease at final follow-up and consequently no recurrence of "off-track" lesions occurred.

LEVEL OF EVIDENCE

Case series; Level of evidence, IV.

Localization of the ilioischial line on axial computed tomography images for preoperative planning of total hip arthroplasty

BACKGROUND

If the bony region indicating the ilioischial line is established on the preoperative axial computed tomography (CT) image, the distance between the simulated cup and the ilioischial line can be measured on this image so that the surgeon can use these data to define a more accurate preoperative two-dimensional (2D) template of total hip arthroplasty (THA). This study aimed to verify the hypothesis that on the CT axial image, the cortical bone area, indicated by the superimposition of a line (line α) with a perspective projection angle to the ilioischial line on radiography and tangent to the medial acetabular wall, is the cortical bone that represents the ilioischial line on radiography.

METHODS

Study 1: If the two measured distances (distance A' and distance B) are sufficiently equal, then the hypothesis can be supported. Distance A' was calculated by multiplying the distance A, between the ilioischial line and the medial margin of the metal cup after THA measured at the level of the hip joint center on the pelvic radiograph, by 0.91 to correct for radiographic magnification. Distance B was defined as the distance between the medial margin of the metal cup and line α on the axial CT image at the level of the hip joint center. These two distances were measured for all 51 hip joints included in the study. Study 2: The difference between distance A and distance A^# (distance A on the 2D template) was compared between the group containing 59 primary THAs in which distance B' was measured (distance B in the simulation) and the control group containing 59 primary THAs.

RESULTS

Study 1: The average distance for A' was 4.5 ± 2 mm, and the average distance for B was 4.7 ± 2.1 mm. The difference between distances A and B was 0.2 ± 0.2 mm. Study 2: The mean difference between distance A and distance A^# for the measurement and control groups was 1.8 ± 1.3 mm and 3.7 ± 2.4 mm, respectively (P < 0.001).

CONCLUSIONS

The ilioischial line is located in the bony region where line α intersects the medial acetabular wall with a maximum overlap on axial CT images.

Evaluating Bone Loss in Anterior Shoulder Instability

Anterior shoulder instability is a common orthopaedic condition that often involves damage to the bony architecture of the glenohumeral joint in addition to the capsulolabral complex. Patients with recurrent shoulder dislocations are at increased risk for glenohumeral bone loss, as each instability event leads to the accumulation of additional glenoid and/or humeral head bone defects. Depending on the degree of bone loss, successful treatment may need to address bony lesions in addition to injured soft-tissue structures. As such, a thorough understanding of methods for evaluating bone loss preoperatively, in terms of location, size, and significance, is essential. Although numerous imaging modalities can be used, three-dimensional imaging has proven particularly useful and is now an integral component of preoperative planning.

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.

Managing Bone Loss in Shoulder Instability-Techniques and Outcomes: a Scoping Review

PURPOSE OF REVIEW

The aim of this scoping review is to provide an overview of the literature published over the past 5 years related to the management of bone loss in anterior shoulder instability.

RECENT FINDINGS

During recent years, there has been a focus on patients at high risk for failure following soft tissue anterior stabilization (Bankart repair). A growing body of evidence suggests that anterior capsulolabral repair is insufficient in the setting of subcritical glenoid bone loss with an off-track Hill Sachs lesion. In such cases, the addition of a remplissage procedure to a Bankart repair or a bone-block augmentation to the glenoid (Latarjet, for example) is often advocated to decrease the risk of recurrent instability. Recent studies have also evaluated the role of alternative bone-block procedures in comparison to the Latarjet, outcomes with arthroscopic and open techniques as well as various fixation methods and radiological outcomes (bone graft resorption, glenohumeral osteoarthritis). Advances in our understanding of subcritical glenoid bone loss and the glenoid track concept have significantly impacted clinical decision making and treatment selection. The development of arthroscopic techniques has allowed for minimally invasive and safe arthroscopic bone-block procedures as an alternative to open procedures. Further research related to free bone-block procedures will inform long-term outcomes between these procedures and the gold standard Latarjet. Additionally, high-quality evidence is lacking to identify the ideal treatment for patients with glenoid subcritical glenoid bone defect. Variability in outcome reporting suggests the need to standardize outcome measures for future instability trials.

With the exception of the Hill-Sachs interval, CT and MRI show no significant differences in the diagnostic value of the HSL measurement regardless of the measurement technique

PURPOSE

The aim of the current study was to compare the diagnostic precision and reliability of different methods in measuring Hill-Sachs lesions (HSLs) using MRI and CT.

METHODS

A total of 80 consecutive patients with a history of anterior shoulder instability were retrospectively included. The preoperative CT and MRI scans of the affected shoulders were analysed. To investigate the ability of the Franceschi grading, Calandra classification, Richards, Hall, and Rowe grading scale, Flatow percentage and "glenoid track" assessment according to Di Giacomo et al. to quantify the extent of humeral bone loss, the results of each measurement method obtained with MRI were compared with those achieved with CT. In addition, the intra- and inter-rater reliabilities of each measurement method using CT and MRI were calculated and compared.

RESULTS

A significant difference was found between CT and MRI in the determination of the Hill-Sachs interval (HSI) (p = 0.016), but not between the results of any of the other measurement techniques. With the exceptions of the Franceschi grade and Calandra classification, all measurement methods showed good or excellent intra- and inter-rater reliabilities for both MRI and CT.

CONCLUSIONS

While the determination of the HSI with MRI was more accurate, all other analysed techniques for measuring the amount of humeral bone loss showed similar diagnostic precision. With regard to the intra- and inter-rater reliabilities, all measurement techniques analysed, with the exception of the Franceschi and Calandra classifications, provided good to very good reliabilities with both CT and MRI.

LEVEL OF EVIDENCE

III.

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.

The routine cutoff displacement of 2 mm may not reliably reflect the stability of paediatric lateral humeral condyle fractures

INTRODUCTION

Lateral humeral condyle fracture is one of the most common fractures in children. However, the prediction of the stability of the fracture with a cutoff displacement of 2 mm remains controversial. The aim of this study was to evaluate the reliability of the routine cutoff displacement of 2 mm in predicting the stability of paediatric lateral humeral condyle fractures.

METHODS

A cohort of 79 children with imaging results for lateral humeral condyle fractures from 2013 to 2019 was evaluated. The displacement on the radiographs was measured by three surgeons at different levels, and ultrasound images were obtained by two senior surgeons. The interobserver and intraobserver reliability was assessed by the intraclass correlation coefficient (ICC). A binary logistic regression model and receiver operating characteristic (ROC) curves were used to evaluate the association between the measurement and the integrity of cartilage hinges.

RESULTS

The ICC for the interobserver reliability was 0.85, and the intraobserver reliability was 0.93. For each additional millimetre of displacement, the odds of cartilage hinge disruption increased by 70%. The ROC curve determined that the Youden index was only 0.07 (sensitivity, 97.8%; specificity, 8.8%) with a cutoff displacement of 2 mm.

CONCLUSIONS

The routine cutoff displacement of 2 mm may not reliably reflect the stability of paediatric lateral humeral condyle fractures. The cutoff value is sensitive but not specific for predicting whether the cartilage hinge is intact.

When to Abandon the Arthroscopic Bankart Repair: A Systematic Review

CONTEXT

Bone loss is a major factor in determining surgical choice in patients with anterior glenohumeral instability. Although bone loss has been described, there is no consensus on glenoid, humeral head, and bipolar bone loss limits for which arthroscopic-only management with Bankart repair can be performed.

OBJECTIVE

To provide guidelines for selecting a more complex repair or reconstruction (in lieu of arthroscopic-only Bankart repair) in the setting of glenohumeral instability based on available literature.

DATA SOURCES

An electronic search of the literature for the period from 2000 to 2019 was performed using PubMed (MEDLINE).

STUDY SELECTION

Studies were included if they quantified bone loss (humeral head or glenoid) in the setting of anterior instability treated with arthroscopic Bankart repair.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Study design, level of evidence, patient demographics, follow-up, recurrence rates, and measures of bone loss (glenoid, humeral head, bipolar).

RESULTS

A total of 14 studies met the inclusion criteria. Of these, 10 measured glenoid bone loss, 5 measured humeral head bone loss, and 2 measured "tracking" without explicit measurement of humeral head bone loss. Measurement techniques for glenoid and humeral head bone loss varied widely. Recommendations for maximum glenoid bone loss for arthroscopic repair were largely <15% of glenoid width in recent studies. Recommendations regarding humeral head loss were more variable (many authors providing only qualitative descriptions) with increasing attention on glenohumeral tracking.

CONCLUSION

It is essential that a standardized method of glenoid and humeral head bone loss measurements be performed preoperatively to assess which patients will have successful stabilization after arthroscopic Bankart repair. Glenoid bone loss should be <15%, and humeral head lesions should be "on track" if an arthroscopic-only Bankart is planned. If there is greater bone loss, adjunct or open procedures should be performed.

Reliability of humeral head measurements performed using two- and three-dimensional computed tomography in patients with shoulder instability

Purpose

The aim of the study was to compare two measurement methods of humeral head defects in patients with shoulder instability. Intra- and inter-observer reliability of humeral head parameters were performed with the use of 2D and 3D computed tomography.

Methods

The study group was composed of one hundred humeral heads measured with the use of preoperative 2D and 3D computed tomography by three independent observers (two experienced and one inexperienced). All observers repeated measurements after 1 week. The intra-class correlation coefficient (ICC) and the minimal detectable change with 95% confidence (MDC₉₅%) were used for statistical analysis of diagnostic agreement.

Results

For 3D inter-observer reliability, ICC values were “excellent” for all parameters and MDC₉₅% values were “excellent” or “reasonable.” All intra-observer ICC and MDC₉₅% values for 3D were “excellent” for experienced and inexperienced observers. For 2D-CT, ICC values were usually “good” or “moderate” with MDC₉₅% values higher than 10 or 30%.

Conclusions

Three-dimensional CT measurements are more reliable than 2D for humeral head and Hill-Sachs lesion assessment. This study showed that 2D measurements, even performed by experienced observers (orthopaedic surgeons), are burdened with errors. The 3D reconstruction decreased the risk of error by eliminating inaccuracy in setting the plane of the measurements.

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.

Management of Recurrent Anterior Shoulder Instability With Bipolar Bone Loss: A Systematic Review to Assess Critical Bone Loss Amounts

BACKGROUND

There is increasing evidence to suggest that the amount of glenoid bone loss to indicate bone block procedures may be lower than previously thought, particularly in the presence of a Hill-Sachs defect.

PURPOSE

To better establish treatment recommendations for anterior shoulder instability among patients with bipolar bone lesions.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A systematic review of the literature was performed with PubMed, EMBASE, Cochrane Library, and Scopus databases according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. Studies evaluating outcomes of operative management in anterior shoulder instability that also reported glenoid bone loss in the presence of Hill-Sachs defects were included. Recurrence rates, glenoid bone loss, and humeral bone loss were pooled and analyzed with forest plots stratified by surgical procedure. Methods of quantification were analyzed for each article qualitatively.

RESULTS

Thirteen articles were included in the final analysis, with a total of 778 patients. The mean ± SD age was 24.9 ± 8.6 years. The mean follow-up was 30.1 months (range, 11-240 months). Only 13 of 408 (3.2%) reviewed bipolar bone loss articles quantified humeral and/or glenoid bone loss. Latarjet procedures had the greatest glenoid bone loss (21.7%; 95% CI, 14.8%-28.6%), followed by Bankart repairs (13.1%; 95% CI, 9.0%-17.2%), and remplissage (11.7%; 95% CI, 5.5%-18.0%). Humeral bone loss was primarily reported as percentage bone loss (22.2%; 95% CI, 13.1%-31.3% in Bankart repairs and 31.7%; 95% CI, 21.6%-41.1% in Latarjet) or as volumetric defects (439.1 mm³; 95% CI, 336.3-541.9 mm³ in Bankart repairs and 366.0 mm³; 95% CI, 258.4-475.4 mm³ in remplissage). Recurrence rates were as follows: Bankart repairs, 19.5% (95% CI, 14.5%-25.8%); remplissage, 4.4% (95% CI, 1.3%-14.0%); and Latarjet, 8.7% (95% CI, 5.0%-14.7%). Bankart repairs were associated with significantly greater recurrence of instability in included articles (P = .013).

CONCLUSION

There exists a need for universal and consistent preoperative measurement of humeral-sided bone loss. The presence of concomitant Hill-Sachs defects with glenoid pathology should warrant more aggressive operative management through use of bone block procedures. Previously established values of critical glenoid bone loss are not equally relevant in the presence of bipolar bone loss.

CT Analysis of a Potential Safe Zone for Placing External Fixator Pins in the Humerus

BACKGROUND

Iatrogenic radial nerve injures are a common complication during the placement of external fixator pins at the lateral aspect of the humeral shaft. This study uses a three-dimensional measurement technique to locate a safe entry point for humeral pins when externally fixating the elbow. Methods: We fixed a guide wire to the radial nerve by a suture string, and used computed tomography (CT) to scan the upper limbs of cadaver specimens. Then, we measured the deviation angles of the radial nerve on the CT scans, and the distance from the radial nerve to the "elbow rotation center" (ERC). Result: The average distance from the radial nerve to the ERC was 87.3 ± 8.5 mm (range: 68-100 mm), 58.3 ± 11.3 mm (range: 32.12-82.84 mm), 106.3 ± 5.8 mm (range: 86.93-115.08 mm), and 113.9 ± 4.8 mm (range: 97.93-120.22 mm) at radial nerve deviation angles of 0°, -30°, 30°, and 45°, respectively. The average radial nerve deviation angle was -37.7° ± 7.7° and 123.9° ± 19.9° at 50 and 150 mm, respectively. Relative to 0°, the distance between the radial nerve and the ERC at radial nerve deviation angles of -30°, 30°, and 45° showed a significant difference (t = 18.20, p < 0.05; Z = 6.07, p < 0.001; Z = 6.40, p < 0.001, respectively). Conclusions: Pins inserted into the proximal humerus should be about 150 mm from the ERC with a radial nerve deviation angle of 30° anteriorly, and 50 mm from the ERC with a deviation angle of 30°-45° posteriorly.

[Current concepts of diagnostic techniques and measurement methods for bone defect in patient with anterior shoulder instability]

Objective

To summarize the diagnosis and measurement methods of bone defect in anterior shoulder instability (glenoid bone defect and Hill-Sachs lesion).

Methods

The related literature on the diagnosis and measurement of the bone defect in anterior shoulder instability was reviewed and summarized.

Results

The commonly used techniques for the diagnosis of anterior glenoid bone defect and Hill-Sachs lesion of humeral head include X-ray, CT, MRI, arthroscopy, arthrography. The methods for measuring the degree of anterior glenoid bone defect include Griffith method, glenoid index method, Pico method, and best-fit circle method. The indexes for measuring the Hill-Sachs lesion include the length, width, depth, and volume. X-ray is mainly used for primary screening. Best-fit circle method on three-dimensional (3D) CT reconstruction is commonly used to measure the glenoid bone defect currently. Glenoid track theory on 3D CT reconstruction is popular in recent years. Reliability of measuring the glenoid bone defect and Hill-Sachs lesion with MRI and arthroscopy is still debatable. Arthrography is more and more used in the diagnosis of shoulder joint instability of bone defect and concomitant soft tissue injury.

Conclusion

How to improve the accuracy of evaluating glenoid bone defect and Hill-Sachs lesion before surgery still need further study.

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