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

[Imaging of posttraumatic shoulder instability : Current concepts]

Posttraumatic instability accounts for more than 95% of all shoulder instabilities with the highest incidence in patients between 20 and 30 years of age. In this age group, lesions of the capsulolabral complex are the most common sequelae after the first shoulder dislocation. Typical acute findings are the Bankart and Perthes lesions and humeral avulsion of the glenohumeral ligament (HAGL). Chronic sequelae are anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions, and nonclassifiable lesions with deficient anterioinferior labrum and glenohumeral ligaments. Recently, quantification of Hill-Sachs and bony Bankart lesions with glenoid defects have become the focus of interest: bipolar bone loss has emerged to be one important factor of recurrent instability that has not been addressed during the first stabilizing operation. The glenoid track concept emphasizes the importance of bipolar bone loss, where the glenoid track refers to the contact area between the humeral head and the glenoid at the end-range of motion in abduction, extension and external rotation. Any lesion of the humeral head that extends beyond the glenoid track is considered high risk for engagement of the humeral head at the glenoid margin with subsequent dislocation. Both the Hill-Sachs interval and the glenoid track can be determined using computed tomography (CT) and magnetic resonance imaging and, thus, help to define the status of the shoulder (on-track vs. off-track), which is prerequisite for planning the appropriate operative procedure. Similar tendencies also exist for posttraumatic posterior instabilities which are much rarer.

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.

Glenoid Bone Loss Directly Affects Hill-Sachs Morphology: An Advanced 3-Dimensional Analysis

BACKGROUND

While the glenoid track concept presents a useful prediction for recurrent glenohumeral instability, little is known about the humeral head bony architecture as it relates to glenoid erosion in the setting of bipolar bone loss.

PURPOSE

To (1) qualitatively and quantitatively analyze the interplay between glenoid bone loss (GBL) and Hill-Sachs lesions (HSLs) in a cohort of patients with anterior instability using 3-dimensional imaging software and (2) assess the relationships between GBL and HSL characteristics.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Patients were identified who had anterior shoulder instability with a minimum 5% GBL and evidence of HSL confirmed on computed tomography. Unilateral 3-dimensional models of the ipsilateral proximal humeral head and en face sagittal oblique view of the glenoid were reconstructed using MIMICS software (Materialise NV). GBL surface area, width, defect length, and glenoid track width were quantified. The volume, surface area, width, and depth of identified HSLs were quantified with their location (medial, superior, and inferior extent) on the humeral head. Severity of GBL was defined as percentage glenoid bone surface area loss and categorized as low grade (5%-10%), moderate grade (>10% to 20%), high grade (>20% to 30%), and extensive (>30%). Analysis of variance was then computed to determine significance (P < .05) between severity of GBL and associated HSL parameters.

RESULTS

In total, 100 patients met inclusion criteria (mean age, 27.9 years; range, 18-43 years), which included 58 right shoulders and 42 left shoulders (84 male, 16 female). Among groups, there were 32 patients with low-grade GBL (mean GBL = 6.1%), 38 with moderate grade (mean GBL = 16.2%), 17 with high grade (mean GBL = 23.7%), and 13 with extensive (mean GBL = 34.0%), with an overall mean GBL of 18.1% (range, 5%-39%). Patients with 5%-10% GBL had significantly narrower HSLs (average and maximum width; P < .03) and deeper HSLs (average depth; P = .002) as compared with all other GBL groups, while greater GBL was associated with wider and shallower HSLs. GBL width, percentage width loss, defect length, and glenoid track width all significantly differed across the 4 GBL groups (P < .05).

CONCLUSION

HSLs had significantly different morphological characteristics depending on the severity of GBL, indicating that GBL was directly related to the characteristics of HSLs. Patients presenting with smaller glenoid defects had significantly narrower and deeper HSLs with less humeral head surface area loss, while greater GBL was associated with wider and shallower HSLs.

Reporting of glenoid bone loss measurement in clinical studies and the need for standardization : a systematic review

AIMS

The amount of glenoid bone loss is an important factor in deciding between soft-tissue and bony reconstruction when managing anterior shoulder instability. Accurate and reproducible measurement of glenoid bone loss is therefore vital in evaluation of shoulder instability and recommending specific treatment. The aim of this systematic review is to identify the range methods and measurement techniques employed in clinical studies treating glenoid bone loss.

METHODS

A systematic review of the PubMed, MEDLINE, and Embase databases was undertaken to cover a ten-year period from February 2011 to February 2021. We identified clinical studies that incorporated bone loss assessment in the methodology as part of the decision-making in the management of patients with anterior shoulder instability. The Preferred Reporting Items for Systematic Reviews (PRISMA) were used.

RESULTS

A total of 5,430 articles were identified from the initial search, of which 82 studies met the final inclusion criteria. A variety of imaging methods were used: three studies did not specify which modality was used, and a further 13 used CT or MRI interchangeably. There was considerable heterogeneity among the studies that specified the technique used to quantify glenoid bone loss. A large proportion of the studies did not specify the technique used.

CONCLUSION

This systematic review has identified significant heterogeneity in both the imaging modality and method used to measure glenoid bone loss. The recommendation is that as a minimum for publication, authors should be required to reference the specific measurement technique used. Without this simple standardization, it is impossible to determine whether any published paper should influence clinical practice or should be dismissed. Cite this article: Bone Joint J 2022;104-B(1):12-18.

Location of the Suture Anchor in Hill-Sachs Lesion Could Influence Glenohumeral Cartilage Quality and Limit Range of Motion After Arthroscopic Bankart Repair and Remplissage

BACKGROUND

No study has reported clinical evidence for cartilage change in the glenohumeral joint or the cause of loss in range of motion (ROM) after arthroscopic Bankart repair with remplissage technique (BR).

PURPOSE

To investigate the postoperative features of glenohumeral joint cartilage, ROM, and anchor placement for remplissage at a minimum of 2 years of follow-up after BR and to analyze the correlations.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 21 patients who underwent BR received follow-up for a minimum of 2 years. At both preoperative assessment and final follow-up, passive shoulder ROM, Oxford Shoulder Instability Score, Simple Shoulder Test score, and Single Assessment Numerical Evaluation score were assessed. All patients underwent 3.0-T magnetic resonance imaging (MRI) examination at final follow-up. The clinical outcomes, glenohumeral cartilage or Hill-Sachs lesion-related MRI parameters, and their potential correlations were analyzed.

RESULTS

The mean follow-up was 55.0 months (range, 24-119 months). Compared with preoperative assessment, all functional scores significantly improved (P < .001). At the final follow-up, a significant ROM loss (>15°) of external rotation (ER) at the side (ER₀) was found in 12 patients, among whom 8 patients had significant ROM loss of ER at 90° of abduction as well. Further, 12 patients with decreased ER had significantly higher signal intensity of cartilage on the anterior, middle, and posterior humeral head (anterior, P = .002; middle, P < .001; posterior, P < .001) than 9 patients with normal ER. The ratio of the width of the remplissage anchor to the diameter of the humeral head (w:d ratio) was significantly greater (P = .031) in the decreased ER group than in the normal ER group. Correlation analysis showed that signal intensity on the posterior humeral head and ER₀ loss (ΔER₀) had a significantly positive correlation (r = 0.516; P = .034), while the w:d ratio and ΔER₀ had a significantly positive correlation (r = 0.519; P = .039).

CONCLUSION

At a minimum of 2 years of follow-up, patients who underwent BR showed significant clinical improvement compared with preoperative assessment, except for limitations in ER. The glenohumeral cartilage degeneration (higher signal intensity) after BR had a significantly positive correlation with the postoperative ER loss, which was found to be associated with a relatively medial placement of the remplissage anchor.

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.