Reporting of glenoid bone loss measurement in clinical studies and the need for standardization

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.

Reverse Shoulder Arthroplasty with Bony and Metallic versus Standard Bony Reconstruction for Severe Glenoid Bone Loss. A Retrospective Comparative Cohort Study

There are different techniques to address severe glenoid erosion during reverse shoulder arthroplasty (RSA). This study assessed the clinical and radiological outcomes of RSA with combined bony and metallic augment (BMA) glenoid reconstruction compared to bony augmentation (BA) alone. A review of patients who underwent RSA with severe glenoid bone loss requiring reconstruction from January 2017 to January 2019 was performed. Patients were divided into two groups: BMA versus BA alone. Clinical outcome measurements included two years postoperative ROM, Constant score, subjective shoulder value (SSV), and the American Shoulder and Elbow Surgeons Shoulder (ASES) score. Radiological outcomes included radiographic evidence of scapular complications and graft incorporation. The BMA group had significantly different glenoid morphology (p < 0.001) and greater bone loss thickness than the BA group (16.3 ± 3.8 mm vs. 12.0 ± 0.0 mm, p = 0.020). Both groups had significantly improved ROM (anterior forward flexion and external rotation) and clinical scores (Constant, SSV and ASES scores) at 2 years. Greater improvement was observed in the BMA group in terms of anterior forward flexion (86.3° ± 27.9° vs. 43.8° ± 25.6°, p = 0.013) and Constant score (56.6 ± 10.1 vs. 38.3 ± 16.7, p = 0.021). The BA group demonstrated greater functional and clinical improvements with higher postoperative active external rotation and ASES results (active external rotation, 49.4° ± 17.0° vs. 29.4° ± 14.7°, p = 0.017; ASES, 89.1 ± 11.3 vs. 76.8 ± 11.0, p = 0.045). The combination use of bone graft and metallic augments in severe glenoid bone loss during RSA is safe and effective and can be considered in cases of severe glenoid bone loss where bone graft alone may be insufficient.

Open Posterior Glenoid Reconstruction Using a Distal Tibial Allograft

Background: Posterior instability is less common than anterior instability but can be seen in contact athletes and posttraumatically. Distal tibial allograft reconstruction for glenoid bone loss was first described by Provencher and colleagues in 2009 and an arthroscopic technique for posterior glenoid reconstruction using a distal tibial allograft was later described by Gupta et al in 2013. Indications: The primary indications for posterior distal tibial allograft include the failure of conservative management, recurrent instability after an arthroscopic stabilization, or glenoid bone loss > 20% to 25%. Technique Description: The patient is positioned in lateral decubitus, and examination under anesthesia is performed. Following arthroscopic evaluation, an incision is made medial to the posterolateral aspect of the acromion at the glenohumeral joint level. Electrocautery is carried to the deltoid, which is split in line with its fibers. A split between the infraspinatus and teres minor is performed. Vertical capsulotomy is performed, and deep retractors are placed. Attention is turned to the back table for graft preparation. The graft is measured, marked on the lateral aspect of the articular surface, and cut accordingly. Two 3.5-mm holes are drilled 1 cm apart, and the graft is thoroughly irrigated before being placed into the wound. A 2.5-mm drill is used in the 3.5-mm holes, and two 3.5-mm solid fully threaded screws are placed under power and tightened by hand. The wound is closed in the traditional fashion. Results: Graft nonunion and/or resorption are the primary concerns following posterior distal tibial allograft. Amar et al found no cases of nonunion or partial unions on 6-month computerized tomography (CT) scan, most patients having no or <50% resorption. Millet et al also found bony union by CT scan and improved patient-reported outcome measures. A case series by Gilat et al found 90% of patients reported restoration of stability. Discussion/Conclusion: Posterior distal tibial allograft is a successful surgical intervention for patients with recurrent posterior shoulder instability with glenoid bone loss.

Early outcomes of the arthroscopic Latarjet procedure in a series of 37 patients with shoulder instability

Background Anterior shoulder dislocation remains a clinical challenge. This study aimed to assess the graft position and clinical outcomes of the arthroscopic Latarjet procedure and capsular repair for the treatment of recurrent anterior shoulder dislocation with significant glenoid bone loss in 37 patients. Methods Between 2017 and 2017, 37 patients underwent arthroscopic Latarjet plus capsular repair procedure for recurrent anterior shoulder dislocation combined with significant glenoid bone loss. In follow-up examinations, Walch-Duplay scores, subjective shoulder value (SSV) scores, Rowe scores, and active range of motion (AROM) were assessed. Three-dimensional computed tomography (CT) was used to evaluate coracoid graft position and bone resorption. A new method of evaluating the position of the coracoid bone block after Latarjet (H-Z method) was developed. Results Thirty-seven patients were included in this study. Follow-up ranged from 6 to 36 months postoperatively (with an average of 13 months). No recurrent dislocation occurred at the final follow-up, and there was no significant effect on the AROM (all p > 0.05). Rowe (from 42.2 ± 5.6 to 91.1 ± 3.3), Walch-Duplay (from 31.5 ± 8.0 to 92.6 ± 3.7), and SSV (from 63.9 ± 6.1 to 79.3% ± 5.0%) scores were improved significantly after surgery (all p < 0.001). CT showed that the 29 patients had varying degrees of bone resorption, and 23 recovered to the preinjury level of motional function within 6–12 months after surgery. Conclusions In active patients with recurrent anterior shoulder dislocations and significant glenoid bone loss, the arthroscopic Latarjet procedure plus capsular repair could restore shoulder stability satisfactory.

Inconsistencies in Controlling for Risk Factors for Recurrent Shoulder Instability After Primary Arthroscopic Bankart Repair: A Systematic Review

Background: Failure rates after arthroscopic shoulder stabilization are highly variable in the current orthopaedic literature. Predictive factors for risk of failure have been studied to improve patient selection, refine surgical techniques, and define the role of bony procedures. However, significant heterogeneity in the analysis and controlling of risk factors makes evidence-based management decisions challenging. Purpose: The goals of this systematic review were (1) to critically assess the consistency of reported risk factors for recurrent instability after arthroscopic Bankart repair, (2) to identify the existing studies with the most comprehensive inclusion of confounding factors in their analyses, and (3) to give recommendations for which factors should be reported consistently in future clinical studies. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was performed in accordance with the PRISMA guidelines. An initial search yielded 1754 titles, from which 56 full-text articles were screened for inclusion. A total of 29 full-text articles met the following inclusion criteria: (1) clinical studies regarding recurrent anterior shoulder instability; (2) surgical procedures performed including arthroscopic anterior labral repair; (3) reported clinical outcome data including failure rate; and (4) assessment of risk factors for surgical failure. Further subanalyses were performed for 15 studies that included a multivariate analysis, 17 studies that included glenoid bone loss, and 8 studies that analyzed the Instability Severity Index Score. Results: After full-text review, 12 of the most commonly studied risk factors were identified and included in this review. The risk factors that were most consistently significant in multivariate analyses were off-track lesions (100%), glenoid bone loss (78%), Instability Severity Index Score (75%), level of sports participation (67%), number of anchors (67%), and younger age (63%). In studies of bone loss, statistical significance was more likely to be found using advanced imaging, with critical bone loss thresholds of 10% to 15%. Several studies found predictive thresholds of 2 to 4 for Instability Severity Index Score by receiver operating characteristic or multivariate analysis. Conclusion: Studies reporting risk factors for failure of arthroscopic Bankart repair often fail to control for known confounding variables. The factors with the most common statistical significance among 15 multivariate analyses are off-track lesions, glenoid bone loss, Instability Severity Index Score, level of sports participation, number of anchors, and younger age. Studies found significance more commonly with advanced imaging measurements or arthroscopic assessment of glenoid bone loss and with lower thresholds for the Instability Severity Index Score (2-4). Future studies should attempt to control for all relevant factors, use advanced imaging for glenoid bone loss measurements, and consider a lower predictive threshold for the Instability Severity Index Score.

ROLE OF 3D CT SCAN IN QUANTIFYING GLENOID BONE LOSS IN RECURRENT UNILATERAL SHOULDER DISLOCATION

Purpose: Patients with recurrent shoulder instability often present with osseous injury to the glenoid and humeral head. Glenoid bone loss can easily be quantied on a three-dimensional computed tomography scan by modeling the inferior portion of the glenoid contour as a true circle on an en face view. This study investigated the accuracy of CT in determining the presence and severity of glenoid bone loss in patients with unilateral recurrent shoulder dislocation. Methodology: This prospective cross-sectional study was done among patients with unilateral recurrent shoulder dislocation. Forty patients with anterior shoulder dislocation underwent shoulder CT examination before arthroscopy. Results: Glenoid bone loss was evident in 38 (95%) of the 40 patients at arthroscopy. Compared with arthroscopy, CT had sensitivity in detecting glenoid bone loss of 92.1%; specicity, 100%; positive predictive value, 100%; and negative predictive value, 40.0%. Three false-negative CT assessments had 5%, 5%, and 20% glenoid bone loss, respectively, at arthroscopy. There was a strong correlation between CT and arthroscopy with respect to the severity of glenoid bone loss (r = 0.73). Conclusion: CT has both a high sensitivity and a high specicity for detecting glenoid bone loss, and agreement with arthroscopy regarding the severity of glenoid bone loss is good. CT can be used to assess glenoid bone loss and the need for bone augmentation surgery.