Glenoid Bone Loss In Patients Research Articles

Comparison of Glenoid Dimensions Between 3D Computed Tomography and 3D Printing.

Glenoid dimensions can be measured in vivo with various imaging methods including two-dimensional (2D) and three-dimensional computed tomography (CT) and magnetic resonance imaging scans. Printing of three-dimensional (3D) models of the glenoid using imaging data is feasible and can be used to better understand skeletal trauma and complex skeletal deformations such as glenoid bone loss in patients with shoulder instability. The purpose of this study was to compare measurements of glenoid dimensions on 3D CT scan reconstructed models and 3D printed models of the glenoid. CT scans from 62 young, male adults acquired for non-trauma-related causes were evaluated. Following volume rendering, a stereolithography model of each scapula was constructed and a 3D model was printed. Additionally, 3D CT models of each glenoid were reconstructed using dedicated software. Measurements of the maximum glenoid height and width were performed on both the 3D printed and the 3D reconstructed models. To assess intra- and interrater reliability, measurements of 15 glenoids were repeated by two observers after three weeks. The measurements of the 3D printed and 3D reconstructed models were compared. Inter- and intra-rater reliability was excellent or perfect. Analysis of height and width values demonstrated a strong correlation of 0.91 and 0.89 respectively (p<0.001) for both the 3D printed models and the 3D reconstructed models. There was a strong correlation between the height and width, but no significant difference between the glenoid width and height in both models. There was no statistical significance between height and width when measurements on the two models were examined (p=0.12 and 0.23 respectively). 3D printed glenoid models can be used to evaluate the glenoid dimensions, width, and height, as they provide similar accuracy with 3D reconstructed models as provided from CT scan data.

Arthroscopic Bone Block Cerclage Suture Fixation of Fresh Distal Tibial Allograft for Anterior Glenoid Reconstruction

Glenoid bone loss in patients with recurrent anterior shoulder instability poses a unique challenge to treating surgeons. Various bone block procedures have been used to reconstruct the glenoid, including autologous coracoid transfer, iliac crest autograft, distal clavicle autograft, and distal tibia allograft. Distal tibia allograft has been increasingly used because of its advantages over autologous graft sources. Having started out as an open procedure, glenoid reconstruction with distal tibia allograft has now found its way to evolving into an arthroscopic procedure. Various techniques have been devised for arthroscopic distal tibia allograft fixation, including screw, suture anchor, and suture button. This technical note describes an arthroscopic distal tibia allograft fixation technique, using a transglenoid parallel drill guide and 2 cerclage tape sutures that are fastened using a tensioner. This technique provides strong graft fixation while avoiding the potential complications and technical challenges of metal screw fixation.

Mid-term results of the use of structural humeral head autograft to correct glenoid bone loss in reverse total shoulder arthroplasty

BackgroundNative glenoid bone loss presents technical challenges in shoulder arthroplasty. The purpose of this study is to report the mid-term clinical and radiographic outcomes of patients treated with structural humeral head autograft reconstruction of glenoid bone loss in the setting of reverse total shoulder arthroplasty (rTSA). MethodsRetrospective review of 30 shoulders in 28 patients undergoing rTSA with a structural humeral head autograft to correct glenoid bone loss. Demographics, comorbidities, anatomic details, and patient-reported outcome measures were collected for analysis. ResultsRange of motion and patient-reported outcome measures were all significantly improved postoperatively (P < .001). Bone grafts were found to incorporate into 100% of shoulders, with no protheses displaying signs of loosening or other structural concerns. No revision procedures were performed, and all patients were satisfied with their shoulder postoperatively. Two patients developed scapular notching on follow-up. DiscussionThe use of a humeral head autograft to reconstruct glenoid bone loss in patients undergoing rTSA is a safe and effective procedure. It allows for a local graft source to be utilized thus avoiding potential comorbidity and complications associated with the use of alternative site autografts or allografts and has the advantage of nearly congruent fit within the defect.

Contribution of the Bony Bankart in Calculating Glenoid Bone Loss.

Determining the magnitude of glenoid bone loss in patients with anterior shoulder instability is an important step in guiding management. Most calculations to estimate the bone loss do not include the bony Bankart fragment. However, if it can be reduced and adequately fixed, the estimation of bone loss may be decreased. To derive a simple equation to calculate the surface area of the bony fragment in Bankart fractures. Case series; Level of evidence, 4. A total of 26 patients suspected of having clinically significant bone loss underwent computed tomography imaging preoperatively, and the percentage of glenoid bone loss (%BL) was approximated with imaging software using a freehand region of interest area measurement with and without the inclusion of the bony Bankart fragment. By assuming this bony fragment as a hemi-ellipse with height, H, and thickness, d, we represented the surface are of the bony piece (), and subtracted it from the overall %BL. They compared this value with the one found using imaging software. Without the inclusion of the bony Bankart, the overall %BL by the standard true-fit circle measured using imaging software was 23.8% ± 9.7%. When including the bony Bankart, the glenoid %BL measured using imaging software was found to be 12.1% ± 8.5%. The %BL calculated by our equation with the bony Bankart included was 10% ± 11.1%. There was no statistically significant difference between the %BL values measured using the equation and the imaging software (P = .46). Using a simple equation that approximates the bony Bankart fragment as a hemiellipse allowed for estimation of the glenoid bone loss, assuming that the fragment can be reduced and adequately fixed. This method may serve as a helpful tool in preoperative planning when there are considerations for incorporating the bony fragment in the repair.

Radiological and Histological Analyses of Nonrigid Versus Rigid Fixation for Free Bone Block Procedures in a Rabbit Model of Glenoid Defects

Background: Nonrigid fixation techniques have been recently introduced in free bone block (FBB) procedures to treat substantial glenoid bone loss in patients with anterior shoulder instability. However, the radiological and histological effectiveness of nonrigid fixation versus conventional rigid fixation have not been comprehensively understood in vivo. Purpose: To (1) explore the radiological and histological characteristics of nonrigid fixation for FBB procedures in a rabbit model of glenoid defects and (2) further compare them with those of conventional rigid fixation. Study Design: Controlled laboratory study. Methods: Unilateral shoulder glenoid defects were created in 36 mature New Zealand White rabbits, of which 24 underwent FBB procedures using allogenic iliac crest bone and were randomly divided into rigid fixation (RF) and nonrigid fixation (N-RF) groups, with the remaining divided into 2 control groups: 6 with sham surgery for glenoid defects (GD group) and 6 native glenoids (normal group). In the RF and N-RF groups, 6 rabbits were sacrificed at 6 or 12 weeks postoperatively for radiological and histological analyses of the reconstructed glenoid, and all rabbits in the GD and normal groups were sacrificed at 12 weeks. The radiological glenoid morphology was evaluated via micro–computed tomography. Moreover, the graft-glenoid healing and graft remodeling processes were determined using histological staining. Results: At 6 weeks, both the N-RF and RF groups had similarly improved radiological axial radian and en face area of the glenoid compared with the GD group, but the N-RF group showed superiority in restoration of the glenoid radian and area compared with the RF group at 12 weeks, with the native glenoid as the baseline. Histologically, the bone graft in both groups was substantively integrated into the deficient glenoid neck at 6 and 12 weeks, showing similar osseous healing processes at the graft-glenoid junction. Moreover, the bone graft histologically presented similar regenerated vascular density, total graft bone, and integrated graft bone in both groups. In contrast, the N-RF group had a different remodeling profile on radiological and histological analyses regarding regional bone resorption, mineralization, and fibrous tissue replacement during osseointegration. Conclusion: Compared with rigid fixation, nonrigid fixation resulted in superior reconstructed glenoid morphology radiologically and similar graft-glenoid osseous healing histologically, showing different graft remodeling profiles of regional bone resorption, mineralization, and fibrous tissue replacement. Clinical Relevance: The nonrigid fixation technique can be feasible for FBB procedures to treat glenoid bone loss in anterior shoulder instability. More clinical evidence is required to determine its pros and cons compared with conventional rigid fixation.

Poster 183: Acromial Morphology Predicts Glenoid Bone Loss in Patients with Posterior Glenohumeral Instability

Objectives:The relationship between acromial morphology and glenohumeral instability is not well understood. It is unknown whether a flatter acromion predisposes a nonarthritic shoulder to increased posterior glenoid bone loss (GBL). The purpose of this study was to determine whether acromial morphology influences the extent or pattern of posterior glenoid bone loss in a cohort of patients with posterior glenohumeral instability.Methods:A comprehensive review of case logs between two academic institutions was performed to identify patients treated for primary posterior glenohumeral instability. MRI and/or CT scans were examined by two independent reviewers and the following measurements were obtained: total area glenoid bone loss (GBL) using the perfect circle technique, glenoid version, obliquity of GBL relative to the long axis of the glenoid, arc of GBL, acromial tilt, posterior acromial height (PAH), and anterior/posterior acromial coverage. The primary outcome was the association between acromial morphology parameters and glenoid bone loss.Results:A total of 89 shoulders with primary posterior glenohumeral instability were included. The mean age was 28.3 years (range 18-49), and male:female ratio was 11:1. Fifty-nine patients had measurable posterior glenoid bone loss and 30 patients had posterior labral tears without bone loss. Linear regression analysis revealed a significant negative correlation between acromial tilt and posterior GBL (R2= 0.09, p=0.005), a positive correlation between PAH and posterior GBL (R2= 0.04, p=0.046), and a negative correlation between posterior acromial coverage and posterior GBL (R2= 0.03, p=0.005). Increasing PAH and decreasing posterior acromial coverage were associated with a more superior extent of GBL (R2= 0.1, p=0.044 and 0.024, respectively). Subgroup analysis stratified by total area of GBL demonstrated that the area of posterior glenoid bone loss increases as the acromial tilt decreases.Conclusions:A flatter, higher acromion with less posterior coverage relative to the center of the glenoid is associated with increased posterior glenoid bone loss in patients with posterior glenohumeral instability.Table 1.

No Difference in Outcomes After Arthroscopic Bankart Repair With Remplissage or Arthroscopic Latarjet Procedure for Anterior Shoulder Instability

PurposeTo evaluate the outcomes of arthroscopic Bankart repair with remplissage (ABRR) compared with the arthroscopic Latarjet (AL) procedure for anterior shoulder instability in patients with a labral tear and a concomitant engaging Hill-Sachs lesion.MethodsA retrospective review of patients who underwent either ABRR or the AL procedure for a diagnosis of anterior shoulder instability with a concomitant engaging Hill-Sachs lesion between 2011 and 2019 was performed. Recurrent instability, the visual analog scale score, the Subjective Shoulder Value, the Western Ontario Shoulder Instability score, patient satisfaction, willingness to undergo surgery again, and return to work or sport were evaluated.ResultsOur study included 41 patients treated with ABRR and 26 treated with the AL procedure. At final follow-up, there was no difference between patients who underwent ABRR and those who underwent the AL procedure in the reported Western Ontario Shoulder Instability score (21.8% vs 28.2%, P = .33) or any of its components, the visual analog scale score (0.9 vs 1.4, P = .32), the Subjective Shoulder Value (78.4 vs 74.5, P = .6062), the rate of satisfaction (81.6% vs 85.6%, P = .54), or whether patients would undergo surgery again (81.6% vs 96.1%, P = .16). Overall, 5 patients in the ABRR group and 2 patients in the AL group had recurrent instability events (12.2% vs 7.8%, P = .70), with no significant difference in the rate of recurrent dislocation (12.2% vs 3.8%, P = .39).ConclusionsIn patients with anterior shoulder instability and a concomitant Hill-Sachs lesion, both ABRR and the AL procedure were shown to be reliable treatments, with a low rate of recurrent instability and excellent patient-reported outcomes in appropriately selected patients. However, our study could not determine whether there was critical glenoid bone loss in patients undergoing ABRR, and surgeons should still exercise caution in performing ABRR in patients with high-grade glenoid bone loss or in those with failed prior stabilizations.Level of EvidenceLevel III, retrospective cohort study.

Anterior and posterior glenoid bone loss in patients receiving surgery for glenohumeral instability is not the same: a comparative 3-dimensional imaging analysis.

BackgroundAnterior and posterior glenoid bone loss morphology have both been individually and morphologically described in previous studies. While there exists substantial literature on anterior bone loss, and emerging evidence describing posterior bone loss, a direct comparison between the two is lacking in the current literature. The purpose of this study is to quantitatively compare the anatomic and morphological differences in glenoid bone loss (GBL) in operative patients with anterior versus posterior glenohumeral instability.MethodsAll patients over a 3-year period indicated for operative stabilization with posterior glenohumeral instability and suspected glenoid bone loss who underwent a computed tomography (CT) scan were reviewed. Included patients were then singularly matched by gender, laterality, and age (±3 years) to a collection of patients who presented for operative stabilization of anterior glenohumeral instability. GBL parameters were assessed based on the following characterizing measurements: (1) percentage of GBL, (2) glenoid vault version, (3) slope of the glenoid defect relative to the glenoid surface, (4) superior-inferior defect height, and (5) anterior-posterior defect width.ResultsSixty patients (30 anterior GBL, 30 posterior GBL) were included in the final analysis (60 males), with a mean age of 28.8 ± 8.15 years (range 16.0 to 51.0 years). Patients with anterior instability presented with higher GBL (24.94% ± 7.69 vs. 9.22% ± 5.58, P < .001), greater superior-inferior defect height (23.89 ± 4.21 mm vs. 21.88 ± 3.42 mm, P = .047), and steeper slope of glenoid defect (58.80° ± 11.86 vs. 38.59° ± 14.30, P < .001), while patients with posterior instability had greater retroversion (1.53° ± 4.04 vs. 7.59° ± 7.71, P < .001). Additionally, the anterior instability cohort had significantly more patients with moderate- to high-grade glenoid bone loss (n = 30) than patients with posterior instability (n = 11) (P < .001).ConclusionAnterior instability presents with a steeper slope of glenoid defect, higher percentage GBL, and greater superior-inferior defect height, whereas posterior instability presents with greater retroversion. This underscores the finding that anterior and posterior instability bone loss are not the same morphologically, and this should be considered in the operative treatment of glenohumeral instability.

Patient Factors Associated With Increased Risk for Complications After the Latarjet Procedure.

Background:The open Latarjet has become the most common method of addressing significant glenoid bone loss in patients with recurrent glenohumeral instability.Purpose:To describe national trends in Latarjet procedures and risk factors for complications associated with this procedure.Study Design:Cohort study; Level of evidence, 3.Methods:Eligible patients were identified through the National Surgical Quality Improvement Program (NSQIP) data set over the years 2014 to 2018 by using the Current Procedural Terminology (CPT) code for “capsulorrhaphy anterior with coracoid process transfer” (CPT 23462). Patient and surgical outcome variables were extracted and analyzed from the NSQIP database. Logistic regression analysis and odds ratios (ORs) were performed to evaluate the relative risk of complications.Results:The authors identified 458 patients (399 men and 59 women) from the data set. The mean body mass index was 27.4 kg/m2, and mean operative time was 130.2 minutes. Statistically significant variables included smoking status and sex, which were further stratified. Smokers were 2.19 times more likely to experience at least 1 adverse outcome, including deep vein thrombosis (DVT), pulmonary embolism, reoperation, wound infection, unplanned readmission, or readmission (95% CI, 0.62-7.82). Specifically, smokers were 7.8 times more likely to have a DVT (95% CI, 0.58-105.96), 1.4 times more likely to undergo reoperation (95% CI, 0.14-5.73), and 2.4 times more likely to have an unplanned readmission (95% CI, 0.19-28.68). Women were 2.2 times more likely to experience at least 1 adverse outcome. Specifically, women were found to be 6.4 times more likely to have a DVT (95% CI, 0.76-54.87), 4.1 times more likely to have an unplanned readmission (95% CI, 0.00-106.21), and 4.7 times more likely to have a readmission (95% CI, 0.00-13.92).Conclusion:The results indicate that smokers and female patients are at a higher risk of experiencing adverse outcomes and may require additional pre- and postprocedural precautions when undergoing the Latarjet procedure. With the increase in frequency, providers should be aware of patient-related factors that may lead to adverse outcomes.

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.

Long-Term Value May Determine if RTSA for Cuff-Intact Osteoarthritis with Glenoid Defects Does Not Require Bone Grafts or Augments: Commentary on an article by Edward G. McFarland, MD, et al.: "Reverse Total Shoulder Arthroplasty without Bone-Grafting for Severe Glenoid Bone Loss in Patients with Osteoarthritis and Intact Rotator Cuff. A Concise 5-Year Follow-up of a Previous Report".

Long-Term Value May Determine if RTSA for Cuff-Intact Osteoarthritis with Glenoid Defects Does Not Require Bone Grafts or Augments: Commentary on an article by Edward G. McFarland, MD, et al.: "Reverse Total Shoulder Arthroplasty without Bone-Grafting for Severe Glenoid Bone Loss in Patients with Osteoarthritis and Intact Rotator Cuff. A Concise 5-Year Follow-up of a Previous Report".

Reverse Total Shoulder Arthroplasty without Bone-Grafting for Severe Glenoid Bone Loss in Patients with Osteoarthritis and Intact Rotator Cuff: A Concise 5-Year Follow-up of a Previous Report.

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Técnica de Eden Hybinette en inestabilidad anterior de hombro con pérdida de stock óseo en paciente con epilepsia: reporte de caso

Shoulder instability is occasionally associated with glenoid bone loss in patients with epilepsy. There have been few articles that describe specific surgical treatments for this type of injury. This case report shows a successful surgical approach used in an epileptic patient with multiple right shoulder dislocations that occurred mainly during seizures, through the Eden Hybinette technique, performed using an iliac crest autograft. The patient has been followed up for one year postoperatively, without new episodes of right shoulder dislocation, without complaints of pain, with good range of movement of the shoulder without limitations for daily or work activities. Different surgical methods have been published for these patients, including soft tissue repair operations, as well as skeletal reconstructions with bone graft, Eden Hybinette being one of these. This surgery is a valid option, since it allows an adequate position of the graft in the glenoid defect, potentially reducing the risk of neurovascular and myotendinous lesions; although, more importantly, it reduces the recurrences of shoulder dislocation in patients with uncontrolled epilepsy and gives them the opportunity for a good quality of life.Evidence Level: IV

Glenoid Bone Loss in Shoulder Instability: Superiority of Three-Dimensional Computed Tomography over Two-Dimensional Magnetic Resonance Imaging Using Established Methodology.

BackgroudRecent literature suggests that three-dimensional magnetic resonance imaging (3D MRI) can replace 3D computed tomography (3D CT) when evaluating glenoid bone loss in patients with shoulder instability. We aimed to examine if 2D MRI in conjunction with a validated predictive formula for assessment of glenoid height is equivalent to the gold standard 3D CT scans for patients with recurrent glenohumeral instability.MethodsPatients with recurrent shoulder instability and available imaging were retrospectively reviewed. Glenoid height on 3D CT and 2D MRI was measured by two blinded raters. Difference and equivalence testing were performed using a paired t-test and two one-sided tests, respectively. The interclass correlation coefficient (ICC) was used to test for interrater reliability, and percent agreement between the measurements of one reviewer was used to assess intrarater reliability.ResultsUsing an equivalence margin of 1 mm, 3D CT and 2D MRI were found to be different (p = 0.123). The mean glenoid height was significantly different when measured on 2D MRI (39.09 ± 2.93 mm) compared to 3D CT (38.71 ± 2.89 mm) (p = 0.032). The mean glenoid width was significantly different between 3D CT (30.13 ± 2.43 mm) and 2D MRI (27.45 ± 1.72 mm) (p < 0.001). The 3D CT measurements had better interrater agreement (ICC, 0.91) than 2D MRI measurements (ICC, 0.8). intrarater agreement was also higher on CT.ConclusionsMeasurements of glenoid height using 3D CT and 2D MRI with subsequent calculation of the glenoid width using a validated methodology were not equivalent, and 3D CT was superior. Based on the validated methods for the measurement of glenoid bone loss on advanced imaging studies, 3D CT study must be preferred over 2D MRI in order to estimate the amount of glenoid bone loss in candidates for shoulder stabilization surgery and to assist in surgical decision-making.

The novel arthroscopic subscapular quadriceps tendon\u2013bone sling procedure provides increased stability in shoulder cadavers with severe glenoid bone loss

PurposeTreatment of anterior glenoid bone loss in patients with recurrent anterior shoulder instability is a challenge. The subscapular sling method with quadriceps tendon bone (QTB) graft is a modification of the subscapular sling with a semitendinosus (ST) graft. The aim of the study was to test the biomechanical stability of the QTB sling procedure in human shoulder cadavers with severe anterior glenoid bone loss.MethodsFourteen cadaveric shoulders were tested with a force–moment-guided robot in three conditions: physiologically intact, anterior glenoid bone resection, and the subscapular sling procedure with a QTB graft. Joint stability was measured in anterior, anterior inferior and inferior directions in four glenohumeral joint positions: 0° and 60° of glenohumeral abduction, with each at 0° and 60° of external rotation. Maximum external rotation was measured at 0° and 60° glenohumeral abduction. Computer tomography scans were obtained preoperatively to plan the glenoid bone resection, as well as postoperatively to calculate the proportion of the glenoid bone actually resected.ResultsSignificantly decreased translations were observed in the shoulders with the QTB sling compared to the intact joint and the glenoid bone loss model. No significant differences in maximum external rotation were observed between the three different conditions.ConclusionThis biomechanical study revealed a significant stabilizing effect of the arthroscopic subscapular QTB graft sling procedure in human shoulder cadavers without compromising external rotation. Clinical trials may reveal the usefulness of this experimental method.

Outcomes of Posterior Glenoid Bone-Grafting in Anatomical Total Shoulder Arthroplasty: A Systematic Review.

Total shoulder arthroplasty offers a reliable means with which to treat glenohumeral joint arthritis. Posterior glenoid bone loss presents a unique challenge with an increased risk of glenoid component failure. The use of posterior bone-grafting is one method to address glenoid bone loss in patients undergoing anatomical total shoulder arthroplasty. The purpose of the present study was to assess the outcome and survival of the glenoid component following the use of bone graft to address posterior glenoid bone loss in patients undergoing anatomical total shoulder arthroplasty. A systematic review of posterior glenoid bone-grafting in patients undergoing anatomical total shoulder arthroplasty was performed. Studies evaluating patient-reported outcomes, complications, and imaging assessments of the glenoid component as well as of bone graft structural healing and integrity following posterior glenoid bone-grafting were included. Data extracted included demographic characteristics, Walch classification, bone-grafting method, clinical outcomes measures, complications, radiolucency around the glenoid component, graft failure, posterior humeral head subluxation, and time of the latest follow-up. Six studies met the inclusion and exclusion criteria. Ninety-four patients from these 6 studies underwent posterior glenoid bone-grafting with anatomical total shoulder arthroplasty. The mean age was 59.7 years, and the mean duration of follow-up was 5.7 years. Overall, 57% of the patients had an excellent postoperative Neer score. At the time of the latest follow-up, 28.7% had evidence of radiolucency and 35% had humeral head subluxation or instability. Thirteen patients (14%) underwent revision of the glenoid component by the time of the latest follow-up. The present study demonstrated a 28.7% complication rate, a 14% revision rate, a 17% graft failure rate, and a 35% rate of recurrence of posterior humeral head subluxation. Posterior glenoid bone-grafting to correct bone loss is associated with a substantial risk of postoperative complications. The treatment of posterior glenoid bone loss remains a challenge in patients undergoing anatomical total shoulder arthroplasty. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Paper #1 - Prospective evaluation of glenoid bone loss after first-time and recurrent anterior glenohumeral instability events

Background:Determining the amount of glenoid bone loss in patients after anterior glenohumeral instability events is critical to guiding appropriate treatment. One of the challenges in treating the...

Prospective Evaluation of Glenoid Bone Loss After First-time and Recurrent Anterior Glenohumeral Instability Events

Background: Determining the amount of glenoid bone loss in patients after anterior glenohumeral instability events is critical to guiding appropriate treatment. One of the challenges in treating the shoulder instability of young athletes is the absence of clear data showing the effect of each event. Purpose: To prospectively determine the amount of bone loss associated with a single instability event in the setting of first-time and recurrent instability. Study Design: Cohort study; Level of evidence, 2. Methods: The authors conducted a prospective cohort study of 714 athletes surveilled for 4 years. Baseline assessment included a subjective history of shoulder instability. Bilateral noncontrast shoulder magnetic resonance imaging (MRI) was obtained for all participants with and without a history of previous shoulder instability. The cohort was prospectively followed during the study period, and those who sustained an anterior glenohumeral instability event were identified. Postinjury MRI with contrast was obtained and compared with the screening MRI. Glenoid width was measured for each patient’s pre- and postinjury MRI. The projected total glenoid bone loss was calculated and compared for patients with a history of shoulder instability. Results: Of the 714 athletes (1428 shoulders) who were prospectively followed during the 4-year period, 22 athletes (23 shoulders) sustained a first-time anterior instability event (5 dislocations, 18 subluxations), and 6 athletes (6 shoulders) with a history of instability sustained a recurrent anterior instability event (1 dislocation, 5 subluxations). On average, there was statistically significant glenoid bone loss (1.84 ± 1.47 mm) after a single instability event (P < .001), equivalent to 6.8% (95% CI, 4.46%-9.04%; range, 0.71%-17.6%) of the glenoid width. After a first-time instability event, 12 shoulders (52%) demonstrated glenoid bone loss ≥5% and 4 shoulders, ≥13.5%; no shoulders had ≥20% glenoid bone loss. Preexisting glenoid bone loss among patients with a history of instability was 10.2% (95% CI, 1.96%-18.35%; range, 0.6%-21.0%). This bone loss increased to 22.8% (95% CI, 20.53%-25.15%; range, 21.2%-26.0%) after additional instability (P = .0117). All 6 shoulders with recurrent instability had ≥20% glenoid bone loss. Conclusion: Glenoid bone loss of 6.8% was observed after a first-time anterior instability event. In the setting of recurrent instability, the total calculated glenoid bone loss was 22.8%, with a high prevalence of bony Bankart lesions (5 of 6). The findings of this study support early stabilization of young active patients after a first-time anterior glenohumeral instability event.

Imaging Quantification of Glenoid Bone Loss in Patients With Glenohumeral Instability: A Systematic Review.

To listen to the podcast associated with this article, please select one of the following: iTunes, Google Play, or direct download. OBJECTIVE. The purpose of this study is to determine the most accurate imaging techniques to measure glenoid bone loss in anterior glenohumeral instability through a systematic review of existing literature. MATERIALS AND METHODS. We performed a comprehensive literature search of five databases for original research measuring glenoid bone loss at radiography, CT, or MRI, using prospective or retrospective cohort, case-control, or cadaveric study designs up to January 2018. The Quality Assessment of Diagnostic Accuracy Studies-2 tool aided qualitative assessment of the methods. Data extraction included results, index test interobserver agreement, and accuracy analysis. RESULTS. Twenty-seven studies (evaluating 1425 shoulders) met inclusion criteria after full-text review by two independent readers. Glenoid bone loss was assessed, comparing several index tests to nonimaging (n = 18 studies) and imaging (n = 11) reference standards. Compared with arthroscopic or cadaveric measurements, 2D CT was accurate in six of seven studies (86%), 3D CT was accurate in eight of 10 studies (80%), 2D MRI was accurate in five of seven studies (71%), 3D MRI was accurate in four of four studies (100%), and radiographs were accurate in zero of four studies (0%). Best-fit circle methods (glenoid width or Pico surface area) were the most common and both were accurate (86-90% and 75-100%, respectively) using CT and MRI. Studies had good external validity (78%). Most risk for bias arose from patient selection and reference standards. Only two studies reported sensitivity and specificity, both comparing CT to arthroscopy using different bone loss thresholds (20% and 25%). CONCLUSION. CT and MRI (2D or 3D) accurately measure glenoid bone loss in anterior shoulder instability, but radiographs do not. Best-fit circle measurement techniques are reliable and accurate. Current literature about glenoid bone loss is heterogeneous, and future studies should focus on diagnosis of clinically relevant glenoid bone loss.

Prospective Evaluation of Glenoid Bone Loss After First-Time and Recurrent Anterior Glenohumeral Instability Events

Objectives:Determining the amount of glenoid bone loss in patients following anterior glenohumeral instability events is critical to guiding appropriate treatment. One of the challenges in managing shoulder instability in young athletes is the absence of clear data showing the impact of each event. The purpose of this study was to prospectively determine the amount of bone loss associated with a single instability event, in the setting of both first-time and recurrent instability.Methods:We conducted a prospective cohort study of 714 athletes followed for four years. Baseline assessment included a subjective history of shoulder instability. Bilateral shoulder MRIs were obtained in all participants with and without a history of previous shoulder instability. The cohort was prospectively followed during the study period and those who sustained an anterior glenohumeral instability event were identified. A post-injury MRI was obtained and compared to the screening MRI. Glenoid width was measured for each patient’s pre- and post-injury MRI. The projected total glenoid bone loss was calculated and compared for patients with a prior history of shoulder instability.Results:Of the 714 athletes that were prospectively followed during the four-year period, 23 shoulders in 22 subjects sustained a first-time anterior instability event (5 dislocations, 18 subluxations), and six subjects with a previous history of instability sustained a recurrent anterior instability event (1 dislocation, 5 subluxations). On average, there was statistically significant glenoid bone loss (1.84 ± 1.47 mm) following a single instability event (p<0.001), equivalent to 6.8% (95% CI: 4.46%, 9.04%, range 0.71%-17.6%) of the glenoid width. Twelve shoulders (52%) demonstrated glenoid bone loss ≥ 5%, 4 shoulders demonstrated glenoid bone loss ≥13.5% and no shoulders had ≥20% glenoid bone loss after a first-time instability event. Pre-existing glenoid bone loss in subjects with a history of instability was 10.2% (95% CI: 1.96%, 18.35%, range 0.6% - 21.0%). This bone loss increased to 22.8% (95% CI: 20.53%, 25.15%, range 21.2% to 26.0%) following an additional instability event (P=0.0117). All six shoulders with recurrent instability had >20% glenoid bone loss.Conclusion:Glenoid bone loss of 6.8% was observed after a first-time anterior instability event. In the setting of recurrent instability, the total calculated glenoid bone loss was 22.8% with a high prevalence of bony Bankart lesions (5/6). The findings of this study support early stabilization of young, active subjects following a first-time anterior glenohumeral instability event.Figure 2.Clinical demonstration of a sagital en face MRI obtained prior to any instability event (A) and following a single subluxatiion event (B) with 14% bone loss and a bony Bankart.Table 2:Glenoid Bone Loss in First-time and Recurrent Instability CohortsInstability TypeNo. ShouldersΔ Glenoid Width (mm)ΔGlenoid Width (%)Total Glenoid Bone Loss* (%)P valueFirst-time231.85 ± 1.496.8%6.8%< .0001Recurrent63.75± 2.3713.6%22.8%.0117