Shoulder Instability In Patients Research Articles

The Arthroscopic Subscapular Sling Procedure Results in Low Recurrent Anterior Shoulder Instability at 24 Months of Follow-Up

The purpose of this study was to analyze the results of the subscapular sling procedure developed for anterior shoulder instability in patients with less than 10 % anterior glenoid bone loss. The aim was to explore if this procedure would be successful in preventing recurrent shoulder dislocation. Patients were treated surgically with the arthroscopic subscapular sling procedure. A semitendinosus graft was used to reconstruct the anterior labrum and to establish a sling suspension around the upper part of the subscapularis tendon. The patients were followed by x-ray (12 and 24 months). Magnetic resonance imaging (MRI) of the shoulder region and clinical examinations were performed at 3, 12 and 24 months. Recurrent dislocation was the primary endpoint. The Western Ontario Shoulder Instability Index (WOSI) and MRI results were secondary outcome measures. An independent physiotherapist assessed residual instability and ROM. Fifteen patients were included with a dislocation rate of zero % after 24 months follow-up. There was a significant clinical improvement of the WOSI score from 57 % (904) at baseline to 88 % (241) at 24 months (p < 0.001). The proportion of patients with an improvement in the WOSI Total score larger than the estimated Minimal Clinically Important Difference (MCID) was 100% both at 12 and 24 months. MRI showed an intact sling in all patients. External rotation was not significantly reduced (52° at baseline vs 47° at 24 months, p = 0.211). Flexion and abduction were significantly improved from 152° to 174° (p=0.001) and 141° to 170° (p<0.001) after 24 months. The surgical procedures were completed without any intraoperative complications. The subscapular sling procedure resulted in low recurrent shoulder instability and improved patient-reported outcome measures at 24-months follow-up.

Rotator Cuff Tears are Significantly More Frequent in Recurrent Shoulder Instability Patients With Initial Dislocation at Age 40 or Older

PurposeThe purpose of this study was to investigate and compare the pathologies and clinical outcomes of patients with traumatic anterior shoulder instability who underwent arthroscopic stabilization at 40 years or older between shoulders with initial dislocation before and after 40 years old. MethodsShoulders that underwent arthroscopic stabilization for recurrent traumatic anterior shoulder instability at 40 years or older with a minimum of two-year follow-up were included. The subjects were divided into two groups according to the age at initial dislocation after a propensity score matching to reduce potential bias: Group 1, < 40 years old; Group 2, ≥40 years. Radiographic findings, pathologies, clinical outcomes, and complications were compared between the groups ResultsGroup 1 included 56 shoulders in 56 patients (26 males and 30 females) with a mean age of 51 (range, 40-77) years. Group 2 included 28 shoulders in 28 patients (13 males and 15 females) with a mean age of 51 (range, 40-77) years. The glenoid bone loss was greater in Group 1 than in Group 2 (p=.004). Rotator cuff tears were more frequently observed in Group 2 than in Group 1 (P<.001). Both groups demonstrated significant improvement in the West Ontario Shoulder Instability Index (P<.001 for each) and flexion (P<.001 for each). Recurrence was seen in 4% in Group 1 and 7% in Group 2. ConclusionsThe incidence of concomitant rotator cuff tears was significantly higher in shoulders with initial dislocation after 40 years than those before. Arthroscopic stabilization yielded a low recurrence rate and favorable outcomes with good sports return in patients 40 years or older.

Arthroscopic Posterior Glenoid Osteotomy

Management of posterior shoulder instability in patients with excessive glenoid retroversion can be challenging. However, a corrective posterior glenoid osteotomy is an option. Although various open techniques are available, minimally invasive and arthroscopy surgery are the most advantageous. This study describes the feasibility and safety of an arthroscopic posterior open wedge glenoid osteotomy using an autologous scapular spine graft along with additional posterior capsulolabral complex reattachment. This procedure is a viable option for patients with symptomatic posterior shoulder instability.

Biomechanical comparison of open Bankart repair vs. conjoint tendon transfer in a 10% anterior glenoid bone loss shoulder instability model

The treatment of shoulder instability in patients with subcritical glenoid bone loss poses a difficult problem for surgeons as new evidence supports a higher failure rate when a standard arthroscopic Bankart repair is used. The purpose of this study was to compare a conjoint tendon transfer (soft-tissue Bristow) to an open Bankart repair in a cadaveric instability model of 10% glenoid bone loss. Eight cadaveric shoulders were tested using a custom testing system that allows for a 6-degree-of-freedom positioning of the glenohumeral joint. The rotator cuff muscles were loaded to simulate physiologic muscle conditions. Four conditions were tested: (1) intact, (2) Bankart lesion with 10% bone loss, (3) conjoint tendon transfer, and (4) open Bankart repair. Range of motion, glenohumeral kinematics, and anterior-inferior translation at 60° of external rotation with 20 N, 30 N, and 40 N were measured in the scapular and coronal planes. Glenohumeral joint translational stiffness was calculated as the linear fit of the translational force-displacement curve. Force to anterior-inferior dislocation was also measured in the coronal plane. Repeated measures analysis of variance with a Bonferroni correction was used for statistical analysis. A Bankart lesion with 10% bone loss increased the range of motion in both the scapular (P=.001) and coronal planes (P=.001). The conjoint tendon transfer had a minimal effect on the range of motion (vs. intact P=.019, .002), but the Bankart repair decreased the range of motion to intact (P=.9, .4). There was a significant decrease in glenohumeral joint translational stiffness for the Bankart lesion compared with intact in the coronal plane (P=.021). The conjoint tendon transfer significantly increased stiffness in the scapular plane (P=.034), and the Bankart repair increased stiffness in the coronal plane (P=.037) compared with the Bankart lesion. The conjoint tendon transfer shifted the humeral head posteriorly at 60° and 90° of external rotation in the scapular plane. The Bankart repair shifted the head posteriorly in maximum external rotation in the coronal plane. There was no significant difference in force to dislocation between the Bankart repair (75.8±6.6 N) and the conjoint tendon transfer (66.5±4.4 N) (P=.151). In the setting of subcritical bone loss, both the open Bankart repair and conjoint tendon transfer are biomechanically viable options for the treatment of anterior shoulder instability; further studies are needed to extrapolate these data to the clinical setting.

Mask Region-Based Convolutional Neural Network segmentation of the humerus and scapula from proton density-weighted axial shoulder magnetic resonance images.

This study aimed to evaluate the effectiveness of Mask Region-Based Convolutional Neural Network (R-CNN) in humerus and scapula segmentation. The study included 665 axial proton density (PD)-weighted magnetic resonance images of 665 consecutive shoulder instability patients (412 males, 253 females; mean age: 27±5.2 years; range, 18 to 42 years) between January 2011 and December 2014. Mask R-CNN was used to automatically segment humerus and scapula regions simultaneously. Segmentation success of Mask R-CNN was compared to the manual segmentation results of an orthopedic surgeon. Statistical evaluation was done with the Dice coefficient and the mean average precision) score. According to the humeral head structure three groups were generated: the healthy humeral head group, the edematous humeral head group, and the Hill-Sachs group (humeral heads with Hill-Sachs lesions). In the test images, 81 humeral heads were healthy, 100 were edematous, and 38 had a Hill-Sachs lesion. According to the Dice metric, the overall success rate of Mask R-CNN configuration was 96.47 and 93.87% for the segmentation of the humeral head and scapula, respectively, and 95.86 and 92.35% for an intersection over union of 0.5 according to the mean average precision. According to the Dice metric, the segmentation success of the humerus and scapula of the healthy group was 94.58 and 97.42%, the segmentation success of the edematous humerus group was 93.56 and 96.53%, and the segmentation success of the Hill-Sachs group was 93.47 to 95.48%. The segmentation success of scapula in the case of discontinuity was 92.86% according to Dice metric. Mask R-CNN-based humerus and scapula segmentation provided promising results compared to manual segmentation of an expert. Mask R-CNN overcomes the problem of discontinuous edges and Rician noise in axial PD-weighted shoulder magnetic resonance imaging.

Poster 366: EVALUATION OF A DEPRESSION SCREENING PROGRAM IN PEDIATRIC ORTHOPAEDIC SPORTS CLINICS: WHICH PATIENTS ARE IDENTIFIED AS AT RISK?

Objectives: Universal depression screening of patients ≥12 years of age was instituted at our facility in 2018 in an effort to combat the suicide rate among teenagers. The purpose of this study was to quantify the significance of depression in adolescents being treated within a sports clinic at a pediatric institution and attempt to identify predictors of at risk patients. Methods: A retrospective review was performed to identify all patients, ages 12-21 years, who were administered the Patient Health Questionnaire (PHQ-2/PHQ-9) over a 2-year period within our pediatric orthopaedic sports clinics. Patients were grouped into four broad diagnostic categories; knee instability, knee other, other sports related, or shoulder injury. The rate of a positive screen prompting administration of PHQ9 (PHQ2&gt;3), rate of depression risk (PHQ9≥10), and rate of patients indicating self-harm were evaluated. Multivariate binary logistic regression to identify available demographic and diagnosis predictors of risk of self-harm was performed. Results: There were 3,298 patients screened in orthopedic sports clinics from 2018-2021. The overall rate of positive screens was 4.2% (n=138), rate of depression risk was 1.9% (n=63), and self-harm was 0.9% (n=29). The distribution of these rates for each diagnostic category are seen in Table 1. Self-harm showed a significant difference in the proportion at risk across the four diagnostic categories (p=0.038), with shoulder and knee instability having the highest rate. Black or African American race (OR 3.8, 95% CI 1.3-11, p=0.02), female gender (OR 3 95%CI 1.3-6.9, p=0.01), public/government insurance (OR 3.8, 95% CI 1.3-11, p=0.02), shoulder diagnosis (OR 3.5 95%CI 1.3-9.4, p=0.016), and knee instability diagnosis (OR 2.8 95%CI 1.2-6.5, p=0.02) were associated with increased risk of self-harm. Conclusions: This study demonstrated a 2% rate of depression risk and 1% rate of self-harm risk in this adolescent population being treated within sports clinics. Variability in rate of risk was identified, with the shoulder and knee instability patients having higher risk profiles. Aside from diagnosis groups, gender, race, and insurance were factors that were also independently predictive of patients at risk for depression or self-harm. Knowledge of risk factors can help increase awareness and recognition of potential mental health conditions that may need addressing during the course of treatment for the sports-related injury. [Table: see text]

Paper 04: Acromial Morphology Differences in Primary versus Revision Posterior Shoulder Instability Patients

Objectives: Predisposing factors for failure of shoulder posterior stabilization surgery are not well defined. Characterization of revision posterior instability patients allows for insight into potentially identifiable risk factors for failure. Methods: A series of patients who underwent stabilization surgery for posterior shoulder instability as well as revision posterior instability cases performed between 2005-2019 were identified. Patient demographics were collected and glenoid morphology was quantified by measuring posterior bone loss, acromial tilt, and posterior acromial height on shoulder MRIs. Continuous variables were compared with Student’s t-test. Results: 42 active duty servicemembers who underwent successful primary posterior stabilization (primaries, P) and 41 who underwent revision posterior stabilization (revisions, R) and were identified. Mean ages of the primaries and revisions at time of primary surgery were 28.7 (±6.0; 18-39) and 23.0 (±5.2; 18-41) years respectively (p &lt; 0.005). Males made up 92.9% (P) and 92.7% (R) of each group. Mean posterior glenoid bone loss at index MRI was 4.5% (±7.2; P) and 6.3% (±7.8; R) (p = 0.316). Mean index acromial tilt (from horizontal) was 40.9 degrees (±10.2; P) and 28.8 degrees (±10.6; R) (p &lt; 0.005). Index posterior acromial height was 14.2 mm (±7.4; P) and 19.8 mm (±7.6; R) (p = 0.001). In the revision group, the progression of bone loss from index MRI to pre-revision MRI was 6.3% (±7.8) to 6.6% (±6.2) (p = 0.456). Index bone loss greater than 15% was present in 5/41 revision patients; when excluding these, mean index bone loss was 3.4% (±3.3), significantly less than that at pre-revision MRI (p = 0.038). Additional surgery occurred in 9.8% (4/41) of the revision group, and 2/4 separated from the military. In the revision group, 17.1% (7/41) separated, while an additional 7.3% (3/41) remained on active duty with upper extremity activity limitations. Conclusions: Index acromial tilt and posterior acromial height were respectively lower and higher in a population of revision posterior stabilization than in a cohort of patients who underwent successful posterior stabilization. A “high and flat” acromial morphology may predispose patients to failure of standard posterior stabilization procedures, potentially justifying further study into supplemental techniques to decrease failure risk.

Remplissage reduces recurrent instability in high-risk patients with on-track Hill-Sachs lesions.

The purpose of this study was to compare recurrent instability rates between patients with on-track Hill-Sachs lesions who underwent arthroscopic labral repair (ALR) alone and those who underwent ALR with remplissage (ALR-R). Our hypothesis was that ALR-R would decrease the rate of recurrent instability, especially among patients at high risk of recurrent instability after ALR, such as contact athletes with near-track Hill-Sachs lesions. We performed a multicenter, retrospective analysis of patients aged 14-50 years with on-track Hill-Sachs lesions who underwent ALR-R or ALR without remplissage between January 2014 and December 2019 with minimum 2-year follow-up. The exclusion criteria included prior ipsilateral shoulder surgery, >15% glenoid bone loss (GBL), off-track Hill-Sachs lesion, concomitant shoulder procedure, and connective tissue disorder. Age, sex, follow-up, and contact sports participation were recorded. GBL, Hills-Sachs interval (HSI), glenoid track, and distance to dislocation (DTD) were determined from preoperative magnetic resonance imaging scans. Affected-shoulder range of motion, Western Ontario Shoulder Instability Index scores, Subjective Shoulder Value scores, and recurrent dislocation and/or revision surgery status were also collected. A subgroup analysis was performed on "high-risk" patients (defined as participants in contact sports with DTD <10 mm) from each cohort. The ALR-R cohort included 56 patients, and the ALR cohort included 127. ALR-R patients had greater GBL (P=.004) and a greater HSI (P<.001). In the ALR-R cohort, only 1 patient (1.8%) had a recurrent dislocation and there were no revision operations. In comparison, in the ALR cohort, 14 patients (11.0%) had recurrent dislocations (P=.040) and 8 (6.3%) underwent revision operations (P=.11). Univariate analysis showed that remplissage protected against recurrent dislocation (P=.040) whereas younger age (P=.004), contact sports participation (P=.001), and increased GBL (P=.048) were associated with recurrent dislocation. Multivariate analysis showed that HSI (P=.001) and contact sports participation (P=.002) predicted recurrent dislocation. Among high-risk patients, only 1 patient (4.2%) in the ALR-R group had a recurrent instability event vs. 6 (66.7%) in the ALR group (P<.001). The high-risk ALR-R subgroup also had significantly better final Western Ontario Shoulder Instability Index (P=.008) and Subjective Shoulder Value (P=.001) scores than the high-risk ALR subgroup. Anterior shoulder instability patients with on-track Hill-Sachs lesions have lower recurrent dislocation rates after ALR plus remplissage when compared with ALR alone. This is especially true for high-risk patients, such as contact athletes with a DTD <10 mm.

Management of Shoulder Instability in Patients with Seizure Disorders

Patients with seizure disorders commonly suffer shoulder dislocations and subsequent instability. Due to high rates of recurrence and bone loss, management of this instability and associated pathology has proven to be more complex than that of patients without seizure disorders. The ultimate goal of this review is to outline the various treatment modalities and their respective outcomes in this complex patient population. Optimization of medical management of seizure disorders is imperative. However, despite these efforts, the incidence of post-operative seizure activity continues to be a concern. These subsequent episodes increase the risk of further instability and failure of surgical procedures. Overall, the use of soft tissue procedures has proven to result in increased recurrence of instability compared to bone-block augmenting and grafting procedures. There are a variety of bone-block procedures that have been described for anterior and posterior instability. Despite their success in decreasing further instability, they are associated with several complications that patients should be informed of. There is no consensus regarding the optimal surgical management of shoulder instability in patients with seizure activity. A multidisciplinary approach to the management of the seizure activity is paramount to the success of their treatment. Further studies are required to evaluate the optimal timing and type of surgical intervention for individualized cases.

Surgical treatment of shoulder instability in active-duty service members with subcritical glenoid bone loss: Bankart vs. Latarjet.

Subcritical bone loss has been identified as a risk factor for potentially inferior outcomes following typical arthroscopic soft tissue repair. One alternative that has been presented as an option for patients with bone loss is the Latarjet, an ipsilateral coracoid transfer to the anteroinferior glenoid. The purpose of this study is to compare the outcomes between the arthroscopic Bankart repair and the open Latarjet for the treatment of anterior shoulder instability in patients with subcritical bone loss. We hypothesize that the open Latarjet will provide higher patient-reported outcome measure scores and lower rates of dislocation. A retrospective cohort comparison of patients with anterior glenohumeral instability procedures was performed. Inclusion criteria included symptomatic anterior shoulder instability, subcritical glenoid bone loss (13.5%-24%), surgical treatment with arthroscopic Bankart repair or open Latarjet, and minimum follow-up of 2 years. Outcomes included recurrent instability (defined as postoperative dislocation or subjective subluxation), permanent physical restrictions, Western Ontario Shoulder Index (WOSI), and Single Assessment Numeric Evaluation (SANE) scores. Forty-seven patients were included, 25 of whom underwent an arthroscopic Bankart repair and 23 patients an open Latarjet. The average bone loss was 17.8% and 19.3%, respectively. Overall, 8 patients experienced recurrent instability, 6 in the arthroscopic Bankart group and 2 in the open Latarjet group (P=.162). The average postoperative SANE score for arthroscopic Bankart group was 48% and for the open Latarjet group, 84% (P<.001). The average postoperative WOSI score for the arthroscopic Bankart group was 53.6% and for the open Latarjet group, 67.9% (P=.069). There were significantly more patients placed on permanent physical restrictions in the arthroscopic Bankart repair group (16) compared with open Latarjet (3) (P<.001). In patients with subcritical glenoid bone loss (defined as 13.5%-24%), patients treated with an open Latarjet have insignificantly higher SANE and WOSI scores and lower permanent physical restrictions than patients treated with an arthroscopic Bankart repair. We found no statistically significant difference in recurrent instability rates between the open Latarjet and arthroscopic Bankart repair (P=.162).

Cost-effectiveness analysis of arthroscopic Bankart repair versus open Latarjet reconstruction in anterior shoulder instability.

The ideal surgical treatment for anterior shoulder instability is still under debate. In the healthcare setting, both clinical and economic factors must be considered for optimal resource allocation. From the clinical perspective, the Instability Severity Index Score (ISIS) is a helpful and validated tool for surgeons, although a gray area between 4 and 6 exists. In fact, patients with an ISIS < 4 and > 6 can be treated effectively with arthroscopic Bankart repair and open Latarjet, respectively. The purpose of this study was to conduct a cost-effectiveness analysis of arthroscopic Bankart repair versus open Latarjet in patients with an ISIS between 4 and 6. A decision-tree model was constructed to simulate the clinical scenario of an anterior shoulder dislocation patient with an ISIS between 4 and 6. Based on previously published literature, outcome probabilities and utility values in the form of Western Ontario Instability Score (WOSI) were assigned to each branch of the tree, alongside institutional cost. The primary outcome assessed was an Incremental cost-effectiveness ratio (ICER) of the two procedures. Eden-Hybbinette was also considered in the model as a salvage procedure for failed Latarjet. A two-way sensitivity analysis was performed to identify the most impactful parameters on the ICER upon their variation within a pre-determined interval. Base case cost was 1245.57 € (1220.48-1270.65 €) for arthroscopic Bankart repair, 1623.10 € (1580.82-1665.39 €) for open Latarjet and 2.373.95 € (1940.81-2807.10 €) for Eden-Hybbinette. Base-case ICER was 9570.23 €/WOSI. Sensitivity analysis showed that the most impactful parameters were the utility of arthroscopic Bankart repair, the probability of success of open Latarjet, the probability of undergoing surgery after post-operative recurrence of instability and the utility of Latarjet. Of these, utility of arthroscopic Bankart repair and Latarjet had the most significant impact on the ICER. From a hospital perspective, open Latarjet was more cost-effective than arthroscopic Bankart repair in preventing further shoulder instability in patients with an ISIS between 4 and 6. Despite its several limitations, this is the first study to analyze this subgroup of patients from a European hospital setting from both an economic and clinical perspective. This study can help surgeons and administrations in the decision-making process. Further clinical studies are needed to prospectively analyze both aspects to further delineate the best strategy.

Management of Shoulder Instability in Patients with Underlying Hyperlaxity.

Shoulder instability in patients with underlying joint hyperlaxity can be challenging to treat. Poorly defined terminology, heterogeneous treatments, and sparse reports on clinical outcomes impair the development of best practices in this patient population. This article provides a review of the current literature regarding optimal management of patients suffering from shoulder instability with concomitant hyperlaxity of the shoulder, from isolated shoulder joint hyperlaxity to congenital hypermobility spectrum disorders (HSD). Current research shows specialized physiotherapy protocols focused on strengthening of periscapular muscles and improvement of sensorimotor control are a promising non-surgical therapeutic avenue in certain patients, which can be augmented by device-based intervention in select cases. If surgical treatment is warranted, arthroscopic techniques such as pancapsular shift or plication continue to demonstrate favorable outcomes and are currently considered the benchmark for success. The long-term success of more recent innovations such as coracoid process transfers, conjoint tendon transfers, subscapularis tendon augmentation, and capsular reconstruction remains unproven. For patients affected by connective tissue disorders, treatment success is generally less predictable, and the entire array of non-operative and operative interventions needs to be considered to achieve the best patient-specific treatment results. In the treatment of shoulder instability and concomitant hyperlaxity, specialized physiotherapy protocols augmented by device-based interventions have emerged as powerful, non-operative treatment options for select patients. Successful surgical approaches have been demonstrated to comprehensively address capsular redundancy, labral lesions, and incompetence of additional passive stabilizers in a patient-specific fashion, respective of the underlying connective tissue constitution.

Arthroscopic Remplissage Combined With Bankart Repair Results in a Higher Rate of Return to Sport in Athletes Compared With Bankart Repair Alone or the Latarjet Procedure: A Systematic Review and Meta-analysis

Background: Traumatic anterior shoulder instability affects athletes at a higher rate compared with the general population. In recent years, indications for arthroscopic remplissage, an adjunct procedure classically used to reduce the recurrence of anterior shoulder instability in patients with off-track Hill-Sachs lesions, have expanded. Purpose: To investigate return-to-sport (RTS) rates, functional outcomes, and adverse events in athletes who underwent arthroscopic Bankart repair with remplissage compared with surgical alternatives such as Bankart repair alone or the Latarjet procedure. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: A literature review of the Embase, PubMed (MEDLINE), and Web of Science databases was conducted for articles published before May 22, 2022. For the systematic review, 16 of 457 studies that reported RTS rates at any time point after remplissage were deemed eligible for inclusion in quantitative analysis and 17 of 457 studies in qualitative analysis. For the meta-analysis, 8 of 457 studies reported RTS rates after remplissage compared with surgical alternatives including Bankart repair alone or the Latarjet procedure and were deemed eligible for inclusion. Results: In total, 538 athletes underwent remplissage and were included in the study. RTS at any level was achieved by 86% (395/457) of patients, and the odds of RTS at any level were significantly higher after remplissage compared with surgical alternatives (odds ratio [OR], 2.71 [95% CI, 1.14-6.43]; P = .02). The odds of RTS at a previous or higher level were also significantly higher after remplissage compared with surgical alternatives (OR, 2.07 [95% CI, 1.29-3.31]; P = .002). The mean Rowe score increased significantly from 43.9 ± 7.77 preoperatively (n = 173) to 92.2 ± 4.02 after remplissage (n = 397) (P < .001), but there was no significant difference in Rowe scores between remplissage and surgical alternatives (P = .54). After remplissage, the recurrence rate was 5.0% for athletes (n = 220) and 7.3% for all patients (n = 634), with a mean time to recurrence of 24.0 ± 12.5 months. Reoperations occurred in 3.6% of athletes (n = 110) and 4.1% of all patients (n = 445). Recurrence and reoperations were significantly less likely after remplissage compared with surgical alternatives (OR, 0.18 [95% CI, 0.08-0.39]; P < .001 and OR, 0.17 [95% CI, 0.06-0.50]; P = .001, respectively). Conclusion: Arthroscopic Bankart repair with remplissage augmentation significantly improved RTS rates among athletes, both at any level and at previous levels of play. Additionally, remplissage appeared to significantly decrease recurrence and reoperation rates compared with surgical alternatives such as Bankart repair alone or the Latarjet procedure.

Anterior Shoulder Instability and Open Procedures: History, Indications, and Clinical Outcomes.

The shoulder, being the most mobile joint in the human body, is often susceptible to dislocations and subluxations more so than other joints. As such, shoulder instability constitutes a common complaint among patients worldwide, especially those who are young, participate in contact sports, and have increased innate flexibility in their joints. Management options in the setting of instability vary between conservative and surgical options that aim to mitigate symptoms and allow return of function. Surgical options can be arthroscopic and open, with a general shift among surgeons towards utilizing arthroscopic surgery in the past several decades. Nevertheless, open procedures still play a role in managing shoulder instability patients, especially those with significant bone loss, recurrent instability, coexisting shoulder pathologies, and high risk of failure with arthroscopic surgery. In these clinical settings, open procedures, like the Latarjet procedure, open Bankart repair, glenoid bone augmentation using iliac crest autograft or distal tibial allograft, and salvage options like glenohumeral arthrodesis and arthroplasty may show good clinical outcomes and low recurrence rates. Each of these open procedures possesses its own set of advantages and disadvantages and entails a specific set of indications based on published literature. It is important to cater treatment options to the individual patient in order to optimize outcomes and reduce the risk of complications. Future research on open shoulder stabilization procedures should focus on the long-term outcomes of recently utilized procedures, investigate different graft options for procedures involving bone augmentation, and conduct additional comparative analyses in order to establish concrete surgical management guidelines.

Natural History of First-Time Anterior Shoulder Dislocation in Patients Older Than 50 Years: A Study of 179 Patients With a Mean Follow-up of 11 Years.

There is a dearth of knowledge on anterior shoulder instability in older patients. The purposes of this study were to describe the incidence and epidemiology, injury characteristics, and treatment and outcomes in patients ≥50 years old with first-time anterior shoulder instability. We also describe the historical trends in diagnosis and treatment. It was hypothesized that the rates of obtaining a magnetic resonance imaging (MRI) scan and surgical intervention have increased over the past 20 years. Descriptive epidemiology study. An established geographic database was used to identify 179 patients older than 50 years who experienced new onset anterior shoulder instability between 1994 and 2016. Medical records were reviewed to obtain patient characteristics, imaging characteristics, and surgical treatment and outcomes, including recurrent instability. Comparative analysis was performed to identify differences between age groups. Mean follow-up time was 11 years. The incidence of first-time anterior shoulder dislocation in our study population was 28.8 per 100,000 person-years, which is higher than previously reported. Full-thickness rotator cuff tears were found in 62% of the 66 patients who underwent MRI scans. Of all patients, 26% progressed to surgery at a mean time of 1.6 years after injury; 57% of all surgical procedures involved a rotator cuff repair, and 17% included anterior labral repair. All patients who underwent a labral repair also underwent concomitant rotator cuff repair. The rate of recurrent instability for the cohort was 15% at a median of 176 days after the initial instability event. There were no instances of recurrent instability after operative intervention. At an average of 7.5 years after the initial instability event, 14% of patients developed radiographic progression of glenohumeral arthritis. The rate of surgical intervention within 1 year of initial dislocation increased from 5.1% in 1994 to 1999 to 52% in 2015 to 2016. The incidence of first-time anterior shoulder instability in patients aged ≥50 years was 28.8 per 100,000 person-years. Full-thickness rotator cuff tears (62%) were the most common condition associated with anterior shoulder instability, followed by Hill-Sachs lesions (56%). The rate of recurrent instability for the entire cohort was 15%, with no instances of recurrent instability after operative intervention.

Anteroinferior Glenoid Rim Fractures Are a Relatively Common Finding in Shoulder Instability Patients Aged 50 Years or Older but May Not Portend a Worse Prognosis

PurposeTo investigate the incidence of anteroinferior glenoid rim fractures (AGRFs) after anterior shoulder instability (ASI) in patients aged 50 years or older, identify risk factors for surgical intervention for AGRFs, compare initial treatment strategies, and compare clinical outcomes of patients with and without associated AGRFs.MethodsAn established geographic medical record system was used to identify patients aged 50 years or older with ASI between 1994 and 2016. Patients with radiographic evidence of AGRFs were identified and matched 1:1 to patients without AGRFs. Outcome measures included recurrent instability, recurrent pain events, conversion to arthroplasty, and osteoarthritis graded with the Samilson-Prieto classification for post-instability arthritis.ResultsOverall, 177 patients were identified, with a mean follow-up period of 10.8 years. Of these patients, 41 (23.2%) had AGRFs and were matched to 41 control patients without AGRFs. The average age was 58.6 and 58.2 years for the AGRF and control groups, respectively. Rates of surgical intervention (27% vs 49%), recurrent instability (12% vs 20%), progression of osteoarthritis (34% vs 39%), and conversion to arthroplasty (2% vs 5%) were similar between AGRF patients and controls. For patients with AGRFs, increased bone fragment size (odds ratio, 1.1) and increased body mass index (odds ratio, 1.2) correlated with an increased risk of surgery. The cutoff value for an increased risk of surgery in patients with AGRFs was a fragment size 33% of the glenoid width or greater.ConclusionsOf patients aged 50 years or older at presentation of ASI, 23.2% presented with an associated AGRF. A fragment size 33% of the glenoid width or greater and a higher patient body mass index were significant factors for surgical intervention; however, most patients did not require surgery and still showed acceptable clinical outcomes, and the most common reason for surgical intervention was a rotator cuff tear. Overall, the presence of an AGRF did not portend a worse prognosis as treatment strategies and long-term outcomes including recurrent instability, progression of osteoarthritis, and conversion to arthroplasty were similar to those in patients without AGRFs.Level of EvidenceLevel III, retrospective comparative study.

The Glenoid Track Concept: On-Track and Off-Track—A Narrative Review

Shoulder instability is described as a functional deficiency caused by excessive mobility of the humeral head over the glenoid. Various Glenohumeral Instability (GI) types have been described, but the traumatic anteroinferior form is the most frequent. The differences between engaging and non-engaging Hill–Sachs lesions (HSLs) are linked to bone loss assessment. On the contrary, the novel difference between “on-track” and “off-track” lesions is strictly related to surgical techniques. The specific involvement of glenoid and humerus bone defects in recurrent GI was poorly assessed in the literature before the glenoid-track concept (GT). Magnetic Resonance Imaging (MRI) and Arthro-MRI have been widely used to identify and characterize lesions to the ligamentous structures. However, only new technologies (3 Tesla MRI) accurately detect HSLs. On the contrary, Computed Tomography (CT) has been adopted to quantify glenoid bone deficit. The GT concept is a valuable tool for evaluating anterior shoulder instability in patients. Shoulders out of alignment may require more than just an arthroscopic Bankart, and a remplissage or bone transfer may be necessary. Specifically, isolated Bankart repair should be considered in patients with recurrent instability and an on-track lesion with less than 25% glenoid bone loss. In off-track lesions and less than 25% glenoid bone loss, remplissage should be used. Bone transplant surgery is required for patients with a glenoid bone defect of more than 25%. This narrative review aims to report the most updated findings on “on-track” and “off-track” lesions in GI.

Paper 74: Psychopathology and Volitional Instability: Who should we be operating on?

Objectives:There has been a hesitation by surgeons to operate on shoulder instability patients with maladaptive psychopathological traits, especially those with volitional instability, as these may portend a poor prognosis. The purpose of this study was to investigate the prevalence of maladaptive psychopathological traits, volitional instability, and their effect on two-year outcomes in patients undergoing shoulder stabilization surgery.Methods:A prospective multi-center cohort study led by the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Group targeted all subjects having surgical shoulder stabilization and collected patient-reported outcomes at baseline and at two years postoperatively. Psychopathological traits were assessed using the Personality Assessment Screener (PAS), a validated personality assessment tool. Longitudinal analyses were performed using multivariable regression models to determine predictors of two-year outcomes adjusting for confounders measured at index such as age, sex, smoking, BMI, volitional instability, and intraarticular pathology.Results:The cohort (n = 890) was 80% male with a median age of 21.5 years. The prevalence of psychopathological traits was 20%. While all patients improved between baseline and 2 years, with adjusted analyses, the presence of maladaptive psychological traits present at the time of index surgery were predictive of lower WOSI (p = 0.001), ASES (p = 0.016), SANE (p = 0.03), and SF-36 MCS (p = 0.001) scores as well as a higher risk of failure (p = 0.04) at two years. As a main effect, volitional instability was not a predictor of WOSI, ASES, SANE, SF-36 or failure at two years. However, all models allowed for the interaction between volitional instability and the PAS, and this interaction was significant for WOSI (p = 0.006), SANE (p = 0.03), and SF-36 MCS (p = 0.003) scores at two years. In other words, the effect of volitional instability on the WOSI, SANE, and SF-36 MCS scores depends on the value of the PAS, and with high PAS scores it is associated with worse outcomes. This data is depicted in Figures 1-3.Conclusions:While all patients improved, the presence of maladaptive psychopathological traits at the time of index surgery was a predictor of poorer outcomes at two years. Voluntary dislocators did similarly as non-voluntary dislocators up to a PAS score of ˜ 20, where above this they had worse WOSI, SANE, SF-36 MCS and higher failure rates at 2 years post-operatively.Figure 1.Adjusted effects of PAS score and volitional instability on WOSI score at 2 yearsFigure 2.Adjusted effects of PAS score and volitional instability by gender on predicted MCS Score at two yearsFigure 3.Adjusted effects of PAS score and volitional instability on probability of failure

Poster 165: Psychosocial Factors Play a Greater Role in Preoperative Symptoms for Patients with Atraumatic Shoulder Instability: Data from the Moon-Shoulder Instability Group

Objectives:Previous studies have demonstrated altered brain activation patterns on functional MRI for those with shoulder instability suggesting a potential link between recurrent instability, depression, and emotional wellbeing. It is unknown whether this potential link would differ between those with traumatic vs. atraumatic instability. The purpose of this study was to determine whether psychosocial factors and/or comorbid depression play a greater role in preoperative symptoms for patients with atraumatic or traumatic mechanisms of shoulder instability. We hypothesized that when controlling age, sex, and direction of instability, psychosocial factors and comorbid depression would be more predictive of shoulder-related pain and symptoms for patients with atraumatic instability than patients with traumatic instability.Methods:As part of the IRB-approved Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, 1553 patients provided informed consent and completed pre- and intraoperative data collection. Patients were categorized based on self-reports of whether the mechanism of shoulder instability was traumatic (n=1267) or atraumatic (n=286). Multivariable linear regressions were performed to determine whether psychological factors (VR12, Mental Component Score (MCS), Depression Diagnosis, PAS-22) were predictive of preop ASES and WOSI score in the atraumatic group, controlling for age, sex, and the direction of instability. The same model was repeated for the traumatic instability group, and the model fit was compared between groups using the methods described by Cohen, Cohen, and West with p < 0.05 considered statistically significant.Results:Sex and Mental Component Scores (MCS) were significantly predictive of preop ASES and WOSI scores for the group with atraumatic instability (ASES r2=0.15, p<0.001; WOSI r2=0.17 p<0.001). The same model performed significantly worse for both ASES and WOSI scores in the group with traumatic instability (ASES r2=0.06, WOSI r2=0.07, p<0.05 for both ASES and WOSI).Conclusions:Preoperative psychosocial factors were found to be more predictive of shoulder-related pain and symptoms for patients with atraumatic instability. Across multiple orthopedic conditions, depression and emotional wellbeing have been associated with worse preoperative symptoms and inferior postoperative patient-reported outcomes. As opposed to medically optimizing patients prior to surgery, the current findings identify a subset of shoulder instability patients that may need to be psychologically optimized either prior to surgery or early in the postoperative period to potentially improve postoperative outcomes.

Poster 151: Latarjet Treatment of Anterior Shoulder Instability: The Effect of Pre-Operative MRI Coracoid Dimensions on Post-Operative Outcomes

Objectives:While pre-operative coracoid dimensions have been previously evaluated utilizing CT, no studies have utilized MRI to evaluate coracoid dimensions before Latarjet surgery. Also, no studies have evaluated post-operative outcomes based on pre-operative coracoid dimensions in Latarjet patients. Therefore, the purpose is to determine the effect of coracoid length and width as measured on pre-operative imaging (MRI) on outcomes following Latarjet treatment of anterior shoulder instability. We hypothesized that patients with longer and wider coracoid dimensions would have improved post-operative outcomes after Latarjet treatment for anterior shoulder instability.Methods:Patients who underwent primary Latarjet surgery between 2009-2019 were identified. Inclusion criteria were an available pre-operative MRI and minimum of 2-year post-operative follow-up. Longitudinal coracoid length was measured on axial MRI sequences as the distance from the coracoclavicular ligament insertion to the distal tip. Width measurements were obtained perpendicular to length at three locations – the coracoid base, midpoint and tip – and then averaged. Inter-rater reliability was good for measuring both coracoid length (ICC=0.75) and coracoid width (ICC=0.76). The primary outcomes of interest were recurrent instability, re-operation, complications, rate of and time until return-to-sport (RTS), and American Shoulder and Elbow Surgeons (ASES) score. Comparisons were made between shorter vs. longer coracoid length, narrower vs. wider coracoid width, and male vs. female coracoid dimensions.Results:56 patients were included with an average age of 28.4 years and 16% were female. There were no statistically significant demographic differences between coracoid length and coracoid width groups. Coracoid length averaged 21.6 ± 2.4 mm (range: 16.7-26.9 mm), coracoid width 10.0 ± 1.0 mm (range: 8.3-13.2 mm), and glenoid bone loss 13.7% ± 8.2% (range: 0.0%-32.4%). There were 41 patients (73.2%) with harvestable coracoid length ≥ 20 mm. 55 patients received two coracoid screws for fixation, and only one patient was limited to one screw. Patients with a smaller coracoid length (<22 mm, n=30) had similar rate of recurrent instability (smaller length 6.7% vs. longer length 3.8%), complication (10.0% vs. 15.4%), re-operation (3.3% vs. 7.7%), rate of RTS (76.5% vs. 58.8%), and post-operative ASES scores (85.0 vs. 81.6) (all p>0.05), relative to patients with a larger coracoid length (>22 mm, n=26). Likewise, patients with a smaller coracoid width (<10 mm, n=29) had similar prevalence of recurrent instability (smaller width 6.9% vs. larger width 3.7%), complication (17.2% vs. 7.4%), re-operation (3.5% vs. 7.4%), rate of RTS (66.7% vs. 68.4%), and post-operative ASES scores (87.1 vs. 80.0) (all p>0.05), relative to patients with a larger coracoid length (>10 mm, n=27). Finally, male patients had a larger average coracoid width (10.1 ± 1.0 mm) than female patients (9.3 ± 0.5 mm) (p=0.001).Conclusions:This MRI protocol closely accounts for the specific landmarks utilized during the Latarjet osteotomy by focusing on identification of the CC ligament insertion. A minimum pre-operative coracoid length of 25 mm is not needed as previously stated, as anterior shoulder instability patients experience favorable post-operative outcomes after Latarjet surgery regardless of pre-operative coracoid dimensions based on our findings. Surgeons who are treating patients with significant glenoid bone loss may utilize this MRI protocol if they are concerned about the anatomy of the coracoid pre-operatively.Figure 1.Demonstration of coracoid width measurements. (Figure 2A) First, on the coronal T1 weighted oblique sequence the coracoclavicular ligaments were identified (between the red arrows), outlined by fat, including the more medial trapezoid ligament and lateral conoid ligament. (Figure 2B) Using scout localizers, the insertion of the coracoclavicular ligaments on the fluid sensitive axial sequence was identified (red arrow). A line from this point to the anterior margin of the glenoid was drawn (yellow dotted line) denoting the width of the coracoid base. Coracoid width measurements were then collected at three locations: 5 mm anteriorly from the coracoid base, midpoint, and 5 mm posteriorly from the coracoid tip. A straight line from the midpoint of the base to tip (not shown) was drawn to approximate coracoid length.Figure 2.Difference between mean pre-operative coracoid length (on left) and width (on right) between female (dark) and male (not dark) patients as measured on MRI. UPLOAD-https://planion-client-files.s3.amazonaws.com/AOSSM/blobs/d06d5b2e-8ec8-40b2-a9b0-fd58358533b7/1/Table_2_Coracoid_Dimensions.doc Table 1.Comparison of post-operative complications, recurrent instability, and re-operation between smaller (<22 mm) and larger (≥22 mm) coracoid length, and between smaller (<10 mm) and larger (≥10 mm) coracoid width. Categorical data presented as n (%), continuous data presented as mean ± standard deviation.Table 2.Comparison of post-operative American Shoulder and Elbow Surgeons (ASES) scores, return to play (RTP) rates, and RTP time between smaller (<22 mm) and larger (≥22 mm) coracoid length, and between smaller (<10 mm) and larger (≥10 mm) coracoid width. Categorical data presented as n (%), continuous data presented as mean ± standard deviation.