Bony Bankart Lesion: Diagnosis, Management, and Outcomes.

¼ Bony Bankart lesions are fractures of the anteroinferior glenoid rim, commonly associated with a traumatic anterior shoulder dislocation, and are diagnosed through radiological imaging and physical examination. Young male athletes playing contact sports are at highest risk of these injuries. Early diagnosis and treatment are crucial because, if left untreated, recurrent anterior shoulder instability and glenoid bone loss can occur. Both nonsurgical and surgical treatment options are available depending on the size of the lesion, with arthroscopic repair being the most common treatment method. After repair, patients typically have favorable outcomes with low rates of recurrent instability. This review aims to discuss the etiology, diagnosis, and treatment of bony Bankart lesions.¼ Bony Bankart lesions are fractures of the anteroinferior glenoid rim and occur in up to 22% of first-time anterior shoulder dislocations.¼ Young men involved in contact sports or combat training are at the highest risk of sustaining bony Bankart lesions.¼ Diagnosis and treatment of bony Bankart lesions are essential to prevent long-term shoulder instability.¼ Bony Bankart lesions can be treated either nonoperatively or operatively (arthroscopic vs open repair), with the size of the glenoid defect being the primary determinant of treatment.

Comparison of Return to Sports and Competition After the Arthroscopic Bristow-Latarjet Procedure Versus Arthroscopic Bankart Repair in Adolescents With Recurrent Anterior Shoulder Instability.

BACKGROUND: The use of isolated soft tissue repair versus bone block stabilization for the treatment of recurrent anterior shoulder instability in adolescents has no scientific evidence. PURPOSE: To compare the clinical outcomes of adolescent patients who underwent isolated arthroscopic Bankart (iB) repair with those who underwent the arthroscopic Bristow-Latarjet procedure in addition to Bankart (BLB) repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 60 shoulders in adolescents (aged 13-18 years) were reviewed with a minimum 2 years' follow-up: iB repair (n = 36) and arthroscopic Bankart repair with an additional Bristow-Latarjet procedure (BLB; n = 24). The characteristics of the patients in each group in terms of age at the first instability episode, age at surgery, hyperlaxity, participation in at-risk sports, and Instability Severity Index Score were comparable. The mean follow-up was longer in the iB group (7.7 vs 4.1 years, respectively), whereas the rates of patients engaged in competition and those with glenoid lesions were higher in the BLB group. The primary outcome measures were failure, defined as the recurrence of instability (clinical dislocation or subluxation), and return to sports. The mean follow-up was 6.2 years (range, 2-16 years). RESULTS: At the last follow-up, the rate of recurrence was significantly higher in the iB group, with 22% (8/36) failures, than in the BLB group, with 8% (2/24) instability recurrences (P < .05). The rate of return to sports at the same level was significantly higher after the BLB repair than after iB repair (79% vs 47%, respectively; P < .001). No statistical difference was found in patient-reported outcome scores between treatment groups (P > .05). Although failures occurred early after the BLB repair, 88% of failures after iB repair occurred after 2 years. On multivariate analysis, adolescents in the iB group with >3 episodes of preoperative dislocation and shoulder hyperlaxity (external rotation >90°) had a 60% recurrence rate (P < .005). CONCLUSION: Adolescent patients undergoing the BLB repair had a lower rate of recurrent instability and higher rates of return to sports and competition than those undergoing iB repair. Patients with shoulder hyperlaxity (external rotation >90°) and >3 dislocations had an unacceptable failure rate of 60% after iB repair.

The New Double-row Bankart Repair Recovered Shoulder Stability without Excessive Motion Limitation: A Case-Control Study with Single-row Bankart Repair.

OBJECTIVES: Bankart lesion is one of the most common lesions of the glenohumeral joint. Several double-row suture methods were reported for Bankart repair, which could provide more stability, yet more motion limitation and complications. Therefore, we introduced a new double-row Bankart repair technique, key point double-row suture which used one anchor in the medial line. The purpose of this article is to investigate the clinical outcomes of this new method and to compare it with single-row suture. METHODS: Seventy-eight patients receiving key point double-row suture or single-row suture from October 2010 to June 2014 were collected retrospectively. The basic information including gender, age, dominant arm, and number of episodes of instability was collected. Before surgery, the glenoid bone loss was measured from the CT scan. The visual analogue scale, American shoulder and elbow surgeons, the University of California at Los Angeles shoulder scale, and subjective shoulder value were valued before surgery and at the last follow-up. RESULTS: Forty-four patients (24 patients receiving single-row suture and 20 patients receiving key point double-row suture) were followed up successfully. The follow-up period was 9.2 ± 1.1 years (range, 7.8-11.4 years). At the last follow-up, no significant differences were detected for any of the clinical scores. The recurrence rate was 12.5% for the single-row group and 10% for the double-row group, respectively (p = 0.795) 14 patients (31.8%) in the single-row group and nine patients (26.5%) in the double-row group were tested for active range of motion. A statistically significant difference was found only for the internal rotation at 90° abduction (48.9° for single-row and 76.7° for key point double-row, p = 0.033). CONCLUSION: The key point double-row sutures for Bankart lesions could achieve similar long-term outcomes compared with single-row suture, and one medial anchor did not result in a limited range of motion. The low recurrence rate and previous biomechanical results also indicate the key point double-row suture is a reliable method.

Editorial Commentary: Anterior Shoulder Stabilization Combining Arthroscopic Bankart and Inferior Capsular Shift Avoids Open Surgery in Athletes Without Critical Glenoid Bone Loss.

Traumatic anterior shoulder dislocations can cause a myriad of injuries, each with their own unique set of challenges with respect to surgical management. The debate of whether open or arthroscopic management is the superior approach is one that predates most currently practicing orthopaedic surgeons yet remains one of the most actively researched areas of orthopaedics. Current trends favor arthroscopic management for anterior instability secondary to a Bankart lesion in patients without other risk factors for instability, such as critical glenoid bone loss. However, excellent results are not guaranteed following arthroscopic Bankart repair, particularly in athletes, due to high rates of recurrence. While the technique of inferior to superior capsular shift is not new, transitioning a historically open technique to the arthroscopic world may represent another tool in the glenohumeral instability management toolbox. While perspectives are evolving, more evidence supporting arthroscopic techniques like the capsular shift are needed to better identify appropriate patient populations.

Infraspinatus function impairment after arthroscopic Bankart repair with Hill Sachs remplissage. Isokinetic, functional, and radiographic analysis.

PURPOSE: Arthroscopic Bankart repair with Hill Sachs remplissage (BHSR) is an option for anterior shoulder instability with humeral defect. Our hypothesis was that infraspinatus capsulo-tenodesis is an effective solution, with good clinical results and no consequences on shoulder strength and ranges of motion. METHODS: We performed a retrospective case-control study involving 22 patients operated with arthroscopic BHSR. We compared isokinetic evaluation of both shoulders using a dynanometer in concentric, eccentric force and endurance. Ranges of motion were measured using a goniometer and compared to the contralateral unaffected side. Functional assessment included Constant, Rowe, Walch and Duplay and WOSI scores. Healing and fatty degeneration were analyzed with magnetic resonance imaging. RESULTS: At mean 37.2 months follow-up, 21 patients (95.4%) were satisfied or very satisfied with the intervention. Range of motion in external rotation of the affected side decreased by 10.8° in adduction and 6° at 90° of abduction (p<0.05). Deficit in external rotation strength of the affected side greater than 15% was found in all isokinetic tests (p<0.05). Walch and Duplay, Rowe, WOSI and adjusted Constant average scores were respectively 71.05±14.1 (40-90), 67.63±19.7 (15-100), 34.6%±19.9 (8.43-76.23) and 69.8±13.57 (36.7-101). Postoperative MRI showed good capsulo-tenodesis healing without infraspinatus muscle fatty degeneration. CONCLUSION: Arthroscopic BHSR provides satisfactory functional outcomes but significant infraspinatus functional impairments in both strength and ranges of motion in external rotation. LEVEL OF EVIDENCE: III; case-control study.

Stabilizing Mechanisms in Patients Treated Using Hill-Sachs Remplissage With Bankart Repair in Abduction-External Rotation Position.

BACKGROUND: Hill-Sachs lesion (HSL) remplissage with Bankart repair (RMBR) provides a minimally invasive solution for treating HSLs and glenoid bone defects of <25%. The infraspinatus tendon is inserted into the HSL during the remplissage process, causing the infraspinatus to shift medially, leading to an unknown effect on glenohumeral alignment during the resting abduction-external rotation (ABER) and muscle-active states. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the possible check-rein effect and muscle-active control in stabilizing the glenohumeral joint after RMBR in vivo. We hypothesized that the check-rein effect and active control would stabilize the glenohumeral joint in the ABER position in patients after RMBR. STUDY DESIGN: Controlled laboratory study. METHODS: We included 42 participants-22 patients in group A who met the inclusion criteria after RMBR and 20 healthy participants in group B without shoulder laxity. Three-dimensional magnetic resonance imaging was performed to analyze the alignment relationship of the glenohumeral joint with and without muscular activity. Ultrasonic shear wave elastography was used to evaluate the elastic properties of the anterior capsule covered with the anterior bands of the inferior glenohumeral ligament. RESULTS: Patients who underwent RMBR demonstrated more posterior (-1.81 ± 1.19 mm vs -0.76 ± 1.25 mm; P = .008) and inferior (-1.05 ± 0.62 mm vs -0.45 ± 0.48 mm; P = .001) shifts of the humeral head rotation center and less anterior capsular elasticity (70.07 ± 22.60 kPa vs 84.01 ± 14.08 kPa; P = .023) than healthy participants in the resting ABER state. More posterior (-3.17 ± 0.84 mm vs -1.81 ± 1.19 mm; P < .001) and less-inferior (-0.34 ± 0.56 mm vs -1.05 ± 0.62 mm; P < .001) shifts of the humeral head rotation center and less anterior capsular elasticity (36.57 ± 13.89 kPa vs 70.07 ± 22.60 kPa; P < .001) were observed in the operative shoulder during muscle-active ABER than in resting ABER states. CONCLUSION: The check-rein effect and muscle-active control act as stabilizing mechanisms in RMBR during the ABER position. CLINICAL RELEVANCE: Stabilizing mechanisms in RMBR during the ABER position include the check-rein effect and muscle-active control.

Defining Critical Humeral Bone Loss: Inferior Craniocaudal Hill-Sachs Extension as Predictor of Recurrent Instability After Primary Arthroscopic Bankart Repair.

BACKGROUND: The glenoid track concept for shoulder instability primarily describes the medial-lateral relationship between a Hill-Sachs lesion and the glenoid. However, the Hill-Sachs position in the craniocaudal dimension has not been thoroughly studied. HYPOTHESIS: Hill-Sachs lesions with greater inferior extension are associated with increased risk of recurrent instability after primary arthroscopic Bankart repair. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The authors performed a retrospective analysis of patients with on-track Hill-Sachs lesions who underwent primary arthroscopic Bankart repair (without remplissage) between 2007 and 2019 and had a minimum 2-year follow-up. Recurrent instability was defined as recurrent dislocation or subluxation after the index procedure. The craniocaudal position of the Hill-Sachs lesion was measured against the midhumeral axis on sagittal magnetic resonance imaging (MRI) using either a Hill-Sachs bisecting line through the humeral head center (sagittal midpoint angle [SMA], a measure of Hill-Sachs craniocaudal position) or a line tangent to the inferior Hill-Sachs edge (lower-edge angle [LEA], a measure of Hill-Sachs caudal extension). Univariate and multivariate regression were used to determine the predictive value of both SMA and LEA for recurrent instability. RESULTS: In total, 176 patients were included with a mean age of 20.6 years, mean follow-up of 5.9 years, and contact sport participation of 69.3%. Of these patients, 42 (23.9%) experienced recurrent instability (30 dislocations, 12 subluxations) at a mean time of 1.7 years after surgery. Recurrent instability was found to be significantly associated with LEA >90° (ie, Hill-Sachs lesions extending below the humeral head equator), with an OR of 3.29 (P = .022). SMA predicted recurrent instability to a lesser degree (OR, 2.22; P = .052). Post hoc evaluation demonstrated that LEA >90° predicted recurrent dislocations (subset of recurrent instability) with an OR of 4.80 (P = .003). LEA and SMA were found to be collinear with Hill-Sachs interval and distance to dislocation, suggesting that greater LEA and SMA proportionally reflect lesion severity in both the craniocaudal and medial-lateral dimensions. CONCLUSION: Inferior extension of an otherwise on-track Hill-Sachs lesion is a highly predictive risk factor for recurrent instability after primary arthroscopic Bankart repair. Evaluation of Hill-Sachs extension below the humeral equator (inferior equatorial extension) on sagittal MRI is a clinically facile screening tool for higher-risk lesions with subcritical glenoid bone loss. This threshold for critical humeral bone loss may inform surgical stratification for procedures such as remplissage or other approaches for at-risk on-track lesions.

Arthroscopic Bankart with remplissage results in lower rates of recurrent instability with similar range of motion compared to isolated arthroscopic Bankart for anterior glenohumeral instability: A systematic review and meta-analysis.

PURPOSE: The addition of the remplissage procedure to an arthroscopic Bankart procedure has been shown to improve clinical outcomes, yet at the expense of potentially decreasing shoulder range of motion. The purpose of this study was to assess recurrent instability, range of motion, functional outcomes and rates of return to sport outcomes in patients undergoing an isolated arthroscopic Bankart repair compared to those undergoing arthroscopic Bankart repair in addition to the remplissage procedure. METHODS: According to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, a search was conducted using three databases (MEDLINE/OVID, EMBASE and PubMed). Retrieved studies were screened based on predefined inclusion and exclusion criteria for comparative studies. Data were extracted and meta-analysis performed using a random-effects model. RESULTS: A total of 16 studies (13 level III studies, 2 level II studies and 1 level I) were included with a total of 507 and 704 patients in the Bankart plus remplissage and isolated Bankart repair groups, respectively. No studies reported glenoid bone loss of >20% with the least percentage of glenoid bone loss reported among studies being <1%. There was a significantly increased rate of recurrent dislocations (odds ratio [OR] = 4.22, 95% confidence interval [CI]: 2.380-7.48, p < 0.00001) and revision procedures (OR = 3.36, 95% CI: 1.52-7.41, p = 0.003) in the isolated Bankart repair group compared to the Bankart plus remplissage group. Additionally, there were no significant differences between groups in terms of external rotation at side (n.s.), in abduction (n.s.) or at forward flexion (n.s.) at final follow-up. Furthermore, return to preinjury level of sport favoured the Bankart plus remplissage group (OR = 0.54, 95% CI: 0.35-0.85, p = 0.007). CONCLUSION: Patients undergoing arthroscopic Bankart plus remplissage for anterior shoulder instability have lower rates of recurrent instability, higher rates of return to sport, and no significant difference in range of motion at final follow-up when compared to an isolated arthroscopic Bankart repair. Further large, prospective studies are needed to further determine which patients and degree of bone loss would benefit most from augmentation with the remplissage procedure. LEVEL OF EVIDENCE: Level III.

Studies on Bankart Repair for Anterior Shoulder Instability Show Poor Reporting of Data and Reflect Low Level of Evidence: A Systematic Review.

PURPOSE: To assess the quality and level of evidence of studies reporting on Bankart repair for anterior shoulder instability. METHODS: A search was performed using the PubMed/Medline database for all studies that reported clinical outcomes on Bankart repair for anterior shoulder instability. The search term "Bankart repair" with all results were analyzed via strict inclusion and exclusion criteria. Two independent investigators scored each included study based on the 10 criteria of the Modified Coleman Methodology Score (CMS) out of 100 and gave each study a score out of 25 based on the Anterior Shoulder Instability (ASI) Methodology criteria. RESULTS: Two hundred sixty-six studies were included in the analysis and encompassed a total of 19,156 patients and 19,317 surgical procedures for Bankart repair for shoulder instability. Overall, 81.6% of studies were Level III or IV evidence. The mean CMS score for the studies was 55.3 out of 100, and the mean ASI Methodology score for the studies was 12.1 out of 25. Weaknesses in the studies were identified in sample size, description of preoperative investigations and diagnoses, reporting of mean glenoid bone loss, nonsubjective clinical outcome reporting, and description of associated pathologies. CONCLUSIONS: A large proportion of studies reporting the clinical outcomes of Bankart repair for anterior shoulder instability are of low methodological quality and have a low level of evidence. CLINICAL RELEVANCE: This study emphasizes need for greater reporting of many variables such as body mass index, mean glenoid bone loss, and patient-reported outcomes and provides a framework for future studies reporting.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Humeral Head Reconstruction of Reverse Hill-Sachs Lesions.

Compared with anterior instability, posterior shoulder dislocations are a rare entity and are often missed at presentation. A concomitant anteromedial impression fracture of the humeral head, or a reverse Hill-Sachs lesion, is commonly present with these dislocations and is more pronounced with a longer timeline to reduction. Treatment of these defects ranges from nonsurgical treatment to soft-tissue procedures, bony reconstruction, and arthroplasty. Management may be dictated by various factors, such as patient demands, defect size and location, concomitant injuries, and underlying etiology. Small reverse Hill-Sachs defects without engagement can generally be treated nonsurgically or with benign neglect, whereas larger defects (>20%) often require surgery. The most reported surgical techniques are the (arthroscopic) McLaughlin and modified McLaughlin procedure, disimpaction and bone grafting, or reconstruction of the defect with autograft or with fresh (or fresh-frozen) osteochondral allograft. Finally, arthroplasty is generally required for large defects, where more than 45% to 50% of the articular cartilage is involved. Overall, reported outcomes generally reflect patient satisfaction for most patients, with a low incidence of secondary instability or posttraumatic arthritis, although better results are achieved when recognizing and treating these injuries in the more acute setting.

[Anterior shoulder instability with Hill-Sachs on-track. Bankart or Bankart-remplissage?] / Inestabilidad anterior de hombro con lesión de Hill-Sachs on-track. ¿Bankart o Bankart-remplissage?

INTRODUCTION: in patients with anterior glenohumeral (GH) instability together with an off-track or engaging Hill-Sachs (HS) defect, Bankart-remplissage (B-R) surgery reduces the recurrence rate when compared to Bankart (B) surgery alone. There is controversy regarding whether the recurrence rate also decreases in patients with on-track or non-engaging Hill-Sachs defects. OBJECTIVE: to compare the recurrence rate and clinical evolution of patients with anterior glenohumeral instability with 'on-track' Hill-Sachs defect treated with either B or B-R surgery. MATERIAL AND METHODS: non-randomized, retrospective, single-center cohort study of patients with anterior glenohumeral instability and on-track Hill-Sachs defect, operated between January 2010 and December 2018. Patients operated with B versus B-R were compared. Recurrence, complications and re-operation were recorded. In addition, VAS, SSV, WOSI and qDASH scores were obtained and compared in both groups. RESULTS: of the 105 patients who met the inclusion criteria, 78 (74.3%) patients had a complete follow-up (52 B and 26 B-R, 4.3 years median follow-up). There was a higher recurrence rate in group B compared to B-R, with this difference not reaching statistical significance (17.3% vs 7.7%, p = 0.21). There were no significant differences in residual pain, feeling of instability, complications or VAS, qDASH, SSV or WOSI scores between both groups. In the subgroup analysis, patients who practiced contact sports and were operated with B showed higher recurrence rates (24.1% vs 0%, p = 0.08) and complications (41.4% vs 18.2%, p = 0.16) when compared to B + R, although these differences were not significant. CONCLUSION: there were no significant differences in recurrence rates and functional evolution between patients with anterior glenohumeral instability operated with B or B-R surgery. Comparative, prospective studies should be performed to establish definitive recommendations.

INTRODUCCIÓN: en pacientes con inestabilidad glenohumeral (GH) anterior con defecto de Hill-Sachs (HS) off-track o enganchante, Bankart-remplissage (B + R) reduce tasa de recurrencia en comparación a Bankart aislado (B). Hay controversia si tasa de recurrencia también disminuye en pacientes con defecto de HS on-track o no enganchantes. OBJETIVO: comparar la tasa de recurrencia y evolución clínica entre la cirugía de B versus B-R en pacientes operados por inestabilidad glenohumeral anterior con defecto de Hill-Sachs on-track. MATERIAL Y MÉTODOS: estudio de cohorte, no randomizado, retrospectivo y unicéntrico, en pacientes operados por inestabilidad glenohumeral anterior, entre Enero 2010 y Diciembre de 2018. Se incluyen sólo pacientes con defecto de Hill-Sachs on-track. Fueron comparados pacientes operados con cirugía de B versus B + R. Se consigna recurrencia, complicación, reoperación y sensación de inestabilidad. Además, se realizan y comparan puntajes de EVA, SSV, WOSI y qDASH. RESULTADOS: de los 105 pacientes que cumplieron criterios de inclusión, 78 (74.3%) realizaron seguimiento completo (52 B y 26 B + R, 4.3 años mediana de seguimiento). Hubo mayor tasa de recurrencia en grupo B en comparación a B + R, siendo esta diferencia no significativa (17.3% versus 7.7%, p = 0.21). No hubo diferencia significativa en dolor residual, sensación de inestabilidad residual, complicaciones o puntajes de escala EVA, qDASH, SSV ni WOSI. En análisis por subgrupo, pacientes con deportes de contacto, B tienen mayor tasa de recurrencia (24.1% versus 0%, p = 0.08) y complicaciones comparadas con B + R (41.4% versus 18.2%, p = 0.16), siendo estas diferencias no significativas. CONCLUSIÓN: no hubo diferencias significativas en tasa de recurrencia y evolución funcional entre cirugía de Bankart aislado o Bankart-remplissage para inestabilidad glenohumeral anterior asociada a defecto de Hill-Sachs on-track. Estudios comparativos, prospectivos deben realizarse para establecer recomendaciones definitivas.

Correlation of Glenoid Concavity With Surgical Failure After Arthroscopic Stabilization for Recurrent Anterior Shoulder Instability.

BACKGROUND: Glenoid concavity compression by rotator cuff muscle contraction is one of the key mechanisms in the stability of the glenohumeral joint. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the effects of glenoid concavity, as represented by the bony shoulder stability ratio (BSSR) and other factors, including glenoid bone defect size, on the surgical failure of arthroscopic stabilization procedures for recurrent anterior shoulder instability. The authors also aimed to determine the critical value of BSSR. It was hypothesized that both glenoid concavity and glenoid bone defect size would be correlated with surgical failure, with glenoid concavity having a stronger correlation. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 120 patients who underwent arthroscopic stabilization procedures for recurrent anterior shoulder instability were included. Patients with bony Bankart lesions were excluded to eliminate the postoperative effects of bony fragment restoration on the glenoid concavity. For each patient, variable factors including BSSR, glenoid bone defect size, presence of off-track Hill-Sachs lesions, and age at first dislocation were recorded. Chi-square analysis and Student t test were performed to analyze the effect of each variable on surgical failure. Multivariate logistic regression analysis was used to determine the combined effect of >2 variables on surgical failure. The critical value of BSSR was analyzed using a receiver operating characteristic curve. RESULTS: Nine patients (7.5%) had recurrent instability requiring revision surgery. BSSR (patients with recurrence, 18.6% ± 19.4%; patients without recurrence, 41.8% ± 10.5%; P = .01), glenoid bone defect size (17.5% ± 3.6% vs 11.7% ± 7.0%; P = .02), age at the time of first dislocation (18.8 ± 3.9 years vs 22.0 ± 6.5 years; P = .04), and number of suture anchors used (4.1 ± 0.3 vs 5.8 ± 1.6; P < .001) showed significant differences between patients with and without surgical failure. Multivariate logistic regression analysis revealed surgical failure to be correlated with BSSR (odds ratio, 0.849; P = .02) and the number of suture anchors used (odds ratio, 0.070; P = .03). The critical value of BSSR was 29.3% (area under the curve, 0.84; 95% CI, 0.67-1.00; P < .001; sensitivity, 78%; specificity, 93%). CONCLUSION: Glenoid concavity is strongly correlated with surgical failure after arthroscopic stabilization procedures for anterior shoulder instability. The value of BSSR reflects shoulder instability caused by glenoid bone morphology more accurately than glenoid bone defect size.

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

OBJECTIVES: This study aimed to evaluate the effectiveness of Mask Region-Based Convolutional Neural Network (R-CNN) in humerus and scapula segmentation. PATIENTS AND METHODS: 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). RESULTS: 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. CONCLUSION: 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.

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

BACKGROUND: Although Hill-Sachs lesions (HSLs) are assumed to be influenced by glenoid characteristics in the context of bipolar bone loss, little is known about how glenoid concavity influences HSL morphology. PURPOSE: To investigate the relationship between the native glenoid depth and HSL morphological characteristics. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Computed tomography images of bilateral shoulders from 151 consecutive patients with traumatic unilateral anterior shoulder instability were retrospectively reviewed. Patients were categorized into flat (<1 mm), moderate (1-2 mm), and deep (>2 mm) groups based on the native glenoid depth measured from the contralateral unaffected shoulder. The HSL morphological characteristics included size (depth, width, length, and volume), location (medial, superior, and inferior extent), and orientation (rim and center angle). The glenoid characteristics included diameter, depth, version, and bone loss. The patient, glenoid, and HSL morphological characteristics were compared among the 3 depth groups. Subsequently, the independent predictors of some critical HSL morphological characteristics were determined using multivariate stepwise regression. RESULTS: After exclusion of 55 patients, a total of 96 patients were enrolled and classified into the flat group (n = 31), moderate group (n = 35), and deep group (n = 30). Compared with those in the flat group, patients in the deep group were more likely to have dislocation (38.7% vs 93.3%; P = .009) at the primary instability and had a significantly larger number of dislocations (1.1 ± 1.0 vs 2.2 ± 1.8; P = .010); moreover, patients in the deep group had significantly deeper, wider, larger volume, more medialized HSLs and higher incidences of off-track HSLs (all P≤ .025). No significant differences were detected among the 3 groups in HSL length, vertical position, and orientation (all P≥ .064). After adjustment for various radiological and patient factors in the multivariate regression model, native glenoid depth remained the strongest independent predictor for HSL depth (ß = 0.346; P < .001), width (ß = 0.262; P = .009), volume (ß = 0.331; P = .001), and medialization (ß = -0.297; P = .003). CONCLUSION: The current study sheds light on the association between native glenoid depth and the morphology of HSLs in traumatic anterior shoulder instability. Native glenoid depth was independently and positively associated with HSL depth, width, volume, and medialization. Patients with deeper native glenoids were more likely to have off-track HSLs and thus require more attention in the process of diagnosis and treatment.

Incidence of bony Bankart lesions in Sweden: a study of 790 cases from the Swedish fracture register.

BACKGROUND: A bony Bankart lesion directly affects the stability of the shoulder by reducing the glenoid joint-contact area. The aim of this study was to report on the epidemiological data relating to bony Bankart lesions in Sweden using the Swedish fracture register. The purpose is to evaluate age and sex distribution in the population with bony Bankart lesions, its impact on treatment strategy and further to analyse patient-reported outcomes. METHODS: This was an epidemiological descriptive study. The inclusion criteria were all patients with a unilateral bony Bankart lesion registered between April 2012 and April 2019. The patients' specific data (age, sex, type and time of injury, treatment option and patient-reported outcomes) were extracted from the Swedish fracture register database. RESULTS: A total of 790 unilateral bony Bankart fractures were identified. The majority of the patients were male (58.7%). The median age for all patients at the time of injury was 57 years. Females had a higher median age of 66 years, compared with males, 51 years. Most of the bony Bankart lesions, 662 (91.8%), were registered as a low-energy trauma. More than two-thirds of all treatment registered cases, 509/734 patients (69.3%), were treated non-surgically, 225 (30.7%) were treated surgically, while, in 17 patients (7.5% of all surgically treated patients), the treatment was changed from non-surgical to surgical due to recurrent instability. Surgical treatment was chosen for 149 (35%) of the males and for 76 (25%) of the females. Patient quality of life decreased slightly in both surgically and non-surgically treated groups 1 year after bony Bankart injury. CONCLUSION: This national register-based study provides detailed information on the epidemiology, choice of treatment and patient-reported outcomes in a large cohort of bony Bankart lesions. Most bony Bankart lesions affected males between 40 and 75 years after low-energy falls and non-surgical treatment dominated.

The Influence of Glenoid Bone Loss and Graft Positioning on Graft and Cartilage Contact Pressures After the Latarjet Procedure.

BACKGROUND: Glenohumeral joint contact loading before and after glenoid bone grafting for recurrent anterior instability remains poorly understood. PURPOSE: To develop a computational model to evaluate the influence of glenoid bone loss and graft positioning on graft and cartilage contact pressures after the Latarjet procedure. STUDY DESIGN: Controlled laboratory study. METHODS: A finite element model of the shoulder was developed using kinematics, muscle and glenohumeral joint loading of 6 male participants. Muscle and joint forces at 90° of abduction and external rotation were calculated and employed in simulations of the native shoulder, as well as the shoulder with a Bankart lesion, 10% and 25% glenoid bone loss, and after the Latarjet procedure. RESULTS: A Bankart lesion as well as glenoid bone loss of 10% and 25% significantly increased glenoid and humeral cartilage contact pressures compared with the native shoulder (P < .05). The Latarjet procedure did not significantly increase glenoid cartilage contact pressure. With 25% glenoid bone loss, the Latarjet procedure with a graft flush with the glenoid and the humerus positioned at the glenoid half-width resulted in significantly increased humeral cartilage contact pressure compared with that preoperatively (P = .023). Under the same condition, medializing the graft by 1 mm resulted in humeral cartilage contact pressure comparable with that preoperatively (P = .097). Graft lateralization by 1 mm resulted in significantly increased humeral cartilage contact pressure in both glenoid bone loss conditions (P < .05). CONCLUSION: This modeling study showed that labral damage and greater glenoid bone loss significantly increased glenoid and humeral cartilage contact pressures in the shoulder. The Latarjet procedure may mitigate this to an extent, although glenoid and humeral contact loading was sensitive to graft placement. CLINICAL RELEVANCE: The Latarjet procedure with a correctly positioned graft should not lead to increased glenohumeral joint contact loading. The present study suggests that lateral graft overhang should be avoided, and in the situation of large glenoid bone defects, slight medialization (ie, 1 mm) of the graft may help to mitigate glenohumeral joint contact overloading.

Remplissage Procedure Indications, Techniques, and Outcomes.

Hill-Sachs lesions are a challenging clinical problem in the context of anterior shoulder instability. Historically, unless very large, these lesions were thought to be less significant than glenoid defects. Recently, more importance has been placed on whether a Hill-Sachs lesion is on-track or offtrack, with off-track lesions predisposing patients to higher risk of postoperative recurrent instability. Given the high risk for recurrent shoulder instability in patients with Hill-Sachs lesions that are off-track, augmentation procedures, such as the remplissage procedure, are often indicated alongside a Bankart repair. The proposed advantages of the remplissage include directly addressing the Hill-Sachs lesion to prevent engagement, the ability to address any associated intraarticular pathologies during the arthroscopy, and to avoid a more invasive open procedure with a higher complication rate. Remplissage has been shown to reduce the recurrence rate compared to those undergoing arthroscopic Bankart repair alone and to have a comparable recurrence rate to the Latarjet procedure in the appropriately selected patient while also having a much lower complication rate than the Latarjet procedure.

Does glenoid bone loss accompany posterior shoulder instability with only labral tear? A magnetic resonance imaging-based study.

BACKGROUND: The primary aim of this study was to investigate bone loss in the glenoid with magnetic resonance imaging in posterior shoulder instability with only a labral tear. METHODS: A total of 76 patients operated on because of posterior and anteroposterior shoulder instability only with a labral tear between 2006 and 2019 (n = 40 and n = 36, respectively) were included in this study. The instability type, a presence of an additional superior labrum anteroposterior (SLAP) lesion, the number of dislocations, and the magnetic resonance imaging-based measurements (the glenoid diameter and the bone defect size in the glenoid, the Hill-Sachs lesion [HSL] and the reverse HSL [rHSL] length, the angle and the arc length of HSL and rHSL, and the humerus head diameter and its area) were analyzed. RESULTS: The size of the anterior glenoid defect, the rHSL measurements (length, angle, and arc length), and the ratio of the anterior glenoid defect size to the glenoid diameter were significantly higher for anteroposterior instability (P < .01) cases. There was no significant difference (P = .49, .64, and .82, respectively) for the presence of an additional SLAP pathology, the glenoid diameter, the posterior glenoid defect, and the ratio of the posterior glenoid defect size to the glenoid diameter in posterior and anteroposterior instability groups. The increased number of dislocations was associated with increased rHSL length and total arc length (P = .04 and .03, respectively). An additional SLAP lesion in posterior shoulder instabilities was not associated with the bone defect size (P = .29). CONCLUSION: Although the posterior shoulder instability with only a labral tear is likely to cause a bone defect, we have shown that the instability is not expected to be caused by the bone defect. Therefore, this study points out that only soft tissue repair without considering the bone defect could be promising in this patient group.

Editorial Commentary: Glenoid Reconstruction With Autologous Tricortical Iliac Crest Represents an Alternative to Bankart Repair and Remplissage for Anterior Shoulder Instability With Subcritical Bone Loss.

Traumatic anterior shoulder dislocations are estimated to occur in approximately 2% of the population, frequently with concomitant anterior-inferior labral tears and associated Hill-Sachs lesions of the humeral head. So-called bipolar (or engaging) lesions with attritional bone loss may be exacerbated by recurrent instability, in terms of both prevalence and severity. The glenoid track concept and distance to dislocation have offered context for evaluating bipolar lesions, and increasingly, options for bone block reconstruction are considered for definitive treatment. Recently, concerns have been raised regarding coracoid transfer or Latarjet treatment, particularly with screw constructs in which catastrophic failure, hardware breakage, and secondary arthritis may develop. The Eden-Hybinette procedure, or tricortical iliac crest autograft bone augmentation, may represent a promising alternative to existing options while also restoring native glenoid bone stock. Additionally, suture button fixation may obviate the traditional pitfalls of prior bone block procedures while also achieving reproducible functional outcomes and low rates of recurrence. However, this must be considered alongside other contemporary arthroscopic treatments, such as combined arthroscopic Bankart repair and remplissage.