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The popularity of arthroscopic Latarjet has increased significantly in recent years due to its perceived advantages. The latter include a smaller surgical incision, faster recovery, quicker return to sports, and ability to treat concomitant intra-articular pathology. Nevertheless, the arthroscopic technique is more technically challenging, has a more significant learning curve, longer operating time, and is less cost-effective. The study aimed to identify the various factors influencing patient decision-making between undergoing arthroscopic or open Latarjet using a stepwise questionnaire model. All patients with a primary, whether arthroscopic or open Latarjet procedure were subjected to a stepwise interviewing process and were asked to select between arthroscopic and open approaches at each step. Fifty patients with a mean age of 28.8 ± 8.8 year old participated in the study. Twenty (40%) consistently selected an arthroscopic approach after analysis of the incision's aspect, whereas 34 (68%) had a final decision different from their initial choice. In addition, out of the 15 patients who chose arthroscopy or were undetermined after presentation of the incisional aspect, 9 (60%) changed their decision to open surgery after presentation of the pros and cons of each approach. Twenty-three (46%) patients were unable to choose and left the choice to their surgeon. The faith in their surgeon and recovery were identified as the 2 most important factors influencing patients' final decisions. The minimally invasive nature of arthroscopic incisions was not considered to be more cosmetically appealing than that of a single open incision. The advantages of the arthroscopic procedure may not be as valued by patients as by surgeons. Patients were more interested in the equivalent short- and mid-term outcomes of both approaches and the shorter surgical duration of the open option. It is crucial to adequately inform patients during preoperative counseling to achieve the best consensus. [ABSTRACT FROM AUTHOR]

Coracoid nonunion is a relevant complication following the Latarjet procedure and is influenced by multiple factors, including the method of graft fixation. The purpose of this study was to evaluate and characterize the biomechanical properties of various two-screw fixation constructs used for coracoid graft fixation in the Latarjet procedure. Forty model scapulae (Sawbones Inc., Vashon, WA, USA) were used for this study. A 15% anterior inferior glenoid bone defect was created. The coracoid was osteotomized at the juncture of the vertical and horizontal aspects, transferred to the anterior-inferior edge of the glenoid, and fixed with either two 3.5 mm fully threaded cannulated cortical screws, two 3.5 mm fully threaded solid cortical screws, two 3.5 mm partially threaded cannulated screws, or two 4.5 mm partially threaded malleolar screws (MS). Biomechanical testing was performed with an Instron material testing machine (Instron Corp., Norwood, MA, USA) by applying loads to the lateral aspect of the transferred coracoid graft. The constructs were preconditioned with nondestructive cyclical loading (0N-20N) to determine construct stiffness. After 100 cycles of dynamic loading, the construct was loaded to failure to determine ultimate failure load, yield displacement, and mode of failure. All failures were associated with plastic deformation of the screws and coracoid graft fracture. There was a significantly lower initial stiffness for partially threaded cannulated screws compared to MS (186 ± 49.3 N/mm vs. 280 ± 65.5 N/mm, P =.01) but no significant differences among the other constructs. There was no difference in ultimate failure load (P =.18) or yield displacement (P =.05) among constructs. Two screw coracoid fixation of the coracoid in a simulated classic Latarjet procedure with 3.5 mm fully threaded cortical and cannulated screws is comparable to 4.5 mm MS in strength, stiffness, and displacement at failure. On the other hand, partially threaded 3.5 mm cannulated screws provide inferior fixation stiffness and could potentially affect clinical outcomes. [ABSTRACT FROM AUTHOR]

The debate surrounding the influence of the open Latarjet procedure on postoperative scapular motions persists, and there is no evidence regarding its effects on periscapular muscle activation. This study aimed to assess the short-term influence of the open Latarjet procedure on scapular kinematics and periscapular muscle activity during arm raising and lowering based on comparisons between patients and healthy athletes. 22 healthy male athletes and 22 male athletes scheduled for glenohumeral stabilization surgery by the open Latarjet procedure were included. Scapular kinematics, periscapular muscle activities, and shoulder-related quality of life were recorded before surgery and 3 months postoperatively for the Latarjet group. For the healthy group, same assessments were performed 3 months apart. Bilateral differences in both scapular kinematics and periscapular muscle activation ratios and the Western Ontario Shoulder Instability (WOSI) index were defined as dependent variables. Scapular kinematics of the operated shoulder, namely scapular upward/downward rotation, internal/external rotation, and anterior/posterior tilt recorded between 20° and 120° of humerothoracic elevation, showed no alterations 3 months after surgery (P >.05) and did not differ from those observed in healthy athletes (P >.05). Similarly, all periscapular muscle activations were not different within time and between groups (P >.05). The WOSI index of the operated shoulder was significantly improved postoperatively (871.9 ± 443.7 vs. 1346.3 ± 552.3) but remained higher than the WOSI indices of the nonoperated shoulder or those of the healthy group (52.7 ± 75.6). This study emphasizes the short-term effects of the open Latarjet procedure, demonstrating an improvement in the shoulder-related quality of life 3 months after surgery. Notably, during this period, both kinematics and periscapular muscle activity remained consistent and similar to the patterns observed for healthy athletes. [ABSTRACT FROM AUTHOR]

In patients with traumatic posterior shoulder instability, little is known about the precise location and size of the reverse Hill-Sachs lesion. Forty-nine shoulders of 47 patients with traumatic posterior instability were included in this study based on the following inclusion criteria: (1) a primary or recurrent traumatic posterior shoulder dislocation and (2) the initial event being caused by trauma. Patients were excluded if they had (1) no history of trauma, (2) prior shoulder surgery, (3) no computed tomographic (CT) examination, or (4) were seizure cases. Three-dimensional images of the humerus reconstructed from CT images were reviewed using an image analysis software. The location and size of the reverse Hill-Sachs lesion were measured and described on a clock face on the humeral head. The reverse Hill-Sachs lesion was observed in 25 of 49 shoulders (51%). The reverse Hill-Sachs lesions were located between 1:37 and 2:48. The depth of the reverse Hill-Sachs lesion (mean ± standard deviation) was 5.8 ± 2.2 mm. The extent of the reverse Hill-Sachs lesion was 35° ± 12°. The average orientation of the reverse Hill-Sachs lesion, represented by an angle measured from the 12 o'clock position, was 64° ± 12° and pointing toward 2:09 on a clock face. The mean length and width of reverse Hill-Sachs lesions were 9.7 ± 4.7 mm and 11.1 ± 3.6 mm, respectively. The reverse Hill-Sachs lesion was a semicircular compression fracture located on the anteromedial aspect of the humeral head. Compared with shoulders with anterior shoulder instability, the humeral defect was smaller and located more inferiorly in shoulders with posterior instability. [ABSTRACT FROM AUTHOR]

The acromion morphology in a shoulder with posterior instability differs from that of a shoulder without glenohumeral instability. Specifically, the acromion with a flatter sagittal tilt, greater posterior acromial height, and less posterior coverage is associated with posterior instability. However, the association between acromion morphology and glenoid bone loss (GBL) in the setting of posterior glenohumeral instability has not previously been investigated. The purpose of this study was to determine whether acromial morphology influences the extent or pattern of posterior GBL in a cohort of patients with posterior glenohumeral instability. This multicenter retrospective study identified 89 shoulders with unidirectional posterior glenohumeral instability. Total area GBL was measured using the best-fit circle method on magnetic resonance imaging (MRI). Shoulders were divided into 3 groups: (1) no GBL (n = 30), (2) GBL 0%-13.5% (n = 45), or (3) GBL ≥13.5% (n = 14). Acromion measurements were performed on MRI and included acromial tilt, posterior acromial height, anterior acromial coverage, and posterior acromial coverage. Patients without GBL had a steeper acromial tilt (58.5° ± 1.4°) compared with those with 0%-13.5% GBL (64.3° ± 1.5°) or GBL ≥13.5% (67.7° ± 1.8°) (P =.004). Patients without GBL also had greater posterior coverage (65.4° ± 1.7°) compared with those with GBL (60.3° ± 1.4°) (P =.015). Posterior acromion height was not significantly different among groups. The results demonstrate that an acromion with a flatter sagittal tilt and less posterior coverage is associated with GBL in the setting of posterior glenohumeral instability. This is important to consider as posterior GBL has been identified as a risk factor for failure of posterior soft tissue–stabilizing procedures. [ABSTRACT FROM AUTHOR]

Intra-articular soft arthroscopic Latarjet technique (in-SALT) involves augmentation of arthroscopic Bankart repair (ABR) with soft tissue tenodesis of long head of biceps to upper subscapularis. This study was conducted to investigate superiority of outcomes of in-SALT–augmented ABR over those of concurrent ABR and anterosuperior labral repair (ASL-R) in management of type V superior labrum anterior-posterior (SLAP) lesion. This prospective cohort study (conducted between January 2015 and January 2022) included 53 patients with arthroscopic diagnosis of type V SLAP lesion. Patients were allocated into 2 consecutive groups: group A of 19 patients managed with concurrent ABR/ASL-R and group B of 34 patients managed with in-SALT–augmented ABR. Outcome measurements included 2-year postoperative pain, range of motion, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and Rowe instability scores. Failure was defined as frank/subtle postoperative recurrence of glenohumeral instability or objective diagnosis of Popeye deformity. The statistically matched studied groups showed significant postoperative improvement in outcome measurements. However, group B demonstrated significantly better 3-month postoperative visual analog scale score (3.6 vs. 2.6, P =.006) and 24-month postoperative external rotation at 0° abduction (44° vs. 50°, P =.020) and ASES (84 vs. 92, P <.001) and Rowe (83 vs. 88, P =.032) scores. Rate of postoperative recurrence of glenohumeral instability was relatively lower in group B (10.5% vs. 2.9%, P =.290). No Popeye deformity was reported. For management of type V SLAP lesion, in-SALT–augmented ABR yielded a relatively lower rate of postoperative recurrence of glenohumeral instability and significantly better functional outcomes compared with concurrent ABR/ASL-R. However, currently reported favorable outcomes of in-SALT should be validated via further biomechanical and clinical studies. [ABSTRACT FROM AUTHOR]

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). [ABSTRACT FROM AUTHOR]

To determine whether the addition of 3-dimensional (3D) magnetic resonance imaging (MRI) to standard MRI sequences is comparable to 3D computed tomographic (CT) scan evaluation of glenoid and humeral bone loss in glenohumeral instability. Eighteen patients who presented with glenohumeral instability were prospectively enrolled and received both MRI and CT within 1 week of each other. The MRI included an additional sequence (volumetric interpolated breath-hold examination [VIBE]) that underwent postprocessing for reformations. The addition of a VIBE protocol, on average, is an additional 4-4.5 minutes in the scanner. CT data also underwent 3D postprocessing, and therefore each patient had 4 imaging modalities (2D CT, 2D MRI, 3D CT reformats, and 3D MRI reformats). Each sequence underwent the following measurements from 2 separate reviewers: glenoid defect, glenoid defect percentage, humeral defect, humeral defect percentage, and evaluation of glenoid track and version. Paired t tests were used to assess differences between imaging modalities and χ2 for glenoid track. Intra- and interobserver reliability were evaluated. Bland-Altman tests were also performed to assess the agreement between CT and MRI. In addition, we determined the cost of each imaging modality at our institution. 3D MRI measurements for glenoid and humeral bone loss measurements were comparable to 3D CT (Table 1). There were no significant differences for glenoid defect size and percentage, or humeral defect size and percentage (P >.05) (Table 2). Bland-Altman analysis demonstrated strong agreement, with small measurement errors for 3D CT and 3D MRI percentage glenoid bone loss. There was also no difference in evaluation for determining on vs. off track between any of the imaging modalities. Inter- and intrarater reliability was good to excellent for all CT and MRI measurements (r ≥ 0.7). 3D MRI measurements for bone loss in glenohumeral instability through use of VIBE sequence were equivalent to 3D CT. At our institution, undergoing MRI with 3D reconstruction was 1.67 times cheaper than MRI and CT with 3D reconstructions. 3D MRI may be a useful adjuvant to standard MRI sequences to allow concurrent soft tissue and accurate assessment of glenoid and humeral bone loss in glenohumeral instability. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the preoperative magnetic resonance arthrography findings in patients who underwent glenohumeral stabilization with a history of primary instability, recurrent instability, or failed stabilization. All patients who presented with glenohumeral instability and underwent stabilization performed by a single surgeon in our institution between 2008 and 2020 were considered for inclusion in this study. The magnetic resonance arthrography findings of all patients were recorded. Imaging findings were compared between patients with primary instability, those with recurrent instability, and those with failed prior stabilization. P <.05 was considered statistically significant. Overall, 871 patients were included, of whom 814 (93.5%) were male patients; the mean age was 23.1 years (range, 13-57 years). There were 200 patients with primary instability, 571 with recurrent instability, and 100 who required revision stabilization surgery, with no significant differences in demographic characteristics between the groups. A significantly higher amount of glenoid bone loss was noted in patients with recurrent instability (43.4%) and failed prior stabilization (56%) than in those with primary instability (26.5%) (P <.0001). Additionally, a significantly higher number of Hill-Sachs lesions were observed in patients with recurrent instability (70.1%) and failed prior stabilization (89%) than in those with primary instability (67.5%) (P <.0001). We found no significant differences between the groups regarding articular cartilage damage, glenolabral articular disruption, anterior labral periosteal sleeve avulsion, humeral avulsion of the glenohumeral ligaments, or superior labral anterior-posterior tears (P >.05). Patients presenting for stabilization with recurrent instability or following a failed stabilization procedure have higher rates of glenohumeral bone loss than those with primary instability. Therefore, stabilization of primary instability, particularly in high-functioning athletes with a view to preventing recurrence, may reduce the overall progression of glenohumeral bone loss and potential subsequent inferior clinical outcomes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate short-term outcomes including medical complications, overnight admission, and 30-day readmission with regard to patient age at the time of shoulder instability surgery. Patients undergoing surgery for glenohumeral instability were collected from the National Surgical Quality Improvement Program between the years of 2005 and 2016. These patients were separated into cohorts of younger than 25 years, 25-34 years, and older than 34 years. Medical complications, hospital admission, and 30-day readmission were compared using multivariate analysis. Of the 5449 patients included, there were 2035 (37.0%) patients younger than 25 years, 1815 (33.0%) between 25 and 34 years, and 1649 (30.0%) 35 and older. Overall, 81.7% of patients underwent an arthroscopic Bankart repair, 12.6% of patients underwent an open Bankart repair, and 5.7% of patients underwent a Latarjet-Bristow procedure. The risk of 30-day readmission increased with age, ranging from 0.24% for <25 years old to 0.92% for 35 years and older (P =.040). Operative duration greater than 60 minutes (odds ratio [OR] 1.76; P =.001), duration greater than 90 minutes (OR 3.58; P <.001), and American Society of Anesthesiologists class III and IV (OR 1.80; P =.001) were associated with increased risk of overnight hospital stay. Compared with arthroscopic Bankart repair, the Latarjet-Bristow procedure was associated with increased total complications (OR 3.30; P =.021), overnight hospital stay (OR 4.64; P <.001), and 30-day readmission (OR 3.39; P =.013). This study demonstrates that even in the relatively young and healthy shoulder instability patient cohort, patients older than 25 years are almost 4 times more likely to experience a complication. Additionally, Latarjet-Bristow procedures are 3-4 times more likely to experience a complication or readmission than other shoulder instability procedures. [ABSTRACT FROM AUTHOR]

Shoulder instability is extremely common, with various outcome scores used to assess its progression after treatment. This review was performed to identify the scores most commonly used and to evaluate them according to the 4 core domains of shoulder trials (according to the Core Outcome Measures in Effectiveness Trials [COMET] initiative) and their respective psychometric qualities. A systematic review of the literature of 3 databases (MEDLINE, Embase, PubMed) was undertaken. Studies were identified using eligibility criteria and critically appraised by 2 authors. Data were extracted using an a priori template. Outcome scores were identified and assessed regarding COMET domain inclusion and their psychometric properties. The most frequently used scores were the Rowe (58%), Constant (33%), Western Ontario Shoulder Instability Index (WOSI; 24%), and American Shoulder and Elbow Surgeons (23%) scores. The majority of outcome scores assessed pain and all assessed physical functioning. Quality of life and a global assessment of treatment success were rarely incorporated. No single outcome score considered all core COMET domains. The WOSI was the most acceptable measure of those assessed with respect to its validity, reliability, and responsiveness. The WOSI incorporated 3 of the 4 core domains for shoulder trials (pain, physical functioning, and health-related quality of life). It had the most psychometric testing of the identified scores, confirming its reliability, validity, and responsiveness in the setting of shoulder instability. We recommend its use in this setting; however, it should be supplemented with additional outcome scores, such as the University of California–Los Angeles score, to cover all of the core COMET domains. [ABSTRACT FROM AUTHOR]

Although glenohumeral instability is common, the mechanism of instability remains unclear. The purpose of this study was to quantitatively evaluate humeral head translation during active external rotation with abduction in patients with glenohumeral instability by use of 4-dimensional computed tomography scans. Ten patients with unilateral glenohumeral instability with a positive fulcrum test were prospectively included in this study. Sequential computed tomography of bilateral shoulders during active external rotation at 90° of shoulder abduction was performed for 6 seconds at 5 frames per second. The 3-dimensional positions of the humeral head center in the anteroposterior, superoinferior, and mediolateral directions were calculated at 0°, 20°, 40°, 60°, and maximum shoulder abduction–external rotation from the starting position. Translation of the humeral head center from the starting position was evaluated using Dunnett multiple-comparison tests, and the differences between the affected and intact shoulders were assessed using Wilcoxon signed rank tests. The humeral head center translated posteriorly, inferiorly, and medially during glenohumeral external rotation with the shoulder in the abducted position on the intact side. However, the affected humeral head showed significantly less posterior translation (P =.028), greater inferior translation (P =.047), and less medial translation (P =.037) than the contralateral side. This study indicated that dysfunction of the anterior band of the inferior glenohumeral ligament causes decreased posterior, increased inferior, and decreased medial translation of the humeral head during active shoulder abduction–external rotation. [ABSTRACT FROM AUTHOR]

Glenohumeral instability is a rare indication for primary reverse total shoulder arthroplasty (RTSA), accounting for fewer than 1% of the indications in the literature. The aim of this study was to analyze the clinical and radiographic outcomes of RTSA for recurrent instability after failed operative repair or instability associated with major bone loss in elderly patients. A retrospective matched case-control study was performed. We compared 11 shoulders treated with RTSA for instability (cases) with 22 matched shoulders treated with RTSA for rotator cuff insufficiency (controls). Clinical and radiographic outcomes were compared. The median follow-up period was 74 months (interquartile range [IQR], 18 months; range, 22-171 months) in cases and 70 months (IQR, 13 months; range, 23-172 months) in controls. The median age was 74 years (IQR, 18 years) in the case group and 70 years (IQR, 13 years) in the control group. No significant differences were found between the 2 groups in satisfaction scores, preoperative and postoperative absolute and relative Constant scores, and complication rates. Active range of motion tended to be superior in the controls for mean flexion (130° vs. 110°, P =.15), abduction (143° vs. 100°, P =.16), and external rotation (28° vs. 20°, P =.86) without the differences reaching statistical significance, possibly because of the small sample size. Postoperative dislocation was not recorded in cases or controls, but subjective insecurity regarding stability was reported once in each group. RTSA seems to represent a valuable treatment option for glenohumeral instability in an elderly population with large bone loss or as a salvage procedure after failed operative glenohumeral stabilization. Postoperative instability was not observed in the case and control groups. [ABSTRACT FROM AUTHOR]

Background The incidence of posterior shoulder instability (PSI) in the general population is not well defined. This study aimed to define the population-based incidence of PSI and describe trends in incidence and surgery rates. Methods The study population included 143 patients (16 females, 127 males) diagnosed with new-onset PSI between January 1, 1994, and December 31, 2015. Medical records were reviewed to extract patient data. Age- and sex-specific incidence rates were calculated and adjusted to the 2010 United States population. Poisson regression was performed to examine trends by timeline, sex, and age. Results Age- and sex- adjusted annual incidence of PSI was 4.64 per 100,000 person-years, and posterior dislocation was 1.30 per 100,000 person-years. Peak PSI incidence for males and females was at 14 to 19 years (31.82 and 5.23 per 100,000 person-years). PSI incidence was higher in males than females (8.86 vs. 1.07 per 100,000 person-years, P <.001). The 5-year cumulative risk of surgery for patients with PSI was 53.1% between 1996 and 2002, 59.9% between 2003 and 2008, and 87.5% between 2009 and 2015. Patients with PSI between 2009 and 2015 had a significantly increased rate of surgery (hazard ratio, 2.2; 95% confidence interval, 1.4-3.6; P =.001) compared with those between 1996 and 2002. Conclusion The age- and sex- adjusted incidence of PSI in the general population was 4.64 per 100,000 person-years. There is a significantly greater incidence of PSI in males than females, with both sexes peaking at 14 to 19 years and incidence rates remaining elevated throughout the third and fourth decades of life. The incidence of PSI remained stable over time; however, the rate of surgical intervention increased significantly, from 53.1% of patients between 1996 and 2002 to 87.5% of patients between 2009 and 2015. [ABSTRACT FROM AUTHOR]

Background Anterior shoulder dislocations in young patients are associated with high rates of recurrent instability. Although some surgeons advocate for surgical stabilization after a single dislocation event in this population, there is sparse research evaluating surgical treatment for first-time dislocators. Methods Patients undergoing surgical stabilization for anterior shoulder instability were prospectively enrolled at multiple institutions from 2015-2017 and stratified by number of dislocations before surgery. Demographic data, preoperative patient-reported outcomes, imaging findings, surgical findings, and procedures performed were compared between groups. Analysis of variance, χ 2 , and multivariate logistic regression were used for statistical analysis. Results The study included 172 patients (mean age, 25.3 years; 79.1% male patients) for analysis (58 patients with 1 dislocation, 69 with 2-5 dislocations, 45 with >5 dislocations). There were no intergroup differences in demographic characteristics, preoperative patient-reported outcomes, or physical examination findings. Preoperative imaging revealed increased glenoid bone loss in patients with multiple dislocation events ( P  = .043). Intraoperatively, recurrent dislocators were more likely to have bony Bankart lesions (odds ratio [OR], 3.26; P  = .024) and biceps pathology (OR, 6.27; P  = .013). First-time dislocators more frequently underwent arthroscopic Bankart repair and/or capsular plication (OR, 2.22; P  = .016), while recurrent dislocators were more likely to undergo open Bristow-Latarjet procedures (OR, 2.80; P  = .049) and surgical treatment for biceps pathology (OR, 5.03; P  = .032). Conclusions First-time shoulder dislocators who undergo stabilization are more likely to undergo an arthroscopic procedure and less likely to have bone loss or biceps pathology compared with recurrent dislocators. Future studies are needed to ascertain long-term outcomes of surgical stabilization based on preoperative dislocation events. [ABSTRACT FROM AUTHOR]

Background The glenoid track concept has been proposed to correlate shoulder stability with bone loss. Accurate assessment of Hill-Sachs lesion size preoperatively may affect surgical planning and postoperative outcomes; however, no measurement method has been universally accepted. This study aimed to assess the accuracy and reliability of measuring Hill-Sachs lesion sizes using 3-dimensional (3D) computed tomography (CT). Methods Nine polyurethane humerus bone substitutes were used to create Hill-Sachs lesions of varying sizes with a combination of lesion depth (shallow, intermediate, and deep) and width (small, medium, and large). Specimens were scanned with a clinical CT scanner for size measurements and a micro-CT scanner for measurement of true lesion size. Six evaluators repeated measurements twice in a 2-week interval. Scans were measured by use of 3D CT reconstructions for length, width, and Hill-Sachs interval and with use of 2D CT for depth. The interclass correlation coefficient evaluated interobserver and intraobserver variability and percentage error, and Student t -tests assessed measurement accuracy. Results Interclass correlation coefficient reliability demonstrated strong agreement for all variables measured (0.856-0.975). Percentage error between measured length and measured depth and the true measurement significantly varied with respect to both lesion depth ( P  = .003 and P  = .005, respectively) and lesion size ( P  = .049 and P  = .004, respectively). Discussion and conclusions The 3D CT imaging is effective and reproducible in determining lesion size. Determination of Hill-Sachs interval width is also reliable when it is applied to the glenoid track concept. Measured values on 3D and 2-dimensional imaging using a conventional CT scanner may slightly underestimate true measurements. [ABSTRACT FROM AUTHOR]

Background Although bone defects of the humeral head and glenoid could affect glenohumeral instability, bone loss has not been sufficiently evaluated. The purpose of this study was to quantify bone defects 3-dimensionally in cases with glenohumeral instability. Methods Three-dimensional surface models of bilateral proximal humeri and glenoids were reconstructed from computed tomography scans of 90 patients with symptomatic, unilateral, recurrent glenohumeral instability. The left-side models were mirrored, and intact bone areas were matched to those of the right-side models. The volume, length, width, and depth of identified bone defects were assessed. After the values were corrected by patient height, the characteristics of the bone defects were evaluated. Results Bone defects were present in 97.8% of the humeral heads and 96.7% of the glenoids, and women had significantly smaller bone defects than men did. The volume of humeral head defects had a mild correlation with that of glenoid defects. The number of traumatic episodes was not correlated with humeral head bone defects, but it was positively correlated with glenoid bone defects. Patients with recurrent dislocations had significantly deeper and larger Hill-Sachs lesions than the other cases. Conclusion Bone defects of the humeral head and the glenoid in cases with symptomatic traumatic glenohumeral instability were quantified 3-dimensionally using a computed tomography surface-matching technique. Almost all cases showed bone defects in the humeral head and glenoid compared with the intact shoulder, and such bone defects may be more common than previously reported. This study suggested that bipolar bone lesions are not always created by the same mechanism. [ABSTRACT FROM AUTHOR]

Background Evidence suggests a relationship between glenoid retroversion and posterior instability, but no literature exists comparing glenoid version referencing the scapular body versus the endosteal vault. This study evaluated glenoid version and its relationship to unidirectional instability and labral tears. Methods Glenoid version in patients with unidirectional instability or labral tears was measured with magnetic resonance imaging by either the Friedman method or the Poon and Ting method. Analyses of variance followed by independent t tests were used to compare 3 groups: anterior instability or labral tears (anterior pathology group, n = 33); posterior instability or labral tears (posterior pathology group, n = 34); and stable controls (n = 30). The referencing error for 2-dimensional axial images was evaluated for variance by imaging facility. Interobserver and intraobserver reliability scores were calculated. Results With the Friedman method, the posterior pathology group (−9°) was more retroverted than the control group (−4°) ( P  = .0005) and the anterior pathology group (−5°) ( P  = .0104) but there was no difference between the control group and anterior pathology group ( P  = .38). The referencing error in the sagittal plane averaged 23° and varied by facility ( P  = .0365). The coronal-plane error averaged 1° and did not vary by facility ( P  = .7180). Intraclass correlation coefficient scores showed good to excellent intrarater and inter-rater reliability. Conclusion The posterior pathology group had 5° more retroversion than controls using the Friedman method. Glenoid version using the Poon and Ting method or the Friedman method did not predict anterior instability or labral tears. Axial magnetic resonance images were constructed with a referencing error in the sagittal plane that varied by magnetic resonance imaging facility and has implications for improving 2-dimensional axial imaging protocols. [ABSTRACT FROM AUTHOR]

Background Traumatic glenohumeral joint (GHJ) dislocations are common, resulting in significant shoulder disability and pain. Previous research indicates that bony morphology is associated with an increased risk of injury in other joints (eg, the knee), but the extent to which bony morphology is associated with traumatic GHJ dislocation is unknown. This study assessed GHJ morphology in patients with anterior GHJ instability and in a control population of healthy volunteers. Methods Bilateral computed tomography scans were used to measure GHJ morphology in both shoulders of 11 patients with instability and 11 control subjects. Specific outcome measures included the glenoid radius of curvature (ROC) in the anterior/posterior (A/P) and superior/inferior (S/I) directions, humeral head ROC, A/P and S/I conformity index, and A/P and S/I stability angle. Results Compared with the control subjects, the glenoid of the instability the injured shoulder in patients with instability was flatter (ie, higher ROC) in the A/P ( P = .001) and S/I ( P = .01) directions and this finding was also true for uninjured, contralateral shoulder (A/P: P = .01, S/I: P = .03). No differences in GHJ morphology were detected between the instability patients' injured and contralateral shoulders ( P > .07). Similarly, no differences in GHJ morphology were detected between the control subjects' dominant and nondominant shoulders ( P > .51). Conclusions There are significant differences in GHJ morphology between healthy control subjects and both shoulders (injured and uninjured, contralateral) of patients diagnosed with anterior instability after GHJ dislocation. These findings are important clinically because they suggest that glenoid morphology may influence the risk of GHJ dislocation. [ABSTRACT FROM AUTHOR]

Background The aim of this study was to investigate, through a computed tomography (CT) scan analysis, the effects of the Latarjet procedure on scapular position in an axial plane. Materials and methods Twenty healthy young male subjects (mean age, 22 years; range, 18-27 years) were enrolled as a control group. Twenty young male patients (mean age, 23 years; range, 17-30 years) with recurrent anterior shoulder dislocation were enrolled as the study group. CT cuts at a proper level allowed the identification of an α angle, which defined the tilt of the scapula relative to the anterior-posterior axis. Results In the control population, the α angles on the right and left shoulders were 48° (44°-52°) and 48° (44°-54°), respectively. In the study group, the preoperative α angles at the affected and healthy shoulders were 49° (46°-52°) and 49° (44°-52°), respectively. At day 45, the corresponding angles were 45° (40°-50°) and 49° (46°-52°). At 6 months, the average α angle of the shoulder operated on was 52° (46°-58°). The α angle value was restored in 5 cases, increased in 9 cases (mean, 8°), and decreased in 6 cases (mean, 3°). Conclusion A general symmetry of scapular position was observed during CT scan analysis. This balance was lost initially after the Latarjet procedure, with a decrease of the α angle and scapular protraction. Six months after surgery, a small trend toward scapular retraction was conversely observed; however, the data were not statistically significant. [ABSTRACT FROM AUTHOR]

Background The incidence of reinjuries due to glenohumeral instability and the major risk factors for primary anterior shoulder dislocation in youth rugby players have been unclear. Purpose The purpose of this study was to investigate the incidence, mechanisms, and intrinsic risk factors of shoulder dislocation in elite high-school rugby union teams during the 2012 season. Methods A total of 378 male rugby players from 7 high-school teams were investigated by use of self-administered preseason and postseason questionnaires. Results The prevalence of a history of shoulder dislocation was 14.8%, and there were 21 events of primary shoulder dislocation of the 74 overall shoulder injuries that were sustained during the season (3.2 events per 1000 player-hours of match exposure). During the season, 54.3% of the shoulders with at least one episode of shoulder dislocation had reinjury. This study also indicated that the persistence of glenohumeral instability might affect the player's self-assessed condition, regardless of the incidence during the current season. By a multivariate logistic regression method, a history of shoulder dislocation on the opposite side before the season was found to be a risk factor for contralateral primary shoulder dislocation (odds ratio, 3.56; 95% confidence interval, 1.27-9.97; P = .02). Conclusions High-school rugby players with a history of shoulder dislocation are not playing at full capacity and also have a significant rate of reinjury as well as a high risk of dislocating the other shoulder. These findings may be helpful in deciding on the proper treatment of primary anterior shoulder dislocation in young rugby players. [ABSTRACT FROM AUTHOR]

Background: This study evaluated the outcomes of patients with failed total shoulder arthroplasty (TSA) who were treated with conversion to reverse shoulder arthroplasty (RSA). Materials and methods: We performed a retrospective case series of 24 consecutive patients with failed TSA who were treated with conversion to RSA. Twenty-two patients (16 women, 6 men) had a minimum 2-year clinical and radiographic follow-up. The average age at the time of revision was 68 years (range, 51-84 years). Indications for conversion to RSA included failure of TSA from glenohumeral instability in 19, mechanical failure of the humeral or glenoid component in 10, and infection in 2. Results: The median total American Shoulder and Elbow Surgeons score improved from 38.5 preoperatively to 67.5 (P < .001). Visual analog scale pain scores decreased from 5 to 1.5 (P < .001), and function improved from 2 to 6.5 (P < .001). The median Simple Shoulder Test improved from 1 to 5 (P = .006). Forward flexion improved from 50° to 130° (P < .001), abduction from 45° to 100° (P < .001), and external rotation from 12.5° to 49.5° (P = .056). Internal rotation improved from a spinal level of S2 to L3 (P = .064). Fourteen patients rated their outcome as excellent, 3 as good, 3 as satisfactory, and 2 as unsatisfactory. The overall complication rate was 22.7% (5 of 22). Conclusion: RSA can be an effective treatment for failed TSA by decreasing pain and improving shoulder function. However, RSA in the revision setting is associated with a higher complication rate. [ABSTRACT FROM AUTHOR]