NeuroPAL: A Multicolor Atlas for Whole-Brain Neuronal Identification in C. elegans.

Comprehensively resolving neuronal identities in whole-brain images is a major challenge. We achieve this in C. elegans by engineering a multicolor transgene called NeuroPAL (a neuronal polychromatic atlas of landmarks). NeuroPAL worms share a stereotypical multicolor fluorescence map for the entire hermaphrodite nervous system that resolves all neuronal identities. Neurons labeled with NeuroPAL do not exhibit fluorescence in the green, cyan, or yellow emission channels, allowing the transgene to be used with numerous reporters of gene expression or neuronal dynamics. We showcase three applications that leverage NeuroPAL for nervous-system-wide neuronal identification. First, we determine the brainwide expression patterns of all metabotropic receptors for acetylcholine, GABA, and glutamate, completing a map of this communication network. Second, we uncover changes in cell fate caused by transcription factor mutations. Third, we record brainwide activity in response to attractive and repulsive chemosensory cues, characterizing multimodal coding for these stimuli.

Magnetic Resonance Arthrogram Outperforms Standard Magnetic Resonance Imaging 2 Weeks After First Shoulder Dislocation for Labral Tear Diagnosis.

PURPOSE: To determine the comparative accuracy and precision of routine magnetic resonance imaging (MRI) versus magnetic resonance (MR) arthrogram in measuring labral tear size as a function of time from a shoulder dislocation. METHODS: We retrospectively evaluated consecutive patients who underwent primary arthroscopic stabilization between 2012 and 2021 in a single academic center. All patients completed a preoperative MRI or MR arthrogram of the shoulder within 60 days of injury and subsequently underwent arthroscopic repair within 6 months of imaging. Intraoperative labral tear size and location were used as standards for comparison. Three musculoskeletal radiologists independently interpreted tear extent using a clock-face convention. Accuracy and precision of MR labral tear measurements were defined based on location and size of the tear, respectively. Accuracy and precision were compared between MRI and MR arthrogram as a function of time from dislocation. RESULTS: In total, 32 MRIs and 65 MR arthrograms (total n = 97) were assessed. Multivariate analysis demonstrated that intraoperative tear size, early imaging, and arthrogram status were associated with increased MR accuracy and precision (P < .05). Ordering surgeons preferred arthrogram for delayed imaging (P = .018). For routine MRI, error in accuracy increased by 3.4° per day and error in precision increased by 2.3° per day (P < .001) from time of injury. MR arthrogram, however, was not temporally influenced. Significant loss of accuracy and precision of MRI compared with MR arthrogram occurred at 2 weeks after an acute shoulder dislocation. CONCLUSIONS: Compared with MR arthrogram, conventional MRI demonstrates time-dependent loss of accuracy and precision in determining shoulder labral tear extent after dislocation, with statistical divergence occurring at 2 weeks. LEVEL OF EVIDENCE: Level II, retrospective radiographic diagnostic study.

Posterior Glenoid Bone Block Reconstruction: Indications, Techniques, and Outcomes.

Posterior shoulder instability is of particular therapeutic interest, as it typically affects patients with high functional demands such as young athletes and active adults. Although posterior capsulolabral repair has high return-to-sport rates, it is associated with recurrent instability of up to 11%. Posterior glenoid bone loss and significant glenoid retroversion have been identified as risk factors for recurrent instability and failure after primary arthroscopic soft-tissue repair. Therefore, posterior glenoid bone block reconstruction may be indicated for glenoid bone loss 20% or greater (as measured by the perfect circle technique) or greater than 10% in the setting of pathologic glenoid, failed primary posterior labral repair, incompetent posterior capsular tissue, or significant risk factors for failure of soft-tissue repair. This procedure may be performed arthroscopically or with a posterior open approach using distal tibial allograft, iliac crest autograft, or scapular spine autograft. Although short-term to midterm outcomes have been promising, there remain concerns regarding long-term outcomes, with potentially high rates of late recurrence, revision, and secondary osteoarthritis.

Infection in Shoulder Arthroplasty: Prevention, Diagnosis, and Treatment.

Prosthetic joint infection is a devastating complication following shoulder arthroplasty that can lead to pain, poor function, and poor quality of life. With the increasing number of shoulder arthroplasties performed annually, recognition of prosthetic infection and treatment is necessary. The skin surrounding the shoulder has a unique microbiome, and Cutibacterium acnes is the most commonly encountered bacteria causing prosthetic joint infection. C acnes is a low-virulence organism that resides in the subcutaneous layer of the skin. As a result, the clinical presentation is typically less obvious than prosthetic infections seen in other joints such as the hip and knee. Therefore, diagnosis is not always straightforward, and optimal treatment strategy is unclear. Guidance on prevention, diagnosis, and treatment of shoulder prosthetic joint infection with special emphasis on the consensus definition established at the 2018 International Consensus Meeting is provided.

Reverse total shoulder arthroplasty for primary osteoarthritis with restricted preoperative forward elevation demonstrates similar outcomes but faster range of motion recovery compared to anatomic total shoulder arthroplasty.

BACKGROUND: Reverse total shoulder arthroplasty (RSA) has been increasingly utilized for a variety of shoulder pathologies that are difficult to treat with anatomical total shoulder arthroplasty (TSA). Few studies have compared the outcomes of TSA vs. RSA in patients with cuff intact glenohumeral osteoarthritis and poor preoperative forward elevation. This study aimed to determine whether there is a difference in functional outcomes and postoperative range of motion (ROM) between TSA and RSA in these patients. METHODS: This retrospective cohort study included 116 patients who underwent RSA or TSA between 2013 and 2022 for the treatment of rotator cuff intact primary osteoarthritis with restricted preoperative forward flexion (FF) and a minimum 1-year follow-up. Each arthroplasty group was divided into 2 subgroups: patients with preoperative FF between 91° and 120° or FF lower than or equal to 90°. Patients' clinical outcomes, including active ROM, American Shoulder and Elbow Surgeons score, visual analog scale for pain, and subjective shoulder value were collected. Clinical and radiographic complications were evaluated. RESULTS: There was no significant difference between RSA and TSA in terms of sex (58.3% male vs. 62.2% male, P = .692), or follow-up duration (20.1 months vs. 17.7 months, P = .230). However, the RSA cohort was significantly older (72.0 ± 8.2 vs. 65.4 ± 10.6, P = .012) and weaker in FF and (ER) before surgery (P < .001). There was no difference between RSA (57 patients) and TSA (59 patients) in visual analog scale pain score (1.2 ± 2.3 vs. 1.3 ± 2.3, P = .925), subjective shoulder value score (90 ± 15 vs. 90 ± 15, P = .859), or American Shoulder and Elbow Surgeons score (78.4 ± 20.5 vs. 82.1 ± 23.2, P = .476). Postoperative active ROM was statistically similar between RSA and TSA cohorts in FF (145 ± 26 vs. 146 ± 23, P = .728) and ER (39 ± 15 vs. 41 ± 15, P = .584). However, internal rotation was lower in the RSA cohort (P < .001). This was also true in each subgroup. RSA led to faster postoperative FF and ER achievement at 3 months (P < .001). There was no statistically significant difference in complication rates between cohorts. CONCLUSION: This study demonstrates that patients with glenohumeral osteoarthritis who have a structurally intact rotator cuff but limited preoperative forward elevation can achieve predictable clinical improvement in pain, ROM, and function after either TSA or RSA. Reverse arthroplasty may be a reliable treatment option in patients at risk for developing rotator cuff failure.

Pseudoparesis and pseudoparalysis in the setting of massive irreparable rotator cuff tear: demographic, anatomic, and radiographic risk factors.

BACKGROUND: The primary purpose of this study was to identify demographic, anatomic, and radiographic risk factors for active forward elevation (AFE) <90° in the setting of massive, irreparable rotator cuff tear (miRCT). The secondary purpose was to identify characteristics differentiating between patients with pseudoparalysis (AFE <45°) and pseudoparesis (AFE >45° but <90°). METHODS: This was a retrospective case-control study reviewing patients with miRCTs at a single institution between January 12, 2016 and November 26, 2020. Patients were separated into 2 cohorts based on presence or absence of preoperative AFE <90° with maintained passive range of motion. Demographics, RCT pattern, and radiographic parameters were assessed as risk factors for AFE <90°. A secondary analysis was conducted to compare patients with pseudoparalysis and pseudoparesis. RESULTS: There were 79 patients in the AFE <90° cohort and 50 patients in the control cohort. Univariate analysis confirmed significant differences between the AFE <90° and control cohort in age (71.9 ± 11.0 vs. 65.9 ± 9.1 years), arthritis severity (34.2% vs. 16.0% grade 3 Samilson-Prieto), acromiohumeral distance (AHD; 4.8 ± 2.7 vs. 7.6 ± 2.6 mm), fatty infiltration of the supraspinatus (3.3 ± 0.9 vs. 2.8 ± 0.8) and subscapularis (2.0 ± 1.2 vs. 1.5 ± 1.0), and proportion of subscapularis tears (55.7% vs. 34.0%). On multivariate analysis, age (odds ratio [OR] 1.08, P = .014), decreased AHD (OR 0.67, P < .001), severe arthritis (OR 2.84, P = .041), and subscapularis tear (OR 6.29, P = .015) were independent factors predictive of AFE <90°. Secondary analysis revealed tobacco use (OR 3.54, P = .026) and grade 4 fatty infiltration of the supraspinatus (OR 2.22, P = .015) and subscapularis (OR 3.12, P = .042) as significant predictors for pseudoparalysis compared to pseudoparesis. CONCLUSIONS: In patients with miRCT, increased age, decreased AHD, severe arthritis, and subscapularis tear are associated with AFE <90°. Furthermore, patients with AFE <90° tend to have greater supraspinatus and subscapularis fatty infiltration. Lastly, among patients with AFE <90°, tobacco use and grade 4 fatty infiltration of the supraspinatus and subscapularis are associated with pseudoparalysis compared with pseudoparesis.

Arthroscopic Bankart Repair with Remplissage Yields Similar Outcomes to Open Latarjet for Primary and Revision Stabilization in The Setting of Subcritical Glenoid Bone Loss.

BACKGROUND: Management of patients with recurrent anterior glenohumeral instability in the setting of subcritical glenoid bone loss (GBL), defined in this study as 20% GBL or less, remains controversial. This study aimed to compare arthroscopic Bankart with remplissage (ABR+R) to open Latarjet for subcritical GBL in primary or revision procedures. We hypothesized that ABR+R would yield higher rates of recurrent instability and reoperation compared to Latarjet in both primary and revision settings. METHODS: A retrospective study was conducted on patients undergoing either arthroscopic ABR+R or an open Latarjet procedure. Patients with connective tissue disorders, critical GBL (>20%), < 2 year follow-up, or insufficient data were excluded. Recurrent instability and revision were the primary outcomes of interest. Additional outcomes of interest included subjective shoulder value (SSV), strength and range of motion (ROM) RESULTS: 108 patients (70 ABR+R, 38 Latarjet) were included with an average follow-up of 4.3 ±2.1 years. In the primary and revision settings, similar rates of recurrent instability (Primary: p=0.60; Revision: p=0.28) and reoperation (Primary: p=0.06; Revision: p=1.00) were observed between Latarjet and ABR+R. Primary ABR+R exhibited better SSV, active ROM, and internal rotation strength compared to primary open Latarjet. However, no differences were observed in the revision setting. CONCLUSION: Similar rates of recurrent instability and reoperation in addition to comparable outcomes with no differences in ROM were found for ABR+R and Latarjet in patients with subcritical GBL in both the primary and revision settings. ABR+R can be a safe and effective procedure in appropriately selected patients with less than 20% GBL for both primary and revision stabilization.

Minimal Important Clinical Difference Values Are Not Uniformly Valid in the Active Duty Military Population Recovering from Shoulder Surgery.

BACKGROUND: There are multiple methods for calculating the minimal clinically important difference (MCID) threshold, and previous reports highlight heterogeneity and limitations of anchor-based and distribution-based analyses. The Warfighter Readiness Survey assesses the perception of a military population's fitness to deploy and may be used as a functional index in anchor-based MCID calculations. The purpose of the current study in a physically demanding population undergoing shoulder surgery was to compare the yields of two different anchor-based methods of calculating MCID for a battery of PROMs, a standard receiver operator curve (ROC) -based MCIDs and baseline-adjusted ROC MCIDs. METHODS: All service members enrolled prospectively in a multicenter database with prior shoulder surgery that completed pre- and postoperative PROMs at a minimum of 12 months were included. The PROMs battery included Single Assessment Numeric Evaluation (SANE), American Shoulder and Elbow Surgeons score (ASES), Patient Reported Outcome Management Information System (PROMIS) Physical Function (PF), PROMIS Pain Interference (PI), and the Warfighter Readiness survey. Standard anchor-based and baseline-adjusted ROC MCIDs were employed to determine if the calculated MCIDs were both statistically and theoretically valid (95% confidence interval either completely negative or positive). RESULTS: There were 117 patients (136 operations) identified, comprised of 83% males with a mean age of 35.7 ± 10.4 years and 47% arthroscopic labral repair/capsulorrhaphy. Using the standard, anchor-based ROC MCID calculation, the area under the curve (AUC) for SANE, ASES, PROMIS PF, and PROMIS PI were greater than 0.5 (statistically valid). For ASES, PROMIS PF, and PROMIS PI, the calculated MCID 95% CI all crossed 0 (theoretically invalid). Using the baseline-adjusted ROC MCID calculation, the MCID estimates for SANE, ASES, and PROMIS PI were both statistically and theoretically valid if the baseline score was less than 70.5, 69, and 65.7. CONCLUSION: When MCIDs were calculated and anchored to the results of standard, anchor-based MCID, a standard ROC analysis did not yield statistically or theoretically valid results across a battery of PROMs commonly used to assess outcomes after shoulder surgery in the active duty military population. Conversely, a baseline-adjusted ROC method was more effective at discerning changes across a battery of PROMs among the same cohort.

Preoperative factors associated with 180°, 270°, and 360° labral tears.

BACKGROUND: Large, circumferential glenoid labral tears are an uncommon injury affecting young, athletic patients. There are limited data describing the clinical presentation of patients with larger tears, especially 270° and 360° labral tears. Additionally, examination and imaging findings have poor reliability in diagnosing these tears. The purpose of this study was to determine the clinical presentation among patients presenting with small (less than 180°), medium (180°-270°), and large (270°-360°) labral tears. METHODS: This is a retrospective comparative study of consecutive patients surgically managed by a single shoulder surgeon for all glenoid labral tears from 2018-2022. The primary outcome was demographic and preoperative clinical risk factors. Demographic data including age, sex, hand dominance, body mass index, as well as clinical presentation (subluxation vs. dislocation, instability history, and participation in contact sports) were recorded. RESULTS: A total of 188 patients met the inclusion criteria: 101 of 188 (53.70%) patients with small tears, 43 of 188 (22.90%) patients with medium tears, and 44 of 188 (23.40%) patients with large tears. Individuals with large and medium-sized labral tears were more likely to have participated in contact sports compared to those with smaller labral tears (P = .003). Medium and smaller tears were more likely to present as dominant-side injury (P = .02). Furthermore, medium and large tears were more likely to present with anterior instability symptoms compared with smaller tears, which more frequently presented with posterior instability and pain (P = .003). CONCLUSION: Males participating in contact sports were the most common demographic population presenting with large, 270°-360° labral tears. Instability was the primary complaint rather than pain, and compared with small tears, medium and large tears were more likely to present with primary anterior instability. Although arthroscopic repair of 270°-360° labral tears can yield excellent clinical outcomes similar to smaller tears, identifying factors associated with larger glenoid labral tears may help in surgical planning and patient counseling.

Margin convergence vs. superior capsular reconstruction for massive irreparable rotator cuff tears: outcomes are equivalent unless there is preoperative pseudoparesis.

BACKGROUND: Margin convergence (MC) and superior capsular reconstruction (SCR) are common treatment options for irreparable rotator cuff tears in younger patients, although they differ in associated costs and operative times. The purpose of this study was to compare range of motion, patient-reported outcomes (PROs), and reoperation rates following MC and SCR. We hypothesized superior outcomes after SCR relative to MC regarding functional outcomes, subjective measures, and reoperation rates. METHODS: This was a multicenter retrospective review of 59 patients from 3 surgeons treating irreparable rotator cuff tears with either MC (n = 28) or SCR (n = 31) and minimum 1-year follow-up from 2014-2019. Visual analog scale (VAS) for pain, Subjective Shoulder Value (SSV), active forward flexion (FF), external rotation (ER), retear rate, and conversion rate to reverse shoulder arthroplasty were evaluated. t tests and χ2 tests were used for continuous and categorical variables, respectively (P < .05). RESULTS: Baseline demographics, range of motion, and magnetic resonance imaging findings were similar between groups. Average follow-up was 31.5 months and 17.8 months for the MC and SCR groups, respectively (P < .001). The MC and SCR groups had similar postoperative FF (151° ± 26° vs. 142° ± 38°; P = .325) and ER (48° ± 12° vs. 46° ± 11°; P = .284), with both groups not improving significantly from their preoperative baselines. However, both cohorts demonstrated significant improvements in VAS score (MC: 7.3 to 2.5; SCR: 6.4 to 1.0) and SSV (MC: 54% to 82%; SCR: 38% to 87%). There were no significant differences in postoperative VAS scores, SSV, and rates of retear or rates of conversion to arthroplasty between the MC and SCR groups. In patients with preoperative pseudoparesis (FF < 90°), SCR (n = 9) resulted in greater postoperative FF than MC (n = 5) (141° ± 38° vs. 67° ± 24°; P = .002). CONCLUSION: Both MC and SCR demonstrated excellent postoperative outcomes in the setting of massive irreparable rotator cuff tear, with significant improvements in PROs and no significant differences in range of motion. Specifically for patients with preoperative pseudoparesis, SCR was more effective in restoring forward elevation. Further long-term studies are needed to compare outcomes and establish appropriate indications.

Reversing chronic pseudoparesis secondary to massive, irreparable rotator cuff tear: superior capsular reconstruction vs. reverse total shoulder arthroplasty.

INTRODUCTION: Recent studies have defined pseudoparesis as limited active forward elevation between 45° and 90° and maintained passive range of motion (ROM) in the setting of a massive rotator cuff tear (RCT). Although pseudoparesis can be reliably reversed with reverse total shoulder arthroplasty (RSA) or superior capsular reconstruction (SCR), the optimal treatment for this indication remains unknown. The purpose of this study was to compare the clinical outcomes of RSA to SCR in patients with pseudoparesis secondary to massive, irreparable RCT (miRCT). METHODS: This was a retrospective cohort study of consecutive patients aged 40-70 years with pseudoparesis secondary to miRCT who were treated with either RSA or SCR by a single fellowship-trained shoulder surgeon from 2016 to 2021 with a minimum 12-month follow-up. Multivariate linear regression modeling was used to compare active ROM, visual analog pain scale (VAS), Subjective Shoulder Value (SSV), and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score between RSA and SCR while controlling for confounding variables. RESULTS: Twenty-seven patients were included in the RSA cohort and 23 patients were included in the SCR cohort with similar mean follow-up times (26.2 ± 21.1 vs. 21.9 ± 14.7 months, respectively). The patients in the RSA group were significantly older than those in the SCR group (65.2 ± 4.4 vs. 54.2 ± 7.8 years, P < .001) and had more severe arthritis (1.8 ± 0.9 vs. 1.2 ± 0.5 Samilson-Prieto, P = .019). The pseudoparesis reversal rate among the RSA and SCR cohorts was 96.3% and 91.3%, respectively. On univariate analysis, the RSA cohort demonstrated significantly greater mean improvement in active FF (89° ± 26° vs. 73° ± 30° change, P = .048), greater postoperative SSV (91 ± 8% vs. 69 ± 25%, P < .001), lower postoperative VAS pain scores (0.6 ± 1.2 vs. 2.2 ± 2.9, P = .020), and less postoperative internal rotation (IR; 4.6° ± 1.6° vs. 6.9° ± 1.8°, P = .004) compared with SCR. On multivariate analysis controlling for age and osteoarthritis, RSA remained a significant predictor of greater SSV (ß = 21.5, P = .021) and lower VAS scores (ß = -1.4, P = .037), whereas SCR was predictive of greater IR ROM (ß = 3.0, P = .043). CONCLUSION: Although both RSA and SCR effectively reverse pseudoparesis, patients with RSA have higher SSV and lower pain scores but less IR after controlling for age and osteoarthritis. The results of this study may inform surgical decision making for patients who are suitable candidates for either procedure.

Modulation of sensory perception by hydrogen peroxide enables Caenorhabditis elegans to find a niche that provides both food and protection from hydrogen peroxide.

Hydrogen peroxide (H2O2) is the most common chemical threat that organisms face. Here, we show that H2O2 alters the bacterial food preference of Caenorhabditis elegans, enabling the nematodes to find a safe environment with food. H2O2 induces the nematodes to leave food patches of laboratory and microbiome bacteria when those bacterial communities have insufficient H2O2-degrading capacity. The nematode's behavior is directed by H2O2-sensing neurons that promote escape from H2O2 and by bacteria-sensing neurons that promote attraction to bacteria. However, the input for H2O2-sensing neurons is removed by bacterial H2O2-degrading enzymes and the bacteria-sensing neurons' perception of bacteria is prevented by H2O2. The resulting cross-attenuation provides a general mechanism that ensures the nematode's behavior is faithful to the lethal threat of hydrogen peroxide, increasing the nematode's chances of finding a niche that provides both food and protection from hydrogen peroxide.

Implementation of an intravenous sotalol initiation protocol: Implications for feasibility, safety, and length of stay.

INTRODUCTION: Oral sotalol initiation requires a multiple-day, inpatient admission to monitor for QT prolongation during loading. A 1-day intravenous (IV) sotalol loading protocol was approved by the United States Food and Drug Administration in March 2020, but limited data on clinical use and administration currently exists. This study describes implementation of an IV sotalol protocol within an integrated health system, provides initial efficacy and safety outcomes, and examines length of stay (LOS) compared with oral sotalol initiation. METHODS: IV sotalol was administered according to a prespecified initiation protocol to adult patients with refractory atrial or ventricular arrhythmias. Baseline characteristics, safety and feasibility outcomes, and LOS were compared with patients receiving oral sotalol over a similar time period. RESULTS: From January 2021 to June 2022, a total of 29 patients (average age 66.0 ± 8.6 years, 27.6% women) underwent IV sotalol load and 20 patients (average age 60.4 ± 13.9 years, 65.0% women) underwent oral sotalol load. The load was successfully completed in 22/29 (75.9%) patients receiving IV sotalol and 20/20 (100%) of patients receiving oral sotalol, although 7/20 of the oral sotalol patients (35.0%) required dose reduction. Adverse events interrupting IV sotalol infusion included bradycardia (seven patients, 24.1%) and QT prolongation (three patients, 10.3%). No patients receiving IV or oral sotalol developed sustained ventricular arrhythmias before discharge. LOS for patients completing IV load was 2.6 days shorter (mean 1.0 vs. 3.6, p < .001) compared with LOS with oral load. CONCLUSION: IV sotalol loading has a safety profile that is similar to oral sotalol. It significantly shortens hospital LOS, potentially leading to large cost savings.

Editorial Commentary: Immediate Surgical Stabilization Following a First-Time Traumatic Anterior Shoulder Dislocation Is Still the Best Evidence-Based Approach.

Traumatic anterior shoulder dislocations are unfortunately common. The initial dislocation is enough to cause permanent anatomic and biomechanical alterations to the glenohumeral joint, which increases the likelihood of further events. When a patient crosses into the multiple dislocator category, further soft-tissue and bony injury occurs. This is almost certainly the reason that the number of preoperative dislocations significantly diminishes the success of an arthroscopic stabilization and increases the need for a more aggressive approach that may carry greater risks of complications. When it comes to recurrent instability, there remains very little doubt regarding the appropriate treatment for a first-time traumatic dislocation: immediate surgical stabilization! Assuming no significant glenoid or humeral bone loss, arthroscopic stabilization remains an effective surgery with a high-benefit, low-risk profile, especially when combined with a remplissage in high-risk circumstances. At least 4 randomized controlled trials support immediate versus nonoperative management for every outcome measured: recurrence, return to sport, patient-reported outcomes, and sustained event-free survival, especially pronounced at 2 years. The decision to recommend surgery, is of course, not always straightforward, necessitating an informed discussion with the patient and the family, especially when other outcomes such as return to play are deemed equally relevant and can be successfully achieved with nonoperative management. Nonetheless, more than any other outcome measure, is there a more important outcome than recurrence regarding long-term health implications? Lastly, can we do better with study designs and outcome measures to better understand risk factors to identify patients better suited for surgery after a first-time event than others? Absolutely. But until then, when up to 60% can sustain a recurrent dislocation in this population, and up to 90% in high-risk individuals, the odds are not in my favor with nonoperative treatment. Despite potential limitations in our current literature, immediate surgery following a first-time dislocation is still the best evidence-based approach.

Increased Failure Rates After Arthroscopic Bankart Repair After Second Dislocation Compared to Primary Dislocation With Comparable Clinical Outcomes.

PURPOSE: The purpose of this study was to compare rates of recurrent dislocation and postsurgical outcomes in patients undergoing arthroscopic Bankart repair for anterior shoulder instability immediately after a first-time traumatic anterior dislocation versus patients who sustained a second dislocation event after initial nonoperative management. METHODS: A retrospective chart review was performed of patients undergoing primary arthroscopic stabilization for anterior shoulder instability without concomitant procedures and minimum 2-year clinical follow-up. Primary outcome was documentation of a recurrent shoulder dislocation. Secondary clinical outcomes included range of motion, Visual Analog Scale (VAS), American Shoulder and Elbow Surgeons Shoulder Score (ASES), and Shoulder Activity Scale (SAS). RESULTS: Seventy-seven patients (mean age 21.3 years ± 7.3 years) met inclusion criteria. Sixty-three shoulders underwent surgical stabilization after a single shoulder dislocation, and 14 underwent surgery after 2 dislocations. Average follow-up was 35.9 months. The rate of recurrent dislocation was significantly higher in the 2-dislocation group compared to single dislocations (42.8% vs 14.2%, P = .03). No significant difference was present in range of motion, VAS, ASES, and SAS scores. The minimal clinically important difference (MCID) was 1.4 for VAS and 1.8 for SAS scores. The MCID was met or exceeded in the primary dislocation group in 31/38 (81.6%) patients for VAS, 23/31 (74.1%) for ASES, and 24/31 for SES (77.4%) scores. For the second dislocation cohort, MCID was met or exceeded in 7/9 (77.8%) for VAS, 4/7 (57.1%) for ASES, and 5/7 for SES (71.4%) scores. CONCLUSION: Immediate arthroscopic surgical stabilization after a first-time anterior shoulder dislocation significantly decreases the risk of recurrent dislocation in comparison to those who undergo surgery after 2 dislocation events, with comparable clinical outcome scores. These findings suggest that patients who return to activities after a primary anterior shoulder dislocation and sustain just 1 additional dislocation event are at increased risk of a failing arthroscopic repair. STUDY DESIGN: Retrospective comparative study; Level of evidence, 3.

Proximal Humerus Fractures: Leave It Alone, Fix It, Replace It?

Proximal humerus fractures are common injuries that account for 10% of all fractures in the elderly. Several options are available for the management of proximal humerus fractures. Optimal treatment is based on the fracture pattern and the patient characteristics. Most of these fractures are minimally displaced and managed nonsurgically. Approximately 15% of proximal humerus fractures are comminuted, head-split, fracture-dislocation, or severely displaced, which make the best treatment option more challenging. Hemiarthroplasty is still a viable option in selected patients of these groups; however, advancements in locking plate designs and introduction of reverse total shoulder arthroplasty have led to better clinical outcome in meticulously selected patients. Nonetheless, the debate continues regarding the best management. It is important to discuss the best treatment options based on current literature.

Treatment Following a First-Time Shoulder Dislocation: What Should I Do?

A first-time shoulder dislocation is a challenging topic that requires consideration of anatomic and patient-specific factors. Initial management is predicated on determining functional demands, activity level, and expectations of the patient, in addition to assessing the risk of recurrent instability. When considering surgical indications, it is imperative to understand the biomechanical implications of injury to the glenohumeral joint complex and how specific surgical procedures can restore stability. It is important to provide an overview of the current treatment algorithm for management of first-time shoulder dislocation, with a special focus on diagnosis and intervention in the young athlete.

Increased superior translation following multiple simulated anterior dislocations of the shoulder.

PURPOSE: Recurrent shoulder dislocations can result in kinematic changes of the glenohumeral joint. The number of prior shoulder dislocations may contribute to increased severity of capsulolabral lesions. The kinematics of the glenohumeral joint following multiple dislocations remain poorly understood. The purpose of this study was to assess the kinematics of the glenohumeral joint during anterior dislocations of the shoulder, and more specifically, altered translational motion following multiple dislocations. The kinematics of the glenohumeral joint were hypothesized to change and correlate with the number of dislocations. METHODS: Eight fresh-frozen cadaveric shoulders were dissected free of all soft tissues except the glenohumeral capsule. Each joint was mounted in a robotic testing system. At 60 degrees of glenohumeral abduction, an internal and external rotational torque (1.1 Nm) were applied to the humerus, and the resulting joint kinematics were recorded. Anterior forces were applied to the humerus to anteriorly dislocate the shoulder and the resulting kinematics were recorded during each dislocation. Following each dislocation, the same rotational torque was applied to the humerus, and the resulting joint kinematics were also recorded. A repeated-measures analysis of variance (ANOVA) was used to compare the kinematics following each dislocation. RESULTS: During the 7th, 8th, 9th, and 10th dislocations, the humerus significantly translated superiorly compared with the shoulder during the 1st dislocation (p < 0.05). Following the 3rd, 4th, 5th, and 10th dislocations, the humeral head significantly translated superiorly compared with the shoulder following the 1st dislocation in the position of 60 degrees of abduction in response to external rotation torque (p < 0.05). CONCLUSION: Multiple anterior shoulder dislocations lead to abnormal translational kinematics and result in increased superior translation of the humerus. This may contribute to pathologic superior extension of capsulolabral injuries. Superior translation of the humerus with overhead motion in the setting of recurrent instability may also place the shoulder at risk for extension of the capsulolabral injuries.

Nonarthroplasty options for massive, irreparable rotator cuff tears have improvement in range of motion and patient-reported outcomes at short-term follow-up: a systematic review.

PURPOSE: To compare various nonarthroplasty treatment options for massive, irreparable rotator cuff tears, including allograft bridging/augmentation, debridement, partial repair, superior capsule reconstruction (SCR), subacromial balloon spacer, and tendon transfer. METHODS: A comprehensive search was conducted through the PubMed, MEDLINE, and EMBASE databases for all articles pertaining to nonarthroplasty treatment options for irreparable rotator cuff tears. Inclusion criteria included manuscripts published between 2009 and 2020 with at least 1 year follow-up and Level I-IV evidence. Articles were separated into six groups: debridement, arthroscopic and open repair, allograft bridging/augmentation, SCR, subacromial balloon spacer, and tendon transfer. Data points included range of motion (external rotation, abduction, forward flexion, and internal rotation), visual analog scale (VAS) pain score, American Shoulder and Elbow Surgeons (ASES) score, Constant score, rate of revision surgery, and rate of conversion to arthroplasty. RESULTS: A total of 83 studies and 3363 patients were included. All treatment options had statistically significant improvements in postoperative range of motion and patient-reported outcomes. Debridement had statistically significantly greater postoperative abduction and forward flexion range of motion, as well as better VAS pain scores, compared to the other treatment options. The SCR subgroup had the greatest improvement in ASES scores postoperatively. The overall revision rate was 7.2% among all surgical options, with the allograft bridging/augmentation group having the lowest rate of revision at 0-8.3%. The overall rate of conversion to arthroplasty was 7.2%, with debridement having the greatest rate of conversion at 15.4%. CONCLUSION: All six nonarthroplasty treatment options for irreparable rotator cuff tears resulted in statistically significant improvements in range of motion and patient-reported outcomes at 1 year follow-up or more, with low rates of revision and conversion to arthroplasty. Debridement had statistically significantly greater postoperative abduction and forward flexion range of motion, as well as better VAS pain scores, compared to the other treatment options. However, these conclusions should be interpreted with caution due to the heterogeneous nature of the data, lack of prospective randomized control trials, and short-term follow-up. The findings of this study highlight the complexity of irreparable, massive rotator cuff tears, and the need for an individualized approach when treating these patients. LEVEL OF EVIDENCE: Level IV.

Knotted and knotless double row transosseous equivalent repair techniques for arthroscopic rotator cuff repair demonstrate comparable post-operative outcomes.

PURPOSE: To compare failure rates and outcomes after transosseous equivalent (TOE) double row (DR) knotted suture bridge versus knotless suture tape bridge repair techniques for rotator cuff tears. METHODS: A consecutive series of 272 shoulders in 256 patients who underwent arthroscopic, double row, TOE repair for full-thickness tears of the supraspinatus tendon were reviewed. Eighty-four shoulders were repaired using knotted suture bridge (KSB) technique, and 188 shoulders were repaired using all knotless suture tape bridge (KTB) technique. Revision procedures and concomitant subscapularis tendon repairs were excluded from analysis. The minimum follow-up was 12 months. Primary outcome was failure of surgical repair, defined as either confirmed retear on MRI and/or need for revision surgery. Secondary clinical outcome measures were assessed including range of motion, strength, visual analog scale (VAS), operative time, subjective shoulder value (SSV), Patient-Reported Outcomes Measurement Information System (PROMIS) mental and physical health, American Shoulder and Elbow Surgeons Shoulder Score (ASES), Brophy shoulder activity scores, and need for manipulation under anesthesia (MUA). RESULTS: A total of 127 shoulders (38 KSB and 89 KTB) met inclusion criteria for the study. No significant difference in demographic variables were present between the groups at baseline. Supraspinatus tear size and average follow-up time did not differ significantly between groups. Failure rates were similar between the KSB and KTB repairs (13.1 vs 7.9%, n.s.). There was no significant difference in functional outcomes including strength, range of motion in forward flexion and external rotation, as well as patient reported outcomes including VAS, SSV, PROMIS, ASES, and Brophy scores between the groups. There was also no difference in post-operative stiffness requiring MUA. CONCLUSION: Both KSB and KTB repair techniques demonstrate low retear rates with excellent functional outcomes when compared to pre-operative examination. Both KSB and KTB techniques are viable options for achieving a successful rotator cuff repair. LEVEL OF EVIDENCE: Level III.