Model-supported decision-making at a contaminated sediment site: Post-audit and site closure.

Computer simulation models have been used to support decision-making at contaminated sediment sites for decades. Nonetheless, their reliability in remedial decision-making has been questioned, and there is a need for retrospective studies of the accuracy of model predictions, that is, post-audits. The Neal's Landfill site near Bloomington, Indiana, provides an example of the successful use of a mathematical simulation model in the selection of a remedy for a site that includes streams with polychlorinated biphenyl (PCB)-affected sediment, water, and fish. A chemical fate and transport and bioaccumulation computer simulation model was developed to compare the effectiveness of alternative remediation plans in reducing fish total PCB concentrations. A post-audit of the model, using several years of data collected after remediation, demonstrates that the model successfully predicted declines in surface water and fish tissue PCB concentrations over a decade, including those associated with longer term natural recovery processes as well as the response to remedial actions. The model predicted, and the post-audit bore out, that risk-based goals would be met using an alternative less extensive than others under consideration. An uncertainty analysis, based on bounding model calculations, provided important support for decision-making, as did the inclusion of a statistical Remedy Confirmation Clause in the Consent Decree for the site. This study demonstrates the utility of a computer simulation model to guide remedial decision-making at a contaminated sediment site. Integr Environ Assess Manag 2022;18:1233-1245. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Predictors of Acute Atrial Fibrillation and Flutter Hospitalization across 7 U.S. Emergency Departments: A Prospective Study.

INTRODUCTION: International rates of hospitalization for atrial fibrillation and flutter (AFF) from the emergency department (ED) vary widely without clear evidence to guide the identification of high-risk patients requiring inpatient management. We sought to determine (1) variation in hospital admission and (2) modifiable factors associated with hospitalization of AFF patients within a U.S. integrated health system. METHODS: This multicenter prospective observational study of health plan members with symptomatic AFF was conducted using convenience sampling in 7 urban community EDs from 05/2011 to 08/2012. Prospective data collection included presenting symptoms, characteristics of atrial dysrhythmia, ED physician impression of hemodynamic instability, comorbid diagnoses, ED management, and ED discharge rhythm. All centers had full-time on-call cardiology consultation available. Additional variables were extracted from the electronic health record. We identified factors associated with hospitalization and included predictors in a multivariate Poisson Generalized Estimating Equations regression model to estimate adjusted relative risks while accounting for clustering by physician. RESULTS: Among 1,942 eligible AFF patients, 1,074 (55.3%) were discharged home and 868 (44.7%) were hospitalized. Hospitalization rates ranged from 37.4% to 60.4% across medical centers. After adjustment, modifiable factors associated with increased hospital admission from the ED included non-sinus rhythm at ED discharge, no attempted cardioversion, and heart rate reduction. DISCUSSION: Within an integrated health system, we found significant variation in AFF hospitalization rates and identified several modifiable factors associated with hospital admission. Standardizing treatment goals that specifically address best practices for ED rate reduction and rhythm control may reduce hospitalizations.

Risk factors associated with atraumatic posterolateral rotatory instability.

BACKGROUND: Traumatic posterolateral rotatory instability after elbow dislocation or fracture dislocation has been well described. However, few reports cover atraumatic posterolateral rotatory instability as a cause of lateral-sided elbow pain. We assessed the risk factors and epidemiology of atraumatic posterolateral rotatory instability in a case-control study. METHODS: A retrospective review of all patients treated operatively for atraumatic posterolateral rotatory instability during a 6-year period was compared with a group of patients with extensor carpi radialis brevis tendinopathy without instability treated during the same time period. Bivariate and multiple logistic regression statistical analyses were used to investigate the following risk factors: gender, age, hand dominance, diabetes, smoking, body mass index, corticosteroid injection history, and duration of symptoms. Disabilities of the Arm, Shoulder, and Hand and pain scores were obtained preoperatively and postoperatively. RESULTS: Thirteen patients with atraumatic posterolateral rotatory instability were compared with 12 patients with extensor carpi radialis brevis tendinopathy. Multivariate analysis revealed patients with atraumatic posterolateral rotatory instability were more likely to have multiple corticosteroid injections (P = .05) and present with a longer duration of symptoms (P = .03). Postoperative pain scores improved in both groups. CONCLUSIONS: Atraumatic posterolateral rotatory instability should be considered in the differential diagnosis of lateral elbow when patients present with a protracted clinical course. Statistically, posterolateral rotatory instability patients more often present with a history of multiple corticosteroid injections.

The impact of precursors on aquatic exposure assessment for PFAS: Insights from bioaccumulation modeling.

Risk assessment for per- and polyfluoroalkyl substances (PFAS) is complicated by the fact that PFAS include several thousand compounds. Although new analytical methods have increased the number that can be identified in environmental samples, a significant fraction of them remain uncharacterized. Perfluorooctane sulfonate (PFOS) is the PFAS compound of primary interest when evaluating risks to humans and wildlife owing to the consumption of aquatic organisms. The exposure assessment for PFOS is complicated by the presence of PFOS precursors and their transformation, which can occur both in the environment and within organisms. Thus, the PFOS to which wildlife or people are exposed may consist of PFOS that was discharged directly into the environment and/or other PFOS precursors that were transformed into PFOS. This means that exposure assessment and the development of remedial strategies may depend on the relative concentrations and properties not only of PFOS but also of other PFAS that are transformed into PFOS. A bioaccumulation model was developed to explore these issues. The model embeds toxicokinetic and bioenergetic components within a larger food web calculation that accounts for uptake from both food and water, as well as predator-prey interactions. Multiple chemicals are modeled, including parent-daughter reactions. A series of illustrative simulations explores how chemical properties can influence exposure assessment and remedial decision making. Integr Environ Assess Manag 2021;17:705-715. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Preoperative tendon retraction, not smoking, is a risk factor for failure with continuity after rotator cuff repair.

BACKGROUND: Smoking is a poor prognostic factor for healing after rotator cuff repair and is associated with inferior results. We hypothesized that smokers would have higher recurrent tear rates and more postoperative myotendinous junction (MTJ) retraction in healed repairs than nonsmokers three months postoperatively. METHODS: Rotator cuff repairs (RCRs) were retrospectively reviewed over a 2-year period. Patients underwent magnetic resonance imaging (MRI) within 6 months prior to surgery and again at 3 months postoperatively. Seventy-nine patients were included and stratified by smokers versus nonsmokers. Baseline patient demographics, tear characteristics, and surgical factors were collected. Preoperative and postoperative MRIs were assessed to quantify the MTJ position and to establish the recurrent tear rate. RESULTS: For the total cohort (nonsmokers, n = 56; smokers, n = 23), significant differences in age, race, and traumatic onset of injury existed between groups. There were no significant differences in recurrent tear between smokers (26%) and nonsmokers (27%), but nonsmokers were more satisfied. For patients with healed RCRs (nonsmokers, n = 41; smokers, n = 17), there were significant differences in race. On univariate analysis, nonsmokers had a significantly more lateral MTJ postoperatively (P = 0.05). On multivariable regression analysis, medialized postoperative MTJ position in healed cuffs was driven only by greater preoperative rotator cuff retraction preoperatively. There were no significant differences in MTJ position based on smoking status for patients with healed RCRs. CONCLUSION: Smoking does not appear to be an independent risk factor for postoperative MTJ retraction in healed RCRs, also known as failure in continuity. Preoperative tear size and retraction play the biggest roles in predicting postoperative MTJ position, regardless of smoking status. There are no significant differences in patient-reported outcomes for patients with healed RCRs, but nonsmokers had more satisfaction following RCR in the total cohort. LEVEL OF EVIDENCE: Level III; Retrospective cohort study; Diagnostic study.

Loss of Elbow Flexion in Congenital Arthrogryposis Treated with a Bipolar Latissimus Transfer: A Case Report.

CASE: A 20-year-old man with congenital arthrogryposis presented for evaluation of biceps dysfunction. Although his left elbow was supple with 0° to 110° passive range of motion (ROM), he had no active ROM and was unable to perform basic activities of daily living such as bringing his hand to his mouth to feed himself. A bipolar latissimus transfer was performed to achieve functional active ROM. CONCLUSION: Bipolar latissimus transfer is a challenging, robust flap able to restore active elbow flexion in select groups of patients with biceps dysfunction, supple elbow, and functional latissimus dorsi.

Population screening for atrial fibrillation by student pharmacists at health fairs.

BACKGROUND: Individuals with unrecognized atrial fibrillation (AF) may be at an increased risk of stroke. There is a need to develop a sustainable and reproducible population-based screening model to identify unrecognized AF. OBJECTIVE: The objective of this study is to evaluate AF screening and education at student pharmacist-driven health fairs. METHODS: Screening for AF was performed by student members of the American Pharmacist Association Academy of Student Pharmacists with preceptor oversight. Participants were screened using the KardiaMobile device (AliveCor, Mountain View, CA), a Food and Drug Administration-cleared device that interprets a medical-grade electrocardiogram in 30 seconds. Student pharmacists also calculated a CHA2DS2-VASc score. Participant education was provided using an American Heart Association AF patient information sheet. Learning assessment was evaluated with 3 multiple choice questions. RESULTS: Students screened a total of 697 participants over a 6-month period at 13 health fairs. Overall, 71% of the participants were women aged 56 ± 15 years (mean ± SD). Sixteen of the participants (2.3%) who were screened received results indicating possible AF. None of the participants with a possible positive finding had symptoms suggestive of AF. Of these 16 participants, 11 (69%) had a CHA2DS2-VASc score greater than or equal to 2 (2.7 ± 0.7). Most participants answered each learning assessment question correctly. More than 95% of participants believed that screening for AF at health fairs was important or very important. CONCLUSION: Student pharmacist-driven health fairs were shown to be feasible models to screen for AF and were effective in providing AF education to the public. Student pharmacists also cultivated a clinical skill that is transferable to their future practice setting, including the community pharmacy setting. Additional studies are needed to assess whether population-based real-time assessment and detection of AF can reduce the risk of stroke in individuals with previously undetected AF.

Risk Factors for Cerebral Desaturation Events During Shoulder Surgery in the Beach Chair Position.

PURPOSE: The goals of this study were 2-fold: (1) to determine the risk factors for cerebral desaturation events (CDEs) after implementation of a comprehensive surgical and anesthetic protocol consisting of patient risk stratification, maintenance of normotensive anesthesia, and patient positioning in a staged fashion, and (2) to assess for subclinical neurologic decline associated with intraoperative ischemic events through cognitive testing. METHODS: One hundred patients undergoing shoulder surgery in the beach chair position were stratified for risk of CDE based on Framingham stroke criteria, body mass index (BMI), and history of cerebrovascular accidents. Cerebral oxygen saturation was monitored with near-infrared spectroscopy. As per a standardized protocol, mean arterial pressure was maintained between 70 and 90 mm Hg. The head was raised in 2 stages separated by 3 minutes. CDE were defined as >20% drop from baseline or <55% O2 absolute threshold. Patients completed a Mini-Mental State Examination during preoperative examination and at the first postoperative visit. RESULTS: The CDE rate was 4% overall and 4.3% in patients undergoing general anesthesia. Forty-five patients were in the higher risk category, and all CDEs occurred in that group. Patients with a Framingham score ≥ 10 or BMI ≥ 35 who underwent general anesthesia had an increased risk of CDE (P = .04). No significant change was noted in Mini-Mental State Examination scores between pre- and postoperative visits. No correlation was shown between CDE and history of diabetes, smoking, cardiovascular disease, or left ventricular hypertrophy. CONCLUSIONS: Our observed CDE rate was lower than previously reported rates, likely because of risk stratification, staged positioning, and normotensive anesthesia. Framingham score ≥ 10 and BMI ≥ 35 are risk factors for CDE in the beach chair position. LEVEL OF EVIDENCE: Level II, prospective observational study with >80% follow-up.

Manganese(iv) oxide amendments reduce methylmercury concentrations in sediment porewater.

Manganese(iv) oxide (pyrolusite, birnessite) mineral amendments can reduce dissolved MeHg concentrations in sediment theoretically by inhibiting microbial sulfate reduction, which is a major methylation pathway in sediments. Anaerobic sediment slurry microcosms in which Hg methylation was stimulated by addition of labile organic carbon (acetate) and HgCl2 showed that manganese(iv) oxide reduced the percent MeHg in slurry porewater (filtered), by 1-2 orders of magnitude relative to controls. Sediment-water mesocosms with pyrolusite or birnessite either directly mixed into the top 5 cm or applied in a thin (5 cm) sand layer over sediment showed reductions in percent MeHg in porewater of 66-69% for pyrolusite and 81-89% for birnessite amendment. A thin sand layer alone resulted in 65% reduction. CO2 respirometry experiments showed that the amendments stimulated microbial activity. Microbial community census by PCR and DNA sequencing indicated that the addition of Mn(iv) oxides did not significantly alter the indigenous sediment microbial community structure, although a small increase in abundance of iron and manganese reducers was observed after a 2 week incubation period. The mechanism of decreasing MeHg relative to Hg concentrations in porewater likely involved an increase in the importance of Mn(iv) reduction (relative to sulfate reduction) in heterotrophic microbial metabolism in the sediments amended with Mn(iv) oxides. Manganese reduction was confirmed as the predominant biogeochemical redox process by microelectrode voltammetry profiling of the sediment microcosms, although adsorption to Mn oxide surfaces, enhanced MeHg demethylation, and abiotic reduction of Mn(iv) also may have been involved in reducing percent MeHg and suppressing net MeHg production. These results represent a novel approach for mitigating MeHg impacts from sediments with potential applicability to a range of aquatic settings including intertidal zones, tidal marshes, seasonal wetlands, reservoirs, and lakes.

Thromboprophylaxis for Patients with High-risk Atrial Fibrillation and Flutter Discharged from the Emergency Department.

INTRODUCTION: Many patients with atrial fibrillation or atrial flutter (AF/FL) who are high risk for ischemic stroke are not receiving evidence-based thromboprophylaxis. We examined anticoagulant prescribing within 30 days of receiving dysrhythmia care for non-valvular AF/FL in the emergency department (ED). METHODS: This prospective study included non-anticoagulated adults at high risk for ischemic stroke (ATRIA score ≥7) who received emergency AF/FL care and were discharged home from seven community EDs between May 2011 and August 2012. We characterized oral anticoagulant prescribing patterns and identified predictors of receiving anticoagulants within 30 days of the index ED visit. We also describe documented reasons for withholding anticoagulation. RESULTS: Of 312 eligible patients, 128 (41.0%) were prescribed anticoagulation at ED discharge or within 30 days. Independent predictors of anticoagulation included age (adjusted odds ratio [aOR] 0.89 per year, 95% confidence interval [CI] 0.82-0.96); ED cardiology consultation (aOR 1.89, 95% CI [1.10-3.23]); and failure of sinus restoration by time of ED discharge (aOR 2.65, 95% CI [1.35-5.21]). Reasons for withholding anticoagulation at ED discharge were documented in 139 of 227 cases (61.2%), the most common of which were deferring the shared decision-making process to the patient's outpatient provider, perceived bleeding risk, patient refusal, and restoration of sinus rhythm. CONCLUSION: Approximately 40% of non-anticoagulated AF/FL patients at high risk for stroke who presented for emergency dysrhythmia care were prescribed anticoagulation within 30 days. Physicians were less likely to anticoagulate older patients and those with ED sinus restoration. Opportunities exist to improve rates of thromboprophylaxis in this high-risk population.

Employment Contracts: The Good, the Bad, and the Ugly.

Recent trends indicate that a greater number of orthopaedic surgeons who complete their residency and/or fellowship training are accepting employment positions at hospitals. Moreover, established orthopaedic surgeons with successful private practices have begun to consider whether aligning with hospitals and larger health systems can be effectively accomplished. A comprehensive evaluation of institution-based employment opportunities is essential for orthopaedic surgeons considering hospital-based employment. Surgeons should be aware of the healthcare, clinical, and administrative opportunities of private practice employment versus hospital-based employment before accepting a clinical position.

Prevalence and risk factors for kidney stones in fibrodysplasia ossificans progressiva.

The worldwide prevalence and risk factors for kidney stones in patients with fibrodysplasia ossificans progressiva (FOP) are unknown. We conducted a survey of 383 patient-members of the International Fibrodysplasia Ossificans Progressiva Association, comprising the entire global membership of the international FOP community. Two hundred seven patients from 31 nations and 6 continents (54%) responded. Nineteen of 207 respondents had kidney stones, revealing a worldwide prevalence of 9.2%. In a confirmatory follow-up study of subjects participating in a longitudinal FOP natural history study, 9 of 114 individuals reported a history of kidney stones (7.9%). In both study populations patients with kidney stones were found to be more functionally impaired compared to those without nephrolithiasis. The prevalence of kidney stones in the adult FOP population of the Unites States was 15.8% (9/57 individuals) compared to a sex- and age-weighted prevalence of 4.5% (p=4×10-5) in the general population. Although geographical variation exists, patients with FOP have an approximately three-fold greater prevalence of kidney stones than the general population. This unusually high prevalence may be due to high bone turnover from chronic immobilization, or to unknown mechanistic effects of the activating FOP mutation in activin A receptor, type I/activin-like kinase-2 (ACVR1/ALK2), increasing the disease burden and morbidity in this already disabling condition.

Arthroscopic Cortical Button Stabilization of Isolated Acute Neer Type II Fractures of the Distal Clavicle.

Neer type II distal clavicle fractures are inherently unstable. The purpose of this study was to review the outcome of Neer type II distal clavicle fractures arthroscopically treated using a suspensory cortical button technique. Between 2008 and 2012, a total of 17 Neer type IIB fractures were managed operatively at the authors' institution. Functional outcomes were assessed using the pain score, the Disabilities of the Arm, Shoulder and Hand score, the Penn Shoulder Score, and the American Shoulder and Elbow Surgeons score. Radiographic union was also assessed. At a mean of 1 year, the mean pain score was 0.9±1.1, the mean Disabilities of the Arm, Shoulder and Hand score was 10.9±11.1, the mean Penn Shoulder Score was 90.3±7.9, and the mean American Shoulder and Elbow Surgeons score was 90.1±10.1. Radiographic union occurred in 14 patients. An all-arthroscopic surgical fixation of Neer type II distal clavicle fractures using a suspensory cortical button technique can result in a predictable outcome with a low complication rate. [Orthopedics. 2017; 40(6):e1050-e1054.].

The timing of retears after arthroscopic rotator cuff repair.

BACKGROUND: Little is known about the time dependence of the failure rate of surgically repaired rotator cuffs. Retears are significant, as they are common and may lead to less satisfactory outcomes and additional operations. Their timing is critical foundational information for understanding failure mechanisms. However, this remains unclear. Currently, there exist a number of studies that have reported retear rates at specific time points. Combining data from these publications can reveal when cuffs retear, which will help inform expectations and guidelines for progression of activity after surgery. METHODS: PubMed, Medline, and Embase were searched for studies relating to rotator cuff repair. Abstracts and articles were evaluated on the basis of predefined inclusion and exclusion criteria. Data were extracted from those publications that satisfied all requirements, and regression analysis was performed. RESULTS: Thirteen articles were included in the final meta-analysis. Retear rates for medium tears increased for approximately 15 months and leveled off at approximately 20%. Retear rates for large tears progressed steadily for about 12 months and approached an upper limit of approximately 40%. Retear rates for massive tears ranged from 20% to 60%, but the distribution of retear rate over time for these cuff tears is not clear from these data. CONCLUSION: Retear rates for medium and large tears generally increase until at least 10-15 months after surgery, after which they are likely to level off. Retear rates for massive tears are variable and may follow a time course different from that of other tear sizes. Retear rates depend on size of the original tear.

Biceps tenotomy in the presence of a supraspinatus tear alters the adjacent intact tendons and glenoid cartilage.

A rotator cuff tear is a common injury in athletes and workers who repeatedly perform overhead movements, and it is not uncommon for this demographic to return to activity shortly after treatment. A biceps tenotomy is often performed in the presence of a rotator cuff tear to help reduce pain and improve joint function. However, the effect of this procedure on the surrounding tissues in the glenohumeral joint is unknown. Therefore, the purpose of this study was to investigate the effect of a biceps tenotomy in the presence of a supraspinatus rotator cuff tear followed by overuse activity on ambulatory function and mechanical and histologic properties of the remaining rotator cuff tendons and glenoid cartilage. 46 rats underwent 4weeks of overuse activity to create a tendinopathic condition, then were randomized into two groups: unilateral detachment of the supraspinatus tendon or detachment of the supraspinatus and long head of the biceps tendons. Ambulatory measurements were performed throughout the 8weeks prior to euthanasia, followed by analysis of the properties of the remaining intact tendons and glenoid cartilage. Results demonstrate that shoulder function was not effected in the biceps tenotomy group. However, the intact tendons and glenoid cartilage showed altered mechanical and histologic properties. This study provides evidence from an animal model that does not support the use of tenotomy in the presence of a supraspinatus tendon rotator cuff tear, and provides a framework for physicians to better prescribe long-term treatment strategies for patients.

The development and application of a risk stratification index system for outpatient shoulder arthroscopy patient management-a single academic center's experience.

BACKGROUND: Our goal was to develop a risk stratification index (RSI) that could guide management of our patients. We hypothesized that the risks of unexpected overstay admission (OS) and emergency department (ED) transfer are predictable on the basis of patient factors for elective outpatient shoulder arthroscopic surgery. METHODS: We first identified 124,860 subjects who received shoulder arthroscopic surgery in the Healthcare Cost and Utilization Project database. We next conducted multivariable regression analysis to identify risk factors associated with unanticipated OS or ED transfer. The risk factors were then adopted to construct the RSI. We last applied the RSI into our practice and prospectively collected outcome data between August 2014 and June 2015. RESULTS: The significant risk factors included arrhythmia, chronic obstructive pulmonary disease, diabetes, obesity, neurologic disease with function impairment, and general anesthesia. All significant risk factors were then adopted to calculate the RSI with equal weight assignment. Simulated analysis concluded that a patient with 2 or fewer risk factors would carry a theoretical rate for OS or ED events of 0.73%. A total of 583 shoulder arthroscopy procedures were performed, among which 472 (81.0%) patients passed the RSI and were successfully managed in the outpatient surgical center without any admission. There were 111 (19.0%) subjects with procedures performed in the main hospital, with 2 unexpected admissions (1.8%). CONCLUSION: We developed an RSI tool for shoulder arthroscopic surgery with an existing national database. It is our conclusion that the RSI system is an effective tool to optimize clinical practice. However, over time, a longer follow-up period might provide more convincing evidence.

Is there a dose response of dexamethasone as adjuvant for supraclavicular brachial plexus nerve block? A prospective randomized double-blinded clinical study.

STUDY OBJECTIVE: The study objective is to examine the analgesic effect of 3 doses of dexamethasone in combination with low concentration local anesthetics to determine the lowest effective dose of dexamethasone for use as an adjuvant in supraclavicular brachial plexus nerve block. DESIGN: The design is a prospective randomized double-blinded clinical study. SETTING: The setting is an academic medical center. PATIENTS: The patients are 89 adult patients scheduled for shoulder arthroscopy. INTERVENTIONS: All patients were randomly assigned into 1 of 4 treatment groups: (i) bupivacaine, 0.25% 30 mL; (ii) bupivacaine, 0.25% 30 mL with 1-mg preservative-free dexamethasone; (iii) bupivacaine, 0.25% 30 mL with 2-mg preservative-free dexamethasone; and (iv) bupivacaine, 0.25% 30 mL with 4-mg preservative-free dexamethasone. All patients received ultrasound-guided supraclavicular brachial plexus nerve blocks and general anesthesia. MEASUREMENTS: The measurements are the duration of analgesia and motor block. MAIN RESULTS: The median analgesia duration of supraclavicular brachial plexus nerve block with 0.25% bupivacaine was 12.1 hours; and 1-, 2-, or 4-mg dexamethasone significantly prolonged the analgesia duration to 22.3, 23.3, and 21.2 hours, respectively (P = .0105). Dexamethasone also significantly extended the duration of motor nerve block in a similar trend (P = .0247). CONCLUSION: Low-dose dexamethasone (1-2 mg) prolongs analgesia duration and motor blockade to the similar extent as 4-mg dexamethasone when added to 0.25% bupivacaine for supraclavicular brachial plexus nerve block.

Glenoid perforation with pegged components during total shoulder arthroplasty.

A subset of patients undergoing primary total shoulder arthroplasty (TSA) have a medialized joint line secondary to glenoid wear. In some cases, the central pegs or peripheral pegs of a peg design glenoid component may violate the medial cortex of the glenoid vault. It is unknown whether this leads to early failure. The objectives of this study were to determine (1) whether glenoid components with uncontained pegs would be associated with a high rate of failure and (2) whether peg perforation would be associated with inferior clinical outcomes. The authors performed a case-control retrospective review comparing 25 TSAs in which one or multiple pegs perforated the medial glenoid vault (uncontained group) with 25 TSAs without peg perforation (contained group). Implant survival was calculated with revision for glenoid component loosening as the primary outcome variable. Clinical outcomes were determined using American Shoulder and Elbow Surgeons (ASES) and Penn Shoulder Scores. Average follow-up was more than 5 years. No patient in either group had symptomatic glenoid loosening. Two (8%) patients in the uncontained group required revision for rotator cuff tears. Penn and ASES scores were significantly lower in the uncontained group (Penn, P=.002; ASES, P=.004). Pain and satisfaction subscores were similar between the groups, but function subscores were significantly lower in the uncontained group (Penn, P=.002; ASES, P=.005). Uncontained pegs of an anchor peg glenoid component are not associated with early glenoid loosening. Similar pain relief is obtained when compared with contained glenoid components, but shoulder function is significantly lower in patients with uncontained pegs.

Disruption of the anterior-posterior rotator cuff force balance alters joint function and leads to joint damage in a rat model.

The rotator cuff assists in shoulder movement and provides dynamic stability to the glenohumeral joint. Specifically, the anterior-posterior (AP) force balance, provided by the subscapularis anteriorly and the infraspinatus and teres minor posteriorly, is critical for joint stability and concentric rotation of the humeral head on the glenoid. However, limited understanding exists of the consequences associated with disruption of the AP force balance (due to tears of both the supraspinatus and infraspinatus tendons) on joint function and joint damage. We investigated the effect of disrupting the APforce balance on joint function and joint damage in an overuse rat model. Twenty-eight rats underwent 4 weeks of overuse to produce a tendinopathic condition and were then randomized into two surgical groups: Detachment of the supraspinatus only or detachment of the supraspinatus and infraspinatus tendons. Rats were then gradually returned to their overuse protocol. Quantitative ambulatory measures including medial/lateral, propulsion, braking, and vertical forces were significantly different between groups. Additionally, cartilage and adjacent tendon properties were significantly altered. These results identify joint imbalance as a mechanical mechanism for joint damage and demonstrate the importance of preserving rotator cuff balance when treating active cuff tear patients.