Non-union of the greater tuberosity in patients undergoing reverse total shoulder arthroplasty for proximal humerus fracture: Is it associated with worse outcomes?

BACKGROUND: 4-part proximal humerus fractures are complex injuries that are often associated with comminution of the greater tuberosity. The purpose of this study is to evaluate the functional outcomes of 4-part humerus fractures that are treated with reverse total shoulder arthroplasty (rTSA) and correlate these outcomes with the healing status of the greater tuberosity. MATERIAL AND METHODS: A retrospective observational study was performed including 65 patients who underwent rTSA following a 4-part proximal humerus fracture. These patients were categorized into 3 groups according to the healing status of the greater tuberosity: patients with healed greater tuberosity in an anatomical position (group A, n = 43), patients with non-union of the greater tuberosity but in anatomical position (group B, n = 14), and patients with resorption or non-union of the greater tuberosity not in anatomical position (group C, n = 8). The Constant-Murley score and range of motion were recorded for each patient at 12 months postoperatively. The clinical and radiographical outcomes of the 3 groups were compared. RESULTS: Patients with healed greater tuberosity (group A) had higher range of motion compared to patients with greater tuberosity migration or reabsorption (group C) regarding forward flexion (130° vs 80°, p < 0.001), abduction (110° vs 65°, p < 0.001) and external rotation (20° vs 10°, p = 0.004). However, no significant changes regarding forward flexion (130° vs 125°, p = 0.67), abduction (110° vs 100°, p = 0.60) and external rotation (20° vs 25°, p = 0.37) were noted between patients with healed greater tuberosity (group A) and those with non-united greater tuberosity that remained attached to the humeral prosthesis (group B). Similarly, Constant- Murley score was similar between patients of group A and group B (65.0 vs 61.5, p = 0.53), while it was higher in patients of group A compared to those of group C (65.0 vs 39.0, p = 0.053). CONCLUSIONS: The outcomes of this study indicate that reliable recovery regarding range of motion and functional status can be achieved in patients who undergo rTSA due to 4-part proximal humerus fractures, as long as the greater tuberosity remains in close proximity to the humeral prosthesis, even if it has signs of non-union with no continuity to the adjacent humerus.

How to Shoot and Edit High-Quality Surgical Videos for Hand and Upper Extremity Surgery.

A surgical video can improve patient care, surgical education, as well as scientific presentations and publications. Previous authors have outlined a basic understanding of how to produce high-quality surgical videos. With continuous technological improvements in video-filming hardware and editing software, multiple options for producing high-quality surgical videos are available. This article described important aspects of filming and editing videos to create a video that the surgeon can watch before performing the procedure. The authors reviewed camera terminology, including resolution, optical and digital zoom, shutter speed, and frame rate, as well as equipment options or setup for recording high-quality surgical videos. We provided information regarding computer requirements and editing on Windows and Macintosh operating systems, optimizing educational value for the viewer.

Obesity and Airway Dysanapsis in Children with and without Asthma.

RATIONALE: For unclear reasons, obese children with asthma have higher morbidity and reduced response to inhaled corticosteroids. OBJECTIVES: To assess whether childhood obesity is associated with airway dysanapsis (an incongruence between the growth of the lungs and the airways) and whether dysanapsis is associated with asthma morbidity. METHODS: We examined the relationship between obesity and dysanapsis in six cohorts of children with and without asthma, as well as the relationship between dysanapsis and clinical outcomes in children with asthma. Adjusted odds ratios (ORs) were calculated for each cohort and in a combined analysis of all cohorts; longitudinal analyses were also performed for cohorts with available data. Hazard ratios (HRs) for clinical outcomes were calculated for children with asthma in the Childhood Asthma Management Program. MEASUREMENTS AND MAIN RESULTS: Being overweight or obese was associated with dysanapsis in both the cross-sectional (OR, 1.95; 95% confidence interval [CI], 1.62-2.35 [for overweight/obese compared with normal weight children]) and the longitudinal (OR, 4.31; 95% CI, 2.99-6.22 [for children who were overweight/obese at all visits compared with normal weight children]) analyses. Dysanapsis was associated with greater lung volumes (FVC, vital capacity, and total lung capacity) and lesser flows (FEV1 and forced expiratory flow, midexpiratory phase), and with indicators of ventilation inhomogeneity and anisotropic lung and airway growth. Among overweight/obese children with asthma, dysanapsis was associated with severe disease exacerbations (HR, 1.95; 95% CI, 1.38-2.75) and use of systemic steroids (HR, 3.22; 95% CI, 2.02-5.14). CONCLUSIONS: Obesity is associated with airway dysanapsis in children. Dysanapsis is associated with increased morbidity among obese children with asthma and may partly explain their reduced response to inhaled corticosteroids.

PACE: Data-Driven Virtual Agent Interaction in Dense and Cluttered Environments.

We present PACE, a novel method for modifying motion-captured virtual agents to interact with and move throughout dense, cluttered 3D scenes. Our approach changes a given motion sequence of a virtual agent as needed to adjust to the obstacles and objects in the environment. We first take the individual frames of the motion sequence most important for modeling interactions with the scene and pair them with the relevant scene geometry, obstacles, and semantics such that interactions in the agents motion match the affordances of the scene (e.g., standing on a floor or sitting in a chair). We then optimize the motion of the human by directly altering the high-DOF pose at each frame in the motion to better account for the unique geometric constraints of the scene. Our formulation uses novel loss functions that maintain a realistic flow and natural-looking motion. We compare our method with prior motion generating techniques and highlight the benefits of our method with a perceptual study and physical plausibility metrics. Human raters preferred our method over the prior approaches. Specifically, they preferred our method 57.1% of the time versus the state-of-the-art method using existing motions, and 81.0% of the time versus a state-of-the-art motion synthesis method. Additionally, our method performs significantly higher on established physical plausibility and interaction metrics. Specifically, we outperform competing methods by over 1.2% in terms of the non-collision metric and by over 18% in terms of the contact metric. We have integrated our interactive system with Microsoft HoloLens and demonstrate its benefits in real-world indoor scenes. Our project website is available at https://gamma.umd.edu/pace/.

Single Incision Modified Tension Slide Technique in Distal Biceps Repair: Improved Load to Failure While Reducing Surgical Pitfalls.

Historically, distal biceps tendon repair through the tension slide technique (TST) using a cortical button has yielded the strongest published repair measured by observed gap formation in both cyclic and maximal load to failure. The modified tension slide technique (MTST) was developed in order to provide the surgeon with a technically simpler and biomechanically more effective way to reduce gap formation and consistently seat/bottom-out the tendon within the bone tunnel through a more direct line of pull. In order to compare the biomechanics of the MTST to the TST, we used 24 matched bovine extensor tendons, and conducted maximal load to failure and cyclical load to failure testing using an Instron 5566 machine. The mean maximal load to failure for the MTST was 444 N versus 229 N for the TST ( P <0.004) while no gap formation was observed in either group after cyclic load testing. These findings indicate that the MTST has a statistically significant increased load to gap formation of ∼2-fold in comparison to TST. In the MTST both limbs of suture are passed back through the tendon, before button implantation, eliminating the "operating in a hole" effect required in the TST, and making for a simpler surgical procedure.

Prevention of surgical resident attrition by a novel selection strategy.

OBJECTIVE(S): We modified the resident selection strategy in an attempt to reduce resident attrition (RA). SUMMARY BACKGROUND DATA: Despite implementation of the Accreditation Council for Graduate Medical Education work rules, lifestyle and generational priorities have fostered a persistent and relatively high attrition rate for surgical trainees. METHODS: An independent external review of residents who left the training program and a detailed analysis of the resident selection strategy were performed by an organizational management expert. Modifications implemented in 2005 (the intervention) included standardization of the screening and interview format. Applicants were required to submit a 500 words essay related to stress management, organizational skills, future aspirations, and prioritization abilities. Their responses formed the basis of an extended, personalized, and structured interview script. Candidate characteristics and RA were compared for the 5 years before and after the intervention, using Fisher exact test or chi2. RESULTS: Age, sex, birthplace, medical school ranking, step 1 score, and American Board of Surgey In-Training Examination performance were not significantly different between the selection strategy groups. Risk factors for RA included ABSITE performance and gender. Resident performance and subsequent RA were significantly affected by the resident selection strategy. CONCLUSIONS: RA was dramatically reduced following the intervention. A custom designed process to identify candidates most likely to succeed substantially improved resident retention in a demanding academic training program.

Flagellar glycosylation in Clostridium botulinum.

Flagellins from Clostridium botulinum were shown to be post-translationally modified with novel glycan moieties by top-down MS analysis of purified flagellin protein from strains of various toxin serotypes. Detailed analyses of flagellin from two strains of C. botulinum demonstrated that the protein is modified by a novel glycan moiety of mass 417 Da in O-linkage. Bioinformatic analysis of available C. botulinum genomes identified a flagellar glycosylation island containing homologs of genes recently identified in Campylobacter coli that have been shown to be responsible for the biosynthesis of legionaminic acid derivatives. Structural characterization of the carbohydrate moiety was completed utilizing both MS and NMR spectroscopy, and it was shown to be a novel legionaminic acid derivative, 7-acetamido-5-(N-methyl-glutam-4-yl)-amino-3,5,7,9-tetradeoxy-D-glycero-alpha-D-galacto-nonulosonic acid, (alphaLeg5GluNMe7Ac). Electron transfer dissociation MS with and without collision-activated dissociation was utilized to map seven sites of O-linked glycosylation, eliminating the need for chemical derivatization of tryptic peptides prior to analysis. Marker ions for novel glycans, as well as a unique C-terminal flagellin peptide marker ion, were identified in a top-down analysis of the intact protein. These ions have the potential for use in for rapid detection and discrimination of C. botulinum cells, indicating botulinum neurotoxin contamination. This is the first report of glycosylation of Gram-positive flagellar proteins by the 'sialic acid-like' nonulosonate sugar, legionaminic acid.

Overweight, Obesity, and Lung Function in Children and Adults-A Meta-analysis.

BACKGROUND: There is conflicting evidence on the effect of obesity on lung function in adults and children with and without asthma. We aimed to evaluate the relation between overweight or obesity and lung function, and whether such relationship varies by age, sex, or asthma status. METHODS: We searched PubMed, Scopus, CINAHL, Cochrane, and EMBASE for all studies (in English) reporting on obesity status (by body mass index) and lung function, from 2005 to 2017. Main outcomes were forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow between 25th and 75th percentile of the forced vital capacity (FEF25-75), total lung capacity (TLC), residual volume (RV), and functional residual capacity (FRC). Random-effects models were used to calculate the pooled risk estimates; each study was weighed by the inverse effect size variance. For each outcome, we compared overweight or obese ("obese") subjects with those of normal weight. RESULTS: All measures of lung function were decreased among obese subjects. Obese adults showed a pattern (lower FEV1, FVC, TLC, and RV) different from obese children (more pronounced FEV1/FVC deficit with unchanged FEV1 or FVC). There were also seemingly different patterns by asthma status, in that subjects without asthma had more marked decreases in FEV1, TLC, RV, and FRC than subjects with asthma. Subjects who were obese (as compared with overweight) had even further decreased FEV1, FVC, TLC, RV, and FRC. CONCLUSIONS: Obesity is detrimental to lung function, but specific patterns differ between children and adults. Physicians should be aware of adverse effects of obesity on lung function, and weight control should be considered in the management of airway disease among the obese.

Living long with short bowel syndrome: a historical case of twenty-nine years of living with home parenteral nutrition.

BACKGROUND: This paper traces the 29-year survival of Robert Thomas, who received home parenteral nutrition (PN), and contrasts his oral narrative with the clinical history of PN. METHODS: Interviews, chart review, review of the literature, and historical analysis. RESULTS: Bobby Thomas was part of an early group of patients scattered throughout the country who, with their medical team, provided the foundation for more successful survival with home PN. They learned together and taught numerous nutrition support clinicians the intricacies of patient management. The importance of the patient to the teaching function of new and experienced practitioners is highly critical. Patients like Robert Thomas gave practitioners firsthand evidence of both the tenacity of the human spirit and the complexity and difficulties of chronic illness and its treatments. CONCLUSIONS: While Bobby struggled with the complications and difficulties that came with the disease and the treatment keeping him alive, his own experiences over 29 years, as told to his medical team during his treatment and to informed interviewers before he died, tell a story that is both intersecting and parallel to the medical history. Pioneering patients like Bobby Thomas confirm the possibility of survival. They also, through their own negotiations to maintain a sense of control, can live lives they themselves help define.

The Patient Safety Leadership Academy at the University of Pennsylvania: the first cohort's learning experience.

BACKGROUND: We based the Patient Safety Leadership Academy (PSLA) on the premise that improving management skills could improve patient safety and employee satisfaction. STUDY DESIGN: Fellows completed baseline surveys on leadership skills knowledge, patient safety knowledge, and program goals. They completed the same surveys 7 months later at the final PSLA session. The fellows also completed a survey assessing how PSLA improved expertise and comparing PSLA to other patient safety learning opportunities. Matched pairs t tests were used to compare baseline and postprogram results. RESULTS: Baseline scores indicated appropriateness of focusing on leadership, with average leadership knowledge (2.48) significantly lower than patient safety knowledge (3.22). For patient safety, postprogram results were significant for 8 of 10 questions. All results were significant for leadership. Fellows also rated skills covered by the curriculum on a scale of 1 to 10. For all areas, the median score for knowledge gained was 7. When compared with other patient safety learning experiences, participants rated PSLA as 4 or 5, where 1 indicated the other experience much more valuable and 5 much more valuable. CONCLUSIONS: PSLA demonstrates that leadership skills are perceived as important by physicians and managers in surgical areas. This study demonstrated that a leadership skills approach to patient safety training could improve knowledge in specific leadership areas and general patient safety.

Patterns and predictions of resident misbehavior--a 10-year retrospective look.

BACKGROUND: Surgical educators are charged with ensuring that their trainees conduct themselves in a professional manner. The authors retrospectively reviewed a 10-year experience of incident reports on surgical housestaff to determine patterns and predictors of behavior. METHODS: A retrospective review of all letters, e-mails, and incident reports was conducted for general surgery residents from 1995 to 2005. Descriptive variables were selected for binary categorization (not mutually exclusive): poor professional conduct, protocol violation, administrative deficiency, verbal mistreatment, physical boundary issues, mistreatment of superiors, and deficient medical student interaction. Resident status was defined as current, graduate, and attrition. RESULTS: Of 110 residents [90 [82%] categorical, 23 [21%] undesignated preliminary (3 overlapped both groups); 87 [79%] male, 23 [21%] female] who trained at the University of Pennsylvania during this period, 66 complaints were generated about 29 individuals. Overall, 50 of the 66 complaints (76%) were directed toward men and the remaining 16 (24%) toward women; 24% of all men and 35% of all women received 1 or more complaints. A total of 76% of complaints concerned categorical residents and 24% undesignated preliminary residents. And 26% of all categorical residents and 26% of all preliminary residents received at least 1 complaint. The most common complaints concerned professional conduct (83%), protocol violation (33%), verbal mistreatment (23%), deficiencies of administrative duties (8%), violations of physical boundaries (5%), deficient medical student interaction (5%), and mistreatment of attendings by residents (3%). Recipients of verbal mistreatment included staff nurses (27%), radiology technicians (13%), medical students (13%), environmental services employees (7%), security guards (7%), patients (7%), surgery attendings (7%), anesthesia attendings (7%), internal medicine chief residents (7%), and pharmacists (7%). A total of 31% of the complaints were regarding residents who involuntarily departed and 7% regarding residents who left voluntarily before completion. The mean PGY level at first complaint was 2.2 years. Of the 29 residents receiving complaints, 16 had recurrent offenses (range 2 to 7 total complaints, positive predictive value [PPV] 53%). CONCLUSION: Resident misbehavior manifests early and recurs often. Furthermore, it is frequently directed toward perceived subordinates. Nondesignated preliminary status, premature departure from the program, and the eventual selection of specific subspecialty fellowships seems to increase the risk for resident misbehavior. Identified residents require close surveillance and remediation.

How do surgical residents and non-physician practitioners play together in the sandbox?

INTRODUCTION: The reduction of resident work hours due to the 80-hour workweek has created pressure on academic health-care systems to find "replacement residents." At the authors' institution, a group of nurse practitioners (NPs) and physician assistants (PAs), collectively referred to as non-physician practitioners (NPPs), were hired as these reinforcements, such that the number of NPPs (56) was almost twice the number of clinical categorical surgery residents (37). An experienced leader with national credibility was hired to run the NPP program. On each service, the call system was changed to a night float system, whereby residents were pulled from traditional resident teams to serve as nighttime residents during the week. A total of 1-3 NPPs were hired for each team, but whether NPPs worked for the team as a whole, or were assigned to individual attendings, was left to the discretion of the division chiefs. One year after the start of this program, the authors wanted to study the effects it has had on both surgery resident education and NPP job satisfaction. METHODS: An electronic, anonymous survey was conducted during a monthly surgery resident meeting, and out of 72 categorical and preliminary surgery residents, 50% submitted answers to 12 questions. A similar electronic survey was administered to all 56 NPPs, with 45% responding. RESULTS: Overall, 63% of residents believed that lines of communication between surgery team members were clear, and 58% of residents and 71% of NPPs believed that attendings, residents, and NPPs worked together effectively. A total of 91% of residents believed that the addition of NPPs to the teams was positive overall, and 80% of NPPs were satisfied with their positions. Overall, 60% of residents and 50% of NPPs felt that educational goals were being met. DISCUSSION: Implementation of the 80-hour workweek and introduction of NPs and PAs onto the inpatient surgical services has altered resident education at the authors' institution. Although overall most residents view the addition of NPPs to the clinical services as positive, there are concerns about the program. Although hired to fill the void left by decreasing labor hours of residents, NPPs do not necessarily have the same goals as surgery residents and there is confusion about how NPPs fit into the hierarchy of the traditional surgical team.

Impact of recent guideline changes on aspirin prescribing after knee arthroplasty.

BACKGROUND: Prior to 2012, the American Academy of Orthopaedic Surgeons (AAOS) and American College of Chest Physicians (ACCP) differed in their recommendations for postoperative pharmacologic venous thromboembolism prophylaxis (VTEP) after total joint arthroplasty. More specifically, aspirin (ASA) monotherapy was not endorsed by the ACCP as an acceptable prophylaxis. In 2012, the ACCP supported ASA monotherapy compared with no prophylaxis. Our aim was to investigate the impact of the convergence of ACCP and AAOS recommendations on surgeon prescribing patterns after knee arthroplasty (KA). METHODS: This is a retrospective chart review. We collected data to assess preoperative VTE risk and examined VTEP prescriptions on postoperative day 1 (POD1) and at discharge (D/C) from 7/2008 to 12/2011 (pre-period) and 1/2012 to 7/2014 (post-period). Adult patients undergoing primary and revision KA were identified by ICD-9 procedure codes. Patients on preoperative full-dose anticoagulation and with hypercoagulability disorders were excluded. RESULTS: Of 368 records reviewed, 329 were included in the analysis. There were no differences between the two period groups for age, sex, BMI, estrogen therapy, malignancy, smoking status, prior VTE, bilateral procedures, or surgery within 3 months. On POD1, in the pre-period, 4.6 % were prescribed ASA monotherapy versus 44.4 % in the post-period (p < 0.001). On D/C, in the pre-period, 13.9 % were prescribed ASA versus 55.6 % in the post-period (p < 0.001). CONCLUSIONS: Our results indicate a statistically significant change in orthopedist prescribing patterns after guideline convergence. Furthermore, there was no apparent change in VTE risk between the two study groups when excluding patients necessitating full anticoagulation. Prior literature has shown that the divergence in guidelines influenced physicians away from ASA and toward more potent anticoagulants in order to avoid potential litigation. Once its role in VTEP was supported by the ACCP, it appears that ASA monotherapy was readily and rapidly incorporated into clinical practice. ASA may be favored over other VTEP agents for its lower bleeding risk profile and cost. This study highlights the profound impact clinical practice guidelines have on clinician prescribing patterns. Although prospective randomized trials are needed to compare the efficacy of ASA with other VTEP agents, ASA is now a predominant part of the VTEP armamentarium after KA.

Methods to study glycoproteins at the blood-brain barrier using mass spectrometry.

Glycosylation is the most common posttranslational modification of proteins in mammalian cells and is limited mainly to membrane and secreted proteins. Glycoproteins play several key roles in the physiology and pathophysiology of the blood-brain barrier (BBB) and are attractive as diagnostic markers and therapeutic targets for many neurological diseases. However, large-scale glycoproteomic studies of the BBB have been lacking, largely due to the complexity of analyzing glycoproteins and a lack of available tools for this analysis. Recent development of the hydrazide capture method and significant advances in mass spectrometry (MS)-based proteomics over the last few years have enabled selective enrichment of glycoproteins from complex biological samples and their quantitative comparisons in multiple conditions. In this chapter, we describe methods for: (1) isolating membrane and secreted proteins from BEC and other cells of the neurovascular unit, (2) enriching glycoproteins using hydrazide capture, and (3) performing label-free quantitative proteomics to identify differential glycoprotein expression in various biological conditions. Hydrazide capture, when coupled with label-free quantitative proteomics, is a reproducible and sensitive method that allows for quantitative profiling of a large number of glycoproteins from biological samples for the purposes of differential expression measurements and biomarker discovery.

Contributions of surgical residents to patient satisfaction: impact of residents beyond clinical care.

PURPOSE: Little is known about the relationship between resident performance and patient satisfaction. To this end, our institution added housestaff-specific questions to Press-Ganey surveys (Press-Ganey, South Bend, Indiana) administered to patients. This study sought to investigate the impact residents have on patients' overall rating of care compared with faculty and nursing staff. Our hypothesis was that residents play an important but historically underappreciated role in patient satisfaction. METHODS: Between April 2005 and June 2006, half of all discharged patients randomly received Press-Ganey surveys, including questions on the following categories: admissions, patient room, food, diagnostic testing, guest services, faculty/attending physician, discharge, emotional needs, housestaff, nurse practitioners, and primary nurse. responses were grouped into overall category scores and used as predictor variables for regression analysis. a separate question asked patients to rate overall care provided. Chief resident schedules and evaluation scores by faculty were provided by the Division of Surgery Education. Regression, and ANOVA models were run using JMP 6 software (JMP 6, SAS Institute, Cary, North Carolina). RESULTS: During this period, 49,081 patients were discharged, 24,540 surveys were mailed, and 5828 surveys were returned (24% response rate). In a simple regression analysis, the predictor variables for nursing, housestaff, and faculty accounted for 57%, 33%, and 28%, respectively, of the variation of overall rating of care delivered (p < 0.005). The actual overall score for each group varied slightly: faculty (89.8), nursing (86.6), and housestaff (84.2) (p < 0.005). In a multiple regression analysis, all predictors above were significant (p < 0.05). A small difference in scores existed between surgical (83.9) and nonsurgical (85.0) housestaff (p < 0.05). When data were sorted by surgical services, ratings of surgical housestaff ranged from a high of 86.8 (thoracic) to a low of 79.0 (orthopedics) (p < 0.05). Admission month had no significant effect on overall rating of care (range, 85-90), although comparing the means of resident scores by month (range, 81-86) showed that at the end (May-June) and at the beginning (July-Aug) of an academic year, a significant reduction in resident scores occurred (p < 0.05). The lowest score of the year (82.4) occurred in June, whereas the highest scores occurred in January-April (85-86). Resident evaluation scores by faculty and ratings of housestaff by patients were completely uncorrelated, although certain housestaff achieved significantly higher ratings by patients than others. CONCLUSIONS: Compared with faculty and residents, nurses have a greater impact on the variation of patient satisfaction. However, the actual scores given to residents, faculty, and nurses are all high. A slight difference exists in scores of surgical and nonsurgical residents. For all residents, the time of the academic year impacts resident scores positively in the middle and negatively in the beginning and end. For surgical residents clear differences exist between specialty services, but it is not apparent whether these differences are caused by individual residents or by the clinical service milieu. Residents contribute significantly to overall satisfaction, and additional investigation of the variation in resident scores is needed.

Flagellin diversity in Clostridium botulinum groups I and II: a new strategy for strain identification.

Strains of Clostridium botulinum are traditionally identified by botulinum neurotoxin type; however, identification of an additional target for typing would improve differentiation. Isolation of flagellar filaments and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that C. botulinum produced multiple flagellin proteins. Nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) analysis of in-gel tryptic digests identified peptides in all flagellin bands that matched two homologous tandem flagellin genes identified in the C. botulinum Hall A genome. Designated flaA1 and flaA2, these open reading frames encode the major structural flagellins of C. botulinum. Colony PCR and sequencing of flaA1/A2 variable regions classified 80 environmental and clinical strains into group I or group II and clustered isolates into 12 flagellar types. Flagellar type was distinct from neurotoxin type, and epidemiologically related isolates clustered together. Sequencing a larger PCR product, obtained during amplification of flaA1/A2 from type E strain Bennett identified a second flagellin gene, flaB. LC-MS analysis confirmed that flaB encoded a large type E-specific flagellin protein, and the predicted molecular mass for FlaB matched that observed by SDS-PAGE. In contrast, the molecular mass of FlaA was 2 to 12 kDa larger than the mass predicted by the flaA1/A2 sequence of a given strain, suggesting that FlaA is posttranslationally modified. While identification of FlaB, and the observation by SDS-PAGE of different masses of the FlaA proteins, showed the flagellin proteins of C. botulinum to be diverse, the presence of the flaA1/A2 gene in all strains examined facilitates single locus sequence typing of C. botulinum using the flagellin variable region.

Surgeon contribution to hospital bottom line: not all are created equal.

OBJECTIVE: We hypothesized that surgeon productivity is directly related to hospital operating margin, but significant variation in margin contribution exists between specialties. SUMMARY BACKGROUND DATA: As the independent practitioner becomes an endangered species, it is critical to better understand the surgeon's importance to a hospital's bottom line. An appreciation of surgeon contribution to hospital profitability may prove useful in negotiations relating to full-time employment or other models. METHODS: Surgeon total relative value units (RVUs), a measure of productivity, were collected from operating room (OR) logs. Annual hospital margin per specialty was provided by hospital finance. Hospital margin data were normalized by dividing by a constant such that the highest relative hospital margin (RHM) in fiscal year 2004 expressed as margin units (mu) was 1 million mu. For each specialty, data analyzed included RHM/OR HR, RHM/case, and RHM/RVU. RESULTS: Thoracic (34.55 mu/RVU) and transplant (25.13 mu/RVU) were the biggest contributors to hospital margin. Plastics (-0.57 mu/RVU), maxillofacial (1.41 mu/RVU), and gynecology (1.66 mu/RVU) contributed least to hospital margin. Relative hospital margin per OR HR for transplant slightly exceeded thoracic (275.74 mu vs 233.94 mu) at the top and plastics and maxillofacial contributed the least (-3.83 mu/OR HR vs 9.36 mu/OR HR). CONCLUSIONS: Surgeons contribute significantly to hospital margin with certain specialties being more profitable than others. Payer mix, the penetration of managed care, and negotiated contracts as well as a number of other factors all have an impact on an individual hospital's margin. Surgeons should be fully cognizant of their significant influence in the marketplace.