Immunizations challenge healthcare personnel and affects immunization rates.

PURPOSE: This study measured 1. medical office immunization rates and 2. health care personnel competency in managing vaccine practices before and after evidence-based immunization education was provided. METHOD: This descriptive study compared 32 family medicine and pediatric offices and 178 medical assistants, licensed practical nurses, registered nurses, nurse practitioners, and physicians in knowledge-based testing pre-education, post-education, and 12-months post-education. Immunization rates were assessed before and 18-months post-education. RESULTS: Immunization rates increased 10.3% - 18months post-education; knowledge increased 7.8% - 12months post-education. Family medicine offices, licensed practical nurses, and medical assistants showed significant knowledge deficits before and 12-months post-education. All demographic groups scored less in storage/handling 12-months post-education. CONCLUSION: This study is one of the first studies to identify competency challenges in effective immunization delivery among medical assistants, licensed practical nurses, and family medicine offices. Formal and continuous education in immunization administration and storage/handling is recommended among these select groups.

Antimicrobial de-escalation of treatment for healthcare-associated pneumonia within the Veterans Healthcare Administration.

OBJECTIVES: The objective of this study was to measure quantitatively antimicrobial de-escalation utilizing electronic medication administration data based on the spectrum of activity for antimicrobial therapy (i.e. spectrum score) to identify variables associated with de-escalation in a nationwide healthcare system. METHODS: A retrospective cohort study of patients hospitalized for healthcare-associated pneumonia was conducted in Veterans Affairs Medical Centers (n = 119). Patients hospitalized for healthcare-associated pneumonia on acute-care wards between 5 and 14 days who received antimicrobials for ≥ 3 days during calendar years 2008-11 were evaluated. The spectrum score method was applied at the patient level to measure de-escalation on day 4 of hospitalization. De-escalation was expressed in aggregate and facility-level proportions. Logistic regression was used to assess variables associated with de-escalation. ORs with 95% CIs were reported. RESULTS: Among 9319 patients, the de-escalation proportion was 28.3% (95% CI 27.4-29.2), which varied 6-fold across facilities [median (IQR) facility-level de-escalation proportion 29.1% (95% CI 21.7-35.6)]. Variables associated with de-escalation included initial broad-spectrum therapy (OR 1.5, 95% CI 1.4-1.5 for each 10% increase in spectrum), collection of respiratory tract cultures (OR 1.1, 95% CI 1.0-1.2) and care in higher complexity facilities (OR 1.3, 95% CI 1.1-1.6). Respiratory tract cultures were collected from 35.3% (95% CI 32.7-37.7) of patients. CONCLUSIONS: De-escalation of antimicrobial therapy was limited and varied substantially across facilities. De-escalation was associated with respiratory tract culture collection and treatment in a high complexity-level facility.

Description and validation of a spectrum score method to measure antimicrobial de-escalation in healthcare associated pneumonia from electronic medical records data.

BACKGROUND: Comparison of antimicrobial de-escalation rates between healthcare settings is problematic. To objectively and electronically measure de-escalation a method based upon the spectrum of antimicrobial regimens administered (i.e., spectrum score) was developed. METHODS: A Delphi process was used to develop applicable concepts. Spectrum scores were created for 27 antimicrobials based upon susceptibility for 19 organisms. National VA susceptibility data was used to estimate microbial spectrum. Susceptibility estimates were converted to ordinal scores, and values for organisms with multi-drug resistance potential were weighted more heavily. Organism scores were summed to create antibiotic-specific spectrum scores and extended mathematically to score multi-antimicrobial regimens. Vignettes were created from antimicrobial regimens administered to 300 patients hospitalized with pneumonia. Daily spectrum scores were calculated for each case. Hospitalization day 4 scores were subtracted from day 2 scores (i.e., spectrum score ∆). A positive spectrum score ∆ defined de-escalation. Experts ranked each pneumonia case on a 7-point Likert scale (Likert >4 indicated de-escalation). Spectrum score ∆s were compared to expert review. Findings were used to identify score deficiencies. Next, 40 pairs of cases were modified to include antimicrobial administration routes. Each pair contained almost similar regimens; however, one contained oral (PO) the other only intravenous (IV) antimicrobials on day 4 of therapy. Experts reviewed cases as described. Spectrum score ∆ credits to account for PO conversion were derived from the mean paired differences in Likert Score. De-escalation status was evaluated in 100 vignettes containing antimicrobial route by different experts and compared to the modified method. RESULTS: Initial sensitivity and specificity of the spectrum score ∆ to detect expert classified de-escalation events was 86.3 and 96.0%, respectively. In paired cases, the mean (± SD) Likert score was 5.0 (1.5) and 4.6 (1.5) for PO and IV (P = 0.002), respectively. To improve de-escalation event detection, two credits were added to spectrum score ∆s based upon the percentage of antimicrobials administered PO on day 4. The final method, exhibited sensitivity and specificity to detect expert classified de-escalation events of 96.2 and 93.6%, respectively. CONCLUSIONS: The final spectrum score method exhibited excellent agreement with expert judgments of de-escalation events in pneumonia.

Articular chondral damage of the first metatarsal head and sesamoids: analysis of cadaver hallux valgus.

BACKGROUND: Evidence of successful correction on postoperative hallux valgus imaging studies may not always correlate with patient satisfaction. Recent attention to the association of cartilaginous degeneration and hallux valgus may provide new insight into treatment algorithms and patient expectations. The purpose of this cadaveric study was to evaluate the degree of chondral damage as it relates to increasing hallux valgus deformity. METHODS: A total of 39 cadaver first metatarsophalangeal joints were evaluated by radiography, and then dissected to evaluate for chondral damage. Chondral lesion grade, size, and location were recorded and then analyzed based on patient demographics and hallux valgus angle. RESULTS: Twenty-nine of 39 specimens were considered to have hallux valgus characterized by a hallux valgus angle of 15 degrees or greater. Four of 39 (10%) specimens revealed absence of chondral lesions, and 3 of those were found in the group with a hallux valgus angle of less than 15 degrees. Chondral lesions of increasing size and grade were seen more commonly with a more severe hallux valgus deformity. Particular locations on the metatarsal head appeared to be more prone to cartilaginous lesions when compared to other locations. CONCLUSION: Assessment of first metatarsophalangeal joint articular damage with regard to hallux valgus may be an important clinical parameter for consideration. CLINICAL RELEVANCE: Operative intervention to realign the first metatarsophalangeal joint may correct malalignment and relieve pressure on the widened forefoot, but residual pain within the joint may emanate from preexisting articular cartilaginous lesions. These findings support the concept that earlier intervention with operative realignment of a hallux valgus deformity and specifically the sesamoid complex may diminish degenerative changes.

Health care providers' knowledge assessment of measles, mumps, and rubella vaccine.

The aim of this study was to assess educational needs of health care personnel in vaccine storage and handling. The Immunization Knowledge Assessment Tool (IKAT) was used to evaluate knowledge related to delivery and storage of measles, mumps and rubella (MMR) vaccine among health care personnel in Idaho. Using descriptive analysis, only 61% of respondents achieved a passing score of 80%. Knowledge deficits were revealed among health care personnel, physicians, and other providers in immunization administration and handling of the MMR vaccine. Scores were highest among registered nurses, licensed practical nurses, and medical assistants.

Impact of Implementation of BacT/Alert Virtuo on Blood Culture Time to Positivity in Sepsis Patients.

Time to positivity (TTP) for blood culture bottles incubated in the BacT/Alert Virtuo instrument was compared to the BacT/Alert 3D. TTP was significantly shorter with the Virtuo (median 16.2 h) than 3D (median 21.1 h; P < 0.001). Switching from 3D to Virtuo significantly improved TTP in this multicenter hospital setting study. IMPORTANCE Sepsis affects millions of people around the world each year, and accounts for a significant number of deaths in hospital intensive care units (ICU). Timely diagnosis is key to decreasing morbidity and mortality. One important element of sepsis diagnosis is organism detection using blood cultures. In this study, we examined the impact of implementing the BacT/Alert Virtuo automated blood culture detection system on time to positivity in an ICU patient population at a multicenter hospital setting.

Guideline-based antibiotics and mortality in healthcare-associated pneumonia.

BACKGROUND: Guidelines recommend administration of antibiotics with activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa for treatment of healthcare-associated pneumonia (HCAP). It is unclear if this therapy improves outcomes for patients with HCAP. OBJECTIVE: To determine if administration of guideline-similar therapy (GST) was associated with a reduction in 30-day mortality for HCAP. DESIGN: Multi-center retrospective study. PARTICIPANTS: Thirteen hundred and eleven admissions for HCAP in six Veterans Affairs Medical Centers. INTERVENTIONS: Each admission was classified as receiving GST, anti-MRSA or anti-pseudomonal components of GST, or other non-HCAP therapy initiated within 48 hours of hospitalization. Association between 30-day mortality and GST was estimated with a logistic regression model that included GST, propensity to receive GST, probability of recovering an organism from culture resistant to antibiotics traditionally used to treat community-acquired pneumonia (CAP-resistance), and a GST by CAP-resistance probability interaction. MAIN MEASURES: Odds ratios and 95% confidence intervals [OR (95% CI)] of 30-day mortality for patients treated with GST and predicted probability of recovering a CAP-resistant organism, and ratio of odds ratios [ROR (95% CI)] for treatment by CAP-resistance probability interaction. KEY RESULTS: Receipt of GST was associated with increased odds of 30-day mortality [OR = 2.11 (1.11, 4.04), P = 0.02)] as was the predicted probability of recovering a CAP-resistant organism [OR = 1.67 (1.26, 2.20), P < 0.001 for a 25% increase in probability]. An interaction between predicted probability of recovering a CAP-resistant organism and receipt of GST demonstrated lower mortality with GST at high probability of CAP resistance [ROR = 0.71(≤1.00) for a 25% increase in probability, P = 0.05]. CONCLUSIONS: For HCAP patients with high probability of CAP-resistant organisms, GST was associated with lower mortality. Consideration of the magnitude of patient-specific risk for CAP-resistant organisms should be considered when selecting HCAP therapy.

Weight gain associated with insulin detemir vs insulin glargine in clinical practice: A retrospective longitudinal cohort study.

PURPOSE: In comparative randomized studies, use of insulin detemir has been consistently demonstrated to be associated with less weight gain than the industry standard, insulin glargine. However, the magnitude of the relative reduction in weight gain with use of insulin determir vs insulin glargine in regulatory studies (reported values ranged from 0.77 kg to 3.6 kg) may not be generalizable to patients in real-world practice conditions. A study was conducted to substantiate detemir's purported weight-sparing advantage over insulin glargine in newly treated patients with type 2 diabetes mellitus under the conditions found in a clinical practice setting. METHODS: A retrospective longitudinal cohort study design was applied in reviewing electronic medical records to identify insulin-naive, overweight patients with type 2 diabetes who received insulin detemir or insulin glargine therapy continued for up to 1 year. Patient weights at baseline and at each subsequent clinic visit after treatment initiation were identified. The primary outcome was the maximum weight increase from baseline after exposure to insulin detemir or glargine. The difference-in-differences (DiD) mean total body weight change was tested by analysis of covariance (ANCOVA). RESULTS: One hundred nine patient records (56 of patients who received insulin glargine and 53 of patients who received insulin detemir) met study criteria and underwent full abstraction. The covariate-adjusted estimated mean change in body weight associated with use of insulin detemir vs insulin glargine was -1.5 kg (95% CI, -2.89 to -0.12 kg; P = 0.04). CONCLUSION: The mean weight gain associated with detemir use was significantly less than the mean weight change observed with glargine use. The magnitude of weight change was consistent with that demonstrated in randomized controlled trials. These results further substantiate detemir's purported comparative weight-sparing properties under conditions found in a real-world practice setting.

Comparative effectiveness of amoxicillin versus amoxicillin-clavulanate among adults with acute sinusitis in emergency department and urgent care settings.

OBJECTIVE: To compare the effectiveness of amoxicillin-clavulanate versus amoxicillin for adults diagnosed with acute sinusitis (AS). A secondary objective compared antibiotic effectiveness in patients meeting risk criteria for treatment failure. METHODS: A retrospective cohort study of adults diagnosed with AS prescribed amoxicillin ± clavulanate within Veterans Affairs emergency departments from 2012-2019 was conducted. The primary outcome was sinusitis-related return visits for amoxicillin versus amoxicillin-clavulanate. Secondary outcomes included 30-day infectious complications, gastrointestinal-related adverse events (AEs), and hospitalizations. Propensity-score matching and logistic regression models adjusted for potential confounders. RESULTS: A total of 89,627 AS patient visits were identified: 18,576 prescribed amoxicillin and 71,051 amoxicillin-clavulanate. Most patients were male (75,604; 84.4%) and afebrile (80,624; 91.7%). The propensity score-matched cohort comprised 17,929 amoxicillin and 42,294 amoxicillin-clavulanate patient visits. There was no difference in sinusitis-related return visits between amoxicillin (4.9%) and amoxicillin-clavulanate (5.1%) (adjusted odds ratio [OR], 0.96; 95% confidence interval [CI], 0.88, 1.04; P = 0.317). Infectious complications (amoxicillin [0.3%] vs amoxicillin-clavulanate [0.4%]); (adjusted OR, 0.78; 95% CI, 0.57, 1.07; P = 0.124) and hospitalization (amoxicillin [2.0%] vs amoxicillin-clavulanate [2.4%]); (adjusted OR, 0.92; 95% CI, 0.81, 1.04; P = 0.173) were not different. Gastrointestinal-related AEs were lower with amoxicillin (0.5%) relative to amoxicillin-clavulanate (0.7%); (adjusted OR, 0.67; 95% CI, 0.53, 0.86; P = 0.002). Comorbidity was the only guideline-recommended risk factor that was a significant predictor of infectious complications with respect to treatment (amoxicillin vs amoxicillin-clavulanate, OR, 0.63; 95% CI, 0.40 to 0.94; P = 0.022). CONCLUSION: Amoxicillin demonstrated similar efficacy to amoxicillin-clavulanate for AS with fewer gastrointestinal-related AEs. Amoxicillin is a viable option in adults with AS meeting criteria for antibiotic therapy.

Use of polychlorinated biphenyl and toxic equivalent concentrations in scat from mink(Neovison vison) fed fish from the upper Hudson River to predict dietary and hepatic concentrations and health effects.

To evaluate health effects associated with consumption of fish contaminated with polychlorinated biphenyls (PCBs) from the upper Hudson River, farm-raised mink were fed diets containing fish collected from the river. Endpoints assessed included adult reproductive performance, offspring growth and mortality, and organ mass and pathology of adults and their offspring. Scat samples were collected from adult males at the time of necropsy and from adult females just prior to whelping. Scat samples were analyzed for PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). The present study provides the results of these analyses and compares ∑PCB and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalent (TEQ) concentrations in scat with dietary and hepatic concentrations associated with effects reported previously. Dry weight concentrations of ∑PCBs and ∑TEQs in scat generally increased with dietary concentration and reflected corresponding increases in hepatic concentrations of ∑PCBs and ∑TEQs. Maternal concentrations of ∑PCBs in scat expressed on a dry, wet, and lipid weight basis predicted to result in 50% kit mortality (LC50) were 1.0, 0.30, and 12 µg ∑PCBs/g. Concentrations of ∑PCBs in scat expressed on a dry, wet, and lipid weight basis predicted to result in 50% incidence of a previously reported jaw lesion (EC50) were 1.7, 0.48, and 24 µg ∑PCBs/g in adult females and 2.5, 0.87, and 19 µg ∑PCBs/g in adult males. Environ Toxicol Chem 2018;37:563-575. © 2017 SETAC.

Outcomes Associated With Antimicrobial De-escalation of Treatment for Pneumonia Within the Veterans Healthcare Administration.

De-escalation, an antimicrobial stewardship concept, involves narrowing broad-spectrum empiric antimicrobial therapy based on clinical data. Current health outcomes evidence is lacking to support de-escalation. Studying Veterans Healthcare Administration pneumonia patients, de-escalation was associated with improved length of stay without affecting 30-day readmission or 30-day Clostridium difficile infection rates.

Evaluation of an intervention designed to decrease the rate of nosocomial methicillin-resistant Staphylococcus aureus infection by encouraging decreased fluoroquinolone use.

OBJECTIVE: Society for Health Care Epidemiology guidelines recommend decreasing the use of fluoroquinolone antibiotics in institutions where methicillin-resistant Staphylococcus aureus (MRSA) is endemic. We evaluated whether an intervention to limit fluoroquinolone use was associated with a lower rate of nosocomial MRSA infection and summarized changes in antibiotic use, changes in other variables potentially correlated with a lower rate of MRSA infection, and rates of nosocomial infections due to other pathogens. DESIGN: Single-center quasi-experimental design. A time series of nosocomial MRSA infections was measured at monthly intervals from July 2001 through June of 2004; there were 80 MRSA infections recorded. Segmented regression analysis (ie, quasi-Poisson generalized linear models) was used to evaluate variables possibly associated with the nosocomial MRSA infection rate. SETTING: An 87-bed Veterans Affairs teaching hospital with an extended-care facility. INTERVENTION: A physician-directed computer-generated intervention designed to limit the use of fluoroquinolone antibiotics was initiated, and institutional changes in antibiotic use and nosocomial MRSA infection rates were tracked. RESULTS: After the intervention, fluoroquinolone use decreased by approximately 34%, and levofloxacin use decreased by approximately 50%. Decreased fluoroquinolone use was offset by increased cephalosporin, piperacillin-tazobactam, and trimethoprim-sulfamethoxazole use. The nosocomial MRSA infection rate decreased from 1.37 to 0.63 episodes per 1,000 patient-days after the study intervention (P=.02). Coagulase-negative Staphylococcus and Enterococcus infection rates also decreased. However, the rate of infection with gram-negative organisms increased. The rate of MRSA infection was positively correlated with levofloxacin use (P=.01) and azithromycin use (P=.08), whereas it was negatively correlated with summer season (P=.05). In a subsequent model, the rate of MRSA infection was negatively correlated with the study intervention (P=.04). CONCLUSION: Reduction in the institutional use of fluoroquinolones may be associated with a lower nosocomial MRSA infection rate.

Evaluation of a Computerized Decision Support Intervention to Decrease Use of Anti-Pseudomonal Carbapenems in Penicillin Allergic Patients.

Allergies to ß-lactam antibiotics are commonly documented in hospitalized patients; however, true allergy is uncommon. Cross-reactivity rates for advanced generation cephalosporins and carbapenems are low; particularly for patients without a history of symptoms consistent with type 1 hypersensitivity. We observed that providers preferentially prescribed antipseudomonal carbapenems (APC) over advanced generation cephalosporins for patients with ß-lactam allergy history, including those with low risk for antimicrobial-resistant infections. Information was inserted into the computerized decision support system (CDSS) to aid clinicians in assessing ß-lactam cross-reactivity risk and selecting appropriate therapy. A retrospective evaluation was conducted in a small hospital to assess the impact of the CDSS changes in APC prescribing. Inpatients (n = 68) who received at least one APC dose during hospitalization over a 13 month pre-intervention period were compared to inpatients who received an APC during the 15 month post-intervention period (n = 59) for documented APC indications and ß-lactam allergy history. APC initiations were measured and corrected per 1000 patient-days; interrupted time-series analysis was performed to assess changes in use before and after implementation. Aggregate monthly APC initiations decreased from 7.01 to 6.14 per 1000 patient-days after the implementation (p = 0.03). Post-intervention APC initiations for patients with low-risk ß-lactam histories decreased from 92% to 83% (p = 0.17). No adverse events were observed in patients with low-risk ß-lactam histories. The intervention was associated with a reduction in APC initiations.

Evaluation of a protocol to optimize duration of pneumonia therapy at hospital discharge.

PURPOSE: A protocol to optimize the duration of antimicrobial therapy (DAT) for uncomplicated pneumonia at hospital discharge was evaluated. METHODS: This retrospective quasiexperimental study was conducted at Boise Veterans Affairs Medical Center from March 2013 through June 2015. Patients were included in the study if they were diagnosed with pneumonia, were hospitalized for more than 24 hours, received antimicrobial treatment within 48 hours of admission, and survived until hospital discharge. The intervention included development of a pneumonia DAT triage algorithm, a process for assessment of the appropriate DAT by pharmacists, and recommendations to providers to limit excessive discharge DATs prescribed. Interrupted time-series analysis was performed to determine the mean monthly DAT per patient and the 30-day readmission rate. RESULTS: Of the 707 patients discharged with a diagnosis of pneumonia, 560 met the criteria for study inclusion (366 in the preimplementation group and 194 in the postimplementation group). Change in slope of monthly mean DAT per patient postimplementation was significantly reduced (p = 0.03) from the preimplementation slope (p = 0.95), indicating an association between the intervention and mean DAT per patient. The intervention was not associated with the 30-day readmission rate. The mean ± S.D. DAT decreased from 9.5 ± 2.4 days preimplementation to 8.2 ± 2.9 days postimplementation, primarily due to the reduction of outpatient DAT from 5.2 ± 3.0 days preimplementation to 4.2 ± 3.0 days postimplementation. CONCLUSION: A pharmacy-based triage algorithm helped to reduce excessive DATs for patients with pneumonia at hospital discharge without negatively affecting 30-day readmission rates.

Growth and reproductive effects from dietary exposure to Aroclor 1268 in mink (Neovison vison), a surrogate model for marine mammals.

Polychlorinated biphenyls (PCBs) from the commercial mixture Aroclor 1268 were historically released into the Turtle-Brunswick River estuary (southeastern Georgia, USA) from industrial operations. Sum PCBs (ΣPCBs) in blubber samples from Turtle-Brunswick River estuary bottlenose dolphins (Tursiops truncatus) have been reported at concentrations more than 10-fold higher than those observed in dolphins from adjacent regional estuaries. Given that toxicity data specific to Aroclor 1268 and applicable to marine mammals are limited, predicting the toxic effects of Aroclor 1268 in dolphins is uncertain, particularly because of its unique congener profile and associated physiochemical characteristics compared with other PCB mixtures. American mink (Neovison vison) were chosen as a surrogate model for cetaceans to develop marine mammalian PCB toxicity benchmarks. Mink are a suitable surrogate species for cetaceans in toxicity studies because of similarities in diet and taxonomic class, and a characteristic sensitivity to PCBs provides a potential safety factor when using mink toxicology data for cross-species extrapolations. Effects of dietary exposure to Aroclor 1268 on reproduction, growth, and mortality in mink were compared with both a negative control and a positive control (3,3',4,4',5-pentachlorobiphenyl, PCB 126). Aroclor 1268 dietary ΣPCB concentrations ranged from 1.8 µg/g feed wet weight to 29 µg/g feed wet weight. Whelp success was unaffected by Aroclor 1268 exposure at any level. Treatment mean litter size, kit growth, and kit survival were adversely affected relative to the negative control at dietary ΣPCB concentrations of 10.6 µg/g feed wet weight and greater.

Development of an antibiotic spectrum score based on veterans affairs culture and susceptibility data for the purpose of measuring antibiotic de-escalation: a modified Delphi approach.

OBJECTIVE: Development of a numerical score to measure the microbial spectrum of antibiotic regimens (spectrum score) and method to identify antibiotic de-escalation events based on application of the score. DESIGN: Web-based modified Delphi method. PARTICIPANTS: Physician and pharmacist antimicrobial stewards practicing in the United States recruited through infectious diseases-focused listservs. METHODS: Three Delphi rounds investigated: organisms and antibiotics to include in the spectrum score, operationalization of rules for the score, and de-escalation measurement. A 4-point ordinal scale was used to score antibiotic susceptibility for organism-antibiotic domain pairs. Antibiotic regimen scores, which represented combined activity of antibiotics in a regimen across all organism domains, were used to compare antibiotic spectrum administered early (day 2) and later (day 4) in therapy. Changes in spectrum score were calculated and compared with Delphi participants' judgments on de-escalation with 20 antibiotic regimen vignettes and with non-Delphi steward judgments on de-escalation of 300 pneumonia regimen vignettes. Method sensitivity and specificity to predict expert de-escalation status were calculated. RESULTS: Twenty-four participants completed all Delphi rounds. Expert support for concepts utilized in metric development was identified. For vignettes presented in the Delphi, the sign of change in score correctly classified de-escalation in all vignettes except those involving substitution of oral antibiotics. The sensitivity and specificity of the method to identify de-escalation events as judged by non-Delphi stewards were 86.3% and 96.0%, respectively. CONCLUSIONS: Identification of de-escalation events based on an algorithm that measures microbial spectrum of antibiotic regimens generally agreed with steward judgments of de-escalation status.

First metatarsocuneiform joint mobility: radiographic, anatomic, and clinical characteristics of the articular surface.

BACKGROUND: The first metatarsocuneiform joint is involved in first ray biomechanics and related forefoot pathology. The purpose of this study was to evaluate the first metatarsocuneiform joint radiographic findings in relation to angular position of the radiographic beam, and to assess the joint mobility as it relates to the anatomic orientation of the facets on both radiographic imaging and gross anatomic dissection. METHODS: Thirty-nine cadaveric lower extremity limbs were stratified as normal, mild, moderate, or severe hallux valgus deformity. Mobility of the first metatarsocuneiform joint for each specimen was assessed using the Klaue device. The medial inclination angle (obliquity) of the first metatarsocuneiform joint was determined on both 10-degree and 20-degree anteroposterior radiographs. The lateral inclination angle of both the dorsal and plantar facets was determined on lateral radiographs. Each specimen was then dissected to directly inspect the metatarsocuneiform joint. RESULTS: The metatarsocuneiform joint mean height was 28.3 mm and the mean width was 13.1 mm. Twenty-three feet demonstrated a continuous cartilaginous surface, 15 feet demonstrated a bilobed cartilaginous surface, and 1 foot demonstrated completely separated facets. Dorsal facets were curved in 37 specimens and flat 2 specimens. Plantar facets were flat in 30 specimens and curved in 9 specimens. The medial inclination angle measured 15.8 degrees on the 10-degree radiograph and 2.6 degrees on the 20-degree radiograph. We were unable to establish any correlations of metatarsocuneiform joint angles or facet contour with mobility measured by the Klaue device. CONCLUSIONS: The metatarsocuneiform joint has a height to width ratio of nearly 2:1. Continuous and bilobed facets are both very common anatomic variants. The contour of the dorsal facet was predominantly curved and the contour of the plantar facet was predominantly flat. First metatarsocuneiform joint mobility does not appear to be dependent on the contour of the facets or the degree of medial inclination of the joint. CLINICAL RELEVANCE: Anatomic and radiographic findings with regard to mobility of the first metatarsocuneiform joint may assist the surgeon in interpreting the joint's relationship to hallux valgus deformity and to aid in clinical decision making. Our findings suggest that radiographic interpretation of medial inclination is unreliable and should not be used to determine the appropriateness of specific operative procedures.

Dietary exposure of mink (Mustela vison) to fish from the upper Hudson River, New York, USA: effects on reproduction and offspring growth and mortality.

The effects of feeding farm-raised mink (Mustela vison) diets containing polychlorinated biphenyl (PCB)-contaminated fish from the upper Hudson River (New York, USA) on adult reproductive performance and kit growth and mortality were evaluated. Diets contained 2.5 to 20% Hudson River fish, providing 0.72 to 6.1 µg ∑PCBs/g feed (4.8-38 pg toxic equivalents [TEQWHO 2005 ]/g feed). The percentage of stillborn kits per litter was significantly increased by dietary concentrations of 4.5 µg ∑PCBs/g feed (28 pg TEQWHO 2005 /g feed) and greater. All offspring exposed to dietary concentrations of 4.5 and 6.1 µg ∑PCBs/g feed (28 and 38 pg TEQWHO 2005 /g feed) died by 10 weeks of age, and all offspring exposed to 1.5 and 2.8 µg ∑PCBs/g feed (10 and 18 pg TEQWHO 2005 /g feed) died by 31 weeks of age, leaving juveniles in the control and 0.72 µg ∑PCBs/g feed (0.41- and 4.8 pg TEQWHO 2005 /g feed) groups only. The dietary concentration predicted to result in 20% kit mortality (LC20) at six weeks of age was 0.34 µg ∑PCBs/g feed (2.6 pg TEQWHO 2005 /g feed). The corresponding maternal hepatic concentration was 0.80 µg ∑PCBs/g liver, wet weight (13 pg TEQWHO 2005 /g liver, wet wt). Mink residing in the upper Hudson River would be expected to consume species of fish that contain an average of 4.0 µg ∑PCBs/g tissue. Thus, a daily diet composed of less than 10% Hudson River fish could provide a dietary concentration of ∑PCBs that resulted in 20% kit mortality in the present study.

Dietary exposure of mink (Mustela vison) to fish from the upper Hudson River, New York, USA: effects on organ mass and pathology.

The authors evaluated effects of feeding ranch mink (Mustela vison) diets containing polychlorinated biphenyl (PCB)-contaminated fish from the upper Hudson River (New York, USA) on adult and offspring organ mass and pathology. Diets contained 2.5 to 20% Hudson River fish, providing 0.72 to 6.1 µg ΣPCBs/g feed (4.8-38 pg toxic equivalents [TEQWHO 2005 ]/g feed). Absolute thyroid and adrenal gland masses were increased in adult females and 31-week-old juveniles, respectively, and absolute liver and heart masses were decreased in six-week-old kits exposed to dietary PCBs. Dietary concentrations of 0.72 µg ΣPCBs/g feed (4.8 pg TEQWHO 2005 /g feed) and greater induced mandibular and maxillary squamous epithelial proliferation in adult animals. The dietary concentration of ΣPCBs predicted to result in 20% incidence of the jaw lesion (EC20) was 2.3 µg ΣPCBs/g feed (15 pg TEQWHO 2005 /g feed), and the hepatic concentration was 2.8 µg ΣPCBs/g liver (89 pg TEQWHO 2005 /g liver). The EC20 values were greater than the dietary and hepatic concentrations predicted to result in a 20% increase in kit mortality (LC20) at six weeks of age (0.34 µg ΣPCBs/g feed or 2.6 pg TEQWHO 2005 /g feed and 0.80 µg ΣPCBs/g liver or 13 pg TEQWHO 2005 /g liver). However, the EC20 values reflect exposure of adults to PCBs for approximately six months, and the LC20 values reflect exposure of offspring from conception onward.