The Effect of Surgeon Volume on Revision for Periprosthetic Joint Infection: An Analysis of 602,919 Primary Total Knee Arthroplasties.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication of total knee arthroplasty (TKA). An association between low surgeon volume and higher rates of infection following primary TKA has been suggested. The purpose of the present study was to determine if there was a relationship between surgeon volume and the rate of revision for infection after primary TKA. METHODS: We searched the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) to identify all primary TKA procedures that were performed for the treatment of osteoarthritis from September 1, 1999, to December 31, 2020, and were subsequently revised because of infection. Surgeon volume was defined as the annual volume of procedures performed by a surgeon during the same year in which the primary TKA (which was subsequently revised for infection) was performed. Surgeon volume was defined as <25, 25 to 49, 50 to 74, 75 to 99, or ≥100 primary TKA procedures/year. The cumulative percent revision (CPR) for infection was determined with use of Kaplan-Meier estimates. Cox proportional hazards methods were used to compare rates of revision for infection by surgeon volume, with subanalyses for patellar resurfacing and polyethylene use. Further analyses for patients <65 years of age and male patients were undertaken. RESULTS: Overall, 602,919 primary TKA procedures were performed for the treatment of osteoarthritis, of which 5,295 were revised because of infection. High-volume surgeons (≥100 TKAs/year) had a significantly lower rate of revision for infection, with a CPR at 1 and 19 years of 0.4% (95% confidence interval [CI], 0.3 to 0.4) and 1.5% (95% CI, 1.2 to 2.0), respectively, compared with 0.6% (95% CI, 0.5 to 0.7) and 2.1% (95% CI, 1.8 to 2.3), respectively, for low-volume surgeons (<25 TKAs/year). Hazard ratios (HRs), adjusted for age and sex, comparing these 2 groups varied, depending on the time point, between 3.07 (95% CI, 2.02 to 4.68) and 1.44 (95% CI, 1.26 to 1.63) but remained significant (p < 0.001). When the analysis was adjusted for age, sex, American Society of Anesthesiologists (ASA) classification, and body mass index (BMI), there remained an increased risk of revision for PJI for all lower surgeon volume levels in comparison with the high- surgeon-volume group (≥100 TKAs/year). The results were similar when stratified by patellar resurfacing and cross-linked polyethylene (XLPE) and adjusted for age and sex. CONCLUSIONS: High-volume surgeons had lower rates of revision for infection. A better understanding of how surgical volume contributes to decreasing this complication is important and requires in-depth study. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Metal nanoinks as chemically stable surface enhanced scattering (SERS) probes for the analysis of blue BIC ballpoint pens.

Metal nanoinks constituted by Ag nanoparticles and Au nanorods were employed as probes for the Surface Enhanced Raman Scattering (SERS) analysis of a blue BIC ballpoint pen. The dye components of the pen ink were first separated by thin layer chromatography (TLC) and subsequently analysed by SERS at illumination wavelengths of 514 nm and 785 nm. Compared to normal Raman conditions, enhanced spectra were obtained for all separated spots, allowing easy identification of phthalocyanine Blue 38 and triarylene crystal violet in the ink mixture. A combination of effects such as molecular resonance, electromagnetic and chemical effects were the contributing factors to the generation of spectra enhanced compared to normal Raman conditions. Enhancement factors (EFs) between 5 × 103 and 3 × 106 were obtained, depending on the combination of SERS probes and laser illumination used. In contrast to previous conflicting reports, the metal nanoinks were chemically stable, allowing the collection of reproducible spectra for days after deposition on TLC plates. In addition and in advance to previously reported SERS probes, no need for additional aggregating agents or correction of electrostatic charge was necessary to induce the generation of enhanced SERS spectra.

A prospective review of appetite loss and recovery time in primary joint replacement patients.

INTRODUCTION: Appetite loss is commonly reported by patients following major surgery, including total joint arthroplasty (TJA). A number of studies have examined related problems, particularly in relation to physiological responses to surgery. However, no published paper has looked specifically at the duration of appetite loss in total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients. METHODS: A simple, established appetite screening tool was administered preoperatively and at 2-week intervals postoperatively in 50 TJA patients until appetite levels returned to preoperative levels. The results were examined for various descriptive parameters and compared using the chi-squared test. RESULTS: Thirty-three patients underwent TKA and 17 THA. There were 27 female and 23 male patients. No patients were lost to follow-up. The median time for return of appetite in both male and female patients was 4 weeks (interquartile range [IQR]: male, 2-4; female, 4-6). The median time for return of appetite was 4 weeks both in TKA patients (IQR 4-6) and in those undergoing THA (IQR 4-4). The time to return of appetite was not significantly associated with either the gender of the patients (p=0.13) or the type of joint replacement (p=0.49). CONCLUSIONS: The study provides a clear time frame for return of appetite in uncomplicated primary joint replacements. This is a commonly noted patient problem that has not previously been specifically reviewed.

Human sperm sex chromosome disomy and sperm DNA damage assessed by the neutral comet assay.

STUDY QUESTION: Is there an association between human sperm sex chromosome disomy and sperm DNA damage? SUMMARY ANSWER: An increase in human sperm XY disomy was associated with higher comet extent; however, there was no other consistent association of sex chromosome disomies with DNA damage. WHAT IS KNOWN ALREADY: There is limited published research on the association between sex chromosome disomy and sperm DNA damage and the findings are not consistent across studies. STUDY DESIGN, SIZE, AND DURATION: We conducted a cross-sectional study of 190 men (25% ever smoker, 75% never smoker) from subfertile couples presenting at the Massachusetts General Hospital Fertility Clinic from January 2000 to May 2003. PARTICIPANTS/MATERIALS, SETTING, METHODS: Multiprobe fluorescence in situ hybridization for chromosomes X, Y and 18 was used to determine XX, YY, XY and total sex chromosome disomy in sperm nuclei using an automated scoring method. The neutral comet assay was used to measure sperm DNA damage, as reflected by comet extent, percentage DNA in the comet tail, and tail distributed moment. Univariate and multiple linear regression models were constructed with sex chromosome disomy (separate models for each of the four disomic conditions) as the independent variable, and DNA damage parameters (separate models for each measure of DNA damage) as the dependent variable. MAIN RESULTS AND THE ROLE OF CHANCE: Men with current or past smoking history had significantly greater comet extent (µm: regression coefficients with 95% CI) [XX18: 15.17 (1.98, 28.36); YY18: 14.68 (1.50, 27.86); XY18: 15.41 (2.37, 28.45); Total Sex Chromosome Disomy: 15.23 (2.09, 28.38)], and tail distributed moment [XX18: 3.01 (0.30, 5.72); YY18: 2.95 (0.24, 5.67); XY18: 3.04 (0.36, 5.72); Total Sex Chromosome Disomy: 3.10 (0.31, 5.71)] than men who had never smoked. In regression models adjusted for age and smoking, there was a positive association between XY disomy and comet extent. For an increase in XY disomy from 0.56 to 1.47% (representing the 25th to 75th percentile), there was a mean increase of 5.08 µm in comet extent. No other statistically significant findings were observed. LIMITATIONS, REASONS FOR CAUTION: A potential limitation of this study is that it is cross-sectional. Cross-sectional analyses by nature do not lend themselves to inference about directionality for any observed associations; therefore we cannot determine which variable is the cause and which one is the effect. A small sample size may be a further limitation. Comparison of these findings to other studies is limited due to methodological differences. WIDER IMPLICATIONS OF THE FINDINGS: Although consistent associations across sex chromosome disomies or DNA damage measures were not observed, this study highlights the need to explore etiologies of sperm DNA damage and sex chromosome disomy to better understand the potential mechanistic overlaps between the two. STUDY FUNDING/COMPETING INTERESTS: This work was supported by NIOSH Grant T42 OH008416, and NIH/NIEHS Grants ES 009718, ES 000002, and R01 ES017457. During the study M.E.M. was affiliated with the Department of Environmental Health at the Harvard School of Public Health. TRIAL REGISTRATION NUMBER: N/A.

The association between sperm sex chromosome disomy and semen concentration, motility and morphology.

STUDY QUESTION: Is there an association between sex chromosome disomy and semen concentration, motility and morphology? SUMMARY ANSWER: Higher rates of XY disomy were associated with a significant increase in abnormal semen parameters, particularly low semen concentration. WHAT IS KNOWN ALREADY: Although some prior studies have shown associations between sperm chromosomal abnormalities and reduced semen quality, results of others are inconsistent. Definitive findings have been limited by small sample sizes and lack of adjustment for potential confounders. STUDY DESIGN, SIZE AND DURATION: Cross-sectional study of men from subfertile couples presenting at the Massachusetts General Hospital Fertility Clinic from January 2000 to May 2003. PARTICIPANTS/MATERIALS, SETTING, METHODS: With a sample of 192 men, multiprobe fluorescence in situ hybridization for chromosomes X, Y and 18 was used to determine XX, YY, XY and total sex chromosome disomy in sperm nuclei. Sperm concentration and motility were measured using computer-assisted sperm analysis; morphology was scored using strict criteria. Logistic regression models were used to evaluate the odds of abnormal semen parameters [as defined by World Health Organization (WHO)] as a function of sperm sex chromosome disomy. MAIN RESULTS AND THE ROLE OF CHANCE: The median percentage disomy was 0.3 for XX and YY, 0.9 for XY and 1.6 for total sex chromosome disomy. Men who had abnormalities in all three semen parameters had significantly higher median rates of XX, XY and total sex chromosome disomy than controls with normal semen parameters (0.43 versus 0.25%, 1.36 versus 0.87% and 2.37 versus 1.52%, respectively, all P< 0.05). In logistic regression models, each 0.1% increase in XY disomy was associated with a 7% increase (odds ratio: 1.07, 95% confidence interval: 1.02-1.13) in the odds of having below normal semen concentration (<20 million/ml) after adjustment for age, smoking status and abstinence time. Increases in XX, YY and total sex chromosome disomy were not associated with an increase in the odds of a man having abnormal semen parameters. In addition, autosomal chromosome disomy (1818) was not associated with abnormal semen parameters. LIMITATIONS, REASONS FOR CAUTION: A potential limitation of this study, as well as those currently in the published literature, is that it is cross-sectional. Cross-sectional analyses by nature do not lend themselves to inference about directionality for any observed associations; therefore, we cannot determine which variable is the cause and which one is the effect. Additionally, the use of WHO cutoff criteria for dichotomizing semen parameters may not fully define fertility status; however, in this study, fertility status was not an outcome we were attempting to assess. WIDER IMPLICATIONS OF THE FINDINGS: This is the largest study to date seeking to understand the association between sperm sex chromosome disomy and semen parameters, and the first to use multivariate modeling to understand this relationship. The findings are similar to those in the published literature and highlight the need for mechanistic studies to better characterize the interrelationships between sex chromosome disomy and standard indices of sperm health. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from NIOSH (T42 OH008416) and NIEHS (R01 ES009718, P30 ES000002 and R01 ES017457). The authors declare no competing interests. At the time this work was conducted and the initial manuscript written, MEM was affiliated with the Environmental Health Department at the Harvard School of Public Health. Currently, MEM is employed by Millennium: The Takeda Oncology Company. TRIAL REGISTRATION NUMBER: N/A.

Venous thromboembolism risk assessments in acute care.

This article is aimed at nurses and other health professionals working in clinical practice and involved in venous thromboembolism (VTE) risk assessments. The article adds to the body of published literature relating to patient risk assessment for VTE by exploring practical clinical perspectives of introducing a sustainable risk assessment process. It reports on a series of small scale changes carried out during a project in an acute medicine unit at the Heart of England NHS Foundation Trust in Birmingham, which aimed to improve the level of compliance with carrying out VTE risk assessments and administering prophylaxis. The results of two audits conducted over a seven-month period at the beginning and end of the project illustrate an improvement in compliance from 6.25% to 62.5%. The article concludes that leadership from medical consultants acting as clinical champions is imperative and that nurses and healthcare assistants also have a pivotal role in promoting patient assessments, and in maintaining the momentum and sustainability of VTE risk assessments in clinical areas.

Image fusion using CT, MRI and PET for treatment planning, navigation and follow up in percutaneous RFA.

AIM: To evaluate the feasibility of fusion of morphologic and functional imaging modalities to facilitate treatment planning, probe placement, probe re-positioning, and early detection of residual disease following radiofrequency ablation (RFA) of cancer. METHODS: Multi-modality datasets were separately acquired that included functional (FDG-PET and DCE-MRI) and standard morphologic studies (CT and MRI). Different combinations of imaging modalities were registered and fused prior to, during, and following percutaneous image-guided tumor ablation with radiofrequency. Different algorithms and visualization tools were evaluated for both intra-modality and inter-modality image registration using the software MIPAV (Medical Image Processing, Analysis and Visualization). Semi-automated and automated registration algorithms were used on a standard PC workstation: 1) landmark-based least-squares rigid registration, 2) landmark-based thin-plate spline elastic registration, and 3) automatic voxel-similarity, affine registration. RESULTS: Intra- and inter-modality image fusion were successfully performed prior to, during and after RFA procedures. Fusion of morphologic and functional images provided a useful view of the spatial relationship of lesion structure and functional significance. Fused axial images and segmented three-dimensional surface models were used for treatment planning and post-RFA evaluation, to assess potential for optimizing needle placement during procedures. CONCLUSION: Fusion of morphologic and functional images is feasible before, during and after radiofrequency ablation of tumors in abdominal organs. For routine use, the semi-automated registration algorithms may be most practical. Image fusion may facilitate interventional procedures like RFA and should be further evaluated.

Brain volume measurements in patients with human T-cell lymphotropic virus-1-associated tropical spastic paraparesis.

Human T-cell lymphotropic virus (HTLV)-1 is associated with a chronic progressive neurologic disease known as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) that affects 0.2% to 3% of HTLV-1-infected people. The authors aimed at exploring, in vivo, whether brain volume reduction occurs in patients with HAM/TSP through the use of magnetic resonance imaging (MRI). T1 pre/postcontrast spin echo-weighted images (WIs) and T2WIs of the brain were obtained in 19 HAM/TSP patients and 14 age-and sex-matched healthy volunteers. Both patients and healthy individuals were imaged at a 1.5-Tesla magnet by employing a conventional head coil. Focal T1 and T2 abnormalities were calculated and two measurements of brain parenchyma fraction (BPF) were obtained by using SIENAx (Structural Image Evaluation,using Normalisation, of Atrophy; University of Oxford, Oxford, UK) and MIPAV (Medical Image Processing, Analysis, and Visualization; National Institutes of Health, Bethesda, USA) from T1WIs. No significant differences in BPF were found between patients and healthy subjects when using either SIENAx or MIPAV. Analysis of individual patients detected that BPF was lower by 1 standard deviation (SD) relative to patients' average BPF in one patient. The authors conclude that reductions in BPF do not occur frequently in patients with HAM/TSP. However, the authors believe that one individual case of significant brain atrophy raises the question as to whether atrophy selectively targets the spinal cord of HAM/TSP patients or may involve the brain as well. A larger patient population analyzing regional brain volume changes could be helpful in determining whether brain atrophy is a marker of disease in patients with HAM/TSP.

Impact of malocclusion and orthognathic reconstruction surgery on resonance and articulatory function: an examination of variability in five cases.

Articulatory patterns and nasal resonance were assessed before and 6 months after orthognathic reconstruction surgery in five patients with dentofacial deformities. Perceptual and physiological assessments showed disorders of nasality and articulatory function preoperatively, two patients being hyponasal, and one hypernasal. Four patients had mild articulatory deficits, and four had reduced maximal lip or tongue pressures. Operation resulted in different patterns of change. Nasality deteriorated in three patients and articulatory precision and intelligibility improved in only one patient and showed no change in the other four. Operation improved interlabial pressures in three patients, while its impact on tongue pressures varied, being improved in one case, deteriorating in one, and remaining unchanged in the other three. The variability in the results highlights the need for routine assessment of speech and resonance before and after orthognathic reconstruction.

Depletion of systemic macrophages by liposome-encapsulated clodronate attenuates striatal macrophage invasion and neurodegeneration following local endotoxin infusion in gerbils.

CNS-localized inflammation with microglial activation and macrophage infiltration contributes to the pathogenesis of a broad spectrum of neurologic diseases. A direct injection of lipopolysaccharide (LPS) into the striatum of gerbils induced lectin-positive macrophage parenchymal invasion, minimal local microglial staining but extensive neurodegeneration (cresyl violet and silver staining) when evaluated 4 days later. In mice, LPS activated microglia (increased lectin staining of morphologically identified cells) with substantially less macrophage invasion but no neurodegeneration was seen at 4 days post LPS infusion. To evaluate the role of infiltrating macrophages in the neurodegenerative response in gerbils, peripheral macrophages were depleted by an intravenous injection of liposome-encapsulated clodronate. This preparation depleted spleen and liver macrophages (>95%), decreased blood monocytes by 55% and attenuated striatal macrophage infiltration (32 to 73% in five representative sections). Notably, the liposome-encapsulated clodronate reduced the severity of LPS-induced neurodegeneration, as visualized by cresyl violet staining and quantified in 20 serially stained silver sections (total volume, 1.32+/-0.41 mm(3) in liposome-encapsulated clodronate-treated versus 3.04+/-0.72 mm(3) in saline-treated controls). These results indicate that a local LPS infusion in gerbil brain may be a useful model in which to investigate the role of invading macrophages and other inflammatory responses in neurodegeneration in inflammatory neurological disease.

Tongue-to-palate contact patterns and variability of four English consonants in an /i/ vowel environment.

Minimal data exist describing tongue-to-palate contact patterns and their variability in normal speakers of English. Consequently, the aims of the present study were to examine, using a comprehensive profile of data analysis, tongue-to-palate contact patterns and their variability in a group of ten normal speakers of English using the Reading Electropalatography3 (EPG3) system. Each speaker produced ten repetitions of the target words tea, leap, sea, and key following the carrier phrase 'I saw a ...'. Results revealed that the contact patterns produced exhibited similar characteristics to those described in earlier research. Additionally, the lateral approximant /i/ exhibited the highest degree of intra-subject variability with the alveolar fricative /s/ exhibiting the least. The results of this study are discussed in relation to existing normative data.

Search for bipolar disorder susceptibility loci: the application of a modified genome scan concentrating on gene-rich regions.

Conducting genome wide screens for evidence of genetic linkage has become a well-established method for identifying regions of the human genome harboring susceptibility loci for complex disorders. For bipolar disorder, a number of such studies have been performed, and several regions of the genome have potentially been implicated in the disorder. The classic design for a genome screen involves examining polymorphic genetic markers spaced at regular intervals throughout the genome, typically every 10 cM, for evidence of linkage. An alternative design, based on the observation that genes do not appear to be evenly distributed, was proposed, enabling the number of markers examined in a genome wide screen to be reduced. This article describes the application of such a modified screen to a collection of 48 Irish families with bipolar disorder, comprising a total of 82 affected sib-pairs. From the results obtained a number of regions are highlighted for further study. One of these regions (17q11.1-q12) coincides with the location of a candidate gene, the serotonin transporter, whereas others concur with the findings of published studies. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:728-732, 2000.

Functional speech outcomes after laryngectomy and pharyngolaryngectomy.

OBJECTIVE: To compare and contrast functional speech outcomes of patients having undergone total laryngectomy and pharyngolaryngectomy who use tracheoesophageal speech as their primary mode of communication. DESIGN: Group comparison design. SETTING: Adult acute tertiary care hospital. PATIENTS: Thirty patients who underwent total laryngectomy and 13 who underwent pharyngolaryngectomy with free jejunal interposition reconstruction. All patients used tracheoesophageal speech. INTERVENTION: Group comparisons across measures of speech intelligibility, voice quality, tracheoesophageal speech use, voice satisfaction and levels of perceived voice disability, handicap, and well-being/distress. MAIN OUTCOME MEASURE: The existence of any significant differences between the 2 groups on measures of intelligibility, voice quality, tracheoesophageal speech use, and voice satisfaction and levels of voice disability, handicap, and well-being/distress. RESULTS: Statistical comparisons confirmed reduced functional intelligibility (P<.05), reduced vocal quality (P<.01), and higher levels of disability (P<.05) in the pharyngolaryngectomy group. However, no significant difference was observed between the proportion of patients classified as "successful" tracheoesophageal speech users in either group. Low levels of handicap and high levels of patient well-being were recorded in both groups. CONCLUSION: Despite the perceptual differences in voice quality and intelligibility observed between the 2 groups, tracheoesophageal speech that is functional, effective, and perceived by the patients as satisfactory can be achieved after total laryngectomy and pharyngolaryngectomy with free jejunal interposition reconstruction.

Nurse anesthesia practice and research--a worldwide need.

In 1992, nurse anesthetists from 94 countries participated in our transnational research by completing surveys (in English, French, German, or Spanish) and providing descriptions about their practice, education, and regulation. Five years later (1997), nurse anesthetists from 81 countries completed expanded and revised questionnaires. Their responses validated the 1992 findings that nurses may be the main administerers of anesthesia in many countries. They are administering both general and regional anesthesia, in rural and urban areas in all regions of the world, and in countries from all levels of development, working with and without anesthesiologists. Their major duties are primarily those that are performed inside operating rooms, a factor that may be contributing to a lack of visibility of the profession. In order to contribute to both clinical and health policy decision making, nurse anesthetists must first document their practice and then participate in collaborative research at the local, regional, national, and international levels.

Substituted indoles as potent and orally active 5-lipoxygenase activating protein (FLAP) inhibitors.

This paper reports on the SAR investigation of inhibitors of 5-lipoxygenase activating protein (FLAP) based on MK-0591. Emphasis was made on modifications to the nature of the link between the indole and the quinoline moieties, to the substitution pattern around the two heterocycles and to possible replacements of the quinoline moiety. Lead optimization culminated in (3-[1-(4-chlorobenzyl)-3-(t-butylthio)-5-(pyridin-2-ylmethoxy)-ind ol-2-yl]-2,2-dimethylpropanoic acid (18k), as a potent inhibitor of leukotriene biosynthesis that is well absorbed and active in functional models.