The statistical relationship between varus deformity,surgeon's experience,BMI and tourniquet time for computer assisted total knee replacements

The outcome of total knee arthroplasty (TKA) with severe pre-operative varus deformity is significantly worse than in well aligned knees. Computer navigated TKA has addressed some of the problems by ensuring accurate post-operative alignment. Our aims were to see if navigation could reproducibly correct a varus deformity to 3° of the mechanical axis and to investigate the relationships between the tourniquet time and severity of the preoperative deformity, BMI and a surgeon's experience.The 172 e.motion floating platform TKA's were implanted using the OrthoPilot^® Navigation system (B Braun-Aesculap, Tuttlingen, Germany). Pre-operative deformity and post-operative alignment were measured by the software. Tourniquet times were recorded automatically.All knees were corrected to within 3° of the neutral axis (mean 0.48°). Statistically significant relationships between tourniquet time (TT) and degree of pre-operative varus (p < 0.001), total number of previous e.motion TKA's performed (p < 0.001), and body mass index (p = 0.013) were found. A linear relationship between the variables can be expressed as a statistical formula:TT = 49.5 + PreOp Varus + 0.6(BMI) ? 0.1(total previous). Tourniquet time is measured in minutes and preoperative varus is measured in degrees from the mechanical axis. Total previous is the total number of navigated TKA's implanted by the surgeon.Tourniquet time is increased with larger pre-operative deformities and high BMI and decreased with surgical experience. The formula may give us a method of predicting the length of a procedure for a particular surgical team and may allow us to plan operating lists more accurately.     

Pathogen Profiling: Rapid Molecular Characterization of Staphylococcus aureus by PCR/Electrospray Ionization-Mass Spectrometry and Correlation with Phenotype

There are few diagnostic methods that readily distinguish among community-acquired methicillin (meticillin)-resistant Staphylococcus aureus strains, now frequently transmitted within hospitals. We describe a rapid and high-throughput method for bacterial profiling of staphylococcal isolates. The method couples PCR to electrospray ionization-mass spectrometry (ESI-MS) and is performed on a platform suitable for use in a diagnostic laboratory. This profiling technology produces a high-resolution genetic signature indicative of the presence of specific genetic elements that represent distinctive phenotypic features. The PCR/ESI-MS signature accurately identified genotypic determinants consistent with phenotypic traits in well-characterized reference and clinical isolates of S. aureus. Molecular identification of the antibiotic resistance genes correlated strongly with phenotypic in vitro resistance. The identification of toxin genes correlated with independent PCR analyses for the toxin genes. Finally, isolates were correctly classified into genotypic groups that correlated with genetic clonal complexes, repetitive-element-based PCR patterns, or pulsed-field gel electrophoresis types. The high-throughput PCR/ESI-MS assay should improve clinical management of staphylococcal infections.Invasive infections caused by methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) are among the most common complications of health care in the United States. Klevens et al. estimate that 94,360 invasive MRSA infections occur in the United States each year, with associated deaths in 18,650 cases (26). Infections are subcategorized as health care-associated MRSA (HA-MRSA) infections or as community-associated MRSA (CA-MRSA) infections; the latter occur in otherwise healthy people who have not experienced a hospital stay within the past 12 months (24, 35). CA-MRSA infections have largely been attributable to a few strains, designated pulsed-field types (PFTs) USA300 and USA400 (26, 29). Once introduced into a health care environment, CA-MRSA strains can be readily transmitted, blending with or replacing entrenched HA-MRSA strains (25, 35).Microbial genotyping analysis allows investigation into the clonality of an outbreak and risk factors associated with infection (5). Methods such as pulsed-field gel electrophoresis (PFGE) (39), repetitive-element-based PCR (rep-PCR) (42), and multilocus sequence typing (MLST) (10, 11) are used for microbial genotyping but are costly and labor-intensive and do not enable specific characterization of acquired genetic elements encoding virulence factors or toxins or of genes that mediate antibiotic resistance (40). A rapid technique for determining the MRSA strain genotype and its broader complement of genetic elements would enable a more comprehensive understanding of transmission dynamics and could lead to more effective actionable decisions related to bed management, prioritization of infection control resources, and treatment.Here, we describe the use of a rapid and high-throughput method to simultaneously genotype and characterize S. aureus specimens with respect to acquired genes encoding virulence factors, toxins, and antibiotic resistance determinants. The method is based on PCR coupled to electrospray ionization-mass spectrometry (ESI-MS) (8, 22, 37).The PCR/ESI-MS assay uses several novel strategies. First, broad-range primers, targeting sites that are highly conserved in all members of a microbe family, are used to amplify PCR products from groupings of microbes rather than single species. These primers are coupled with species- or strain-specific primers for the identification of specific pathogens or antibiotic targets. Second, PCR conditions are, by design, permissive and thus tolerant of mismatches, so that even sequences from novel strains can be amplified. Third, inosine and other “wild-card” nucleotides are used in primers to facilitate PCR analysis of mispaired sequences. Fourth, because MS simply measures the mass-to-charge ratio (m/z), the sequence of the amplicon need not be known in order to detect it. The technology offers advantages over routine single-target and multiplex PCR in that it is a full bioinformatics sequence analysis system.After amplification, MS is used to rapidly determine the precise mass-to-charge ratio for the amplified nucleic acid fragments present, and the A, C, T, and G contents (i.e., the base composition) of each amplicon are determined using proprietary software that creates a signature to allow organism identification and genotyping. This novel MS technology enables the rapid, sensitive, cost-effective, and simultaneous detection of a wide range of typical pathogenic organisms.We used the PCR/ESI-MS assay to analyze a well-characterized set of S. aureus strains from the CDC and geographically distinct clinical isolates from Maryland and Arizona. The PCR/ESI-MS technology effectively combines genotyping and characterization on a single high-throughput platform suitable for surveillance, infection control interventions, and patient management.     

Fatal delayed post-operative cerebral venous thrombosis after excision of hypoglossal nerve schwannoma

Lower cranial nerve schwannomas are rare tumours. We present a 35 year old female patient who had a lower cranial nerve schwannoma with both intracranial and extracranial components. The internal jugular vein was injured during the dissection of the extracranial portion of the tumour. Ligation of the internal jugular vein is not associated with significant post-operative complications. Our patient however, developed retrograde cortical venous thrombosis on the 14(th) post-operative day resulting in multiple areas of haemorrhagic venous infarction with raised intracranial pressure. Such a delayed contiguous cortical venous thrombosis has not been reported. We present this report to highlight this event and to outline the probable causes for the same.     

miRNAs and their potential for use against cancer and other diseases

miRNAs are 19-24 nucleotide long noncoding RNAs found in almost all genetically dissected species, including viruses, plants, nematodes, flies, fish, mice and humans. Rapid advances have been made in understanding their physiological functions, while abnormal patterns of miRNA expression have been found in many disease states, most notably human cancer. It is now clear that miRNAs represent a class of genes with a great potential for use in diagnosis, prognosis and therapy. In this review we will focus on the discoveries that elucidate their crucial role in mammalian diseases, particularly in cancer, and propose that miRNA-based gene therapy might become the potential technology of choice in a wide range of human diseases including cancer.     

Hippocampal volume change in the Alzheimer Disease Cholesterol-Lowering Treatment trial

Numerous clinical studies suggest a link between elevated cholesterol and increased risk of Alzheimer disease (AD), and the preponderance of data suggests that statin therapy may reduce the risk of AD later in life. The first clinical investigation of statin therapy in patients with AD, the AD Cholesterol-Lowering Treatment (ADCLT) trial, found that atorvastatin 80 mg/day was associated with improvements relative to placebo on some, but not all, cognitive measures after 6 months and 1 year of therapy. We report here findings from a pilot ADCLT substudy showing a nonsignificant reduction in total hippocampal volume with 1 year of atorvastatin therapy compared with placebo, driven by a highly significant reduction in right hippocampal volume with atorvastatin therapy.     

Traumatic transepiphyseal separation of the upper femoral epiphysis following seizures in two children with cerebral palsy

Transepiphyseal separation of the neck of the femur following grand mal seizures is described in two children with cerebral palsy. Closed reduction and percutaneous fixation was followed by a period in a hip spica. Although the incidence of avascular necrosis of the femoral head is high following such injury, this has not occurred in these patients at a follow-up of 18 months.     

Yellow Lid Sign in Wegner's Granulomatosis

Orbital manifestations in Wegener's granulomatosis develop in over 50% of patients. Ischemic vasculitis and optic nerve compression result in visual impairment. This case report highlights the importance of the yellow lid sign in the diagnosis of orbital granulomatosis as well as provides an explanation for the reversal of this phenomenon.     

Management of head and neck trauma in a developing country

Purpose  

To investigate cases of trauma in head and neck region; to elucidate the characteristic problems in a developing country.     

Risk factors for adverse neurodevelopment in extremely low birth weight infants with normal neonatal cranial ultrasound.

OBJECTIVES: To determine risk factors associated with adverse developmental outcome at 5 years in extremely low birth weight infants or extremely premature infants (<28 weeks) with normal neonatal cranial ultrasounds. DESIGN/METHODS: Data were collected prospectively on 152 infants with gestation <28 weeks or birth-weight <1000 g. Infants were grouped into those with normal development, mild-to-moderate impairment (IQ 70 to 84, or hearing loss 30 to 89 dB, visual acuity 6/18 to 6/60, or mild/moderate cerebral palsy (CP)) and severe impairment (IQ <70, hearing loss > or =90 dB, visual acuity <6/60, or severe CP). RESULTS: Five-year outcomes were available for 144/152 children (95%). In all, 89 (62%) infants had normal development, 39 (27%) had mild-moderate impairment and 16 (11%) had severe impairment. On multivariate logistic regression analysis, factors associated with developmental impairment were serum bilirubin > or =200 micromol/l (odds ratio (OR) - 4.06, p=0.003) and retinopathy of prematurity (ROP) (OR - 1.6, p=0.03). CONCLUSIONS: A serum bilirubin > or =200 micromol/l and presence of ROP are postnatal risk factors associated with an adverse developmental outcome in infants with normal cranial ultrasounds.