Complications and Predictors of Need for Return to the Operating Room in the Treatment of Supracondylar Humerus Fractures in Children.

UNLABELLED: Supracondylar humerus fractures are common pediatric injuries. Little is known about the risk factors for repeat operative procedures. A retrospective chart review of 709 patients treated for a displaced supracondylar humerus fracture was performed to identify risk factors for return to the operating room during the initial post-operative period. Deviations of routine fracture care were recorded and complication rates were compared between Gartland type 2 and 3 fractures using logistic regression. Type 3 fractures were found to have a higher complication rate, and, specifically, more peri-operative nerve palsies, more likely to need to return to the operating room for hardware removal, to lose fracture reduction, and require a return to the operating room for any reason. Five risk factors which may require returning to the operating room were identified: younger patient age, left sided fractures, type 3 fractures, peri-operative nerve palsy, and post-operative infection. In conclusion, Gartland type 3 supracondylar humerus fractures are associated with more complications then type 2 fractures. Risk factors for the need to return to the operating room in the post-operative period include: younger patient age, left sided fractures, type 3 fractures, peri-operative nerve palsy, and post-operative infection. Patients with these risk factors should be considered at risk for return to the OR and fracture fixation and follow up protocols should be adjusted for this risk. LEVEL OF EVIDENCE: Prognostic Study, Level II.

The perfect reduction: approaches and techniques.

Anatomic reduction of femoral neck fractures is difficult to obtain in a closed fashion. Open reduction provides for direct and controlled manipulation of fracture fragments. This can be accomplished via multiple approaches. The anterolateral, or Watson-Jones, approach or Smith-Petersen, or direct anterior, approach are the two most frequently used. Percutaneous techniques have also been described, though they lack the visual confirmation of reduction of a traditional open approach. These can be performed using a fracture table or with a free leg on a radiolucent table in either supine or lateral positions. Knowledge of the hip and pelvis anatomy is crucial for the preservation of critical femoral neck vasculature. Intra-operative fluoroscopy together with direct visualization provides the framework for successful manipulation of the fracture fragments, temporary stabilization, and ultimately fracture fixation.

Detection of periprosthetic infections with use of ribosomal RNA-based polymerase chain reaction.

BACKGROUND: Previously described molecular biology techniques used to detect periprosthetic infections have been complicated by false-positive results. We have reported the development of a messenger RNA (mRNA)-based procedure to reduce these false-positive results. The limitations of this procedure are the lack of a universal target and reduced sensitivity due to a low concentration of bacterial mRNAs in test samples. The objective of the present study was to determine whether reverse transcription-quantitative polymerase chain reaction (RT-qPCR) using universal primers can be used to detect the more abundant bacterial ribosomal RNA (rRNA) as an indicator of periprosthetic infection. METHODS: Serial dilutions of simulated synovial fluid infections were analyzed with rRNA RT-qPCR to determine the detection limit of this assay. Escherichia coli cultures treated with gentamicin were analyzed with RT-qPCR over a twenty-day time course to determine the degradation of rRNA as compared with the decrease in the viable cell count as determined by means of cell plating. As a proof of concept, group-specific polymerase chain reaction primers were developed for Streptococcus species and were tested against fifteen orthopaedically relevant organisms to show the potential for speciation with this assay. Sixty-four patients with a symptomatic effusion at the site of a total knee arthroplasty were enrolled, and complete patient information was documented in a prospective manner. Synovial fluid analysis with rRNA RT-qPCR was performed in a blind fashion. RESULTS: The rRNA RT-qPCR assay was able to detect as few as 590 colony forming units/mL of Staphylococcus aureus and 2900 colony forming units/mL of Escherichia coli. The rRNA RT-qPCR signal closely followed cell death, pointing to its potential use as a viability marker. Three group-specific primer sets correctly identified their intended targets without amplifying closely related species. Clinically, the test correctly identified all six patients with a confirmed infection and all fifty patients who clearly did not have an infection. Eight patients had some laboratory or clinical signs of infection, but their status could not be confirmed. Infection was indicated by rRNA RT-qPCR in three of these patients who had elevated synovial fluid white blood-cell counts but negative results on culture. For statistical purposes, all patients who were categorized as indeterminate were considered to have an infection for the purpose of analysis, for a prevalence of 22% in this cohort. CONCLUSIONS: With respect to current diagnostic tests, rRNA-based RT-qPCR demonstrated 100% specificity and positive predictive value with a sensitivity equivalent to that of intraoperative culture. The RT-qPCR signal followed bacterial culture trends but exhibited detectable level for seven days after sterilization, allowing for the detection of infection after the antibiotic administration. These findings indicate that rRNA RT-qPCR is a sensitive and reliable test that retains the universal detection and speciation of DNA-based methods while functioning as a viability indicator.

Altered fatty acid composition of dopaminergic neurons expressing alpha-synuclein and human brains with alpha-synucleinopathies.

Alpha-synuclein (alphaS) is an abundant neuronal protein that accumulates in insoluble inclusions in Parkinson's disease (PD) and the related disorder, dementia with Lewy bodies (DLB). A central question about the role of alphaS in the pathogenesis of PD and DLB concerns how this normally soluble protein assembles into insoluble aggregates associated with neuronal dysfunction. We recently detected highly soluble oligomers of alphaS in normal brain supernatants and observed their augmentation in PD and DLB brains. Further, we found that polyunsaturated fatty acids (PUFAs) enhanced alphaS oligomerization in intact mesencephalic neuronal cells. We now report the presence of elevated PUFA levels in PD and DLB brain soluble fractions. Higher PUFA levels were also detected in the supernatants and high-speed membrane fractions of neuronal cells over-expressing wild-type or PD-causing mutant alphaS. This increased PUFA content in the membrane fraction was accompanied by increased membrane fluidity in the alphaS overexpressing neurons. In accord, membrane fluidity and the levels of certain PUFAs were decreased in the brains of mice genetically deleted of alphaS. Together with our earlier observations, these results suggest that alphaS-PUFA interactions help regulate neuronal PUFA levels as well as the oligomerization state of alphaS, both normally and in human synucleinopathies.

Calix[4]arene, calix[4]resorcarene, and cyclodextrin derivatives and their lanthanide complexes as chiral NMR shift reagents.

Calix[4]arenes, calix[4]resorcarenes, and anionic cyclodextrin derivatives were examined as chiral NMR solvating agents. The calix[4]arenes were prepared by attachment of amino acids through the hydroxyl groups of the phenol rings. Chloroform-, methanol-, and water-soluble derivatives were prepared and tested with a range of substrates. Chloroform-soluble chiral calix[4]resorcarenes were prepared by attachment of chiral primary and secondary amines and examined in NMR applications with a variety of substrates. Sulfated and carboxymethylated beta-cyclodextrin are effective at causing enantiomeric discrimination in the (1)H NMR spectra of organic cations. Lanthanide ions associate at the carboxymethyl groups and cause sizeable shifts and enhancements in enantiomeric discrimination in the spectra of organic cations. The enhancements caused by the lanthanide ion are large enough that much lower concentrations of the cyclodextrin can be used as compared to conventional analyses.