Diagnosing Periprosthetic Joint Infection: a Scoping Review

Purpose of ReviewThe goal of this review is to provide an up to date understanding of the utility and limitations of the current tests utilized in the diagnosis of periprosthetic joint infection (PJI) in total knee and hip arthroplasty.Recent FindingsDespite the growth in literature surrounding PJI diagnosis, there remains challenges in establishing a diagnosis of PJI. A combination of clinical, serum, and synovial tests and microbiologic and histologic examinations can yield a diagnosis in the majority of cases. Novel molecular and imaging studies may be beneficial for indeterminant cases. A number of emerging diagnostic tests have been proposed and may be incorporated into diagnostic algorithms in the future. Recently proposed stepwise diagnostic algorithms have shown high sensitivity and specificity.SummaryThe diagnosis of PJI remains challenging due to a lack of tests that can definitively rule out infection. Diagnosis and investigations should occur in a stepwise fashion. There has been a plethora of new diagnostic tests introduced in attempts to improve the accuracy of diagnostic algorithms. The definition and algorithms for the diagnoses of PJI will continue to evolve as new techniques and tests are introduced.     

Preoperative assessment of the risk of postoperative death in patients with oral squamous cell carcinoma: a consideration beyond age,sex, and stage of cancer

Despite improvements in the management of patients in critical care, about 3% patients who have an operation with curative intent for oral squamous cell carcinoma (SCC) do not survive their stay in hospital. Our aim was to assess the risk factors for postoperative death that were independent of the stage of the cancer, or the age and sex of the patients. We screened 4760 consecutive inpatients at a maxillofacial tertiary care centre from 2011 to 2016, and 34 of them had died within the first three months after operation. We matched them with a further 34 patients with the same TNM stage, age, and sex. General personal and clinical data and preoperative laboratory values were screened, and we applied a Charlson Comorbidity Score (for anaesthetic risk) for each group. Patients’ mean (SD) age was 66 (12) years old. There was no significant difference in sex (p = 1), age (p = 0.718), or TNM classification. Those who died after operation had significantly more renal (p = 0.027) and gastrointestinal (p = 0.006) diseases, but cardiac diseases (p = 0.468) and diabetes mellitus (p = 1) were not significant risk factors in themselves. Patients who died postoperatively had significantly worse risk scores (p = 0.001) overall. The most common causes of death were septic shock (n = 10) and acute cardiac (n = 9) or respiratory failure (n = 7). Our findings suggested that general diseases were not intrinsically a contraindication for operation with curative intent. The Charlson Comorbidity Score helped to detect potentially fatal courses and could be useful in the preoperative assessment of patients whose general health is not good.     

Live/Real Time Three‐Dimensional Transesophageal Echocardiographic Assessment of Ventricular Septal Volume and Mass before and after Myectomy in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. In patients resistant to medical management, myectomy is the surgical procedure of choice to reduce the symptoms of left ventricular outflow obstruction. Two‐dimensional transesophageal echocardiography (2DTEE) has become part of the operative procedure by decreasing the incidence of postoperative complications. However, because of the three‐dimensional geometry of left ventricular outflow tract, it is unable to comprehensively assess the location and severity of the obstruction and to provide accurate guidance during myectomy. In this study, 10 patients with HCM underwent live/real time three‐dimensional transesophageal echocardiography (3DTEE) intra‐operatively to measure the volume of the resected septum. This volume correlated well with the volume of the resected septal muscle directly obtained using a graduating cylinder containing water (r = 0.9, P < 0.000). 3DTEE may be potentially used as an adjunct to guide the surgeon in performing an adequate myectomy with a lower incidence of residual obstruction and complications such as an iatrogenic ventricular septal defect.     

Escherichia coli tetracycline efflux determinants in relation to tetracycline residues in chicken

ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tc^r) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tc^r E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment.     

Acute,sub-acute and general pharmacological evaluation of 5-(3,4-methylenedioxyphenyl)-4-ethyl-2E,4E-pentadienoic acid piperidide (SK-20): A novel drug bioavailability enhancer

An efflux pump inhibitor, SK-20 (5-(3,4-methylenedioxyphenyle)-4 ethyl-2E,4E-pentadienoic acid piperidide), was assessed for its toxicity at three different pharmacological profiles: acute, sub-acute and general pharmacology with pharmacokinetics. In acute study, the SK-20 was found safe up to a dose of 2000 mg/kg (b.wt.); and at sub-acute, dosages of 50 and 100 mg/kg (b.wt.) were found to be safe. However, dosages of 200 mg or above per kg (b.wt.) showed some morphological alterations in cellular architecture of both liver and kidneys in both sexes, viz., mild vascular congestion along with sporadic hemorrhages and infiltration into renal and hepatic parenchyma by mononucleate cell. General pharmacological studies did not result into any alterations in analgesic, convulsions, rectal temperatures and in the rhythm or the rate of the intestinal motility or the secretion of the bile. While the respiratory and the cardiac rate remained normal, the only parameter to show was the blood pressure, which at all the doses tested, showed a tendency toward reduction. Characteristically, the SK-20 at all doses influenced pentobarbital-induced hypnosis positively and negatively to spontaneous motor activity in a dose dependent manner. Pharmacokinetics of SK-20 revealed it to have retention time at 10.2 min and half life 2.47 h.     

Practical guidelines for getting the most out of the gastrocnemius muscle flap units: a presented algorithm for the best flap choice

Although with the reported versatility, vascular reliability, and easy harvesting and elevation of the gastrocnemius muscle flap, still it is used for a narrow aspect of reconstructions including only small and nearby defects. The flap is unfortunately full of limited applications, unreachable coverage, and soft tissue shortage. In this work, we are presenting 20 cases of gastrocnemius muscle flap of different etiologies, in which we applied a group of modifications to have a higher grade of applicability, more arc of rotation, and more tissue surface area. The validity of these modifications was intraoperatively tested in different defect sites and sizes to report if they are really meaningful. All flaps had survived with no complications. We have summarized these modifications in four golden rules, making these muscle flaps more versatile and more applicable. An algorithm is suggested as a leading tool for the best choice of the gastrocnemius muscle units in different situations.