A Novel Approach to Measure Variability in the Anterior Cruciate Ligament Deficient Knee During Walking: The Use of the Approximate Entropy in Orthopaedics

Objective. The evaluation of variability of biological rhythmic activities through measures such as Approximate Entropy (ApEn) has provided important information regarding pathology in disciplines such as cardiology and neurology. This research lead to the “loss of complexity hypothesis” where decreased variability is associated with loss of healthy flexibility rendering the system more rigid and unable to adapt to stresses. ApEn as a measure of variability and complexity, correlates well with pathology while, in some cases, it is predictive of subsequent clinical changes. The study of human gait could benefit from the application of ApEn since it is also a rhythmical oscillation. Our aim was to assess the variability of the ACL deficient knee, since ACL rupture is a common musculoskeletal injury and is accompanied by altered gait patterns and future pathology in the joint. We hypothesized that the ACL deficient knee will exhibit more regular and less variable walking patterns than the contralateral intact knee. Methods. Ten subjects with unilateral deficiency walked on a treadmill at their self-selected speed, 20% faster, and 20% slower, while kinematics were collected (50 Hz) from 80 consecutive strides for each condition. The ApEn of the resulted knee joint flexion-extension time series was calculated. Results. Significantly smaller ApEn values were found in the ACL deficient knee when compared with the contralateral intact (F = 5.57, p = 0.022), for all speeds. ApEn values significantly increased (F = 5.79, p = 0.005) with increases in walking speed. Conclusions. The altered properties of the ACL deficient knee, which exhibits more regular and less variable patterns than the contralateral intact knee, may decrease the adaptability of the system rendering it less able to adjust to perturbations. This could explain the increased future pathology found in the deficient knee. ApEn can be an important tool in assessing pathology and therapeutic interventions in orthopaedics.     

History of Biliary Surgery

Since ancient times biliary surgery has been one of the major interests of doctors and other scientists around the world. From the ancient Greeks and Egyptians to the greatest scientists of modern times biliary surgery has advanced remarkably. Especially during the last century huge progress has been made in this field. Minimally invasive surgical techniques have been developed and combined with general anesthesia and antisepsis that have made biliary surgery particularly safe for every patient and have made cholecystectomy one of the most common operations in the world today.     

The Torg-Pavlov ratio for the prediction of acute spinal cord injury after a minor trauma to the cervical spine

Background contextAcute cervical spinal cord injury (SCI) has been observed in some patients after a minor trauma to the cervical spine. The discrepancy between the severity of the trauma and the clinical symptoms has been attributed to spinal canal stenosis. However, to date, there is no universally established radiological parameter for identifying critical spinal stenosis in these patients. The spinal canal–to–vertebral body ratio (Torg-Pavlov ratio) has been proposed for assessing developmental spinal canal stenosis. The relevance of the Torg-Pavlov ratio for predicting the occurrence and severity of acute cervical SCI after a minor trauma to the cervical spine has not yet been established.PurposeTo investigate the Torg-Pavlov ratio values of the cervical spine in patients suffering from acute cervical SCI after a minor trauma to the cervical spine and the use of the Torg-Pavlov ratio for identifying patients at risk of cervical SCI and predicting the severity and course of symptoms.Study design/settingRetrospective radiological study of consecutive patients.Patient sampleForty-five patients suffering from acute cervical SCI and 68 patients showing no neurologic symptoms after a minor trauma to the cervical spine.Outcome measuresMidvertebral sagittal cervical spinal canal diameter and the sagittal vertebral body diameter. Calculation of the Torg-Pavlov ratio values.MethodsConventional lateral radiographs of the cervical spine (C3–C7) were analyzed to determine the Torg-Pavlov ratio values. Receiver operating characteristic curves were calculated for evaluating the classification accuracy of the Torg-Pavlov ratio for predicting SCI.ResultsThe Torg-Pavlov ratio values in the SCI group were significantly (p<.04) smaller compared with that in the control group. A Torg-Pavlov ratio cutoff value of 0.7 yielded the greatest positive likelihood ratio for predicting the occurrence of SCI. However, there were no significant differences in the Torg-Pavlov ratio values between the different American Spinal Injury Association Impairment Score groups and between patients with complete, partial, and no recovery of symptoms.ConclusionsDevelopmental cervical spinal canal stenosis assessed by the Torg-Pavlov ratio was characteristic for patients suffering from acute cervical SCI after a minor trauma to the cervical spine. Patients at risk of SCI after a minor trauma to the cervical spine can be identified by applying a Torg-Pavlov ratio cutoff value of 0.7. Other factors in addition to the spinal canal–to–vertebral body ratio affect the severity and course of symptoms as a result of cervical SCI.     

Blood pressure target for hypertension in chronic kidney disease: One size does not fit all

There is disagreement between the American and the European guidelines for hypertension management in regard to the optimal blood pressure target in patients with chronic kidney disease (CKD). Randomized clinical trials and meta‐analyses of individual patient data pooled from these trials do not clearly support an intensive blood pressure target for the entire population of CKD patients with hypertension. However, some evidence suggests that in CKD patients with proteinuria strict blood pressure control might confer benefit in terms of renal outcome. Tailored treatment strategy based on the individual’s proteinuric profile and tolerability along with standardization of blood pressure measurement methodology including out‐of‐office evaluation are of paramount importance in patients with CKD.     

Insight into the 24‐hour ambulatory central blood pressure in adolescents and young adults

This study attempted to investigate the behavior of 24‐hour central ambulatory blood pressure (ABP) in adolescents and young adults. Adolescents and young adults (age 10‐25 years) referred for elevated blood pressure (BP) and healthy volunteers had simultaneous 24‐hour peripheral (brachial) and central (aortic) ABP monitoring using the same automated upper‐arm cuff device (Mobil‐O‐Graph 24h PWA). Central BP was calculated by the device using two different calibration methods (C1SBP using peripheral systolic (pSBP)/diastolic BP and C2SBP using mean arterial/diastolic BP). A total of 136 participants (age 17.9 ± 4.7 years, 54% adolescents, 77% males, 25% volunteers, 34% with elevated peripheral ABP) were analyzed. Twenty‐four‐hour pSBP was higher than C1SBP, with this difference being more pronounced during daytime than nighttime (16.3 ± 4.5 and 10.5 ± 3.2 mm Hg, respectively, P < .001). Younger age, higher body height, and male gender were associated with greater systolic ABP amplification (pSBP‐C1SBP difference). C1SBP followed the variation pattern of pSBP, yet with smaller nighttime dip (8.4 ± 6.0% vs 11.9 ± 4.6%, P < .001), whereas C2SBP increased (2.4 ± 7.2%) during nighttime sleep (P < .001 for comparison with pSBP change). Older age remained independent determinant of larger nighttime BP fall for pSBP and C1SBP, whereas male gender predicted a larger nighttime C2SBP rise. These data suggest that the calibration method of the BP monitor considerably influences the diurnal variation in central BP, showing a lesser nocturnal dip than pSBP or even nocturnal BP rise, which are determined by the individual''s age and gender.     

Spontaneous bacterial peritonitis due to carbapenemase-producing Enterobacteriaceae: Etiology and antibiotic treatment

Carbapenem antibiotics were first introduced in the 1980s and have long been considered the most active agents for the treatment of multidrug-resistant gram-negative bacteria. Over the last decade, carbapenem-resistant Enterobacteriaceae (CRE) have emerged as organisms causing spontaneous bacterial peritonitis. Infections caused by CRE have shown a higher mortality rate than those caused by bacteria sensitive to carbapenem antibiotics. Current antibiotic guidelines for the treatment of spontaneous bacterial peritonitis are insufficient, and rapid de-escalation of empiric antibiotic treatment is not widely recognized. This review summarizes the molecular characteristics, epidemiology and possible treatment of spontaneous bacterial peritonitis caused by CRE.     

Thromboembolic risk and anticoagulant therapy in COVID-19 patients: emerging evidence and call for action

Emerging evidence shows that severe coronavirus disease 2019 (COVID-19) can be complicated with coagulopathy, namely disseminated intravascular coagulation, which has a rather prothrombotic character with high risk of venous thromboembolism. The incidence of venous thromboembolism among COVID-19 patients in intensive care units appears to be somewhat higher compared to that reported in other studies including such patients with other disease conditions. D-dimer might help in early recognition of these high-risk patients and also predict outcome. Preliminary data show that in patients with severe COVID-19, anticoagulant therapy appears to be associated with lower mortality in the subpopulation meeting sepsis-induced coagulopathy criteria or with markedly elevated d-dimer. Recent recommendations suggest that all hospitalized COVID-19 patients should receive thromboprophylaxis, or full therapeutic-intensity anticoagulation if such an indication is present.