Robotic-assisted total knee arthroplasty with the OMNIBot platform: a review of the principles of use and outcomes.

INTRODUCTION: Technology that enables the orthopaedic surgeon to deliver a surgical plan with precision and reproducibility continues to evolve. Robotic TKA represents the next phase of technological development in knee arthroplasty. Multiple propriety robotic platforms are now available for use in TKA, and one such system is the OMNIBotics platform. We conducted a review of this system, reporting its history and principles of use, published outcomes and our own personal experience performing OMNI robotic-assisted TKAs. MATERIALS AND METHODS: A literature review was conducted using the PRISMA guidelines. Thirteen papers were included for the final review. RESULTS: The OMNIBot is an accurate and consistent delivery tool in TKA surgery and compares favourably to instrumented, navigation-assisted and patient-specific cutting guides. The OMNIBot has been shown to be a reliable tool for delivering different alignment philosophies as well as planning and achieving tibio-femoral coronal balancing. The utility of the system is increased when the robot is used in conjunction with a soft-tissue tensioning device-the BalanceBot. Data regarding PROM's are limited, however results to date show reliable outcomes. Survival analysis of RATKA using the OMNIBot is limited to one study which reported 99.26% survivorship at 3 years. We report our own outcomes using the OMNIBot, having performed 766 TKA's using the OMNIBot, since 2014 with 99.48% survivorship at 6 year follow-up. CONCLUSION: The OMNIBot platform is an imageless, passive robotic system available since 2007, with over 30,000 TKA's being performed with its assistance. It has a small physical footprint, is relatively inexpensive and time efficient. Our review demonstrates a high level of precision of the surgical planning, with a modestly improved accuracy compared to conventional and navigation technology. Published outcomes are limited, however demonstrate good short-term PROM's and survivorship data that compare favourably to other robotic TKA cohorts.

Mode properties of telecom wavelength InP-based high-(Q/V) L4/3 photonic crystal cavities.

We present finite-difference time domain simulations and optical characterizations via micro-photoluminescence measurements of InP-based L4/3 photonic crystal cavities with embedded quantum dots (QDs) and designed for the M1 ground mode to be emitting at telecom C-band wavelengths. The simulated M1 Q-factor values exceed 106, while the M1 mode volume is found to be 0.33 × (λ/n)3, which is less than half the value of the M1 mode volume of a comparable L3 cavity. Low-temperature micro-photoluminescence measurements revealed experimental M1 Q-factor values on the order of 104 with emission wavelengths around 1.55 µm. Weak coupling behavior of the QD exciton line and the M1 ground mode was achieved via temperature-tuning experiments.

Progressive secondary exo-focal dopaminergic neurodegeneration occurs in not directly connected midbrain nuclei after pure motor-cortical stroke.

Transsynaptic anterograde and retrograde degeneration of neurons and neural fibers are assumed to trigger local excitotoxicity and inflammatory processes. These processes in turn are thought to drive exo-focal neurodegeneration in remote areas connected to the infarcted tissue after ischemic stroke. In the case of middle cerebral artery occlusion (MCAO), in which striato-nigral connections are affected, the hypothesis of inflammation-induced remote neurodegeneration is based on the temporal dynamics of an early appearance of inflammatory markers in midbrain followed by dopaminergic neuronal loss. To test the hypothesis of a direct transsynaptic mediation of secondary exo-focal post-ischemic neurodegeneration, we used a photochemical induction of a stroke (PTS) in Sprague-Dawley rats restricted to motor cortex (MC), thereby sparing the striatal connections to dopaminergic midbrain nuclei. To dissect the temporal dynamics of post-ischemic neurodegeneration, we analyzed brain sections harvested at day 7 and 14 post stroke. Here, an unexpectedly pronounced and widespread loss of dopaminergic neurons occurred 14 days after stroke also affecting dopaminergic nuclei that are not directly coupled to MC. Since the pattern of neurodegeneration in case of a pure motor stroke is similar to a major stroke including the striatum, it is unlikely that direct synaptic coupling is a prerequisite for delayed secondary exo-focal post ischemic neurodegeneration. Furthermore, dopaminergic neurodegeneration was already detected by Fluoro-Jade C staining at day 7, coinciding with a solely slight inflammatory response. Thus, inflammation cannot be assumed to be the primary driver of exo-focal post-ischemic cell death. Moreover, nigral substance P (SP) expression indicated intact striato-nigral innervation after PTS, whereas opposing effects on SP expression after striatal infarcts argue against a critical role of SP in neurodegenerative or inflammatory processes during exo-focal neurodegeneration.

Prolonged cardiac arrest and resuscitation by extracorporeal life support: favourable outcome without preceding anticoagulation in an experimental setting.

State-of-the-art cardiopulmonary resuscitation (CPR) restores circulation with inconsistent blood-flow and pressure. Extracorporeal life support (ECLS) following CPR opens the opportunity for "controlled reperfusion". In animal experiments investigating CPR with ECLS, systemic anticoagulation before induced cardiac arrest is normal, but a major point of dispute, since preliminary heparinization in patients undergoing unwitnessed cardiac arrest is impossible. In this study, we investigated options for ECLS after an experimental 15 minutes normothermic cardiac arrest, without preceding anticoagulation, in pigs. Neurological recovery was assessed by a scoring system, electroencephalography and brain magnetic resonance imaging. Additionally, brain histology was performed on day seven after cardiac arrest. We demonstrated that preliminary heparin administration was not necessary for survival or neurological recovery in this setting. Heparin flushing of the cannulae seemed sufficient to avoid thrombus formation. These findings may ease the way to using ECLS in patients with sudden cardiac arrest.

[Semiology and propagation of epileptic seizures]. / Semiologie und Propagation epileptischer Anfälle.

The evaluation of episodic seizure-like symptoms is a common challenge in the neurologist's daily routine. The clinical signs (semiology) are the most important puzzle pieces to distinguish epileptic seizures from other episodic entities. Due to the often far-reaching health and social consequences of the diagnosis of epilepsy, the early and rigorous assessment of episodic symptoms by means of the patient history is important. This assessment is based on knowledge of the association of certain semiologies with epileptic syndromes and brain regions; however, certain limitations and pitfalls have to be considered. Typical propagation pathways of seizure activity determine the serial occurrence of semiological features and provide supplementary information.

Pathological alterations in GABAergic interneurons and reduced tonic inhibition in the basolateral amygdala during epileptogenesis.

An acute brain insult such as traumatic head/brain injury, stroke, or an episode of status epilepticus can trigger epileptogenesis, which, after a latent, seizure-free period, leads to epilepsy. The discovery of effective pharmacological interventions that can prevent the development of epilepsy requires knowledge of the alterations that occur during epileptogenesis in brain regions that play a central role in the induction and expression of epilepsy. In the present study, we investigated pathological alterations in GABAergic interneurons in the rat basolateral amygdala (BLA), and the functional impact of these alterations on inhibitory synaptic transmission, on days 7 to 10 after status epilepticus induced by kainic acid. Using design-based stereology combined with glutamic acid decarboxylase (GAD) 67 immunohistochemistry, we found a more extensive loss of GABAergic interneurons compared to the loss of principal cells. Fluoro-Jade C staining showed that neuronal degeneration was still ongoing. These alterations were accompanied by an increase in the levels of GAD and the alpha1 subunit of the GABA(A) receptor, and a reduction in the GluK1 (previously known as GluR5) subunit, as determined by Western blots. Whole-cell recordings from BLA pyramidal neurons showed a significant reduction in the frequency and amplitude of action potential-dependent spontaneous inhibitory postsynaptic currents (IPSCs), a reduced frequency but not amplitude of miniature IPSCs, and impairment in the modulation of IPSCs via GluK1-containing kainate receptors (GluK1Rs). Thus, in the BLA, GABAergic interneurons are more vulnerable to seizure-induced damage than principal cells. Surviving interneurons increase their expression of GAD and the alpha1 GABA(A) receptor subunit, but this does not compensate for the interneuronal loss; the result is a dramatic reduction of tonic inhibition in the BLA circuitry. As activation of GluK1Rs by ambient levels of glutamate facilitates GABA release, the reduced level and function of these receptors may contribute to the reduction of tonic inhibitory activity. These alterations at a relatively early stage of epileptogenesis may facilitate the progress towards the development of epilepsy.

Electrophysiology of focal clonic seizures in humans: a study using subdural and depth electrodes.

Focal clonic seizures are a frequent epileptic phenomenon. However, there are few data about their pathogenesis. Eleven patients with focal epilepsy who experienced focal clonic seizures during prolonged video-EEG monitoring were included in this study. Nine patients had subdural electrodes on the precentral gyrus and one patient had additional bilateral subthalamic nucleus (STN) depth electrodes. In five patients, the EEG was co-registered with the EMG of muscles which were involved in the clonic seizures. The frequency, pattern and evolution of the ictal EEG were analysed and their relationship to STN and EMG activity was studied. Focal clonic seizures were always associated with a polyspike-wave pattern in the EEG of the primary motor area (frequency range 1.6-3.4 Hz), while neighbouring electrodes not overlying the precentral gyrus showed different EEG patterns. At seizure onset, the ictal EEG derived from the precentral gyrus consisted of repetitive spiking for 8-28 s (median 19.5 s), accompanied by a continuous increase in muscle tone. This evolved to a pattern of polyspike-wave complexes which were associated with clinical clonus and lasted for 14-202 s (median 30.5 s). The clonic muscle contractions consisted of bursts of compound muscle action potentials (CMAPs) which occurred synchronously in agonistic and antagonistic muscles and were separated by periods of complete muscle relaxation. Each series of CMAPs followed the polyspikes in the EEG with a latency of 17-50 ms. The periods of muscle relaxation occurred during the EEG slow waves. Only some of the cortical spikes were followed by ipsilateral STN spikes. CMAPs followed the cortical polyspikes independently of whether or not STN spikes were seen. The study suggests that focal clonic seizures are focal tonic-clonic seizures. The epileptic clonus consisted of simultaneous contractions of agonistic and antagonistic muscles at regular intervals and was generated by localized polyspike-wave activity in cortical primary motor areas. Activation of the STN did not appear to be an essential component of clonic seizures.

[Propofol-remifentanil versus sevoflurane-remifentanil for anesthesia for pediatric procedures in infants, children and adolescents]. / Propofol/Remifentanil versus Sevofluran/Remifentanil zur Anästhesie bei Unterbaucheingriffen im Säuglings-, Kindes- und Jugendalter.

INTRODUCTION: The aim of this study was to compare total intravenous anaesthesia (TIVA) using propofol and remifentanil (P/R-group) and balanced anaesthesia (BA) using sevoflurane and remifentanil (S/R-group) for paediatric surgery. PATIENTS AND METHODS: A total of 120 patients aged 6 months to 16 years scheduled for elective minor lower abdominal surgery were randomly assigned to receive either propofol (5-10 mg/kg/h) and remifentanil (0.125-1.0 microgram/kg/min) or sevoflurane (1.0-1.5 MAC) and remifentanil (0.125-1.0 microgram/kg/min). Perioperative haemodynamics as well as recovery and discharge times, PONV and side-effects were studied. The patients vigilance, comfort and pain intensity were assessed postoperatively using the objective pain discomfort scale, the Steward post-anaesthetic recovery score and a visual analogue scale. RESULTS: Postoperative recovery (9.0 vs 11.6 min) and extubation times (11.8 vs. 15.0 min) as well as the time taken until a Steward post-anaesthetic recovery score > 3/4 (15.2 vs. 21.4 min) was reached were significantly shorter in the P/R-group. However, the length of time until discharge to the ward, postoperative comfort, pain intensity and analgesic requirements as well as PONV were comparable in both groups. CONCLUSIONS: With regards to the investigated parameters, TIVA with propofol and remifentanil is equally effective as BA with sevoflurane and remifentanil in paediatric patients. However, considering the selected dosing regimen, recovery times were significantly shorter for children after TIVA.

[Lateralizing and localizing signs and symptoms of epileptic seizures: significance and application in clinical practice]. / Lateralisierende und lokalisierende Anfallssymptome. Bedeutung und Anwendung in der klinischen Praxis.

This report reviews the lateralising and localising signs of epileptic seizures in respect to the differential diagnosis of epilepsy. The lateralising value of epileptic signs and symptoms can frequently be derived from the neuroanatomy. Focal clonic, focal tonic, and versive seizures as well as ictal unilateral dystonia are associated with a seizure onset zone in the contralateral hemisphere. Postictal nose wiping is performed with the hand ipsilateral to the epileptogenic zone. Similarly, unilateral blinking points to an ipsilateral seizure onset. Automatisms with preserved consciousness, ictal speech, and vomiting correlate to an epileptogenic zone in the non-dominant hemisphere, while postictal dysphasia is produced by seizures arising from the dominant hemisphere. Lateralising and localising signs and symptoms of epileptic seizures are of great help in the differential diagnosis of epilepsy from the first diagnosis of epileptic events to presurgical video-EEG monitoring.

Interactions between food components and drugs. Part 3. Interactions between pectin and propranolol.

Bioavailability of drugs can be affected distinctly by interactions with food components. Effects of structural parameters of the soluble dietary fiber pectin on lipid-membrane transport of propranolol (1) was investigated in vitro using a two-compartment model with a dodecanol-collodium membrane at pH 7.2 and 37 degrees C. Starting from practically fully esterified citrus pectin two series of defined and in their structural parameters gradually varied pectins were prepared. In presence of pectins with a blockwise distribution of free COOH-groups the portion of permeated 1 is significantly diminished with a decreasing degree of esterification (DE). On the other hand, only in the smallest DE pectins having statistically distributed free COOH-groups seemed to affect the transport rate of 1. The viscosity of the tested pectins possessed no significant influence on the passage of 1.

Glutathione and peroxide metabolism in malaria-parasitized erythrocytes.

The glutathione metabolism of Plasmodium falciparum, P. vinckei and P. berghei has been investigated. Human erythrocytes with low glutathione reductase and synthetase activity are still capable of harbouring P. falciparum. Both enzymes have been demonstrated in Plasmodium spp. Moreover, evidence is given for a selenium-independent glutathione peroxidase in malaria parasites.

[Color perception in domestic goats (Capra hircus L.)]. / Zum Farbsehvermögen von Hausziegen (Capra hircus L.).

Tests on male goats were designed to determine their capacity for colour vision. The colours yellow, orange, blue, violet and green were tested against gray nuances of like brightness. Goats were found to be able to distinguish between colours and gray nuances. The rate of errors increased in the order: orange, green, red, yellow, violet, blue.

[Selectivity of action of the lipoxygenase from rabbit reticulocytes on mitochondria and erythrocyte membranes]. / Zur Selektivität der Wirkung der Lipoxygenase aus Kaninchenretikulozyten auf Mitochondrien- und Erythrozytenmembranen.

Whereas the lipoxygenase from rabbit reticulocytes caused a large formation of malonyl dialdehyde (MDA) with rat liver mitochondria, erythrocyte ghosts were attacked only slightly independently of their type of preparation. The formation of MDA was not enhanced by release of spectrin-actin from the ghosts. The lipoxygenase did not give rise to hemolysis of intact erythrocytes. The formation of MDA was increased by heat treatment of the ghosts. Addition of cholesterol to a phospholipid emulsion inhibited the formation of MDA by the reticulocyte lipoxygenase. These results indicate that both lipid-protein interactions and the cholesterol content of the membranes may be involved in the preferential attack of the lipoxygenase on mitochondrial membranes.