Novel applications of online pH determinations at temperatures from -35 °C to 130 °C in technical and biological media, which are all but ideal aqueous solutions, require new approaches to pH ...monitoring. The glass electrode, introduced nearly hundred years ago, and chemical sensors based on field effect transistors (ISFET) show specific drawbacks with respect to handling and long-time stability. Proton sensitive metal oxides seem to be a promising and alternative to the state-of-the-art measuring methods, and might overcome some problems of classical hydrogen electrodes and reference electrodes.
The false-positive finding of anterior horn meniscus (pseudo)tear on magnetic resonance imaging (MRI) is an important finding of which to be aware. We have recently seen awareness similarly raised ...regarding root tears of the meniscus, which, if overlooked, could have detrimental consequences. Manifestations of the MRI finding of meniscus pseudotear arise from the variability of the insertion of the transverse geniculate ligament into the anterior horn of the lateral meniscus. Bearing in mind that anterior knee pain is a common reason that patients present for an orthopaedic and sports medicine evaluation, the understanding that this MRI finding does not represent a true meniscus tear may save patients from unnecessary arthroscopic surgery.
Purpose Despite the well-documented advantages of meniscal repair over meniscectomy, horizontal cleavage tears (HCTs) are often not repaired. Reported reasons include difficulty performing the ...repair, potential suture failure due to mechanical stresses, and poor healing rates. In addition, many surgeons have the perception that debriding the tear until the superior and inferior laminae are stable results in a good clinical outcome. Furthermore, many of the tears occur in patients who are older than the generally accepted indicated age for repair and may also have a degenerative component, making them potentially less likely to benefit from repair. This review was performed to evaluate the published outcomes of HCT repairs and test the hypothesis that surgically repaired HCTs have an unacceptably low rate of success. Methods A systematic search of the PubMed and Embase databases was performed in December 2013 to identify studies in which meniscal HCTs were repaired. Inclusion criteria for the analysis were English language, reference to a patient with an HCT repaired by any method, and a report of at least 1 postoperative outcome. For the purposes of this review, a failed outcome was defined as the need for reoperation. Results More than 16,000 abstracts were returned in the search. From these abstracts, we identified 210 articles for further review, of which 9 met the inclusion criteria. A total of 98 repairs of horizontal tears were evaluated in these studies. By use of reoperation as the criterion for treatment failure, 77 of the repairs were successful, for an overall success rate of 77.8%. Conclusions The literature does not support the hypothesis that surgically repaired HCTs have an unacceptably low rate of success. Rather, our results show that existing studies of repaired HCTs show a comparable success rate to repairs of other types of meniscal tears. Level of Evidence Level IV, systematic review of Level IV studies.
Background:
Medial meniscus root tears are a common knee injury and can lead to accelerated osteoarthritis, which might ultimately result in a total knee replacement.
Purpose:
To compare meniscus ...repair, meniscectomy, and nonoperative treatment approaches among middle-aged patients in terms of osteoarthritis development, total knee replacement rates (clinical effectiveness), and cost-effectiveness.
Study Design:
Meta-analysis and cost-effectiveness analysis.
Methods:
A systematic literature search was conducted. Progression to osteoarthritis was pooled and meta-analyzed. A Markov model projected strategy-specific costs and disutilities in a cohort of 55-year-old patients presenting with a meniscus root tear without osteoarthritis at baseline. Failure rates of repair and meniscectomy procedures and disutilities associated with osteoarthritis, total knee replacement, and revision total knee replacement were accounted for. Utilities, costs, and event rates were based on literature and public databases. Analyses considered a time frame between 5 years and lifetime and explored the effects of parameter uncertainty.
Results:
Over 10 years, meniscus repair, meniscectomy, and nonoperative treatment led to 53.0%, 99.3%, and 95.1% rates of osteoarthritis and 33.5%, 51.5%, and 45.5% rates of total knee replacement, respectively. Meta-analysis confirmed lower osteoarthritis and total knee replacement rates for meniscus repair versus meniscectomy and nonoperative treatment. Discounted 10-year costs were $22,590 for meniscus repair, as opposed to $31,528 and $25,006 for meniscectomy and nonoperative treatment, respectively; projected quality-adjusted life years were 6.892, 6.533, and 6.693, respectively, yielding meniscus repair to be an economically dominant strategy. Repair was either cost-effective or dominant when compared with meniscectomy and nonoperative treatment across a broad range of assumptions starting from 5 years after surgery.
Conclusion:
Repair of medial meniscus root tears, as compared with total meniscectomy and nonsurgical treatment, leads to less osteoarthritis and is a cost-saving intervention. While small confirmatory randomized clinical head-to-head trials are warranted, the presented evidence seems to point relatively clearly toward adopting meniscus repair as the preferred initial intervention for medial meniscus root tears.
Early-generation meniscal fixators sometimes caused iatrogenic articular cartilage damage. This resulted in injury to the very structure one tries to preserve when repairing a meniscal tear. Advances ...in suture-based meniscal implants and all-inside suture devices have allowed us to safely repair meniscal tears, even ones thought previously irreparable, and without the need for a secondary incision. As the techniques for meniscal repair continue to improve, orthopaedic surgeons should be encouraged to consider repair with more complex meniscal tear patterns.
Abstract Postoperative infections are going to happen. The question of whether prophylactic antibiotics can lower the infection rate in routine knee arthroscopy is investigated. Although a large ...number of cases were included in the study, the results did not reach statistical significance. Nevertheless, a significant trend toward a lower incidence of deep infection was seen when antibiotics were given.
State-of-charge (SOC) and state-of-health (SOH) of different cell chemistries were investigated using long-time cycle tests. This practical guide illustrates how differential capacity dQ/dU ...(capacitance) obtained from discharge curves, impedance spectra, and cyclic voltammograms can be used for the instant diagnosis of lithium-ion batteries without fully charging and discharging the cell. The increase of dU/dQ is an early indicator of upcoming heat events and deep discharge. The criterion dQ/dU = dU/dQ = 1 could serve as an indicator for “full charge”. The frequency response of capacitance correlates with the available charge of the battery and reflects overcharge events and deep discharges long before the battery fails. It is not necessary to measure down to extremely low frequencies because the charge transfer pseudocapacitance of around 10 Hz reflects well the SOC. Computer-aided calculation methods for the evaluation of measurements in industrial environments and for the training of students are presented.
Meniscus tears are commonly encountered in the clinical and operative setting and vary in presentation, including bucket-handle, radial, and horizontal cleavage tears. Historically, tears were ...treated with benign neglect or partial meniscectomy. However, a great deal of subsequent research has highlighted the biomechanical consequences of tears and meniscectomy, including increased peak local contact forces, progressive postmeniscectomy arthritis, and subsequent arthroplasty. With the advent and evolution of repair devices, increasing attention is being turned to the ideal restorative treatment of meniscus tears. Successful meniscus repair is centered about the ABCs of repair: Anatomic reduction, Biologic preparation and augmentation, and Circumferential compression. Recent advances in repair techniques have included microfracture of the intercondylar notch to provide healing factors and marrow cells for augmented healing, all-inside suture devices enabling the reduction and fixation tears without the need for additional assistants and the morbidity of inside-out exposure, and circumferential compression combined with clot augmentation to reduce and fix horizontal cleavage tears and recreate biomechanics to within 15% of baseline contact forces. Clinical outcomes of meniscus repair using modern techniques have been promising, with reapproximation of native joint biomechanics, substantial improvements in patient subjective outcome scores, and satisfactory reoperation rates. With implementation of the ABCs of meniscus repair as well as the continued expansion of the orthopedic surgeons' meniscus repair toolbox, restoration and preservation of the meniscus are increasingly possible across the spectrum of tear types.
Frequency-dependent capacitance C(ω) is a rapid and reliable method for the determination of the state-of-charge (SoC) of electrochemical storage devices. The state-of-the-art of SoC monitoring using ...impedance spectroscopy is reviewed, and complemented by original 1.5-year long-term electrical impedance measurements of several commercially available supercapacitors. It is found that the kinetics of the self-discharge of supercapacitors comprises at least two characteristic time constants in the range of days and months. The curvature of the Nyquist curve at frequencies above 10 Hz (charge transfer resistance) depends on the available electric charge as well, but it is of little use for applications. Lithium-ion batteries demonstrate a linear correlation between voltage and capacitance as long as overcharge and deep discharge are avoided.
Horizontal cleavage tears have recently received more attention. Historically they were treated with benign neglect or resection. Recent biomechanical studies show that resecting one of the leaflets ...may be as detrimental a partial meniscectomy in tears with a more vertical orientation. New instrumentation has facilitated repair with an all-inside vertical compression stitch. Cadaver studies show repairing horizontal cleavage tears in such a manner can restore the biomechanics of the joint close to the intact state. The approach to treating horizontal cleavage tears has changed and is the focus of this article.
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