Total hip replacement with a collarless polished cemented anatomic stem: clinical and gait analysis results at ten years follow-up

Purpose

The aim of this study was to determine outcomes of total hip replacement (THR) with the Lemania cemented femoral stem.

Methods

A total of 78 THR patients were followed and compared to 17 “fit”, healthy, elderly and 72 “frail” elderly subjects without THR, using clinical outcome measures and a portable, in-field gait analysis device at five and ten years follow-up.

Results

Forty-one patients (53 %), mean age 83.4 years, available at ten years follow-up, reported very good to excellent satisfaction. Mean Harris Hip and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were 81.2 and 10.5 points, respectively, with excellent radiological preservation of proximal femur bone stock. Spatial and temporal gait parameters were close to the fit group and better than the frail group.

Conclusions

Lemania THR demonstrated very good, stable clinical and radiological results at ten years in an older patient group, comparable to other cemented systems for primary THR. Gait analysis confirmed good walking performance in a real-life environment.     

Positive inotropic effect of ouabain on isolated heart is accompanied by activation of signal pathways that link Na+/K+-ATPase to ERK1/2

Exposure of cultured rat cardiac myocytes to ouabain is known to cause the interaction of Na+/K+-ATPase with adjacent proteins, leading to activation of multiple signal transduction pathways, regulation of growth-related genes, and hypertrophy. The aim of this work was to determine if the proximal signaling events identified in cultured myocytes also occur in isolated intact hearts of rat and guinea pig in response to positive inotropic doses of ouabain. Langendorff rat heart preparations were exposed to 50 microM ouabain to produce positive inotropy without toxicity, and assayed for Src kinase, protein kinase C, and extracellular signal-regulated kinases 1 and 2 (ERK(1/2)). These kinases were rapidly activated by ouabain as in cultured cells. In isolated guinea pig hearts, 1 microM ouabain caused ERK(1/2) activation comparable to the effect of 50 microM ouabain in rat heart and consistent with the higher ouabain sensitivity of the contractility of guinea pig heart. These data show that the proximal ouabain-induced signal pathways previously noted in cultured cells are not artifacts of dispersion/culturing of myocytes, and are not the peculiar properties of the rat heart with its relatively low ouabain sensitivity. They also suggest that treatment with positive inotropic doses of cardiac glycosides is likely to be associated with changes in the cardiac phenotype.     

Knee Implant Loosening Detection: A Vibration Analysis Investigation

Knee implant loosening is mainly caused by the weakness of the prosthesis-bone interface and is the main reason for surgical revisions. However, pre-operative diagnosis is difficult due to lack of accurate tests. In this study, we developed a vibration-based system to detect the loosening of the tibial implant of an instrumented knee prosthesis. The proposed system includes an instrumented vibrator for transcutaneous stimulation of the bone in a repeatable manner, and accelerometer sensors integrated into the implants to measure the propagated vibration. A coherence-based detection technique was proposed to distinguish the loosened implants from the secure ones. Fourteen ex vivo lower limbs were used, on which the knee prosthesis was implanted, and harmonic-forced vibration was applied on the tibia. The input–output coherence measure provided 92.26% accuracy, a high sensitivity (91.67%) and specificity (92.86%). This technique was benchmarked against power spectrum based analysis of the propagated vibration to the implant. In particular, loosening detection based on new peak appearance, peak shift, and peak flattening in power spectra showed inferior performance to the proposed coherence-based technique. As such, application of vibration on our instrumented knee prosthesis together with input–output coherence analysis enabled us to distinguish the secure from loose implants.     

Evaluation of IOL power calculation with the Kane formula for pediatric cataract surgery

Graefe's Archive for Clinical and Experimental Ophthalmology - To assess the accuracy of the Kane formula for intraocular lens (IOL) power calculation in the pediatric population. The charts of...     

Classification and characterization of postural transitions using instrumented shoes

The frequency and quality of sit-to-stand and stand-to-sit postural transitions decrease with age and are highly relevant for fall risk assessment. Accurate classification and characterization of these transitions in daily life of older adults are therefore needed. In this study, we propose to use instrumented shoes for postural transition classification as well as transition duration estimation from insole force signals. In the first part, data were collected with 10 older adults and 10 young participants performing transitions in the laboratory while wearing the instrumented shoes, without arm assistance. A wavelet approach was used to transform the insole force data, and candidate events were selected for transition duration estimation. Transition durations were then validated against a model based on force plate reference. Vertical force estimation was also compared to force plate measurement. In the second part, postural transitions were classified in daily life using the instrumented shoes and validated against a highly accurate wearable system. Transition duration was estimated with an error ranging from 10 to 20% while the error for vertical force estimation was 7%. Postural transition classification was achieved with excellent sensitivity and precision exceeding 90%. In conclusion, the instrumented shoes are suitable for classifying and characterizing postural transitions in daily life conditions of healthy older adults.

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Graphical abstract “Experimental setup showing instrumented shoes, reference force plate, as well as IMUs used for postural transition classification and duration estimation comparison”

     

Coping styles of female cocaine addicts

There is an abundance of support in the literature that coping styles may influence frequency of use, treatment completion, and relapse among cocaine addicts. This study reports on the predominant coping styles of a sample of female cocaine addicts upon admission to treatment for substance abuse. This sample demonstrated a great deal of already‐experienced life stressors with little social support to deal with them. They were using emotion‐focused coping more frequently than problem‐focused coping; the overwhelming majority of them were not satisfied with their coping skills, and using cocaine was one way for them to cope with life stressors. Theoretical and practical implications are discussed.     

Perspectives in adolescent risk-taking through instrument development

Understanding the high-risk adolescent's perception of risk taking is essential for health professionals to determine appropriate interventions. The purpose of this study was to examine the psychometric properties of the revised Adolescent Risk-Taking Instrument (ARTI) designed to measure the high-risk adolescent's perception of risk taking. This study also examined the variables that are most predictive of social adaptation and risk taking. An ex post facto design was used to standardize data collection and to assess the psychometric properties of the revised ARTI. The nonprobability sample consisted of 167 adolescents attending school in an urban, health-underserved area. Exploratory factor analysis supported construct validity, and Chronbach's Coefficient Alpha supported internal consistency reliability. The reliability coefficient for the risk taking and social adaptation constructs were .80 and .77, respectively. Current perspectives on adolescent risk taking and implications for the use of the ARTI in clinical practice are addressed.