Use of Headed Reinforcement Bars in Contruction. A Theoretical Approach to Determine the Dimensions of Anchorage Plates and Experimental Tests on Knee Joints Subjected to a Closing Moment

In order to reduce costs and time while improving quality, durability and sustainability in structural concrete constructions, a widely used material nowadays, special care must be taken in some crucial phases of the project and execution, including the structure design and calculation, the dosage, dumping and curing of concrete: another important aspect is the proper design and execution of assembly plans and construction details. The framework, a name designating the whole reinforcement bars cage already assembled as shown in the drawings, can be made up of several components and implies higher or lower industrialization degree. The framework costs constitute about one third of the price per cubic meter placed in concrete works. The best solutions from all points of view are clearly those involving an easier processing to achieve the same goal, and consequently carrying a high degree of industrialization, meaning quality and safety in the work. This thesis aims to provide an indepth analysis of a relatively new type of anchoring by plate known as headed reinforcement bars, which can potentially replace standard or L-shaped hooks, improving the cleaning of construction details and enabling a faster, more flexible, and therefore a more economical assembly. A literature review on the topic and an overview of typical applications is provided, followed by some examples of specific applications in real projects. Since a strict theoretical formulation used to provide the design plate dimensions has not yet been put forward, an equation is proposed for the side-face blowout strength of the anchorage, based on the capacity of concrete to carry concentrated loads in cases in which no transverse reinforcement is provided. The correlation of the calculated ultimate load with experimental results available in the literature is given. Besides, the proposed formulation can be expanded to cases in which a certain development length is available: using a software for nonlinear finite element analysis oriented to the study of reinforced concrete, numerical tests on the bond-bearing interaction are performed. The thesis ends with a testing of eight corner joints subjected to a closing moment, held in the Structures Laboratory of the Polytechnic University of Madrid, aiming to check whether the design of such plates as stated is adequate for these elements and whether an element with plate-anchored reinforcement is equivalent to one with a traditional construction detail.

Nuclease-resistant ribozymes decrease stromelysin mRNA levels in rabbit synovium following exogenous delivery to the knee joint.

Catalytic RNA molecules, or ribozymes, have generated significant interest as potential therapeutic agents for controlling gene expression. Although ribozymes have been shown to work in vitro and in cellular assays, there are no reports that demonstrate the efficacy of synthetic, stabilized ribozymes delivered in vivo. We are currently utilizing the rabbit model of interleukin 1-induced arthritis to assess the localization, stability, and efficacy of exogenous antistromelysin hammerhead ribozymes. The matrix metalloproteinase stromelysin is believed to be a key mediator in arthritic diseases. It seems likely therefore that inhibiting stromelysin would be a valid therapeutic approach for arthritis. We found that following intraarticular administration ribozymes were taken up by cells in the synovial lining, were stable in the synovium, and reduced synovial interleukin 1 alpha-induced stromelysin mRNA. This effect was demonstrated with ribozymes containing various chemical modifications that impart nuclease resistance and that recognize several distinct sites on the message. Catalytically inactive ribozymes were ineffective, thus suggesting a cleavage-mediated mechanism of action. These results suggest that ribozymes may be useful in the treatment of arthritic diseases characterized by dysregulation of metalloproteinase expression.

A comparison of the automatic shoulder belt/knee bolster restraint system with the lap and shoulder belt system in VW Rabbits. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Combined medical-engineering study of injury and damage to the knee joint in impact. Final report.

National Highway Safety Bureau, Washington, D.C.

An account of a new method of treating diseases of the joints of the knee and elbow : : in a letter to Mr. Percival Pott /

Mode of access: Internet.

Knee-high to a grasshopper,

Mode of access: Internet.

Low-bandwidth telerehabilitation for patients who have undergone total knee replacement: preliminary results

We have developed a low-bandwidth, Internet-based telerehabilitation system to provide outpatient rehabilitation to patients who have undergone total knee arthroplasty. The preliminary efficacy of this treatment programme in terms of both physical and functional objective outcome measures was assessed on 21 patients. Subjects receiving a six-week rehabilitation programme were randomized to the telerehabilitation system or the usual face-to-face method. The physical and functional improvements in the telerehabilitation group were similar to those in the control group. There was a non-significant trend for greater improvements in the telerehabilitation group for most outcome measurements. The telerehabilitation programme was well received by patients. The results of this study provide evidence for the efficacy of low-bandwidth telerehabilitation consultations.

A comparison of competing methods for the detection of surgical-site infections in patients undergoing total arthroplasty of the knee, partial and total arthroplasty of hip and femoral or similar vascular bypass

Recent research suggests that the retrospective review of the International Classification of Disease (ICD-9-CM) codes assigned to a patient episode will identify a similar number of healthcare-acquired surgical-site infections as compared with prospective surveillance by infection control practitioners (ICP). We tested this finding by replicating the methods for 380 surgical procedures. The sensitivity and specificity of the ICP undertaking prospective surveillance was 80% and 100%, and the sensitivity and specificity of the review of ICD-10-AM codes was 60% and 98.9%. Based on these results we do not support retrospective review of ICD-10-AM codes in preference prospective surveillance for SSI. (C) 2004 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

The effect of anticoagulation on the restoration of range of motion after total knee arthroplasty: Enoxaparin versus aspirin

Anticoagulation used for thromboembolic prophylaxis following total knee arthroplasty (TKA) could interfere with movement. This study compares the effect of 2 anticoagulants, enoxaparin and aspirin, on restoration of range of motion (ROM) after TKA. Two groups of 75 consecutive patients, matched for age, arthritic severity, and preoperative ROM, underwent TKA. Flexion and extension milestone measures were recorded daily. Results show a highly statistically significant difference (P

The nature of anterior knee pain following injection of hypertonic saline into the infrapatellar fat pad

The infrapatellar fat pad has been implicated as a possible source of anterior knee pain. This study examined the nature, distribution and time-course of experimentally induced pain in the infrapatellar fat pad. Hypertonic saline (5%) was injected into the medial fat pad of 11 healthy individuals with no history of knee pain. Severity of pain was assessed at rest and during activity using an 11 point numerical rating scale (NRS) at regular intervals over 15-30 min following injection. Participants described the size of the pain region from a series of different sized circles while the area and type of pain was established from a body chart and the McGill pain questionnaire. The effect of pain on temperature-pain threshold and sensory thresholds of the anterior knee was assessed. Participants generally reported a deep aching pain that peaked in severity around 3 min and gradually declined over 15 min. Pain levels were not altered by clinical manoeuvres designed to impinge the fat pad. The size of the pain region was related to pain intensity. Pain was most commonly felt in the region of the fat pad medial to the patella, although some individuals reported proximal referred pain as far as the groin region. Thermal and sensory thresholds were not altered at a region close to the injection site during the experimental pain. These results suggest that nociceptive stimulation of the infrapatellar fat pad may cause anterior knee pain that is not necessarily confined locally particularly if pain is severe. This has implications for the investigation of pathological structures in patients presenting clinically with anterior knee pain and provides an experimental model of anterior knee pain. (C) 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.

Rehabilitation after total knee replacement via low-bandwidth telemedicine: the patient and therapist experience

After a total knee replacement, inadequate rehabilitation is associated with poor physical outcomes and a reduced longevity of the knee prosthesis. We have developed a low-bandwidth telemedicine system to enable rehabilitation services to be delivered directly to the home of patients in rural and remote areas. We have examined the experience of clinical physiotherapists and of 31 participants who received treatment via the system. High levels of satisfaction were reported by participants (mean responses >7 on a 10 cm visual analogue scale). The service was found to be effective, safe and easy to use, and it integrated well into current clinical practice. The study demonstrates the potential for delivering physiotherapy services via low-bandwidth Internet connections.

The comprehensive osteoarthritis test: a simple index for measurement of treatment effects in clinical trials

Objective. To assess the measurement properties of a simple index of symptom severity in osteoarthritis (OA) of the hips and knees. Methods. Both the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the proposed new Comprehensive Osteoarthritis Test (COAT) instrument were completed weekly by 125 subjects in the context of a randomized, 12-week, 3 parallel-arm clinical trial. The reliabilities of the various scales were assessed on a weekly basis by use of Cronbach's alpha coefficients. The validity of the COAT total scale was assessed by correlation with the WOMAC total scale on a weekly basis with correlation coefficients, and in terms of the correlations between subject-level intercepts and slopes over time. The relative responsiveness of the WOMAC and COAT total scales was assessed using a multilevel (longitudinal) multivariate (WOMAC, COAT) linear model. Results. The WOMAC and COAT total scales were highly reliable (mean over weeks: WOMAC alpha = 0.98; COAT alpha = 0.97). The correlations between the WOMAC and COAT scales were very high (mean over weeks = 0.92; subject-level intercepts = 0.91, slopes = 0.88). The COAT total scale was significantly more responsive than the WOMAC total scale in the active treatment (34.8% improvement vs 26.8%; p = 0.002). Conclusion. The COAT total scale is simple to administer, reliable, valid, and responsive to treatment effects.