Femorotibial angle scan-rescan reproducibility: A high-precision calculation on a large cohort.

PURPOSE: Femorotibial angle (FTA) is a convenient measure of coronal knee alignment that can be extracted from a short knee radiograph, avoiding the additional radiation exposure and specialist equipment required for full-leg radiographs. While intra- and inter-reader reproducibility from the same image has been reported, the full scan-rescan reproducibility across images, as calculated in this study, has not. METHODS: In this study, 4589 FTA measurement pairs from 2586 subjects acquired a year apart were used to estimate FTA scan-rescan reproducibility using data from the Osteoarthritis Initiative. Subjects with radiographic progression of osteoarthritis or other conditions that may cause a change in coronal knee alignment were excluded. Measurement pairs were analysed using paired-samples  t $t$ tests to detect differences and compared to symptomatic changes in Western Ontario and McMaster Universities Arthritis Index scores for joint pain, stiffness and physical function to detect correlations. RESULTS: The 95% limit of agreement and the paired-samples correlation were calculated with high precision to be [-1.76°, +1.78°] and 0.938, considerably worse than the corresponding figures for intra- and inter-reader reproducibility, without relation to symptomatic or radiographic changes in knee condition. This error will weakly attenuate R 2 ${R}^{2}$ and r $r$ values from their true values in correlative studies involving FTA. The realistic maximum value for R 2 ${R}^{2}$ is 87% and for Pearson's r $r$ is 93%. CONCLUSION: The scan-rescan reproducibility in FTA is almost double the intra- and inter-reader reliability from a single scan. At almost ±2° accuracy, FTA is inappropriate for surgical use, but it is sufficiently reproducible to produce good correlations in studies predicting disease incidence and progression. LEVEL OF EVIDENCE: Level II, retrospective study.

Passive Biotelemetric Detection of Tibial Debonding in Wireless Battery-Free Smart Knee Implants.

Aseptic loosening is the dominant failure mechanism in contemporary knee replacement surgery, but diagnostic techniques are poorly sensitive to the early stages of loosening and poorly specific in delineating aseptic cases from infections. Smart implants have been proposed as a solution, but incorporating components for sensing, powering, processing, and communication increases device cost, size, and risk; hence, minimising onboard instrumentation is desirable. In this study, two wireless, battery-free smart implants were developed that used passive biotelemetry to measure fixation at the implant-cement interface of the tibial components. The sensing system comprised of a piezoelectric transducer and coil, with the transducer affixed to the superior surface of the tibial trays of both partial (PKR) and total knee replacement (TKR) systems. Fixation was measured via pulse-echo responses elicited via a three-coil inductive link. The instrumented systems could detect loss of fixation when the implants were partially debonded (+7.1% PKA, +32.6% TKA, both p < 0.001) and fully debonded in situ (+6.3% PKA, +32.5% TKA, both p < 0.001). Measurements were robust to variations in positioning of the external reader, soft tissue, and the femoral component. With low cost and small form factor, the smart implant concept could be adopted for clinical use, particularly for generating an understanding of uncertain aseptic loosening mechanisms.

Operational patient care pathway: building pragmatic medical interoperability through health engagements.

The future operational demand for medical support in Western militaries will likely outstrip available resources, necessitating burden-sharing through medical interoperability with allies and partners. However, the current North Atlantic Treaty Organization (NATO) model of interoperability through standardisation, while achieving high levels of commonality and integration along the operational patient care pathway (OPCP), is high-cost and resource-intensive. We have termed this model assured interoperability. Assured interoperability, while applicable to well-established partnerships with high-resource nations, is unlikely to be feasible when working with resource-limited partners or, potentially, when in a sustained conflict with a near-peer adversary. In these circumstances, there will be a requirement to develop a far less resource-intensive model of medical interoperability with lower levels of commonality, assurance and standardisation than assured interoperability, but that provides a 'good enough' OPCP for the operational context. We have termed this pragmatic interoperability. By considering these two types of interoperability, the complete continuum of medical interoperability can be mapped with the full spectrum of partners demonstrating increasing levels of interoperability from pragmatic through to assured interoperability, integrateability and interchangeability, reducing the gap between demand and provision of medical support for operations, increasing operational resilience. This is a paper commissioned as a part of the Defence Engagement special issue of BMJ Military Health.

Active osseointegration in an ex vivo porcine bone model.

Achieving osseointegration is a fundamental requirement for many orthopaedic, oral, and craniofacial implants. Osseointegration typically takes three to 6 months, during which time implants are at risk of loosening. The aim of this study was to investigate whether osseointegration could be actively enhanced by delivering controllable electromechanical stimuli to the periprosthetic bone. First, the osteoconductivity of the implant surface was confirmed using an in vitro culture with murine preosteoblasts. The effects of active treatment on osseointegration were then investigated in a 21-day ex vivo model with freshly harvested cancellous bone cylinders (n = 24; Ø10 mm × 5 mm) from distal porcine femora, with comparisons to specimens treated by a distant ultrasound source and static controls. Cell viability, proliferation and distribution was evident throughout culture. Superior ongrowth of tissue onto the titanium discs during culture was observed in the actively stimulated specimens, with evidence of ten-times increased mineralisation after 7 and 14 days of culture (p < 0.05) and 2.5 times increased expression of osteopontin (p < 0.005), an adhesive protein, at 21 days. Moreover, histological analyses revealed increased bone remodelling at the implant-bone interface in the actively stimulated specimens compared to the passive controls. Active osseointegration is an exciting new approach for accelerating bone growth into and around implants.

Wireless implantable bioelectronics with a direct electron transfer lactate enzyme for detection of surgical site infection in orthopaedics.

Periprosthetic infection is one of the most devastating complications following orthopaedic surgery. Rapid detection of an infection can change the treatment pathway and improve outcomes for the patient. In here, we propose a miniaturized lactate biosensor developed on a flexible substrate and integrated on a small-form bone implant to detect infection. The methods for lactate biosensor fabrication and integration on a bone implant are fully described within this study. The system performance was comprehensively electrochemically characterised, including with L-lactate solutions prepared in phosphate-buffered saline and culture medium, and interferents such as acetaminophen and ascorbic acid. A proof-of-concept demonstration was then conducted with ex vivo ovine femoral heads incubated with and without exposure to Staphylococcus epidermidis. The sensitivity, current density and limit-of-detection levels achieved by the biosensor were 1.25 µA mM-1, 1.51 µA.M-1.mm-2 and 66 µM, respectively. The system was insensitive to acetaminophen, while sensitivity to ascorbic acid was half that of the sensitivity to L-lactate. In the ex vivo bone model, S. epidermidis infection was detected within 5 h of implantation, while the control sample led to no change in the sensor readings. This pioneering work demonstrates a pathway to improving orthopaedic outcomes by enabling early infection diagnosis.

Atrogin-1 promotes muscle homeostasis by regulating levels of endoplasmic reticulum chaperone BiP.

Skeletal muscle wasting results from numerous pathological conditions affecting both the musculoskeletal and nervous systems. A unifying feature of these pathologies is the upregulation of members of the E3 ubiquitin ligase family, resulting in increased proteolytic degradation of target proteins. Despite the critical role of E3 ubiquitin ligases in regulating muscle mass, the specific proteins they target for degradation and the mechanisms by which they regulate skeletal muscle homeostasis remain ill-defined. Here, using zebrafish loss-of-function models combined with in vivo cell biology and proteomic approaches, we reveal a role of atrogin-1 in regulating the levels of the endoplasmic reticulum chaperone BiP. Loss of atrogin-1 resulted in an accumulation of BiP, leading to impaired mitochondrial dynamics and a subsequent loss in muscle fiber integrity. We further implicated a disruption in atrogin-1-mediated BiP regulation in the pathogenesis of Duchenne muscular dystrophy. We revealed that BiP was not only upregulated in Duchenne muscular dystrophy, but its inhibition using pharmacological strategies, or by upregulating atrogin-1, significantly ameliorated pathology in a zebrafish model of Duchenne muscular dystrophy. Collectively, our data implicate atrogin-1 and BiP in the pathogenesis of Duchenne muscular dystrophy and highlight atrogin-1's essential role in maintaining muscle homeostasis.

Global Health Education and Latin America / Educación en Salud Global y América Latina

I am writing to commend your Journal for its fine work of informing its readership of the important developments occurring in the health sciences. For eight years I lived and worked in Latin America, including time spent in Colombia working with colleagues to estimate future requirements for health personnel. I became acquainted with the journal through a recent collaboration with Prof. Alfonso J. Rodriguez-Morales and a student, Mr. Daniel Tobon Garcia, in the drafting of a book that will soon be published to provide guidance to students and faculty committed to improving their academic programs as they relate to global health. This much expanded 2nd edition, Developing Global Health Programming: A Guidebook for Medical and Professional Schools, will soon be available both in printed and online format. The importance of training health profession students to have the knowledge, skills and experiences that they will require to address effectively the health care needs of the future is becoming ever more evident. Health care providers must address not only the specific complaints of individual patients but also the many and profound 'upstream' risk factors such as poverty, marginalization, unhealthy behaviors, limited education, cultural barriers, etc., that contribute to illness, and with the resource and organizational constraints that limit the effectiveness of the health systems within which they work.

Les escribo para felicitar a su revista por su excelente labor de informar a sus lectores de los importantes avances que se producen en las ciencias de la salud. Durante ocho años viví y trabajé en América Latina, incluyendo el tiempo que pasé en Colombia trabajando con colegas para estimar las futuras necesidades de personal sanitario. Conocí la revista a través de una reciente colaboración con el profesor Alfonso J. Rodríguez-Morales y un estudiante, el Sr. Daniel Tobón García, en la redacción de un libro que se publicará próximamente para orientar a los estudiantes y profesores comprometidos con la mejora de sus programas académicos en relación con la salud global. Esta 2ª edición, muy ampliada, Developing Global Health Programming: A Guidebook for Medical and Professional Schools, estará pronto disponible tanto en formato impreso como en línea. Cada vez es más evidente la importancia de formar a los estudiantes de las profesiones sanitarias para que tengan los conocimientos, las habilidades y las experiencias que necesitarán para abordar eficazmente las necesidades de atención sanitaria del futuro. Los profesionales de la salud deben abordar no sólo las dolencias específicas de los pacientes individuales, sino también los numerosos y profundos factores de riesgo "ascendentes", como la pobreza, la marginación, los comportamientos poco saludables, la educación limitada, las barreras culturales, etc., que contribuyen a la enfermedad, y con las restricciones de recursos y organizativas que limitan la eficacia de los sistemas sanitarios en los que trabajan.

Orientaciones para planificadores de personal de salud

Planners of health workforces are beset by numerous imponderables but this is not the only reason why their work frequently meets with failure: too often they overlook the most basic principles of workforce planning. The present article reminds us what these are

Health manpower in Peru: a case study in planning

The author opens his study with an analysis of the demand - its conceptualization, evaluation and projection. Dissatisfied with the traditional method of using labor relations as a basis for planning, Dr. Hall focuses on the demand for services, the potential to increase productivity and economic viability

Demand analysis: general considerations

Projection of health manpower requirements presupposes that a suitable method exists to determine the demand that the future population of a region or nation will make for health services. Methods in use for this purpose vary markedly from country to country, and techniques for combining the merits of each one into a single a single formula are not available. This chapter considers the advantages and limitations of three approaches to the measurement and projection of demand, and outlines the method used in the Peru study (AU)

Pharmacists

A career in pharmacy held little attraction for Peruvians in the mid-1960's. At the time of survey, the three schools of pharmacy had twice as many first-year vacancies as qualified applicants. Even many graduates find the career unpromising and currently almost one out of every two leaves the profession (AU)

Nurses

It is widely recognized tha most of Peru's hospitals and outpatient facilities are inefficient. In many general hospitals the average duration of patient stay is over twenty days and only rarely is it less than fifteen. The evidence presented in this chapter suggested that doctors attending ambulatory patients see, on the average, fewer than three patients per hour. Auxiliary nurse effectiveness, too, is considered low. In each case one of the most important factors for the low productivity is the lack of a sufficient supply of professional nursing personnel (AU)

Professional Midwives

Almost four out of every five Peruvian babies are ushered into the world with the assistance of a midwife. But only one of these four is entrusted to the hands of a midwife trained in asepsis and the other basic elements of modern maternity care. The fetal and maternal loss that results from unskilled maternity care is enormous, and all the more tragic because it could so easily be prevented. Should the manpower study consider only the supply of, and demand for, trained midwives, or should the untrained empiric also be included? (AU) These issues will be discussed in this chapter.

The supply of other categories of health manpower

This chapter analysis the professional health personnel wich represent a costly investment and all measures possible that should be taken to ensure their efficient utilization. In recent years Peru has made a concerted effort to improve health facilities, but relatively little importance has been attributed to the preparation of adequate numbers of technical and auxiliary personnel

Issues in health manpower planning

Manpower policy cannot be divorced from health care organization. Organization affects the efficiency with which services are produced, and their cost in manpower, money, and materials. As has been evident throughout this monograph and will be discussed in this chapter