Hip offset and leg-length restoration in revision hip arthroplasty with a monoblock, hydroxyapatite-coated stem.

AIMS: Restoration of normal hip biomechanics in arthroplasty surgery is important in order to achieve good muscle function and joint stability. METHODS: In this retrospective cohort study, we examined the postoperative radiographs of 131 femoral revision arthroplasty procedures using a monoblock, fully hydroxyapatite (HA)-coated titanium stem. Femoral offset, modified-global offset and leg length were measured of the operated and contralateral hips. RESULTS: Femoral offset was restored to ±10 mm in 108 cases (82%), modified-global offset was restored ±10 mm in 93 cases (71%) and leg length was restored to ±10 mm in 102 cases (81%). There were 4 dislocations with a mean follow-up period of 38 months. CONCLUSIONS: Restoration of hip biomechanics is achievable with a monoblock stem and thus is a viable option in revision hip arthroplasty.

Survivorship and Radiological Analysis of a Monoblock, Hydroxyapatite-Coated Titanium Stem in Revision Hip Arthroplasty.

BACKGROUND: We evaluated the survivorship, incidence of complications, radiological subsidence, proximal stress shielding, and patient-reported outcomes of a conservative, monoblock, hydroxyapatite-coated femoral stem. METHODS: This retrospective cohort study reports on 254 revision hip arthroplasties between January 2006 and June 2016. The mean age of patients was 71 years. The mean length of follow-up was 62 months (range 12-152). RESULTS: There were 13 stem re-revisions: infection (4), periprosthetic fracture (4), aseptic stem loosening (3), stem fracture (1), and extended trochanteric osteotomy nonunion (1). Kaplan-Meier aseptic stem survivorship was 97.33% (confidence interval 94-100) at 6 years. There were 29 intraoperative fractures. There were 6 cases of subsidence greater than 10 mm; however, none required revision. Ninety-six percent of cases showed no proximal stress shielding. Thigh pain was reported in 3% of cases. CONCLUSION: This study confirms that this stem provides good survivorship at 6 years, acceptable complication rates, adequate proximal bone loading, low incidences of thigh pain, and reliable clinical performance in revision hip arthroplasty. KEY MESSAGE: A monoblock, fully hydroxyapatite-coated titanium stem is reliable in revision arthroplasty with mild-moderate femur deficiencies.

Loss-of-Huntingtin in Medial and Lateral Ganglionic Lineages Differentially Disrupts Regional Interneuron and Projection Neuron Subtypes and Promotes Huntington's Disease-Associated Behavioral, Cellular, and Pathological Hallmarks.

Emerging studies are providing compelling evidence that the pathogenesis of Huntington's disease (HD), a neurodegenerative disorder with frequent midlife onset, encompasses developmental components. Moreover, our previous studies using a hypomorphic model targeting huntingtin during the neurodevelopmental period indicated that loss-of-function mechanisms account for this pathogenic developmental component (Arteaga-Bracho et al., 2016). In the present study, we specifically ascertained the roles of subpallial lineage species in eliciting the previously observed HD-like phenotypes. Accordingly, we used the Cre-loxP system to conditionally ablate the murine huntingtin gene (Httflx) in cells expressing the subpallial patterning markers Gsx2 (Gsx2-Cre) or Nkx2.1 (Nkx2.1-Cre) in Httflx mice of both sexes. These genetic manipulations elicited anxiety-like behaviors, hyperkinetic locomotion, age-dependent motor deficits, and weight loss in both Httflx;Gsx2-Cre and Httflx;Nkx2.1-Cre mice. In addition, these strains displayed unique but complementary spatial patterns of basal ganglia degeneration that are strikingly reminiscent of those seen in human cases of HD. Furthermore, we observed early deficits of somatostatin-positive and Reelin-positive interneurons in both Htt subpallial null strains, as well as early increases of cholinergic interneurons, Foxp2+ arkypallidal neurons, and incipient deficits with age-dependent loss of parvalbumin-positive neurons in Httflx;Nkx2.1-Cre mice. Overall, our findings indicate that selective loss-of-huntingtin function in subpallial lineages differentially disrupts the number, complement, and survival of forebrain interneurons and globus pallidus GABAergic neurons, thereby leading to the development of key neurological hallmarks of HD during adult life. Our findings have important implications for the establishment and deployment of neural circuitries and the integrity of network reserve in health and disease.SIGNIFICANCE STATEMENT Huntington's disease (HD) is a progressive degenerative disorder caused by aberrant trinucleotide expansion in the huntingtin gene. Mechanistically, this mutation involves both loss- and gain-of-function mechanisms affecting a broad array of cellular and molecular processes. Although huntingtin is widely expressed during adult life, the mutant protein only causes the demise of selective neuronal subtypes. The mechanisms accounting for this differential vulnerability remain elusive. In this study, we have demonstrated that loss-of-huntingtin function in subpallial lineages not only differentially disrupts distinct interneuron species early in life, but also leads to a pattern of neurological deficits that are reminiscent of HD. This work suggests that early disruption of selective neuronal subtypes may account for the profiles of enhanced regional cellular vulnerability to death in HD.

Risk of subsidence and peri-prosthetic fractures using collared hydroxyapatite-coated stem for hip arthroplasty in the elderly.

INTRODUCTION: Subsidence has been noted with both cemented and uncemented stems in hip arthroplasty. On most occasions, it's minimal (i.e. less than 2 mm) and stabilises at 1 year. However, when its progressive and significant, it causes loss of length and horizontal offset, and when symptomatic warrants a revision. MATERIALS AND METHODS: A retrospective radiological review of the patient database was carried out to identify all patients with age ≥ 70 years who underwent elective hip arthroplasty using uncemented HA coated collared stem and had radiographs at 1 year follow up. A total of 176 patients were identified from January 2009 to June 2010. 2 independent investigators classified the proximal femur based on Dorr type and calculated the subsidence based on Engh and Massin method of calculating the distance between the tip of greater trochanter and shoulder of the prosthesis. RESULTS: 7 patients (4 Bs, 2 As, 1 C) had a subsidence of ≥ 2 mm (2-3.2 mm) at 1 year. None of them was symptomatic. 1 of them was secondary to a missed calcar crack and continued to subside for 9 mm before it stabilised on the lesser trochanter at 4 years follow up. There were Dorr 22 (12.5%) type A, 147(83.5%) type B and 7(4%) type C. The mean age was 77.4 years (70-91 years) and male: female ratio was 7:15. 3 patients had an intraoperative calcar crack requiring cabling. All were mobilised full weight-bearing postoperatively, and none had a subsidence of >2 mm at 1 year follow-up. DISCUSSION: Our subgroup analysis identified that subsidence can happen when the collar is "non-functional" and the initial press fit of the stem wasn't achieved. It can also occur in an event of calcar crack, which is missed intraoperatively. In cases of calcar crack which went on to have to cable during the primary procedure, it neither changed the post-operative rehabilitation nor did it show an increased risk of subsidence. CONCLUSION: A fully hydroxyapatite (HA) coated collared stem, when used in elderly age group for elective THR, has only 2% risk of intraoperative periprosthetic fracture. There's a 4% risk of radiologically significant subsidence (i.e. ≥2 mm), however, it has not proven to be clinically significant in our study. Dorr canal type had no bearing on either risk of periprosthetic fracture or subsidence. Collared stems did not have a statistically significant difference in risk of subsidence and peri-prosthetic fracture in comparison to un-collared stem, although there was a non-significant trend in favour of collar use.

Interprofessional Collaborative Practice: How Could Dentistry Participate?

There is a remarkable phenomenon occurring among health professionals: the development of ongoing, routine collaboration, both in educating the next generation of providers and in delivering care. These new approaches, commonly referred to as interprofessional education and interprofessional collaborative practice, have been introduced into academic health settings and delivery systems throughout the U.S. and the rest of the world; however, the full integration of dentistry in health care teams remains unrealized. In academic settings, dentistry has found ways to collaborate with the other health professions, but most practicing dentists still find themselves on the margins of new models of care delivery. This article provides a perspective on the history and context of the evolution of collaborative approaches to health care and proposes ways in which dentistry can participate more fully in the future.

The Sensory Striatum Is Permanently Impaired by Transient Developmental Deprivation.

Corticostriatal circuits play a fundamental role in regulating many behaviors, and their dysfunction is associated with many neurological disorders. In contrast, sensory disorders, like hearing loss (HL), are commonly linked with processing deficits at or below the level of the auditory cortex (ACx). However, HL can be accompanied by non-sensory deficits, such as learning delays, suggesting the involvement of regions downstream of ACx. Here, we show that transient developmental HL differentially affected the ACx and its downstream target, the sensory striatum. Following HL, both juvenile ACx layer 5 and striatal neurons displayed an excitatory-inhibitory imbalance and lower firing rates. After hearing was restored, adult ACx neurons recovered balanced excitatory-inhibitory synaptic gain and control-like firing rates, but striatal neuron synapses and firing properties did not recover. Thus, a brief period of abnormal cortical activity may induce cellular impairments that persist into adulthood and contribute to neurological disorders that are striatal in origin.

Will Large DSO-Managed Group Practices Be the Predominant Setting for Oral Health Care by 2025? Two Viewpoints: Viewpoint 1: Large DSO-Managed Group Practices Will Be the Setting in Which the Majority of Oral Health Care Is Delivered by 2025 and Viewpoint 2: Increases in DSO-Managed Group Practices Will Be Offset by Models Allowing Dentists to Retain the Independence and Freedom of a Traditional Practice.

This Point/Counterpoint article discusses the transformation of dental practice from the traditional solo/small-group (partnership) model of the 1900s to large Dental Support Organizations (DSO) that support affiliated dental practices by providing nonclinical functions such as, but not limited to, accounting, human resources, marketing, and legal and practice management. Many feel that DSO-managed group practices (DMGPs) with employed providers will become the setting in which the majority of oral health care will be delivered in the future. Viewpoint 1 asserts that the traditional dental practice patterns of the past are shifting as many younger dentists gravitate toward employed positions in large group practices or the public sector. Although educational debt is relevant in predicting graduates' practice choices, other variables such as gender, race, and work-life balance play critical roles as well. Societal characteristics demonstrated by aging Gen Xers and those in the Millennial generation blend seamlessly with the opportunities DMGPs offer their employees. Viewpoint 2 contends the traditional model of dental care delivery-allowing entrepreneurial practitioners to make decisions in an autonomous setting-is changing but not to the degree nor as rapidly as Viewpoint 1 professes. Millennials entering the dental profession, with characteristics universally attributed to their generation, see value in the independence and flexibility that a traditional practice allows. Although DMGPs provide dentists one option for practice, several alternative delivery models offer current dentists and future dental school graduates many of the advantages of DMGPs while allowing them to maintain the independence and freedom a traditional practice provides.

Continued Competency Assessment. Its history and role in the health professions.

The concept of an implicit contract between the public and a profession is used as a foundation for the responsibility for professions to develop continued competency assessment and enforcement mechanisms that ensure that the public can expect safe and competent care. The literature in medicine, other health professions, and from other countries is reviewed. There is concern that the fact of continued practice alone does not ensure continued competency in a changing profession and that mandatory continuing education attendance is insufficient. Public-interest groups that have looked at the issue report greater concern among the public than in the professions that effective continued competency mechanism be established and that action be taken where practitioners who are not competent are identified. There has been substantial develop of a variety of approaches in medicine, especially through the specialty boards which account for the majority of medical practitioners, in other health fields, and in several countries.

Continued Competency Assessment. Does it have a necessary role in dentistry?

The responsibility of regulating dental practice in the interest of public safety is vested in the states and is exercised through delegated initial competency evaluation of new graduates, continuing education attendance requirements, and investigations of complaints. Questions have been raised over whether this model can demonstrate effectiveness and whether it ensures continuous professional growth or only identifies the clearly incompetent. There have been reports identifying desireable standards and there are pilot programs for continued competency in dentistry. These are reviewed. A set of criteria for any effective program is presented.

Subsidence of the Corail femoral component in the elderly. A retrospective radiological review.

206 patients age 70 years or older who underwent uncemented total hip arthroplasty (THA) using the Corail stem were studied. Radiographs taken post operatively and at one year were measured for subsidence of the stem. 13 patients had subsidence of the femoral stem of more than 2 mm. 5 of these were associated with fractures (mean age 78.06 years--average subsidence 14.52 mm), while 8 did not have associated fractures (mean age 77.43 years--average subsidence 4.99 mm). These 13 patients were then followed up for an average of 25 months (with fractures) and 26.88 months (without fractures). Radiographs were taken and measured for further subsidence using a VIDAR scanner. There was no evidence of further subsidence in any of the 13 patients, and all the stems had stabilised at one year with good evidence of osteointegration. None of the patients required revision. Uncemented THA using the Corail stem can be employed in this age group and poor bone quality is not a contraindication.

Assessing dental students' competence: best practice recommendations in the performance assessment literature and investigation of current practices in predoctoral dental education.

In this article, the Task Force on Student Outcomes Assessment of the American Dental Education Association's Commission on Change and Innovation in Dental Education describes the current status of student outcomes assessment in U.S. dental education. This review is divided into six sections. The first summarizes the literature on assessment of dental students' performance. Section two discusses catalysts, with a focus on problem-based learning, for development of new assessment methods, while the third section presents several resources and guides that can be used to inform selection of assessment techniques for various domains of competence. The fourth section describes the methodology and results of a 2008 survey of current assessment practices in U.S. dental schools. In the fifth section, findings from this survey are discussed within the context of competency-based education, the educational model for the predoctoral curriculum endorsed by the American Dental Education Association and prescribed by the Commission on Dental Accreditation. The article concludes with a summary of assessments recommended as optimal strategies to measure three components of professional competence based on the triangulation model. The survey of assessment practices in predoctoral education was completed by 931 course directors, representing 45 percent of course directors nationwide, from fifty-three of the fifty-six U.S. dental schools. Survey findings indicate that five traditional mainstays of student performance evaluation-multiple-choice testing, lab practicals, daily grades, clinical competency exams, and procedural requirements-still comprise the primary assessment tools in dental education. The survey revealed that a group of newer assessment techniques, although frequently identified as best practices in the literature and commonly used in other areas of health professions education, are rarely employed in predoctoral dental education.

Does faculty development enhance teaching effectiveness?

Academic dentists and members of the practice community have been hearing, for more than a decade, that our educational system is in trouble and that the profession has lost its vision and may be wavering in the achievement of its goals. A core of consistently recommended reforms has framed the discussion of future directions for dental education, but as yet, most schools report little movement toward implementation of these reforms in spite of persistent advocacy. Provision of faculty development related to teaching and assessment strategies is widely perceived to be the essential ingredient in efforts to introduce new curricular approaches and modify the educational environment in academic dentistry. Analyses of the outcomes of efforts to revise health professions curricula have identified the availability and effectiveness of faculty development as a predictor of the success or failure of reform initiatives. This article will address faculty development for purposes of enhancing teaching effectiveness and preparing instructors for potential new roles associated with curriculum changes. Its overall purpose is to provide information and insights about faculty development that may be useful to dental schools in designing professional growth opportunities for their faculty. Seven questions are addressed: 1) What is faculty development? 2) How is faculty development accomplished? 3) Why is faculty development particularly important in dental education? 4) What happens when faculty development does not accompany educational reform? 5) Why are teaching attitudes and behaviors so difficult to change? 6) What outcomes can be expected from faculty development? and 7) What does the available evidence tell us about the design of faculty development programs? Evidence from systematic reviews pertaining to the teaching of evidence-based dentistry, strategies for continuing professional education, and the Best Evidence in Medical Education review of faculty development outcomes are presented to answer this question: does faculty development enhance teaching effectiveness? Characteristics consistently associated with effective faculty development are described.

The dental education environment.

The second in a series of perspectives from the ADEA Commission on Change and Innovation in Dental Education (CCI), this article presents the CCI's view of the dental education environment necessary for effective change. The article states that the CCI's purpose is related to leading and building consensus in the dental community to foster a continuous process of innovative change in the education of general dentists. Principles proposed by CCI to shape the dental education environment are described; these are critical thinking, lifelong learning, humanistic environment, scientific discovery and integration of knowledge, evidence-based oral health care, assessment, faculty development, and the health care team. The article also describes influences external to the academic dental institutions that are important for change and argues that meaningful and long-lasting change must be systemic in nature. The CCI is ADEA's primary means to engage all stakeholders for the purpose of educating lifelong learners to provide evidence-based care to meet the needs of society.

The case for change in dental education.

This article introduces a series of white papers developed by the ADEA Commission on Change and Innovation (CCI) to explore the case for change in dental education. This preamble to the series argues that there is a compelling need for rethinking the approach to dental education in the United States. Three issues facing dental education are explored: 1) the challenging financial environment of higher education, making dental schools very expensive and tuition-intensive for universities to operate and producing high debt levels for students that limit access to education and restrict career choices; 2) the profession's apparent loss of vision for taking care of the oral health needs of all components of society and the resultant potential for marginalization of dentistry as a specialized health care service available only to the affluent; and 3) the nature of dental school education itself, which has been described as convoluted, expensive, and often deeply dissatisfying to its students.

Educational strategies associated with development of problem-solving, critical thinking, and self-directed learning.

This article was developed for the Commission on Change and Innovation in Dental Education (CCI), established by the American Dental Education Association. CCI was created because numerous organizations within organized dentistry and the educational community have initiated studies or proposed modifications to the process of dental education, often working to achieve positive and desirable goals but without coordination or communication. The fundamental mission of CCI is to serve as a focal meeting place where dental educators and administrators, representatives from organized dentistry, the dental licensure community, the Commission on Dental Accreditation, the ADA Council on Dental Education and Licensure, and the Joint Commission on National Dental Examinations can meet and coordinate efforts to improve dental education and the nation's oral health. One of the objectives of the CCI is to provide guidance to dental schools related to curriculum design. In pursuit of that objective, this article summarizes the evidence related to this question: What are educational best practices for helping dental students acquire the capacity to function as an entry-level general dentist or to be a better candidate to begin advanced studies? Three issues are addressed, with special emphasis on the third: 1) What constitutes expertise, and when does an individual become an expert? 2) What are the differences between novice and expert thinking? and 3) What educational best practices can help our students acquire mental capacities associated with expert function, including critical thinking and self-directed learning? The purpose of this review is to provide a benchmark that faculty and academic planners can use to assess the degree to which their curricula include learning experiences associated with development of problem-solving, critical thinking, self-directed learning, and other cognitive skills necessary for dental school graduates to ultimately become expert performers as they develop professionally in the years after graduation.