Cost-Effectiveness of Dual Mobility and a Value-Based Algorithm of Utilization.

Hip dislocation remains a major concern following total hip arthroplasty due to its high frequency and economic burden. This article evaluates the cost-effectiveness regarding dual mobility as an alternative to standard implant designs. A review of literature analyzing the PubMed Central database was undertaken using the following terms in the primary query: dual mobility, cost-effectiveness, cost-analysis, or economic analysis. Dual mobility systems may be a cost-effective alternative when the price of the implant does not exceed the traditional system by $1023. Dual mobility cups may be an essential component for the future success of value-based total hip arthroplasty.

Cost-comparison of third generation transcatheter aortic valve implantation (TAVI) devices in the German Health Care System.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has a substantial impact on daily cardiovascular care delivery based on issues such as cost effectiveness and economic value within a restricted health care budget. Until now, potential financial benefits of third generation valve models have not been evaluated in a real-world setting. METHODS AND RESULTS: We identified 204 eligible patients (Jan 2014-Sep 2016) who either received the balloon-expandable Edwards Sapien 3 (ES3) or the self-expandable Medtronic Evolut R (MER). Baseline information, procedural characteristics, 30-day outcome as well as in-hospital costs and reimbursement were collected and analyzed. The major cost driver was initial valve-kit costs with a significantly higher amount in the ES3 group, which was set at 0 with the lower price (ES3/MER: +4390.0€â€¯±â€¯3.807.0 vs. 0.0€â€¯±â€¯734.1; p < 0.01). However, initial valve-kit costs were balanced by additional material costs in the MER cohort. Overall costs did not differ significantly between valve models (ES3/MER: x + 13.808.0€â€¯±â€¯5.595.0 vs. x + 10.681.0€â€¯±â€¯4.518.0; p = 0.6885) and reimbursement was moderate (ES3/MER: 1.649.7€ vs. 4776.7€). CONCLUSION: Quality, success rate, and costs were comparable between third generation devices. Initial valve-kit costs were significantly higher in the ES3 group, whereas overall costs did not significantly differ between the two valve types.

Ultra-High-Resolution Computed Tomography Angiography for Assessment of Coronary Artery Stenosis.

BACKGROUND: Limitations of coronary computed tomography (CTA) include false-positive stenosis at calcified lesions and assessment of in-stent patency. A prototype of ultra-high resolution computed tomography (U-HRCT: 1,792 channels and 0.25-mm slice thickness×128 rows) with improved spatial resolution was developed. We assessed the diagnostic accuracy of coronary artery stenosis using U-HRCT.Methods and Results:Seventy-nine consecutive patients who underwent CTA using U-HRCT were prospectively included. Coronary artery stenosis was graded from 0 (no plaque) to 5 (occlusion). Stenosis grading at 102 calcified lesions was compared between U-HRCT and conventional-resolution CT (CRCT: 896 channels and 0.5-mm slice thickness×320 rows). Median stenosis grading at calcified plaque was significantly improved on U-HRCT compared with CRCT (1; IQR, 1-2 vs. 2; IQR, 1-3, P<0.0001). Assessability of in-stent lumen was evaluated on U-HRCT in 79 stents. Stent strut thickness and luminal diameter were quantitatively compared between U-HRCT and CRCT. Of 79 stents, 83.5% were assessable on U-HRCT; 80% of stents with diameter 2.5 mm were regarded as assessable. On U-HRCT, stent struts were significantly thinner (median, 0.78 mm; IQR, 0.7-0.83 mm vs. 0.83 mm; IQR, 0.75-0.92 mm, P=0.0036), and in-stent lumens were significantly larger (median, 2.08 mm; IQR, 1.55-2.51 mm vs. 1.74 mm; IQR, 1.31-2.06 mm, P<0.0001) than on CRCT. CONCLUSIONS: U-HRCT with improved spatial resolution visualized calcified lesions with fewer artifacts. The in-stent lumen of stents with diameter ≥2.5 mm was assessable on U-HRCT.

Three-dimensional printing in cardiology: Current applications and future challenges.

Three-dimensional (3D) printing has attracted a huge interest in recent years. Broadly speaking, it refers to the technology which converts a predesigned virtual model to a touchable object. In clinical medicine, it usually converts a series of two-dimensional medical images acquired through computed tomography, magnetic resonance imaging or 3D echocardiography into a physical model. Medical 3D printing consists of three main steps: image acquisition, virtual reconstruction and 3D manufacturing. It is a promising tool for preoperative evaluation, medical device design, hemodynamic simulation and medical education, it is also likely to reduce operative risk and increase operative success. However, the most relevant studies are case reports or series which are underpowered in testing its actual effect on patient outcomes. The decision of making a 3D cardiac model may seem arbitrary since it is mostly based on a cardiologist's perceived difficulty in performing an interventional procedure. A uniform consensus is urgently necessary to standardize the key steps of 3D printing from imaging acquisition to final production. In the future, more clinical trials of rigorous design are possible to further validate the effect of 3D printing on the treatment of cardiovascular diseases. (Cardiol J 2017; 24, 4: 436-444).

Prosthetic model, but not stiffness or height, affects the metabolic cost of running for athletes with unilateral transtibial amputations.

Running-specific prostheses enable athletes with lower limb amputations to run by emulating the spring-like function of biological legs. Current prosthetic stiffness and height recommendations aim to mitigate kinematic asymmetries for athletes with unilateral transtibial amputations. However, it is unclear how different prosthetic configurations influence the biomechanics and metabolic cost of running. Consequently, we investigated how prosthetic model, stiffness, and height affect the biomechanics and metabolic cost of running. Ten athletes with unilateral transtibial amputations each performed 15 running trials at 2.5 or 3.0 m/s while we measured ground reaction forces and metabolic rates. Athletes ran using three different prosthetic models with five different stiffness category and height combinations per model. Use of an Ottobock 1E90 Sprinter prosthesis reduced metabolic cost by 4.3 and 3.4% compared with use of Freedom Innovations Catapult [fixed effect (ß) = -0.177; P < 0.001] and Össur Flex-Run (ß = -0.139; P = 0.002) prostheses, respectively. Neither prosthetic stiffness (P ≥ 0.180) nor height (P = 0.062) affected the metabolic cost of running. The metabolic cost of running was related to lower peak (ß = 0.649; P = 0.001) and stance average (ß = 0.772; P = 0.018) vertical ground reaction forces, prolonged ground contact times (ß = -4.349; P = 0.012), and decreased leg stiffness (ß = 0.071; P < 0.001) averaged from both legs. Metabolic cost was reduced with more symmetric peak vertical ground reaction forces (ß = 0.007; P = 0.003) but was unrelated to stride kinematic symmetry (P ≥ 0.636). Therefore, prosthetic recommendations based on symmetric stride kinematics do not necessarily minimize the metabolic cost of running. Instead, an optimal prosthetic model, which improves overall biomechanics, minimizes the metabolic cost of running for athletes with unilateral transtibial amputations.NEW & NOTEWORTHY The metabolic cost of running for athletes with unilateral transtibial amputations depends on prosthetic model and is associated with lower peak and stance average vertical ground reaction forces, longer contact times, and reduced leg stiffness. Metabolic cost is unrelated to prosthetic stiffness, height, and stride kinematic symmetry. Unlike nonamputees who decrease leg stiffness with increased in-series surface stiffness, biological limb stiffness for athletes with unilateral transtibial amputations is positively correlated with increased in-series (prosthetic) stiffness.

Implant options for the treatment of intertrochanteric fractures of the hip: rationale, evidence, and recommendations.

AIMS: The aim of this paper is to review the evidence relating to the anatomy of the proximal femur, the geometry of the fracture and the characteristics of implants and methods of fixation of intertrochanteric fractures of the hip. MATERIALS AND METHODS: Relevant papers were identified from appropriate clinical databases and a narrative review was undertaken. RESULTS: Stable, unstable, and subtrochanteric intertrochanteric fractures vary widely in their anatomical and biomechanical characteristics, as do the implants used for their fixation. The optimal choice of implant addresses the stability of the fracture and affects the outcome. CONCLUSION: The treatment of intertrochanteric fractures of the hip has evolved along with changes in the design of the implants used to fix them, but there remains conflicting evidence to guide the choice of implant. We advocate fixation of 31A1 fractures with a sliding hip screw and all others with an intramedullary device. Cite this article: Bone Joint J 2017;99-B:128-33.

Regulatory Considerations in the Design and Manufacturing of Implantable 3D-Printed Medical Devices.

Three-dimensional (3D) printing, or additive manufacturing, technology has rapidly penetrated the medical device industry over the past several years, and innovative groups have harnessed it to create devices with unique composition, structure, and customizability. These distinctive capabilities afforded by 3D printing have introduced new regulatory challenges. The customizability of 3D-printed devices introduces new complexities when drafting a design control model for FDA consideration of market approval. The customizability and unique build processes of 3D-printed medical devices pose unique challenges in meeting regulatory standards related to the manufacturing quality assurance. Consistent material powder properties and optimal printing parameters such as build orientation and laser power must be addressed and communicated to the FDA to ensure a quality build. Postprinting considerations unique to 3D-printed devices, such as cleaning, finishing and sterilization are also discussed. In this manuscript we illustrate how such regulatory hurdles can be navigated by discussing our experience with our group's 3D-printed bioresorbable implantable device.

In vitro assessment of the influence of aortic annulus ovality on the hydrodynamic performance of self-expanding transcatheter heart valve prostheses.

BACKGROUND: Although CT-studies as well as intraoperative analyses have described broad anatomic variations of the aortic annulus, which is predominantly found non-circular, commercially available transcatheter aortic heart valve prostheses are circular. In this study, we hypothesize that the in vitro hydrodynamic function of a self-expanding transcatheter heart valve (Medtronic CoreValve) assessed in an oval compartment representing the aortic annulus will differ from the conventionally used circular compartment. METHODS: Medtronic CoreValve prostheses were tested in specifically designed and fabricated silicone compartments with three degrees of defined ovalities. The measurements were performed in a left heart simulator at three different flow rates. In this setting, regurgitation flow, effective orifice area, and systolic pressure gradient across the valve were determined. In addition, high speed video recordings were taken to investigate leaflet kinematics. RESULTS: The pressure difference across the prosthesis increased with rising ovality. The effective orifice areas were only slightly impacted. The analyses of the regurgitation showed minor changes and partially lower regurgitation when switching from round to slightly oval settings, followed by strong increases for further ovalization. The high speed videos show minor central leakage and impaired leaflet apposition for strong ovalities, but no leaflet/stentframe contact in any setting. CONCLUSION: This study quantifies the influence of oval expansion of transcatheter heart valve prostheses on their hydrodynamic performance. While slight ovalities were well tolerated by a self-expanding prosthesis, more significant ovality led to worsening of prosthesis function and regurgitation.

"Look and feel your best": representations of artificial limb users in prosthetic company advertisements.

PURPOSE: Artificial limbs (prosthetics) are considered important for keeping the person physically active and avoiding an array of negative health outcomes associated with non-use. Increasingly, the potential users of these limbs are the focus of commercial prosthetic company advertisements. It has been argued that it is important to examine such media representations, not least because people's beliefs regarding health and illness are often forged from the discourses and constructions available to them in such material, but because these representations mediate individual lived experience. METHOD: This article provides a thematic analysis, drawing upon discourse analysis and semiotics, of textual-pictorial representations of artificial limb users in the advertisements of prosthetic companies. The data set was comprised of advertisements that appeared over a 2-year period in inMotion, an international magazine produced and distributed by a major amputee advocacy group. RESULTS: The findings indicate that dominant societal constructions of work, gender and family are drawn on in depicting artificial limb users. These offer generally positive representations that draw on socially pervasive stereotypes. CONCLUSIONS: The findings are discussed in relation to literature concerning the experience and meaning of prosthesis use, and the implications for health professionals working with this group are set out. Implications for Rehabilitation People who lose a limb are increasingly being exposed to advertisements from prosthetic companies. Such advertisements have the potential to foster unrealistic expectations regarding rehabilitation following amputation. Healthcare professionals need to be mindful of how these advertisements mediate lived experience and impact on rehabilitation when planning personal care plans.

The influence of control format and hand design in single axis myoelectric hands: assessment of functionality of prosthetic hands using the Southampton Hand Assessment Procedure.

BACKGROUND: It is important to measure the functional capabilities of a prosthesis in order to make informed decisions when prescribing a limb. OBJECTIVES: To measure the functional of a range of commercial single degree of freedom hands to act as baseline comparisons for the newer multi-axis hands. STUDY DESIGN: Form-board and self-timed tasks. METHOD: Repeated measures with a single subject using a validated assessment tool. The test measured the function of three conventional, single axis, powered hands, controlled by five different myocontroller formats. One transcarpal device was also tested. RESULTS: When controlled by the same type of two channel myoelectric controllers (proportional voluntary opening, voluntary closing) the overall functional scores were similar for all similar types of hand, with a maximum score of 94 out of 100. The smaller transcarpel hand had a score of 84. Only when a more limited single channel three state controller was used was the score much lower (81). CONCLUSION: All of the hands were of a similar design and were set in a precision grip, but the precision grip did not achieve the highest individual grip score. Additionally, while the Southampton Hand Assessment Procedure (SHAP) score is dependent on the speed of execution of the task, the speed of the prosthesis did not have as great an impact on the score as the other variables. CLINICAL RELEVANCE: This study provides comparative data between similar designs of commercial hands. This will allow clinicians to be better informed when they prescribe a device for a user.

Central fabrication: carved positive assessment.

BACKGROUND: It is estimated that only 24% of practitioners use CAD/CAM regularly. Socket manufacturing error may be a source of the limited use of central fabrication. OBJECTIVES: The purpose of this study was to investigate the differences in shape between computer-manufactured, centrally fabricated carved models and electronic file shapes, to determine if carving was a major source of socket manufacturing error in central fabrication. STUDY DESIGN: Experimental, mechanical assessment. METHODS: Three different trans-tibial model shapes were sent electronically to each of 10 central fabrication facilities for the fabrication of positive foam models. A custom mechanical digitizer and alignment algorithm were used to measure the model shapes and then compare them with the electronic file shapes. RESULTS: Volume differences between the models and the electronic file shapes ranged from -4.2% to 1.0%, and averaged -0.9 (SD = 1.1)%. Mean radial error ranged from -1.2 mm to 0.3 mm and averaged -0.3 (SD = 0.3) mm. Inter-quartile range was between 0.3 mm and 2.7 mm and averaged 0.6 (SD = 0.5) mm. The models were significantly smaller than sockets made from the same electronic file shapes (p < 0.01), but the range of mean radial error and the interquartile range were not significantly different between the models and sockets. CONCLUSIONS: The results demonstrated that there was considerable variability in model quality among central fabricators in the industry, and that carving was not the sole source of socket fabrication error. CLINICAL RELEVANCE: The results provide insight into the severity and nature of carving error by central fabrication facilities. Because we found a wide range of model quality, there is not a consistent fabrication problem across the industry, but instead some central fabrication facilities practice the art of model fabrication better than others.

Colonic stents: the modern treatment of colonic obstruction.

Colonic stents traditionally have been used for the management of colorectal cancer, either as a palliative treatment or as a bridge to surgery. More recently, colonic stents have also been advocated as part of the therapy of benign strictures. A number of colonic stents are available worldwide, four of which are made in the USA. These stents are classified as covered or uncovered, with similar clinical applications. Technical and clinical success rates are similar among these different stents, as well as the rate of complications, which mainly consist of obstruction and migration. The deployment systems utilize fluoroscopy, endoscopy, or both. More recently, stents became available that are deployed "through the scope" (TTS) making the procedure faster. However, this advance does not exclude the use of fluoroscopy, particularly in those cases where the direct visualization of the proximal end of the stricture is absent. The increasing experience in the management of colorectal cancer with colonic stents decreases the morbidity and mortality, as well as cost, in comparison with surgical intervention for acute colonic obstruction. Management with colonic stents can also rule out proximal synchronous lesions after initial decompression prior to definitive surgery. Benign conditions may also be treated with stents. A multidisciplinary approach for the use of colonic stents during assessment and management of acute colonic obstruction is necessary in order to achieve a satisfactory outcome, whether that be better quality of life or improved survival.

[Process orientation as a tool of strategic approaches to corporate governance and integrated management systems]. / Prozessorientierung als Instrument strategischer Unternehmensführung und integrierter Managementsysteme.

The concept of general process orientation as an instrument of organisation development is the core principle of quality management philosophy, i.e. the learning organisation. Accordingly, prestigious quality awards and certification systems focus on process configuration and continual improvement. In German health care organisations, particularly in hospitals, this general process orientation has not been widely implemented yet - despite enormous change dynamics and the requirements of both quality and economic efficiency of health care processes. But based on a consistent process architecture that considers key processes as well as management and support processes, the strategy of excellent health service provision including quality, safety and transparency can be realised in daily operative work. The core elements of quality (e.g., evidence-based medicine), patient safety and risk management, environmental management, health and safety at work can be embedded in daily health care processes as an integrated management system (the "all in one system" principle). Sustainable advantages and benefits for patients, staff, and the organisation will result: stable, high-quality, efficient, and indicator-based health care processes. Hospitals with their broad variety of complex health care procedures should now exploit the full potential of total process orientation.

Call for standards in technical documentation of intracoronary stents.

At present, the product information of intracoronary stents provided by the industry contains only limited technical data restricting judgments on the in vivo performance of individual products. Available experimental and clinical evidence suggests that interventional target sites display highly heterogeneous biomechanical behavior needed to be matched by specific stent and stent delivery system characteristics. To allow individualized stent-lesion matching, both, understanding of biomechanical properties of the atherosclerotic coronary artery lesions and expert knowledge of the intracoronary stent systems, are required. Here, the authors review some of the initial data on mechanical properties of coronary artery lesions potentially relevant to stenting and suggest standards for technical documentation of intracoronary stents.

Endoprosthetic replacement for primary tumours around the knee: experience from Peking University.

In developing countries locally-made low-cost prostheses are mainly used in limb-salvage surgery to alleviate the economic burden. We retrospectively collected data on 104 patients treated by limb-salvage surgery between July 1997 and July 2005. We used a locally-designed and fabricated stainless-steel endoprosthesis in each case. Oncological and functional outcomes were evaluated at a mean follow-up of 47 months (12 to 118). A total of 73 patients (70.2%) were free from disease, nine (8.7%) were alive with disease, 19 (18.2%) had died from their disease and three (2.9%) from unrelated causes. According to the Musculoskeletal Tumor Society scoring system, the mean functional score was 76.3% (SD 17.8). The five-year survival for the implant was 70.5%. There were nine cases (8.7%) of infection, seven early and two late, seven (6.7%) of breakage of the prosthesis, three (2.9%) of aseptic loosening and two (1.9%) of failure of the polyethylene bushing. Multivariate analysis showed that a proximal tibial prosthesis and a resection length of 14 cm or more were significant negative prognostic factors. Our survival rates and Musculoskeletal Tumor Society functional scores are similar to those reported in the literature. Although longer follow-up is needed to confirm our results, we believe that a low-cost custom-made endoprosthesis is a cost-effective and reliable reconstructive option for limb salvage in developing countries.

Improvement in the assessment of wear of total knee replacements using coordinate-measuring machine techniques.

Total joint replacement is one of the most common elective surgical procedures performed worldwide, with an estimate of 1.5x 10(6) operations performed annually. Currently joint replacements are expected to function for 10-15 years; however, with an increase in life expectancy, and a greater call for knee replacement due to increased activity levels, there is a requirement to improve their function to offer longer-term improved quality of life for patients. Wear analysis of total joint replacements has long been an important means in determining failure mechanisms and improving longevity of these devices. The effectiveness of the coordinate-measuring machine (CMM) technique for assessing volumetric material loss during simulated life testing of a replacement knee joint has been proved previously by the present authors. The purpose of the current work is to present an improvement to this method for situations where no pre-wear data are available. To validate the method, simulator tests were run and gravimetric measurements taken throughout the test, such that the components measured had a known wear value. The implications of the results are then discussed in terms of assessment of joint functionality and development of standardized CMM-based product standards. The method was then expanded to allow assessment of clinically retrieved bearings so as to ascertain a measure of true clinical wear.

In vitro non-rigid life-size model of aortic arch aneurysm for endovascular prosthesis assessment.

PURPOSE: It is essential to evaluate new stent designs before in vivo testing. The purpose of this study was to develop and validate a controlled and reproducible patient-derived process to produce a life-size in vitro model of aortic arch aneurysm for endovascular procedure simulation. METHODS: A three-dimensional magnetic resonance angiography (3D MRA) image derived from a 60-year-old patient with aortic arch aneurysm was segmented using a home-made software package which allows one-click automatic segmentation of the aorta, meshing, and conversion to standard tessellation language (STL) format. A rapid prototyping technique established a stereolithographic model to produce a replica of the whole aorta, including the arch aneurysm and supra-aortic arteries. RESULTS: The final model was made by pouring silicone rubber to obtain a sturdy, life-size, soft, transparent, plastic cast, accurately reproducing both the internal and external anatomy of the aortic aneurysm. This model was used under perfusion by an extracorporeal circulation pump, to test ex vivo stent deployment. CONCLUSION: The combination of easy segmentation and conversion to the STL format with industrial stereolithography techniques enabled a realistic silicon vascular phantom to be created for endovascular procedure simulation, image modality calibration, and new stent design.

What impact have NICE guidelines had on the trends of hip arthroplasty since their publication? The results from the Trent Regional Arthroplasty Study between 1990 and 2005.

The National Institute for Clinical Excellence (NICE) published the guidelines on the selection of prostheses for primary hip replacement in 2000. They supported the use of cemented hip prostheses to the exclusion of uncemented and hybrid implants. The information from the Trent (and Wales) Regional Arthroplasty Study has been examined to identify retrospectively the types of hip prostheses used between 1990 and 2005, and to assess the impact that the guidelines have had on orthopaedic practice. The results show that the publication of the NICE guidelines has had little impact on clinical practice, with the use of uncemented prostheses increasing from 6.7% (137) in 2001 to 19.2% (632) in 2005. The use of hybrid prostheses has more than doubled from 8.8% (181) to 22% (722) of all hips implanted in the same period. The recommendations made by NICE are not being followed, which calls into question their value.