bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterotopic Ossification After the Arthroscopic Treatment of Lateral Epicondylitis
Authors: Desai Mihir J. , Ramalingam Hari , Ruch David S.
Published: April 2017

Background: Heterotopic ossification (HO) is a well-known complication following the surgical treatment of fractures and dislocations about the elbow but it is not commonly discussed as a complication following arthroscopy. We present a case of a young athlete who developed HO after the arthroscopic treatment of lateral epicondylitis. Methods: This is a case report chart review of a 24 year old male with lateral epicondylitis. After failing conservative measures, arthroscopic debridement of the extensor carpi radialis brevis (ECRB) origin ensued. The treatment and patient’s final disposition were reported. Results: The patient developed heterotopic ossification of the elbow follow arthroscopic debridement of the ECRB origin. Further surgery was required to excise the heterotopic ossification. Good recovery of motion was achieved. Conclusion: To our knowledge, we present the first case of HO development after elbow arthroscopy for lateral epicondylitis. As the use of elbow arthroscopy continues to grow, there is a need for identification of the risk factors and primary prophylaxis for HO.
Searching prison cells and prisoner bodies: Redacting carceral power and glimpsing gendered resistance in women’s prisons
Authors: Balfour Gillian
Published: April 2017

In this article, I explore the routinized practices of prisoner discipline: searching bodies and cells in four Canadian federal women’s prisons. Through an analysis of post-search reports as well as reported incidents of use of force, I discuss three key findings: searching and confiscation patterns across institutions are not dictated by size of the inmate population or security level of the institution; the redaction of information by prison authorities is an increasing and pervasive tactic of penal governance legitimated through an inter-legality of privacy and security; and that the searching of prisoner bodies and cells suggests a highly discretionary use of searching authority across women’s federal prisons that produces a gendered organizational logic. The text of the reports implies how women prisoners continue to be censured for their errant behaviour through the confiscation of personal items deemed to be unauthorized. These data also illustrate the ways in which women prisoners seek to achieve agency and self-determination within limited means.
Current Emotion Research in Economics
Authors: Wälde Klaus , Moors Agnes
Published: April 2017

Positive and negative feelings were central to the development of economics, especially in utility theory in classical economics. While neoclassical utility theory ignored feelings, behavioral economics more recently reintroduced feelings in utility theory. Beyond feelings, economic theorists use full-fledged specific emotions to explain behavior that otherwise could not be understood or they study emotions out of interest for the emotion itself. While some analyses display a strong overlap between psychological thinking and economic modelling, in most cases there is still a large gap between economic and psychological approaches to emotion research. Ways how to reduce this gap are discussed.
Intermedia Agenda Setting in the Social Media Age: How Traditional Players Dominate the News Agenda in Election Times
Authors: Harder Raymond A. , Sevenans Julie , Van Aelst Peter
Published: April 2017

Intermedia agenda setting is a widely used theory to explain how content transfers between news media. The recent digitalization wave, however, challenges some of its basic presuppositions. We discuss three assumptions that cannot be applied to online and social media unconditionally: one, that media agendas should be measured on an issue level; two, that fixed time lags suffice to understand overlap in media content; and three, that media can be considered homogeneous entities. To address these challenges, we propose a “news story” approach as an alternative way of mapping how news spreads through the media. We compare this with a “traditional” analysis of time-series data. In addition, we differentiate between three groups of actors that use Twitter. For these purposes, we study online and offline media alike, applying both measurement methods to the 2014 Belgium election campaign. Overall, we find that online media outlets strongly affect other media that publish less often. Yet, our news story analysis emphasizes the need to look beyond publication schemes. “Slow” newspapers, for example, often precede other media’s coverage. Underlining the necessity to distinguish between Twitter users, we find that media actors on Twitter have vastly more agenda-setting influence than other actors do.
Medical treatment or revascularisation as the best approach for spontaneous coronary artery dissection: A systematic review and meta-analysis
Authors: Martins José Luís , Afreixo Vera , Santos Luís , Costa Marco , Santos José , Gonçalves Lino
Published: April 2017

Introduction:

Patients presenting with spontaneous coronary artery dissection (SCAD) may receive either conservative medical management or a revascularisation strategy. There is still a lack of consensus with respect to the best treatment approach for SCAD.

Objectives:

We sought to determine whether outcomes differ between the first-line treatment approaches (conservative versus revascularisation) in patients with SCAD.

Methods:

We searched Medline, EMBASE and the Cochrane Library for studies published from January 1990 to November 2016 that compared first-line treatments for patients with SCAD. We conducted a pooled risk ratio meta-analysis for four main outcomes: mortality, myocardial infarction (MI), SCAD recurrence and target vessel revascularisation (TVR).

Results:

We identified 11 non-randomised studies that included a total of 631 patients. A pooled meta-analysis showed no significant difference between conservative management and revascularisation approaches in mortality (risk difference [RD] = 0.01; 95% confidence interval [CI] = −0.01 to 0.04; I2 = 0%; p = 1), MI (RD = −0.01; 95% CI = −0.04 to 0.03; I2 = 0%; p = 0.5) or SCAD recurrence (RD = −0.01; 95% CI = −0.06 to 0.05; I2 = 0%; p = 0.74). Revascularisation as an initial first-line approach was associated with an estimated additional risk of TVR of 6.3% (RD = 0.06; 95% CI = 0.01−0.11; I2 = 0%; p = 0.96).

Conclusion:

The results demonstrate an increased risk of TVR when revascularisation was used as the initial first-line treatment approach. The treatment decision must be individualised and be based on both clinical and angiographic factors, but conservative therapy should prevail in most cases.
Risk factors of late cardiogenic shock and mortality in ST-segment elevation myocardial infarction patients
Authors: Obling Laust , Frydland Martin , Hansen Rikke , Møller-Helgestad Ole Kristian , Lindholm Matias Greve , Holmvang Lene , Ravn Hanne Berg , Wiberg Sebastian , Thomsen Jakob Hartvig , Jensen Lisette Okkels , Kjærgaard Jesper , Møller Jacob Eifer , Hassager Christian
Published: April 2017

Background:

The incidence of cardiogenic shock (CS) in patients with ST-segment elevation myocardial infarction (STEMI) is as high as 10%. The majority of patients are thought to develop CS after admission (late CS), but the incidence in a contemporary STEMI cohort admitted for primary percutaneous intervention remains unknown.

Aim:

The aim of this study was to assess the incidence and time of CS onset in patients with suspected STEMI admitted in two high-volume tertiary heart centres and to assess the variables associated with the development of late CS.

Methods:

We included consecutive patients admitted for acute coronary angiography with suspected STEMI in a 1-year period. Cardiogenic shock was based on clinical criteria and subdivided into patients with shock on admission, patients developing shock during catheterisation and patients developing shock later during hospitalisation. Follow-up for all-cause mortality was done using registries.

Results:

A total of 2247 patients with suspected STEMI were included, whereof 225 (10%) developed CS. The majority (56%) had CS on admission, 16% developed CS in the catheterisation laboratory and 28% developed late CS. Thirty-day mortality was 3.1% versus 47% in non-CS versus CS patients ( plogrank < 0.0001). Age, stroke, time from symptom onset to intervention, anterior STEMI, heart rate/systolic blood pressure ratio and being comatose after resuscitation from cardiac arrest were independently associated with the development of late CS.

Conclusion:

In this study, 10% of patients admitted with suspected STEMI for acute coronary angiography presented with or developed CS. Most were in shock on admission. Irrespective of the timing of shock, mortality was high.
Profiles of Quality: Supports for Book Interactions and Early Writing Activities in Prekindergarten Classrooms
Authors: O’Leary Patrick M.
Published: April 2017

Head Start teachers and their classrooms ( N = 86) were observed to determine the state of quality of the early literacy and language instruction and environments in prekindergarten. Cluster analysis was used to create profiles of prekindergarten teacher and classroom quality across two constructs: Book Supports and Writing Supports. Descriptive results showed that on average, classrooms received low scores for both reading and writing supports. However, cluster analysis revealed four distinct profiles: Profile 1 (High, High), Profile 2 (Low, Low), Profile 3 (Average, Average), and Profile 4 (High, Low). Results implicate a need for greater attention to language and literacy in general, but especially a need for an increase in early writing supports. Implications for person-oriented analysis (as opposed to variable-oriented analysis) and professional development are also discussed.
Wealth Inequality and Carbon Emissions in High-income Countries
Authors: Knight Kyle W. , Schor Juliet B. , Jorgenson Andrew K.
Published: April 2017

This study contributes to the emerging literature on connections between climate change and economic inequality by investigating the relationship between domestic wealth inequality and consumption-based carbon emissions for 26 high-income countries from 2000 to 2010. Results of the two-way fixed effects longitudinal models indicate that the effect of wealth inequality, measured as the wealth share of the top decile, on per capita emissions in high-income countries is consistently positive and relatively stable over the time period. This finding is consistent with political economy theories arguing that the concentration of political and economic power that accompanies the concentration of wealth plays an important role in increasing environmental degradation and preventing proenvironmental actions.
Transforming Business Value through Digitalized Networks: A Case Study on the Value Drivers of Airbnb
Authors: Boswijk Albert
Published: April 2017

The purpose and central question of this article is to demonstrate that the process of innovation and value creation is more than a one-dimensional activity and that it needs to be considered as a holistic ecosystem, consisting of five interdependent drivers. This article on such an ecosystem was inspired by research on the Competing Values Framework ( Quinn & Rohrbaugh, 1983 ). The article demonstrates the application of the framework on the disrupting business model of Airbnb in the domain of digitalized hospitality networks. The data and the insights in this study are based on interviews the author conducted with Airbnb staff, hosts, and guests, on previous research and on data from Airdna (2015–2016) compared with public data on Airbnb. This case study demonstrates a new form of participatory business value, co-created between hosts, guests and the digitalized network provider, creating a unique authentic guest experience in a networked environment.
How Question Types Reveal Student Thinking: An Experimental Comparison of Multiple-True-False and Free-Response Formats
Authors: Hubbard Joanna K. , Potts Macy A. , Couch Brian A.
Published: April 2017

Assessments represent an important component of undergraduate courses because they affect how students interact with course content and gauge student achievement of course objectives. To make decisions on assessment design, instructors must understand the affordances and limitations of available question formats. Here, we use a crossover experimental design to identify differences in how multiple-true-false (MTF) and free-response (FR) exam questions reveal student thinking regarding specific conceptions. We report that correct response rates correlate across the two formats but that a higher percentage of students provide correct responses for MTF questions. We find that MTF questions reveal a high prevalence of students with mixed (correct and incorrect) conceptions, while FR questions reveal a high prevalence of students with partial (correct and unclear) conceptions. These results suggest that MTF question prompts can direct students to address specific conceptions but obscure nuances in student thinking and may overestimate the frequency of particular conceptions. Conversely, FR questions provide a more authentic portrait of student thinking but may face limitations in their ability to diagnose specific, particularly incorrect, conceptions. We further discuss an intrinsic tension between question structure and diagnostic capacity and how instructors might use multiple formats or hybrid formats to overcome these obstacles.
Image-guided regularization of marine electromagnetic inversion
Authors: Guo Zhenwei , Dong Hefeng , Kristensen Åge
Published: April 2017

Marine electromagnetic (EM) inverse methods have recently been rapidly developed for offshore exploration. However, inverted resistivity results with low resolution are provided by the EM method. To improve this quality of the results, we have developed an image-guided regularization method for inversion of the marine EM data. The method incorporates seismic constraints into EM inversion. Information is extracted from seismic/geologic images and consists of the metric tensor field and sampling on the geologic structure. In addition to the regularization, geologic horizons picked from the seismic images and samplings on the structure can be used to generate an irregular sparse mesh. Compared with an unstructured regular dense mesh, a coherence-based irregular sparse mesh can reduce computational costs. Furthermore, image-guided regularization represents an improvement compared with traditional regularization that are structurally based on seismic images by following geologic features more closely and handling anomalies better. We have determined that image-guided regularization improves the results of EM inversions with irregular sparse meshes. The image-guided regularized inversion can be applied to marine controlled-source electromagnetic (CSEM) data and magnetotelluric (MT) data, and it can be used for joint inversion of CSEM and MT data. Regarding its application to real data, image-guided inversion was successfully applied to CSEM data on the Troll area, using an anisotropic model.
A Prospective, Randomized, Clinical Trial on the Effects of a Valveless Trocar on Respiratory Mechanics During Robotic Radical Cystectomy: A Pilot Study
Authors: Covotta Marco , Claroni Claudia , Torregiani Giulia , Naccarato Alessia , Tribuzi Susanna , Zinilli Antonio , Forastiere Ester
Published: April 2017

BACKGROUND:

Prolonged pneumoperitoneum and Trendelenburg positioning for robot-assisted radical cystectomy (RARC) are essential for optimizing visualization of the operative field, although they worsen hemodynamic and respiratory function. Our hypothesis is that the use of a valveless trocar (VT) may improve respiratory mechanics.

METHODS:

In this prospective, 2-arm parallel trial, patients ASA II to III undergoing RARC were randomly assigned into 2 groups: in the VT group, the capnoperitoneum was maintained with a VT; in the control group, the capnoperitoneum was maintained with a standard trocar (ST group). Inspiratory plateau pressure (Pplat), static compliance (Cstat), minute volume (MV), tidal volume (Vt), and carbon dioxide (CO2) elimination rate were recorded at these times: 15 minutes after anesthesia induction (T0), 10 minutes (T1) and 60 minutes (T2) after first robot docking, 10 minutes before first undocking (T3), 10 minutes (T4) and 60 minutes (T5) after second docking, 10 minutes before second undocking (T6), and 10 minutes before extubation (T7). The primary end point of the study was the assessment of Pplat mean value from T1 to T6.

RESULTS:

A total of 56 patients were evaluated: 28 patients in the VT group and 28 in the ST group. VT group had lower Pplat (means and standard error, VT group 30 [0.66] versus ST group 34 [0.66] cm H2O, with estimated mean difference and 95% confidence interval, −4.1 [−5.9 to −2.2], P < .01), lower MV (means and standard error, VT group 8.2 [0.22] versus ST group 9.8 [0.21] L min−1, P < .01), lower CO2 elimination rate (means and standard error, VT group 4.2 [0.25] versus ST group 5.4 [0.24] mL kg−1 min−1, P < .01), lower end-tidal CO2 (etco
2) (means and standard error, VT group 28.8 [0.48] versus ST group 31.3 [0.46] mm Hg, P < .01), and higher Cstat (means and standard error, VT group 26 [0.9] versus ST group 22.1 [0.9] mL cm H2O−1, P < .01). Both groups had similar Vt (P = .24).

CONCLUSIONS:

During RARC, use of a VT was associated with a significantly lower Pplat and improvement in other respiratory parameters.
Arterial Pressure and the Rate of Elimination of Crystalloid Fluid
Authors: Hahn Robert G.
Published: April 2017

Excretion of crystalloid fluid is slow during general anesthesia. The distribution and elimination of buffered Ringer’s solution were analyzed to determine whether the rate of elimination correlates with a hemodynamic factor, consciousness, patient posture, or the type of general anesthesia. Data were derived from 4 separately published studies in which 30 volunteers and 48 anesthetized patients had received 0.833 (1 series 0.667) mL/kg/min of lactated or acetated Ringer’s solution over 30 minutes. Frequent measurements of the blood hemoglobin and mean urinary excretion were used as input in a kinetic analysis according to a 2-volume model and covariates, using microconstants and mixed-effects modeling software.

The results show that rate of elimination of crystalloid fluid decreased with the mean arterial pressure (MAP) and patient age, but was unaffected by consciousness and inhalational or intravenous anesthesia. The elimination rate constant was 6.5 (95% confidence interval, 5.2–7.9) × 10−3 × (MAP/mean MAP)5.2 × (Age/mean Age)−1.5. The mean MAP for the 2108 data points was 81.3 mm Hg and the mean age was 40 years. The central fluid space that was expanded by infused fluid (V
c, plasma volume) increased with body weight but decreased with general anesthesia and with reductions of MAP.

Simulations revealed a more than 10-fold difference in the excreted fluid volume after a theoretical 30-minute infusion, depending on whether the MAP was 50 or 100 mm Hg.

In conclusion, the rate of elimination of crystalloid fluid decreased in proportion to MAP but was independent of general anesthesia and moderate-sized surgery.
MCTBI: a web server for predicting metal ion effects in RNA structures
Authors: Sun Li-Zhen , Zhang Jing-Xiang , Chen Shi-Jie
Published: April 2017

Metal ions play critical roles in RNA structure and function. However, web servers and software packages for predicting ion effects in RNA structures are notably scarce. Furthermore, the existing web servers and software packages mainly neglect ion correlation and fluctuation effects, which are potentially important for RNAs. We here report a new web server, the MCTBI server (http://rna.physics.missouri.edu/MCTBI), for the prediction of ion effects for RNA structures. This server is based on the recently developed MCTBI, a model that can account for ion correlation and fluctuation effects for nucleic acid structures and can provide improved predictions for the effects of metal ions, especially for multivalent ions such as Mg2+ effects, as shown by extensive theory-experiment test results. The MCTBI web server predicts metal ion binding fractions, the most probable bound ion distribution, the electrostatic free energy of the system, and the free energy components. The results provide mechanistic insights into the role of metal ions in RNA structure formation and folding stability, which is important for understanding RNA functions and the rational design of RNA structures.
Open Online Courses in Public Health: experience from Peoples-uni
Authors: Heller Richard F. , Zurynski Robert , Barrett Alan , Oaiya Omo , Madhok Rajan
Published: April 2017

Open Online Courses (OOCs) are offered by Peoples-uni at http://ooc.peoples-uni.org to complement the courses run on a separate site for academic credit at http://courses.peoples-uni.org. They provide a wide range of online learning resources beyond those usually found in credit bearing Public Health courses. They are self-paced, and students can enrol themselves at any time and utilise Open Educational Resources free of copyright restrictions.  In the two years that courses have been running, 1174 students from 100 countries have registered and among the 1597 enrolments in 14 courses, 15% gained a certificate of completion. Easily accessible and appealing to a wide geographical and professional audience, OOCs have the potential to play a part in establishing global Public Health capacity building programmes.
Recent advances in understanding HIV evolution
Authors: Andrews Sophie M. , Rowland-Jones Sarah
Published: April 2017

The human immunodeficiency virus (HIV) evolves rapidly owing to the combined activity of error-prone reverse transcriptase, recombination, and short generation times, leading to extensive viral diversity both within and between hosts. This diversity is a major contributing factor in the failure of the immune system to eradicate the virus and has important implications for the development of suitable drugs and vaccines to combat infection. This review will discuss the recent technological advances that have shed light on HIV evolution and will summarise emerging concepts in this field.
The Impact of Institutional Distance on the Joint Performance of Collaborating Firms: The Role of Adaptive Interorganizational Systems
Authors: Dong Maggie Chuoyan , Fang Yulin , Straub Detmar W.
Published: April 2017

Firms have made extensive use of interorganizational systems (IOSs) to share knowledge and pursue superior joint performance. Contemporary firms are using IOSs to collaborate widely across the value chain and in an ever-expanding geographic landscape. Thus, institutional distance, which is the difference between the firms’ respective institutional fields, has become a prominent challenge. In this study, we investigate the extent to which institutional distance affects IOS-enabled knowledge sharing and its impact on the joint performance of collaborating firms. We also explore the extent to which IOS adaptability could be a design solution for improving IOS-enabled knowledge sharing, given the challenge of institutional distance. Drawing on institutional theory, we propose that institutional distance, differentially influential via its normative, cognitive, and regulative aspects, not only reduces IOS-enabled knowledge sharing but also weakens the positive impact of such sharing on joint firm performance. Next, extending boundary object theory to the institutional context, we propose that IOS adaptability could be a solution to the challenge of institutional distance because it can directly strengthen IOS-enabled knowledge sharing as well as mitigate the negative effect of institutional distance on such sharing. Our hypotheses were tested through a field study that collected dyadic data from 141 distinct buyer/supplier channel relationships in 4 industries. The results from partial least squares modeling fully support our hypotheses with regard to cognitive distance, partially support those related to normative distance, but do not support those related to regulative distance. We discuss the implications of these findings for theory development and professional practice.

The online appendix is available at https://doi.org/10.1287/isre.2016.0675 .
Management of foreign body ingestions in children: button batteries and magnets
Authors: Kodituwakku Ronan , Palmer Sarah , Prosad Paul Siba
Published: April 2017

Foreign body ingestion and foreign body aspiration commonly affect young children between 6 months and 6 years. A large number of these events remain unwitnessed and asymptomatic while the swallowed foreign body traverses the gastrointestinal tract and is passed in the stool. Recent literature has shown an increase in morbidity associated with button battery and (neomydium) magnet ingestions in children, particularly over the last decade. Early identification and management in a time critical manner is required in cases where button batteries get lodged in the oesophagus or multiple magnets are swallowed. Deaths, although rare, have been reported with these dangerous foreign body ingestions in children where diagnoses were delayed. Nurses through their direct contact with children in different clinical settings play a vital role in managing foreign body ingestions.
Does a checklist reduce the number of errors made in nurse-assembled discharge prescriptions?
Authors: Byrne Corrine , Sierra Hannah , Tolhurst Rowan
Published: April 2017

Background:

The safe supply of medicines is an integral part of being discharged from hospital. Locally, nurses are responsible for assembling medication for discharge prescriptions. Over a 2-year period 15 serious medication errors relating to discharge were reported on the health and ageing unit. This project was designed to evaluate whether a discharge medication checklist could reduce errors on nurse-assembled discharge prescriptions.

Methods and results:

A baseline audit was conducted to identify the number of medication errors on nurse-assembled discharge prescriptions. After the audit period the discharge medication checklist was introduced and education and training was provided to nursing staff. There was a statistically significant reduction in the number of assembled discharge prescriptions with one or more errors (28/56 vs. 9/44; p=0.0478) when re-audited.

Conclusion:

The introduction of a discharge medication checklist demonstrated a significant reduction in errors. The authors recommend that the discharge medication checklist and training programme be rolled out across medical wards to facilitate safe discharge.
The management and treatment of hyperkeratosis
Authors: Elwell Rebecca
Published: April 2017

Rebecca Elwell, Macmillan Lymphoedema Advanced Nurse Practitioner, Royal Stoke University Hospital, discusses recommendations on management of this skin problem, which may co-occur with chronic oedema
Peripheral intravenous cannulation: protecting patients and nurses
Authors: Barton Andrew , Ventura Roy , Vavrik Boris
Published: April 2017

Peripheral intravenous cannulation is a common clinical procedure in today's healthcare setting. There are a range of different devices to choose from, and this article will consider the risk of catheter-related bloodstream infections and needlestick injuries, national and international guidelines on infection prevention and safety in intravenous access, the need for closed catheters, features of the Introcan Safety® 3 (B. Braun Melsungen AG) and research into peripheral cannulas.
Medical adhesive-related skin injuries associated with vascular access
Authors: Hitchcock Jan , Savine Louise
Published: April 2017

Establishing vascular access and preventing infection, both at insertion and during ongoing care is generally the top priority; the maintenance of optimal skin integrity is often a distant secondary consideration. Skin can react to different types of dressings or adhesives, or problems can arise relating to the securement of lines or the development of sensitivities to cleaning solutions. Clearly, these scenarios are not limited to the securement of vascular access devices; however, a patient with a long-term vascular access device may not have other options for vascular access, which makes this a very important and yet largely unrecognised area. A review of the limited literature that existed up to March 2015 showed it was typically concerned with skin tears connected with dressings and removal, and contact irritant dermatitis. The tissue viability team and vascular access team reviewed the current products associated with a typical vascular access dressing to ensure it was fit for purpose and where at all possible had good scientific literature for validation. The team worked proactively to recognise those patients at risk with the early identification of potential medical adhesive-related skin injuries (MARSI). To facilitate this an algorithm was developed that offers a step-by-step approach, clearly outlining what to do to prevent MARSI and its treatment should it develop. These reactions can result from other factors than the dressing alone, and an increase in these kinds of skin reaction in patients who are on chemotherapy regimens is being explored further. Through the implementation of an algorithm, education for both staff and patients and collaborative working between vascular access and tissue viability teams, a reduction in these phenomena has been seen despite an increasing number of at-risk patients.
Errata
Authors: Haddad F. S.
Published: April 2017

Khan OH, Malviya A, Subramanian P, Agolley D, Witt JD Minimally invasive periacetabular osteotomy using a modified Smith-Petersen approach. Bone Joint J 2017;99-B:22-28.
Errata
Authors: Haddad F. S.
Published: April 2017

De Martino I, D'Apolito R, Soranoglou VG, Poultsides LA, Sculco PK, Sculco TP. Dislocation following total hip arthroplasty using dual mobility acetabular components. Bone Joint J;2017;99-B:18-24.
Errata
Authors: Haddad F. S.
Published: April 2017

Haefeli PC, Marecek GS, Keel MJB, Siebenrock KA, Tannast M. Patients undergoing surgical hip dislocation for the treatment of acetabular fractures show favourable long-term outcome. Bone Joint J;2017;99-B:508-515.
Dislocation of a primary total hip arthroplasty is more common in patients with a lumbar spinal fusion
Authors: Buckland A. J. , Puvanesarajah V. , Vigdorchik J. , Schwarzkopf R. , Jain A. , Klineberg E. O. , Hart R. A. , Callaghan J. J. , Hassanzadeh H.
Published: April 2017

Aims

Lumbar fusion is known to reduce the variation in pelvic tilt between standing and sitting. A flexible lumbo-pelvic unit increases the stability of total hip arthroplasty (THA) when seated by increasing anterior clearance and acetabular anteversion, thereby preventing impingement of the prosthesis. Lumbar fusion may eliminate this protective pelvic movement. The effect of lumbar fusion on the stability of total hip arthroplasty has not previously been investigated.

Patients and Methods

The Medicare database was searched for patients who had undergone THA and spinal fusion between 2005 and 2012. PearlDiver software was used to query the database by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedural code for primary THA and lumbar spinal fusion. Patients who had undergone both lumbar fusion and THA were then divided into three groups: 1 to 2 levels, 3 to 7 levels and 8+ levels of fusion. The rate of dislocation in each group was established using ICD-9-CM codes. Patients who underwent THA without spinal fusion were used as a control group. Statistical significant difference between groups was tested using the chi-squared test, and significance set at p < 0.05.

Results

At one-year follow-up, 14 747 patients were found to have had a THA after lumbar spinal fusion (12 079 1 to 2 levels, 2594 3 to 7 levels, 74 8+ levels). The control group consisted of 839 004 patients. The dislocation rate in the control group was 1.55%. A higher rate of dislocation was found in patients with a spinal fusion of 1 to 2 levels (2.96%, p < 0.0001) and 3 to 7 levels (4.12%, p < 0.0001). Patients with 3 to 7 levels of fusion had a higher rate of dislocation than patients with 1 to 2 levels of fusion (odds ratio (OR) = 1.60, p < 0.0001). When groups were matched for age and gender to the unfused cohort, patients with 1 to 2 levels of fusion had an OR of 1.93 (95% confidence interval (CI) 1.42 to 2.32, p < 0.001), and those with 3 to 7 levels of fusion an OR of 2.77 (CI 2.04 to 4.80, p < 0.001) for dislocation.

Conclusion

Patients with a previous history of lumbar spinal fusion have a significantly higher rate of dislocation of their THA than age- and gender-matched patients without a lumbar spinal fusion. Cite this article: Bone Joint J 2017;99-B:585–91.
Radiological and clinical comparison of kinematicallyversusmechanically aligned total knee arthroplasty
Authors: Matsumoto T. , Takayama K. , Ishida K. , Hayashi S. , Hashimoto S. , Kuroda R.
Published: April 2017

Aims

The aim of this study was to compare the post-operative radiographic and clinical outcomes between kinematically and mechanically aligned total knee arthroplasties (TKAs).

Patients and Methods

A total of 60 TKAs (30 kinematically and 30 mechanically aligned) were performed in 60 patients with varus osteoarthritis of the knee using a navigation system. The angles of orientation of the joint line in relation to the floor, the conventional and true mechanical axis (tMA) (the line from the centre of the hip to the lowest point of the calcaneus) were compared, one year post-operatively, on single-leg and double-leg standing long leg radiographs between the groups. The range of movement and 2011 Knee Society Scores were also compared between the groups at that time.

Results

The angles of orientation of the joint line in the kinematic group changed from slight varus on double-leg standing to slight valgus with single-leg standing. The mechanical axes in the kinematic group passed through a neutral position of the knee in the true condition when the calcaneus was considered. The post-operative angles of flexion and functional activity scores were significantly better in the kinematic than in the mechanical group (p < 0.003 and 0.03, respectively).

Conclusion

A kinematically aligned TKA results in a joint line which has a more parallel orientation in relation to the floor during single- and double-leg standing, and more neutral weight-bearing in tMA than a mechanically aligned TKA. Cite this article: Bone Joint J 2017;99-B:640–6.
Anterior knee pain and evidence of osteoarthritis of the patellofemoral joint should not be considered contraindications to mobile-bearing unicompartmental knee arthroplasty
Authors: Hamilton T. W. , Pandit H. G. , Maurer D. G. , Ostlere S. J. , Jenkins C. , Mellon S. J. , Dodd C. A. F. , Murray D. W.
Published: April 2017

Aims

It is not clear whether anterior knee pain and osteoarthritis (OA) of the patellofemoral joint (PFJ) are contraindications to medial unicompartmental knee arthroplasty (UKA). Our aim was to investigate the long-term outcome of a consecutive series of patients, some of whom had anterior knee pain and PFJ OA managed with UKA.

Patients and Methods

We assessed the ten-year functional outcomes and 15-year implant survival of 805 knees (677 patients) following medial mobile-bearing UKA. The intra-operative status of the PFJ was documented and, with the exception of bone loss with grooving to the lateral side, neither the clinical or radiological state of the PFJ nor the presence of anterior knee pain were considered a contraindication. The impact of radiographic findings and anterior knee pain was studied in a subgroup of 100 knees (91 patients).

Results

There was no relationship between functional outcomes, at a mean of ten years, or 15-year implant survival, and pre-operative anterior knee pain, or the presence or degree of cartilage loss documented intra-operatively at the medial patella or trochlea, or radiographic evidence of OA in the medial side of the PFJ. In 6% of cases there was full thickness cartilage loss on the lateral side of the patella. In these cases, the overall ten-year function and 15-year survival was similar to those without cartilage loss; however they had slightly more difficulty with descending stairs. Radiographic signs of OA seen in the lateral part of the PFJ were not associated with a definite compromise in functional outcome or implant survival.

Conclusion

Severe damage to the lateral side of the PFJ with bone loss and grooving remains a contraindication to mobile-bearing UKA. Less severe damage to the lateral side of the PFJ and damage to the medial side, however severe, does not compromise the overall function or survival, so should not be considered to be a contraindication. However, if a patient does have full thickness cartilage loss on the lateral side of the PFJ they may have a slight compromise in their ability to descend stairs. Pre-operative anterior knee pain also does not compromise the functional outcome or survival and should not be considered to be a contraindication. Cite this article: Bone Joint J 2017;99-B:632–9
High failure rates in treatment of streptococcal periprosthetic joint infection
Authors: Akgün D. , Trampuz A. , Perka C. , Renz N.
Published: April 2017

Aims

To investigate the outcomes of treatment of streptococcal periprosthetic joint infection (PJI) involving total knee and hip arthroplasties.

Patients and Methods

Streptococcal PJI episodes which occurred between January 2009 and December 2015 were identified from clinical databases. Presentation and clinical outcomes for 30 streptococcal PJIs in 30 patients (12 hip and 18 knee arthroplasties) following treatment were evaluated from the medical notes and at review. The Kaplan-Meier survival method was used to estimate the probability of infection-free survival. The influence of the biofilm active antibiotic rifampin was also assessed.

Results

The infection was thought to have been acquired haematogenously in 16 patients and peri-operatively in 14. The median follow-up time for successfully treated cases was 39.2 months (12 to 75), whereas failure of the treatment occurred within the first year following treatment on every occasion. The infection-free survival at three years with 12 patients at risk was 59% (95% confidence interval 39% to 75%). Failure of the treatment was observed in ten of 22 PJIs (45%) treated with a two-stage revision arthroplasty, two of six (33%) treated by debridement and prosthesis retention, and in neither of the two PJIs treated with one-stage revision arthroplasty. Streptococcal PJI treated with or without rifampin included in the antibiotic regime showed no difference in treatment outcome (p = 0.175).

Conclusion

The success of treatment of streptococcal PJI in our patient cohort was poor (18 of 30 cases, 59%). New therapeutic approaches for treating streptococcal PJI are needed. Cite this article: Bone Joint J 2017;99-B:653–9.
Long-term outcomes of cemented versus cementless humeral components in arthroplasty of the shoulder
Authors: Werthel J-D. , Lonjon G. , Jo S. , Cofield R. , Sperling J. W. , Elhassan B. T.
Published: April 2017

Aims

In the initial development of total shoulder arthroplasty (TSA), the humeral component was usually fixed with cement. Cementless components were subsequently introduced. The aim of this study was to compare the long-term outcome of cemented and cementless humeral components in arthroplasty of the shoulder.

Patients and Methods

All patients who underwent primary arthroplasty of the shoulder at our institution between 1970 and 2012 were included in the study. There were 4636 patients with 1167 cemented humeral components and 3469 cementless components. Patients with the two types of fixation were matched for nine different covariates using a propensity score analysis. A total of 551 well-balanced pairs of patients with cemented and cementless components were available after matching for comparison of the outcomes. The clinical outcomes which were analysed included loosening of the humeral component determined at revision surgery, periprosthetic fractures, post-operative infection and operating time.

Results

The overall five-, ten-, 15- and 20-year rates of survival were 98.9%, 97.2%, 95.5%, and 94.4%, respectively. Survival without loosening at 20 years was 98% for cemented components and 92.4% for cementless components. After propensity score matching including fixation as determined by the design of the component, humeral loosening was also found to be significantly higher in the cementless group. Survival without humeral loosening at 20 years was 98.7% for cemented components and 91.0% for cementless components. There was no significant difference in the risk of intra- or post-operative fracture. The rate of survival without deep infection and the mean operating time were significantly higher in the cemented group.

Conclusion

Both types of fixation give rates of long-term survival of > 90%. Cemented components have better rates of survival without loosening but this should be weighed against increased operating time and the risk of bony destruction of the proximal humerus at the time of revision of a cemented humeral component. Cite this article: Bone Joint J 2017;99-B:666–73.
When is it safe to resume driving after total hip and total knee arthroplasty?
Authors: van der Velden C. A. , Tolk J. J. , Janssen R. P. A. , Reijman M.
Published: April 2017

Aims

The aim of this study was to assess the current available evidence about when patients might resume driving after elective, primary total hip (THA) or total knee arthroplasty (TKA) undertaken for osteoarthritis (OA).

Materials and Methods

In February 2016, EMBASE, MEDLINE, Web of Science, Scopus, Cochrane, PubMed Publisher, CINAHL, EBSCO and Google Scholar were searched for clinical studies reporting on ‘THA’, ‘TKA’, ‘car driving’, ‘reaction time’ and ‘brake response time’. Two researchers (CAV and JJT) independently screened the titles and abstracts for eligibility and assessed the risk of bias. Both fixed and random effects were used to pool data and calculate mean differences (MD) and 95% confidence intervals (CI) between pre- and post-operative total brake response time (TBRT).

Results

A total of 19 studies were included. The assessment of the risk of bias showed that one study was at high risk, six studies at moderate risk and 12 studies at low risk. Meta-analysis of TBRT showed a MD decrease of 25.54 ms (95% CI -32.02 to 83.09) two weeks after right-sided THA, and of 18.19 ms (95% CI -6.13 to 42.50) four weeks after a right-sided TKA, when compared with the pre-operative value.

Conclusion

The TBRT returned to baseline two weeks after a right-sided THA and four weeks after a right-sided TKA. These results may serve as guidelines for orthopaedic surgeons when advising patients when to resume driving. However, the advice should be individualised. Cite this article: Bone Joint J 2017;99-B:566–76.
Risk factors for failure of the 36 mm metal-on-metal Pinnacle total hip arthroplasty system
Authors: Matharu G. S. , Nandra R. S. , Berryman F. , Judge A. , Pynsent P. B. , Dunlop D. J.
Published: April 2017

Aims

To determine ten-year failure rates following 36 mm metal-on-metal (MoM) Pinnacle total hip arthroplasty (THA), and identify predictors of failure.

Patients and Methods

We retrospectively assessed a single-centre cohort of 569 primary 36 mm MoM Pinnacle THAs (all Corail stems) followed up since 2012 according to Medicines and Healthcare Products Regulation Agency recommendations. All-cause failure rates (all-cause revision, and non-revised cross-sectional imaging failures) were calculated, with predictors for failure identified using multivariable Cox regression.

Results

Failure occurred in 97 hips (17.0%). The ten-year cumulative failure rate was 27.1% (95% confidence interval (CI) 21.6 to 33.7). Primary implantation from 2006 onwards (hazard ratio (HR) 4.30; 95% CI 1.82 to 10.1; p = 0.001) and bilateral MoM hip arthroplasty (HR 1.59; 95% CI 1.03 to 2.46; p = 0.037) predicted failure. The effect of implantation year on failure varied over time. From four years onwards following surgery, hips implanted since 2006 had significantly higher failure rates (eight years 28.3%; 95% CI 23.1 to 34.5) compared with hips implanted before 2006 (eight years 6.3%; 95% CI 2.4 to 15.8) (HR 15.2; 95% CI 2.11 to 110.4; p = 0.007).

Conclusion

We observed that 36 mm MoM Pinnacle THAs have an unacceptably high ten-year failure rate, especially if implanted from 2006 onwards or in bilateral MoM hip patients. Our findings regarding implantation year and failure support recent concerns about the device manufacturing process. We recommend all patients undergoing implantation since 2006 and those with bilateral MoM hips undergo regular investigation, regardless of symptoms. Cite this article: Bone Joint J 2017;99-B:592–600.
The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses
Authors: Zhang J. , Yuan T. , Zheng N. , Zhou Y. , Hogan M. V. , Wang J. H-C.
Published: April 2017

Objectives

After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP).

Methods

Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing.

Results

Histological analysis showed well organised arrangement of collagen fibres and proteoglycan formation in the wounded ATEs in the KGN-PRP group. Furthermore, immunohistochemical analysis revealed fibrocartilage formation in the KGN-PRP-treated ATEs, evidenced by the presence of both collagen I and II in the healed ATE. Larger positively stained collagen III areas were found in both PRP and saline groups than those in the KGN-PRP group. Chondrocyte-related genes, SOX9 and collagen II, and tenocyte-related genes, collagen I and scleraxis (SCX), were also upregulated by KGN-PRP. Moreover, mechanical testing results showed higher ultimate tensile strength in the KGN-PRP group than in the saline control group. In contrast, PRP treatment appeared to have healed the injured ATE but induced no apparent formation of fibrocartilage. The saline-treated group showed poor healing without fibrocartilage tissue formation in the ATEs.

Conclusions

Our results show that injection of KGN-PRP induces fibrocartilage formation in the wounded rat ATEs. Hence, KGN-PRP may be a clinically relevant, biological approach to regenerate injured enthesis effectively. Cite this article: J. Zhang, T. Yuan, N. Zheng, Y. Zhou, M. V. Hogan, J. H-C. Wang. The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses. Bone Joint Res 2017;6:231–244. DOI: 10.1302/2046-3758.64.BJR-2017-0268.R1.