bluuebunny/crossref_metadata_2025 huggingface dataset:
Identifying RR Lyrae Variable Stars in Six Years of the Dark Energy Survey
Authors: Stringer K. M. , Drlica-Wagner A. , Macri L. , Martínez-Vázquez C. E. , Vivas A. K. , Ferguson P. , Pace A. B. , Walker A. R. , Neilsen E. , Tavangar K. , Wester W. , Abbott T. M. C. , Aguena M. , Allam S. , Bacon D. , Bechtol K. , Bertin E. , Brooks D. , Burke D. L. , Carnero Rosell A. , Carrasco Kind M. , Carretero J. , Costanzi M. , Crocce M. , Costa L. N. da , Pereira M. E. S. , De Vicente J. , Desai S. , Diehl H. T. , Doel P. , Ferrero I. , García-Bellido J. , Gaztanaga E. , Gerdes D. W. , Gruen D. , Gruendl R. A. , Gschwend J. , Gutierrez G. , Hinton S. R. , Hollowood D. L. , Honscheid K. , Hoyle B. , James D. J. , Kuehn K. , Kuropatkin N. , Li T. S. , Maia M. A. G. , Marshall J. L. , Menanteau F. , Miquel R. , Morgan R. , Ogando R. L. C. , Palmese A. , Paz-Chinchón F. , Plazas A. A. , Roodman A. , Sanchez E. , Schubnell M. , Serrano S. , Sevilla-Noarbe I. , Smith M. , Soares-Santos M. , Suchyta E. , Tarle G. , Thomas D. , To C. , Varga T. N. , Wilkinson R. D. , Zhang Y. ,   (DES Collaboration)
Published: April 2021

We present a search for RR Lyrae stars using the full six-year data set from the Dark Energy Survey covering ∼5000 deg2 of the southern sky. Using a multistage multivariate classification and light-curve template-fitting scheme, we identify RR Lyrae candidates with a median of 35 observations per candidate. We detect 6971 RR Lyrae candidates out to ∼335 kpc, and we estimate that our sample is >70% complete at ∼150 kpc. We find excellent agreement with other wide-area RR Lyrae catalogs and RR Lyrae studies targeting the Magellanic Clouds and other Milky Way satellite galaxies. We fit the smooth stellar halo density profile using a broken-power-law model with fixed halo flattening (q = 0.7), and we find strong evidence for a break at

R

0

=

32.1

−
0.9

+
1.1

kpc

with an inner slope of

n

1

=
−

2.54

−
0.09

+
0.09

and an outer slope of

n

2

=
−

5.42

−
0.14

+
0.13

. We use our catalog to perform a search for Milky Way satellite galaxies with large sizes and low luminosities. Using a set of simulated satellite galaxies, we find that our RR Lyrae-based search is more sensitive than those using resolved stellar populations in the regime of large (r
h ≳ 500 pc), low-surface-brightness dwarf galaxies. A blind search for large, diffuse satellites yields three candidate substructures. The first can be confidently associated with the dwarf galaxy Eridanus II. The second has a distance and proper motion similar to the ultrafaint dwarf galaxy Tucana II but is separated by ∼5 deg. The third is close in projection to the globular cluster NGC 1851 but is ∼10 kpc more distant and appears to differ in proper motion.
Fast Optical Transients from Stellar-mass Black Hole Tidal Disruption Events in Young Star Clusters
Authors: Kremer Kyle , Lu Wenbin , Piro Anthony L. , Chatterjee Sourav , Rasio Frederic A. , Ye Claire S.
Published: April 2021

Observational evidence suggests that the majority of stars may have been born in stellar clusters or associations. Within these dense environments, dynamical interactions lead to high rates of close stellar encounters. A variety of recent observational and theoretical indications suggest stellar-mass black holes may be present and play an active dynamical role in stellar clusters of all masses. In this study, we explore the tidal disruption of main-sequence stars by stellar-mass black holes in young star clusters. We compute a suite of over 3000 independent N-body simulations that cover a range of cluster mass, metallicity, and half-mass radii. We find stellar-mass black hole tidal disruption events (TDEs) occur at an overall rate of up to roughly 200 Gpc−3 yr−1 in young stellar clusters in the local universe. These TDEs are expected to have several characteristic features, namely, fast rise times of order a day, peak X-ray luminosities of at least 1044 erg s−1, and bright optical luminosities (roughly 1041–1044 erg s−1) associated with reprocessing by a disk wind. In particular, we show these events share many features in common with the emerging class of Fast Blue Optical Transients.
Constraining Galaxy Halos from the Dispersion and Scattering of Fast Radio Bursts and Pulsars
Authors: Ocker Stella Koch , Cordes James M. , Chatterjee Shami
Published: April 2021

Fast radio bursts (FRBs) can be scattered by ionized gas in their local environments, host galaxies, intervening galaxies along their lines of sight (LOS), the intergalactic medium, and the Milky Way. The relative contributions of these different media depend on their geometric configuration and the internal properties of the gas. When these relative contributions are well understood, FRB scattering is a powerful probe of density fluctuations along the LOS. The precise scattering measurements for FRB 121102 and FRB 180916 allow us to place an upper limit on the amount of scattering contributed by the Milky Way halo to these FRBs. The scattering time

τ
∝
(

F

˜

×

DM

2

)

A

τ

, where DM is the dispersion measure,

F

˜

quantifies electron density variations with

F

˜

=
0

for a smooth medium, and the dimensionless constant A

τ
quantifies the difference between the mean scattering delay and the 1/e scattering time typically measured. A likelihood analysis of the observed scattering and halo DM constraints finds that

F

˜

is at least an order of magnitude smaller in the halo than in the Galactic disk. The maximum pulse broadening from the halo is τ ≲ 12 μs at 1 GHz. We compare our analysis of the Milky Way halo with other galaxy halos by placing limits on the scattering contributions from halos intersecting the LOS to FRB 181112 and FRB 191108. Our results are consistent with halos making negligible or very small contributions to the scattering times of these FRBs.
Discovery of an Extremely Short Duration Flare from Proxima Centauri Using Millimeter through Far-ultraviolet Observations
Authors: MacGregor Meredith A. , Weinberger Alycia J. , Loyd R. O. Parke , Shkolnik Evgenya , Barclay Thomas , Howard Ward S. , Zic Andrew , Osten Rachel A. , Cranmer Steven R. , Kowalski Adam F. , Lenc Emil , Youngblood Allison , Estes Anna , Wilner David J. , Forbrich Jan , Hughes Anna , Law Nicholas M. , Murphy Tara , Boley Aaron , Matthews Jaymie
Published: April 2021

We present the discovery of an extreme flaring event from Proxima Cen by the Australian Square Kilometre Array Pathfinder (ASKAP), Atacama Large Millimeter/submillimeter Array (ALMA), Hubble Space Telescope (HST), Transiting Exoplanet Survey Satellite (TESS), and the du Pont Telescope that occurred on 2019 May 1. In the millimeter and FUV, this flare is the brightest ever detected, brightening by a factor of >1000 and >14,000 as seen by ALMA and HST, respectively. The millimeter and FUV continuum emission trace each other closely during the flare, suggesting that millimeter emission could serve as a proxy for FUV emission from stellar flares and become a powerful new tool to constrain the high-energy radiation environment of exoplanets. Surprisingly, optical emission associated with the event peaks at a much lower level with a time delay. The initial burst has an extremely short duration, lasting for <10 s. Taken together with the growing sample of millimeter M dwarf flares, this event suggests that millimeter emission is actually common during stellar flares and often originates from short burst-like events.
Evidence of Extended Emission in GRB 181123B and Other High-redshift Short GRBs
Authors: Dichiara S. , Troja E. , Beniamini P. , O’Connor B. , Moss M. , Lien A. Y. , Ricci R. , Amati L. , Ryan G. , Sakamoto T.
Published: April 2021

We study the high-energy properties of GRB 181123B, a short gamma-ray burst (sGRB) at redshift z ≈ 1.75. We show that, despite its nominal short duration with T
90 < 2 s, this burst displays evidence of a temporally extended emission (EE) at high energies and that the same trend is observed in the majority of sGRBs at z ≳ 1. We discuss the impact of instrumental selection effects on the GRB classification, stressing that the measured T
90 is not an unambiguous indicator of the burst physical origin. By examining their environment (e.g., stellar mass, star formation, offset distribution), we find that these high-z sGRBs share many properties of long GRBs at a similar distance and are consistent with a short-lived progenitor system. If produced by compact binary mergers, these sGRBs with EE may be easier to localize at large distances and herald a larger population of sGRBs in the early universe.
The genus Thalictrum species as promising medicinal plants of the Tomsk region (Western Siberia)
Authors: Nekratova Anna N. , Zinner Nadezhda S. , Shchukina Anastasia V.
Published: April 2021

The genus Thalictrum species (Ranunculaceae) are of interest for study as medicinal plants that are promising for expanding the gene pool and treating socially significant diseases. The data of the analysis of more than 100 geobotanical descriptions obtained in 2010-2017 were used to study the coenotic complexes of Thalictrum minus and Thalictrum simplex growing in Tomsk region and to determine their ecological-coenotic confinement. The aim of our research was to study the species of the genus Thalictrum growing in Tomsk region, their distribution and use in medicine, to investigate the coenotic complex, and to determine the ecological-coenotic confinement of Thalictrum minus L. and Thalictrum simplex L. growing in Tomsk region. The coenotic complex of Thalictrum minus includes 146 species. Thalictrum minus is the reserve of raw materials of Category II, which are identified in species confined to coenoses of different synanthropic degree, where they grow abundantly. The coenotic complex of Thalictrum simplex in Tomsk region includes 62 species. Thalictrum simplex is the reserve of raw materials of Category II.
Neotropical Nilothauma Kieffer, 1921 (Diptera, Chironomidae): Key, eleven new species, re-descriptions, new combination and new records
Authors: Pinho Luiz Carlos , Andersen Trond
Published: April 2021

Nine new species of Nilothauma Kieffer, N. hamadaesp. nov., N. jupausp. nov., N. karitianasp. nov., N. lecciisp. nov., N. marianoisp. nov., N. mateusisp. nov., N. txukuyanasp. nov., N. werekenasp. nov. and N. yekwanasp. nov. are described and figured, based on adult males collected in Brazil and N. mayasp. nov. on an adult male from Mexico; N. terenasp. nov. is described as male, pupa and larva based on a reared specimen from Brazil. Nilothauma aleta Roback, 1960 and N. duena Roback, 1960 are re-described and recorded from Brazil. Nilothauma longissimum Mendes & Andersen, 2009 is transferred to Beardius Reiss & Sublette, 1985 and the diagnosis of Nilothauma is emended. New records of thirteen Neotropical Nilothauma species are given and a key to the males of all known species of Nilothauma is provided.
L'éthique en contexte info-communicationnel numérique
Authors: Arruabarrena Béa
Published: April 2021

Face au développement du Big data, la qualité des données a connu en quelques années, un regain d’intérêt pour devenir un thème central dans le débat sur le traitement des données massives tant du point de vue de la recherche scientifique que de celui des organisations. L’analyse quantitative de données, tributaire des caractéristiques du big data : son Volume, sa Vélocité, sa Variété et sa Valeur, soulèvent de nombreuses questions quant au traitement éthique des données. Cet article a pour objectif d’analyser au travers des débats actuels scientifiques les questions qui se rapportent à la qualité des données et à l’éthique des données tant au niveau des individus, des organisations que de la société. Dans un premier temps, cette démarche conduit à définir la qualité des données, ainsi que les objectifs qu’elle poursuit. Dans un second temps, il est examiné les différents enjeux qu’elle soulève, qu’ils soient éthiques, juridiques, technologiques ou organisationnels. À travers ces analyses, il est ensuite proposé une réflexion sur la qualité des données comme approche éthique inclusive dans les parcours de formation de data sciences .
L'éthique en contexte info-communicationnel numérique
Authors: Cormerais Franck
Published: April 2021

Cet article est consacré, dans une première partie, à un prolongement de la critique de l’économie de l’attention pour penser une transition qui mène à la capture de l’intention comprise comme l’autre face de la « data économie » reposant sur des algorithmes. La tentative de prise de contrôle de l’intention, comme achèvement d’un capitalisme cognitif, conduit à requalifier la relation entre intention et conscience à partir de la trace informatique. Dans une seconde partie, l’article s’attache à la défense d’une éthique et d’une politique de l’intention. Cette démarche conduit à penser les relations entre le volontaire et l’involontaire, réévaluant l’importance d’un consentement éclairé pour envisager un nouveau régime d’engagement collectif devant les écrans et les documents.
Evaluation of Maine's Telelecture Continuing Education Program: Part II
Authors: Rost Mary Ann , Barber Gerard M , Frank Thomas
Published: April 2021

Data collection forms were created to monitor a statewide continuing education program offered via an interactive audio teleconference network to nurses in Maine. These forms were designed as an integral part of the ongoing program of instructional delivery. Course and program utilization indicators as well as data generated about the program's financing arrangement enabled timely and sound decision-making on the part of program staff both in terms of minor adjustments as well as in terms of long range system planning.
Nurses' Willingness to Perform AIDS Patient Care
Authors: Kemppainen Jeanne , St Lawrence Janet S , Irizarry Andre , Weidema Donna R , Benne Candice , Fredericks Christine D , Wilson Marge
Published: April 2021

ABSTRACT

We evaluated nurses from hospitals with different prevalences of AIDS patients and with different levels of nursing education to measure their willingness to provide care to AIDS patients. Nurses who were most experienced in AIDS patient care, employed in high-prevalence hospitals, and who considered themselves most knowledgeable about infectious disease consistently were less willing to provide nursing care for AIDS patients. Nurses with BSN or MSN education employed in hospitals with low and moderate prevalence of AIDS were the most willing to provide AIDS patient care. The results are discussed in light of recent research on universal precautions adherence and factors that may contribute to increasingly negative attitudes for nurses who provide sustained AIDS patient care.
The School Nurse Development Program: An Experiment in Off-Site Delivery
Authors: Cowell Julia Muennich , Kahn Evelyn Henry , Bahrawy Aida A
Published: April 2021

ABSTRACT

The purpose of this study was to evaluate the effectiveness of a teleconferenced program by comparing multiple program outcomes of learners enrolled at three off-campus sites to Chicago-based learners. An adaptation of the Stake (1967) countenance model guided the evaluation. The data analysis consisted of descriptive statistics, cross-tabulations, and content analyses of comments. The results indicated no statistical differences between groups in grade point average, satisfaction with the program generally or with the teleconferencing process, tenure in school nursing, job stability, adoption of management strategies, and school health programs directed to aggregates.
Transfer of Continuing Education to Practice: Testing an Evaluation Model
Authors: Peden Ann R , Rose Harold , Smith Margaret
Published: April 2021

ABSTRACT

A continuing education (CE) program is successful only to the extent that a recommended practice or behavior is implemented. The social system in which the nurse practices and the nurse's own receptiveness to change also influence the application of new knowledge.
Codependency in Nursing: Using a Simulation/Gaming Teaching Method
Authors: Farnsworth Beverly J , Thomas Katherine Jean
Published: April 2021

ABSTRACT

Practicing nurses can benefit by learning to differentiate their caretaking (potentially destructive) from their caregiving (constructive) behaviors, and by learning strategies to facilitate caregiving. A new simulation/game was developed to assist nurses to recognize codependent behaviors in themselves and others and to practice some alternative patterns of behavior. This team-based simulation/game, "The Climb," uses the metaphor of a mountain-climbing expedition. The experiences of the journey promote dynamic insights into the consequences of codependency in the professional and personal lives of the nurse.
CERCLAGE OF THE LATERAL MALLEOLUS IN DISPLACED FRACTURES OF THE ANKLE
Authors: Oh Indong , Nahigian Stanley H , Salas A S , Zahrawi F B
Published: April 2021

ABSTRACT: When open reduction is indicated the lateral malleolus fracture should be reduced as accurately as the medial or posterior malleolar fragments. The cerclage for displaced oblique or spiral fractures of the lateral malleolus is a simple, effective way of internal fixation with a minimal amount of metal implanted. Under direct vision an anatomical reduction is achieved and maintained. The proper use of a 20- or 18 -gauge wire with a mechanical wire tightner-twister is mandatory. A below-the-knee plaster cast is necessary for support for an average of eight weeks. In this series, with correct technique, no wires have loosened or broken. There has been no resorption of bone or refracture at the wire-loop site. No second surgery has been needed for removal of wires. The case material included 50 cases of ankle fractures from 1964 through 1976. In a displaced bimalleolar or trimalleolar fracture, the cerclage can be used in conjunction with various other internal fixation screws or nails applied to the medial and/or posterior malleolar fragment. The exact method varies depending on the type of fracture present. With increasing recognition of the importance of anatomic reduction of the lateral malleolus in the ankle fracture management, cerclage technique will contribute further toward the restoration of the normal ankle joint mechanics.
THE BATEMAN UNIVERSAL PROXIMAL FEMORAL ASSEMBLY: EXPERIENCES WITH 80 CASES
Authors: Schildhaus Andrew I E
Published: April 2021

ABSTRACT: The Bateman Universal Proximal Femoral Assembly has been used primarily in the treatment of subcapital fractures of the femoral head when the acetabulum was judged to be adequate. The indications for this procedure are the same as for a standard hemiarthroplasty. A contraindication against its use is a severe neurologic disorder that might compromise the postoperative management. Its use in other than acute fracture cases is recommended only for special situations. This article discusses the approach, closure, technique of assembly, technique of judging stability, use of cement, problem of adventitious bone, stem type, replacements, and dislocations associated with the use of this appliance. The device is not a substitute for a total hip, but has certain theoretical advantages as an alternative to a hemiarthroplasty of conventional design.
DEGENERATIVE CHANGES OF THE LUMBAR SPINE: ASSESSMENT BY COMPUTED TOMOGRAPHY
Authors: Raskin Stephen P
Published: April 2021

ABSTRACT: Degenerative changes of the lumbar spine may occur in either the anterior or posterior intervertebral articulations. Computed tomography is an ideal modality in evaluating these processes because of its optimal plane of section and its ability to image both osseous and soft tissue structures.
THE RESULTS OF FIRST RIB RESECTION IN THORACIC OUTLET SYNDROME
Authors: Derkash Robert S , Goldberg Victor M , Mendelson Harvey , Mevicker Robert
Published: April 2021

ABSTRACT: Twenty cases of thoracic outlet syndrome in seventeen patients were treated by first rib resections through the transaxillary approach, after conservative therapy failed. The average follow up was twenty-four months. The mean age was thirtyfive years with a range of fifteen to fifty-four years. There were fourteen females and three males. The delay in diagnosis averaged four years with the most common mistaken diagnosis being cervical disc disease. Complications included two cases of pneumothorax, one wound infection, and one intraoperative hemorrhage. Fourteen of the patients had complete relief of pain while two of the patients were improved. There was only one patient who was considered a failure because of recurrent pain. It is concluded that this procedure should be considered when conservative measures fail. The orthopaedist is usually the first to see the patient, and therefore, the diagnosis should be considered in all patients with upper extremity pain.
Preliminary Experience With a Noncemented Nonconstrained Total Joint Arthroplasty for the Metacarpophalangeal Joints
Authors: Beckenbaugh Robert D
Published: April 2021

ABSTRACT: A nonconstrained, nonarticulated ball-and-socket-type stemmed resurfacing implant for the metacarpophalangeal joints of the fingers has been developed. The prosthesis is inserted with a press fit, and is made of a carbon material that allows appositional bone growth and biologic fixation. Preliminary experience in 15 patients (43 joints) with up to two years followup has demonstrated satisfactory clinical results and biologic acceptance of the device. A few complications have occurred, including recurrent deformity and subluxation of the prostheses. The device is indicated in patients with traumatic arthritis, and in younger patients with rheumatoid arthritis who have minimal soft-tissue disease and deformity.
Subtalar Dislocations: A Prognosticating Classification
Authors: Lancaster Steven , Horowitz Marshall , Alonso Jorge
Published: April 2021

ABSTRACT: A review of the literature and analysis of eight cases of subtalar dislocations was undertaken to correlate our experience with others and to determine a classification for prognostication. Our findings corresponded with those found by others. A 75% incidence of associated injuries was present in our series and these represented a continuum of varying degrees of complication. A new system was devised whereby increasing severity of associated injuries correlated with increasing rate of complications, including loss of motion, arthritis, pain and avascular necrosis. Dislocations were classified according to: no associated injuries, those with soft tissue injuries, extra-articular fractures, intra-articular fractures and those prone to development of avascular necrosis, ie, open dislocations and fractures of the body of the talus. It was found that associated fractures increased the immobilization period as well as the incidence of complications. Intra-articular fractures have demonstrated increased rates of arthroses in the subtalar joint. Avascular necrosis, an infrequent but devastating complication, is primarily associated with open dislocations and dislocations with concomitant fractures of the body of the talus. Our series had two open subtalar dislocations, neither of which developed avascular necrosis.
Free Flaps for Coverage of the Foot and Ankle
Authors: Koman L Andrew
Published: April 2021

ABSTRACT: Coverage of complex soft tissue injuries to the foot and ankle is difficult and often can be achieved only by the use of free flaps. Selection of the appropriate flap must be patient-oriented. Indications for composite tissue transfer are presented. In addition, the vascular anatomy and characteristics of commonly used flaps-the groin flap, the scapular flap, and the latissimus dorsi, tensor fascia lata, and gracilis flaps are presented along with case histories illustrating their utilization.
Translunate, Perilunate Fracture-Dislocation of the Wrist: A Case Report
Authors: Mason Gregg C , Bowman Michael W , Fu Freddie H
Published: April 2021

ABSTRACT: The following case report presents an unusual translunate, perilunate fracture-dislocation. To our knowledge, this occurrence has not been reported previously.
Metastatic Cancer in Paget's Disease of Bone: A Case Report
Authors: Nicholas John J , Srodes Charles H , Herbert David , Roy Ronald J , Peel Robert L , Goodman Mark A
Published: April 2021

ABSTRACT: A 50-year-old white male presented with concurrent Paget's disease of bone and metastatic adenocarcinoma. Our review of the literature and our clinical experience suggests that carcinoma coexisting at the site of bone involved with Paget's disease occurs more commonly than has been recognized. The paucity of reports of tumor metastatic to sites of Paget's disease of bone may be due to an artifact of data collection. The differentiation of metastatic from de novo tumors must be accomplished by biopsy, and the diagnosis is essential for appropriate treatment. Commonly a correlation of known tumor types with Paget's disease is made, and metastatic tumors are excluded.
Treatment of Giant Cell Tumor of the Distal Radius by Ulnar Translocation: A Case Report and Review of the Literature
Authors: Lalla Raj N , Bhupathi Srinivasa C
Published: April 2021

ABSTRACT: Presented is a case of giant cell tumor of the distal radius treated successfully by en bloc resection and translocation of the ipsilateral distal ulna. A good functional result was achieved with near full range of pronation and supination and 5° of flexion at the wrist. The advantage of this technique is that the ulna provides a locally available vascularized graft to bridge the gap created by resection of the radius.
Oxalosis: Cause of Degenerative Spinal Stenosis: A Case Report and Review of the Literature
Authors: Knight Reginald Q , Taddonio Rudolph F , Smith Fred B , Weseley Stephen , Pecker Howard M
Published: April 2021

ABSTRACT: The case presented illustrates an unusual entity. The differential diagnosis of degenerative spinal stenosis is voluminous, although incomplete without including oxalosis. Oxalosis as a cause of spinal stenosis has not yet been reported in the orthopedic literature.
Simultaneous Dorsal Dislocation of the Interphalangeal Joints in a Finger: Case Report and Review of the Literature
Authors: Ambrosia John M , Linscheid Ronald L
Published: April 2021

ABSTRACT: A case report and review of the English literature on the simultaneous dorsal dislocation of the interphalangeal joints of the finger are presented. This injury usually occurs on the ulnar side of the hand of young male athletes. It is easily reduced by a closed technique, although slight limitation of motion and joint swelling may persist.
Nonunion of the Tibial Shaft
Authors: Green Stuart A , Moore Thomas A , Spohn Peter J
Published: April 2021

ABSTRACT: Charts of 70 patients with 72 nonunions of the tibial shaft were reviewed, identifying 39 aseptic and 33 infected nonunions. Most nonunions started as an open fracture (76%), although 4 of the 12 patients with closed fractures became infected following surgical treatment. Seven patients (all of the septic group) had a below-knee amputation as their only procedure; amputation was eventually necessary for three other patients. In total, 90% of the aseptic nonunions healed, as did 79% of infected nonunions not amputated at the first procedure. The average time from injury to union was approximately 36 months for both aseptic and infected nonunions. Numerous complications occurred during treatment of tibial nonunions, the most common (61%) being angulation of greater than 5° in at least one plane.
Tibial Plateau Fractures
Authors: Anglen Jeffrey O , Healy William L
Published: April 2021

ABSTRACT: A retrospective study of 128 patients with fractures of the tibial plateau treated at the Johns Hopkins Medical Institutions over a 20-year period was undertaken to compare the results of operative treatment with the results of the nonoperative treatment. Outcome was evaluated with respect to healing, length of hospital stay, time to weight bearing and full activity, and functional result. The fractures were grouped into the four types of the Association for the Study of the Problems of Internal Fixation (AO/ASIF) system, with nondisplaced fractures considered separately. Overall, patients with displaced fractures treated operatively had a shorter average hospital stay (22 days vs 26 days), a higher percentage of satisfactory functional results (78% vs 63%), and a shorter period of immobilization (5 weeks vs 10 weeks), but took longer to return to prefracture activity level (23 weeks vs 18 weeks). The patients treated operatively had more complications with regard to infections (9 vs 2), fewer complications with regard to thromboembolism (2 vs 13), and approximately equal numbers of nonunion or malunion. Our study supports operative therapy for patients with displaced Type III or Type IV fractures and closed treatment for patients with Type I, Type II, and nondisplaced fractures.
Routine Radiographs in Acute Knee Distortions
Authors: Kannus Pekka , Järvinen Markku
Published: April 2021

ABSTRACT: The value of primary knee radiographs was examined in 144 cases with acute anterior cruciate ligament rupture to determine the ability of the films to reveal or confirm the correct diagnosis. In 15% of the patients, the radiographs were found to give significant diagnostic help by revealing typical avulsion fractures associated with injury to the ligament. Primary knee radiographs are recommended in every major knee ligament injury.
The Treatment of Displaced Metaphyseal Fractures with Screws and Wiring Systems
Authors: Rüedi Thomas
Published: April 2021

ABSTRACT: Within the context of modern fracture fixation, buttress plates have traditionally played an important role in stabilizing both intraarticular and extraarticular displaced metaphyseal fractures. While plating has substantially improved the assurance of union and functional recovery in these fractures, there is some interference with physiologic blood supply to the regions of the fracture and, consequently, to the biological elements of healing. This article outlines alternative methods of treatment for these fractures using screws and wiring systems with little, if any, loss of stability. Patients must be selected carefully and must have large fracture fragments and normal or near normal mineralization of their bones. When screw and wiring methods can be used, there is less tissue dissection and, consequently, less interference with the physiologic fracture healing process.
Implant Materials for Fracture Fixation: A Clinical Perspective
Authors: Disegi John A , Wyss Hansjoerg
Published: April 2021

ABSTRACT: The optimum management of traumatic skeletal fractures may involve the installation of high quality surgical implants by a skilled orthopedic surgeon. Satisfactory clinical results are very dependent on the ability to maintain stable fracture fixation. Well designed contemporary implants rely on precise control of material composition and properties to achieve a well tolerated level of biological response. Metallic materials, such as 31 6L stainless steel, pure titanium, and titanium alloys, demonstrate an acceptable combination of strength, ductility, corrosion resistance, and biocompatibility. Polymers, composites, and biodegradable materials may offer selected opportunities for fracture fixation. An understanding of relevant clinical factors is essential to evaluate potential applications for advanced materials.
Osteoarthritis After Colles' Fracture
Authors: Overgaard Søren , Solgaard Søren
Published: April 2021

ABSTRACT: Fifty-six patients with displaced Colles' fractures were examined 7 years after fracture. Slight radiographic changes of osteoarthritis were seen in 17 cases, moderate changes in 7 cases, and severe arthrosis in 1 case. At follow up, the occurrence of osteoarthritis was not related to radial shortening or residual dorsal angulation; it did show, however, a high correlation to the initial displacement of the fracture and the age of the patient. Radiographic osteoarthritis also influenced the function of the wrist, especially in the older patients.
Overuse Syndromes of the Upper Extremity in Interpreters for the Deaf
Authors: Cohn Lester , Lowry Rhonda M , Hart Sandra
Published: April 2021

ABSTRACT: Fourteen of 80 interpreters (18%) for deaf students at a national center on deafness sought medical care for painful conditions of the upper extremity; 11 others (14%) had less severe or transient symptoms. The conditions were brought on by repetitive use and were relieved by rest. All represented overuse syndromes. Tendinitis, fasciitis, synovitis, and nerve entrapment were encountered most often. Conservative treatment (eg, physical therapy, splinting, medications) was of little or no value. Only rest relieved symptoms. Surgery was rarely indicated. The most reasonable approach to treatment would, therefore, seem to be prevention. Suggested methods for avoidance of pain include limiting the duration of interpreting sessions, technique modification, and resistance exercises to increase endurance.
TREVOR DISEASE: DYSPLASIA EPIPHYSEALIS HEMIMELICA
Authors: Schmidt Mary Beth , Lomasney Laurie M
Published: April 2021

RADIOLOGIC CASE STUDY
FAT EMBOLISM SYNDROME
Authors: Johnson Michael J , Lucas George L
Published: April 2021

ABSTRACT

Since it was initially described, fat embolism syndrome (FES) has remained one of the least clearly understood complications of trauma. This article is a review of the classic and current literature on FES with regard to its causes, pathophysiology, clinical presentation, diagnosis, and treatment. FES is associated with many traumatic and nontraumatic conditions, but is most commonly associated with fractures of long bones of the lower extremity. The pathophysiology is thought to be a cascade of events which can lead to adult respiratory distress syndrome (ARDS). Signs and symptoms of clinical FES usually begin within 24 to 48 hours after trauma. The classic triad involves pulmonary changes, cerebral dysfunction, and petechial rash. Clinical diagnosis is key because laboratory and roentgenographic diagnosis is not specific. Treatment consists of careful initial handling, early stabilization of fractures, careful volume replacement, analgesia, respiratory support, and perhaps steroids. The vast majority of patients today survive FES without sequelae.
THE MINIARTHROTOMY TECHNIQUE OF ANKLE ARTHRODESIS: A CADAVER STUDY OF OPERATIVE VASCULAR COMPROMISE AND EARLY CLINICAL RESULTS
Authors: Miller Stuart D , Paremain Guy P , Myerson Mark S
Published: April 2021

ABSTRACT

We present a two-part study of the miniarthrotomy ankle fusion technique for minimally deformed joints: a laboratory investigation of ankle vascularity and a clinical review of the early results. In the laboratory portion, five pairs of cadaver legs were injected with radiographic dye, after which arthrodesis was performed via either the open technique (one leg of each pair) or the miniarthrotomy technique (the contralateral leg of each pair). Two legs in the open arthrodesis group had disruption of the peroneal arterial circulation, but no disruption was identified in the miniarthrotomy group. In the clinical portion of the study, we reviewed the results of 32 patients who had undergone ankle fusion via the miniarthrotomy technique. One patient had a nonunion and two patients had delayed union. The average time to union for the 31 patients was 8 weeks (range: 6 to 22). These results compare favorably to the arthroscopically assisted method of fusion and offers another choice for arthrodesis of minimally deformed ankles. We concluded that with minimal disruption, there is less likelihood of arterial injury and devascularization, which may indirectly have a positive effect on the rate of ankle arthrodesis.
Vascularized Fibular Grafting Compared With Core Decompression in the Treatment of Femoral Head Osteonecrosis
Authors: Kane Steve M , Ward W Alan , Jordan Linda C , Guilford W Bonner , Hanley Edward N
Published: April 2021

ABSTRACT

A prospective study was undertaken to compare vascularized fibular grafting (VFG) with core decompression for Ficat Grade II and III femoral head osteonecrosis. The study group included 39 hips in 34 patients-20 VFGs and 19 core decompressions. Independent evaluation of results was performed by an orthopedic surgeon and a radiologist at a minimum of 2 years postoperatively (range: 2 to 5 years). Disease extent was assessed by Ficat radiographic gradings. VFGs failed (conversion to total hip arthroplasty for functionally incapacitating pain) at a rate of 20%, significantly lower than the 58% failure rate of core decompressions (P = .025). Complications included 2 proximal femur fractures in each group, ankle pain in 6 VFGs, and graft vessel thrombosis in 1 VFG. Vascularized fibular grafting appears superior to core decompression in prolonging hip joint survivorship for Ficat Grades II and III femoral head osteonecrosis.
Early Outcome of Total Hip Arthroplasty Using the Direct Lateral vs the Posterior Surgical Approach
Authors: Barber Thomas C , Roger Douglas B , Goodman Stuart B , Schurman David J
Published: April 2021

ABSTRACT

A consecutive series of 49 patients who had a primary total hip arthroplasty (THA) for osteoarthritis is reviewed to determine the differences in clinical outcome between the direct lateral and the posterior surgical approaches to the hip. Group 1 comprised 28 patients who had THA by the same surgeon using a posterolateral approach. Group 2 comprised 21 patients who had THA using the direct lateral approach, modified from Hardinge. The improvement in the limp, abductor strength, Trendelenburg test, and range of motion over time was similar in the two groups. The average Harris hip score at 1 year was 90 for Group 1 (posterior approach) and Group 2 (lateral approach). At 2-year minimum follow up, the Harris hip score was 94 for both groups. Radiographic review showed that the incidence and severity of heterotopic bone was also similar for both groups. The authors conclude that the clinical and radiographic outcome for THA using the posterior and the lateral approaches to the hip yield similar clinical results.
An Open-Label, Randomized Study to Compare the Safety and Efficacy of Perioperative Epoetin alfa With Preoperative Autologous Blood Donation in Total Joint Arthroplasty
Authors: Stowell Christopher P , Chandler Hugh , Jové Maurice , Guilfoyle Mary , Wacholtz Mary C
Published: April 2021

ABSTRACT

A multicenter, randomized, open-label, parallel-group study was conducted to compare the safety and efficacy of perioperative recombinant human erythropoietin (Epoetin alfa) with the safety and efficacy of preoperative autologous donation (PAD) in total joint arthroplasty. A total of 490 patients scheduled for total joint (i.e., hip or knee) surgery and having hemoglobin (Hb) levelss ≥ 11 to ≤ 13 g/dL were randomized to receive weekly doses of subcutaneous Epoetin alfa on preoperative Days -21, -14, and -7, and on the day of surgery, or to participate in a PAD program. The mean baseline Hb level in both groups was 12.3 ± 0.6 g/dL, increasing to 13.8 g/dL in the Epoetin alfa-treated group and decreasing to 11.1 g/dL in the PAD group before or on the day of surgery. In the PAD group, 156/219 (71 .2%) patients were transfused with autologous blood, and 42/219 (19.2%) patients were transfused with allogeneic blood. A smaller proportion, 27/209 (12.9%) patients, in the Epoetin alfa-treated group were transfused with allogeneic blood (P = .078 compared with the PAD group). Moreover, patients in the PAD group received a total of 325 units of blood (79 allogeneic units and 246 autologous units) compared with patients in the Epoetin alfa group who received a total of 54 units of blood. The mean postoperative Hb level was 11.0 g/dL in the Epoetin alfa-treated group and 9.2 g/dL in the PAD group. Compared with the PAD arm, mean Hb levels measured preoperatively, postoperatively on Day 1, and at discharge visits were significantly greater in the Epoetin alfa-treated arm (P < .0001).
Assessment of Postoperative Vigor in Patients Undergoing Elective Total Joint Arthroplasty: A Concise Patient- and Caregiver-Based Instrument
Authors: Keating E Michael , Ranawat Chitranjan S , Cats-Baril William
Published: April 2021

ABSTRACT

Assessment of early postoperative recuperative power (i.e., vigor and functional ability) in surgery patients is considered to be important for optimizing patient rehabilitation, discharge planning, and health system resource utilization. However, no broadly accepted method of patient assessment has been available to measure these parameters. Therefore, a panel of experts was assembled to design an instrument to assess recuperative power in the total joint arthroplasty setting. The instrument consists of both subjective, patient-based, preoperative and postoperative, fixedended questions and objective, caregiver-based measures of patient function (i.e., muscle strength and hematocrit [HCT]). The prototype instrument employed the vitality subscale of the Short Form-36 (SF-36), the activities of daily living items from the Western Ontario and McMaster University Osteoarthritis Index (WOMAC-ADL), as well as three novel scales: Well-being, Ready to resume activities, and Ready to leave the hospital. The instrument was tested in 65 patients at two medical centers. The reliability and validity of the three novel psychometric scales were tested by measuring internal consistency and validity by comparison with the standard scales. Postoperative patient Well-being and Ready scales correlated strongly with muscle strength (P < .01), while postoperative HCT correlated with muscle strength (r = 0.4) and Ready scale (P < .01 ). This analysis suggested that patient well-being and readiness to resume normal activities may be the best surrogates of patient vigor and that these parametric assessments correlate well with functional and laboratory measures of vigor (i.e., muscle strength and HCT). Based on these findings, the final instrument (Version 4.2) consists of a patient questionnaire that can be completed within approximately 5 minutes (12 preoperative and 14 postoperative questions), and a caregiver questionnaire that includes two objective functional tests: muscle strength and HCT. In conclusion, postoperative vigor may be able to be assessed with a concise, patient-based instrument and may provide valuable information for rehabilitation and discharge planning. The utility of this instrument is currently being assessed in a prospective clinical study.
Migration of the Uncemented CLS Acetabular Component
Authors: Davies M S , Parker B C , Ward D A , Hern E , Hua J , Walker P S
Published: April 2021

ABSTRACT

The migration of uncemented press-fit CLS (Cementless Total Hip Replacement System) acetabular cups was measured retrospectively from standard anteroposterior pelvic radiographs using a digitizer and software specifically developed for this study. A radiographic and clinical review also were undertaken. There were 96 patients in the study group. The mean follow-up for radiographic review was 2.23 years, and the mean foilow-up for clinical review was 3 years. Migration was measured in the cranial and medial directions.

Mean migration of the cup at 2 years was 1 .35 mm in the cranial direction and 2.15 mm in the medial direction. Radiographic appearances altered little over the study period. Fifty-five (57.3%) patients demonstrated bone ingrowth onto the prosthesis, predominantly in DeLee and Chamley zone 1. Twenty-one patients demonstrated nonprogressive sclerotic lines; no lucent lines were encountered. Statistical analysis showed a significant correlation between acetabular ingrowth and reduced cup migration in the medial direction (P=.01 1 at 5 years). There was no statistical relationship between migration of the cup and radiographic features or clinical outcome.
The Effect of Varus Tilt on Contact Stresses in Total Knee Arthroplasty: A Biomechanical Study
Authors: Matsuda Shuichi , Whiteside Leo A , White Stephen E
Published: April 2021

ABSTRACT

The contact stress produced in the tibiofemoral joint from a varus-tilted tibial component was tested in five total knee prostheses. Peak and mean stresses were measured with a digital electronic sensor under compressive load at 15° and 90° flexion. Stresses were measured with the tibial component tilted 0° and 5° in the mediolateral direction. At a 5° tilt, the Advantim, the Miller-Galante II, and the Omnifit prostheses, which have a flat configuration on the femoral and tibial surfaces in the coronal plane, had significantly greater stresses than the LCS and the Prof'ix prostheses, which have tibial and femoral components with matching curved surfaces in the coronal plane. These results suggest that the femoral component surface should have a radius of curvature that matches that of the tibial articular surface in the coronal plane to achieve a large contact area even in varus-valgus tilting.
The Significance of Stem-Cement Loosening of Grit-Blasted Femoral Components
Authors: Schmalzried Thomas P , Zahiri Christopher A , Woolson Steven T
Published: April 2021

ABSTRACT

This study analyzed 1 5 patients who underwent revision for loosening at the stem-cement interface. The femoral components were from the same manufacturer and had grit-blast roughened surfaces. An apparent radiographic deficiency in the cement mantle was present in at least one zone in 1 3 patients. In 9 of 12 patients with localized osteolysis, the osteolysis developed in a zone with an apparent radiographic cement mantle defect. Loosening occurred due to tension failure of the stem-cement interface followed by axial subsidence and movement into relative retroversion. Motion between the stem and the cement mantle fueled an abrasive wear mechanism between the roughened metal surface and the cement mantle, generating excessive metal and cement particles that gained access to endosteal bone via defects in the cement mantle and resulting in localized osteolysis.

Although the roughened surface played a central role in these failures, it is unlikely the layer of polymethylmethacrylate (precoat) played a role in the mechanism of failure. In some cases, debonding occurred as a result of tension failure of the metal-precoat interface. In others, tension failure occurred within the cement mantle, leaving the precoat and some cement from the mantle on the stems. There was no difference in the mechanism of failure of stems with precoat proximally compared to stems with precoat proximally and distally. One stem had no precoat; findings in this patient were indistinguishable from the others. The significance of debonding depends on the surface roughness of the stem. Debonding carries a poorer prognosis with a rougher stem surface because of abrasive wear with the generation of numerous metal and cement particulates, which can lead to rapid osteolysis if there are cement mantle defects. Stems with a higher metal-cement bond strength may require a higher quality cement mantle for long-term success.
Fibula Lengthening Using a Modified Ilizarov Method
Authors: Rozbruch S Robert , DiPaola Matthew , Blyakher Arkady
Published: April 2021

A combination of external and internal fixation techniques for a fibular lengthening procedure using the Ilizarov method is described. The technique is minimally invasive, allows precise deformity correction, enables early weight bearing, and minimizes the time that the patient wears the external fixator.
The Running Near-Near-Far-Far Stitch for Closure of Fasciotomies and Other Large Wounds
Authors: Dahners Laurence E
Published: April 2021

The running near-near-far-far stitch is useful for the closure of large wounds such as those created by fasciotomy. The far limb of the suture can be placed outside the injury zone and the near limb helps approximate the wound edges. The running nature of the suture balances the tension throughout the wound and allows the suture to be tightened once swelling has receded.
Diabetic Neuroarthropathy (Charcot Joints): The Importance of Recognizing Chronic Sensory Deficits in the Treatment of Acute Foot and Ankle Fractures in Diabetic Patients
Authors: Graves Matthew , Tarquinio Thom A
Published: April 2021

Patients with diabetic neuropathy are at a higher risk of developing complications, especially Charcot arthropathy. Early diagnosis and intervention is the key to optimizing outcome. Therefore, diabetic patients with a lower extremity injury should be screened with sensory testing using a 5.07 monofilament.