المؤلفون: Ruben A. Mazzucchelli, Christoph Meier, Peter Wahl

المصدر: JBJS case connector. 12(2)

مصطلحات موضوعية: Hip Fractures, Arthroplasty, Replacement, Hip, Teriparatide, Humans, Osteoporosis, Pain, Orthopedics and Sports Medicine, Surgery, Female, Aged

الوصف: Total hip arthroplasty with an uncemented, tapered, fluted stem was performed in a 79-year-old woman with known osteoporosis to treat an intertrochanteric fracture. Exertional thigh pain and cortical thickening developed at the tip of the stem. The patient was treated with teriparatide for a total of 2 years and became asymptomatic within months. Radiographs showed improved bone quality around the stem of the prosthesis, and dual-energy x-ray absorptiometry scans confirmed remineralization.Stem tip pain is a well-known complication of distally engaging arthroplasty implants. Various surgical options have been suggested to address this condition. Teriparatide is known to help prevent fractures and improve bone healing. This successful off-label use might be of interest for the future treatment of this biomechanical complication.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ad45285cc620ec04ccd3dab533a6e53fTest
https://pubmed.ncbi.nlm.nih.gov/36099530Test

المؤلفون: Ruben A, Mazzucchelli, Tenzin, Lamdark, Christoph, Meier, Egil A, Brøns

المصدر: Unfallchirurgie (Heidelberg, Germany)Literatur. 125(12)

مصطلحات موضوعية: Tendons, Leg, Tendon Injuries, Muscles, Joint Dislocations, Humans, Female, Aged

الوصف: We report the case of a 69-year-old female patient who sustained a traumatic anterior dislocation of the tibialis posterior muscle tendon. A computed tomography (CT) scan demonstrated an osseous avulsion of the flexor retinaculum with the tendon dislocated underneath it. The patient underwent surgical exploration with reduction of the tendon to its anatomical position and screw fixation of the avulsed fragment. The postoperative course showed pain-free mobility and no signs of tibial posterior muscle tendon insufficiency.Eine 69-jährige Patientin zog sich anlässlich eines Distorsionstraumas des Sprunggelenkes eine isolierte anteriore Luxation der M. tibialis-posterior-Sehne zu. Computertomographisch zeigte sich die Sehne nach ventral intraossär disloziert und eingeklemmt. Es erfolgte die operative Versorgung mit Reposition der Sehne in die anatomische Position und Refixation der ossären Avulsion des Retinaculum flexorum. Im Verlauf zeigte sich die Patientin beschwerdefrei mobil. Eine M.-tibialis-posterior-Insuffizienz bestand nicht.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::db950947df8ffb5f83f0abe9d36237cdTest
https://pubmed.ncbi.nlm.nih.gov/35179612Test

المؤلفون: Julia, Spoendlin, Eva, Blozik, Sereina, Graber, Marlene, Rauch, Carole, Marxer, Stephan, Ruegg, Christoph, Meier, Ursula, Winterfeld, Alice, Panchaud

المصدر: Swiss medical weekly. 151

مصطلحات موضوعية: Pregnancy, Valproic Acid, Humans, Female

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::af0ed54e00e228c608fc7281fcea876cTest
https://pubmed.ncbi.nlm.nih.gov/33641107Test

المؤلفون: Bernd Klaeser, Wouter Beel, Fabian Kalberer, Peter Wahl, Christoph Meier

المصدر: JBJS Case Connector. 11

مصطلحات موضوعية: musculoskeletal diseases, Single Photon Emission Computed Tomography Computed Tomography, Arthroplasty, Replacement, Hip, Radiography, medicine.medical_treatment, Prosthesis Design, 03 medical and health sciences, 0302 clinical medicine, Cement mantle, Female patient, Humans, Medicine, Orthopedics and Sports Medicine, 030212 general & internal medicine, Cementation, Aged, 030222 orthopedics, medicine.diagnostic_test, business.industry, Centralizer and normalizer, Low back pain, Arthroplasty, Female, Surgery, Hip Prosthesis, medicine.symptom, Nuclear medicine, business, Emission computed tomography, Total hip arthroplasty

الوصف: Case A 70-year-old female patient underwent total hip arthroplasty (HA) using a stem cemented line-to-line without centralizer. Postoperatively, she complained of load-dependent thigh pain. Conventional radiographs identified cortical overload because of a distal cement mantle discontinuity at the level of the stem's tip, confirmed by single-photon emission computed tomography/computed tomography scan (SPECT/CT). After cement-in-cement revision using a stem with centralizer, pain ceased rapidly. The cortical overload disappeared, as confirmed on a following SPECT/CT performed for low back pain. Conclusion In HA, the stem's tip may cause overload on the bone's cortex if the cement mantle is incomplete. Implanting a stem with centralizer avoids or cures this.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::99207a7f4c76e3d79908457a818f4173Test
https://doi.org/10.2106/jbjs.cc.20.00973Test

المؤلفون: Pascal W. Hasler, Javier Zarranz-Ventura, Catherine A Egan, Christoph Meier, Matthias Mooser, Adnan Tufail, Boris Povazay, Peter Maloca, Simon P. Rothenbuehler, Philipp L. Müller, Luca Cedro, Hendrik P. N. Scholl, Pascal Kaiser, Christian Burri

المصدر: Ophthalmic research. 64(1)

مصطلحات موضوعية: Adult, Male, medicine.medical_specialty, Visual acuity, genetic structures, Ocular Pathology, Retina, Cellular and Molecular Neuroscience, chemistry.chemical_compound, Young Adult, Optical coherence tomography, Reference Values, Ophthalmology, medicine, Humans, Dual wavelength, Prospective Studies, medicine.diagnostic_test, business.industry, Reproducibility of Results, Retinal, General Medicine, Equipment Design, Middle Aged, eye diseases, Sensory Systems, medicine.anatomical_structure, chemistry, Feasibility Studies, Female, sense organs, medicine.symptom, Coaxial, business, Retinal scan, Tomography, Optical Coherence, Follow-Up Studies

الوصف: Purpose: To evaluate the feasibility and safety of a coaxial dual-wavelength optical coherence tomography (OCT) device (marked as Hydra-OCT). Methods: Healthy participants without ocular pathology underwent retinal imaging using the Hydra-OCT allowing for simultaneous measurement of retinal scanning of 840 and 1,072 nm wavelength. Before and after measurement, best-corrected visual acuity and patients’ comfort were assessed. Representative OCT images from both wavelengths were compared by 5 independent graders using a subjective grading scheme. Results: A total of 30 eyes of 30 participants (8 females and 22 males) with a mean age of 26.5 years (range from 19 to 55 years) were included. Dual-wavelength image acquisition was made possible in each subject. The participant’s effort and comfort assessment using the Hydra-OCT imaging revealed an equivalent value as compared to the commercially available OCT machine. No adverse events were reported, and visual acuity was not altered by the Hydra-OCT. Imaging between the systems was comparable. Conclusions: This study provides evidence for the feasibility and safety of a coaxial dual-wavelength OCT imaging method under real-life conditions. The novel Hydra-OCT imaging device may offer additional insights into the pathology of retinal and choroidal diseases.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f068a9f4ab9984150f2388dcb4e949a4Test
https://pubmed.ncbi.nlm.nih.gov/32428922Test

المؤلفون: Ladislav Mica, Jürgen Hänggi, Erika J. Ulbrich, Andreas Müller, Sönke Johannes, Christoph Meier, Lutz Jäncke, Hans-Peter Simmen, Patrizia Dall'Acqua, Markus Schwendinger, Javier Fandino, Richard Glaab

المصدر: Journal of Neurotrauma. 34:3270-3279

مصطلحات موضوعية: Adult, Male, Adolescent, Traumatic brain injury, Prefrontal Cortex, 050105 experimental psychology, Young Adult, 03 medical and health sciences, 0302 clinical medicine, Neuroplasticity, medicine, Humans, 0501 psychology and cognitive sciences, Longitudinal Studies, Effects of sleep deprivation on cognitive performance, Prefrontal cortex, Brain Concussion, Neuroinflammation, medicine.diagnostic_test, business.industry, 05 social sciences, Magnetic resonance imaging, Cognition, Middle Aged, medicine.disease, Magnetic Resonance Imaging, Brain stimulation, Female, Neurology (clinical), business, Neuroscience, 030217 neurology & neurosurgery

الوصف: The objective of this study was to evaluate group-by-time interactions between gray matter morphology of healthy controls and that of patients with mild traumatic brain injury (mTBI) as they transitioned from acute to chronic stages, and to relate these findings to long-term cognitive alterations to identify distinct recovery trajectories between good outcome (GO) and poor outcome (PO). High-resolution T1-weighted magnetic resonance images were acquired in 49 mTBI patients within 7 days and 1 year post-injury and at equivalent times in 49 healthy controls. Using linear mixed-effects models, we performed mass-univariate analyses and associated the results of the interaction with changes in cognitive performance. Morphological alterations indexed by increased or decreased cortical thickness have been expected mainly in frontal, parietal, and temporal brain regions. A significant interaction was found in cortical thickness, spatially restricted to bilateral structures of the prefrontal cortex, showing thickening in mTBI and normal developmental thinning in controls. A discrete thickness increase that can interpreted as the absence of cortical thinning typically seen in the healthy population was associated with cognitive recovery in the GO subgroup, while the exaggerated cortical thickening in the PO patients was linked to worsening cognitive performance. Thickness of the prefrontal cortex is subject to structural alterations during the first year after mTBI. Beside beneficial neuroplasticity, a prolonged state of neuroinflammation for symptomatic patients (maladaptive neuroplasticity) cannot be excluded. If the underlying cellular processes responsible for cortical thickening following mTBI have been determined, brain stimulation or even pharmacological intervention targeting the prefrontal cortex might promote endogenous neural restoration.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ba043e1c4a778e8b0716fb55e58e8877Test
https://doi.org/10.1089/neu.2017.5124Test

المؤلفون: Mathias Völlink, Michel Schläppi, Patrick Grüninger, Christoph Meier, Fabian Wolfensperger, Emanuel Benninger, Michael Dietrich

المصدر: Journal of Shoulder and Elbow Surgery. 26:1462-1468

مصطلحات موضوعية: Male, medicine.medical_specialty, Proximal humerus, medicine.medical_treatment, Pain medication, Reverse shoulder, 03 medical and health sciences, 0302 clinical medicine, Quality of life, Pain control, Shoulder Pain, Dash, Humans, Pain Management, Medicine, Orthopedics and Sports Medicine, Humerus, Prospective Studies, Life Style, Aged, Aged, 80 and over, Analgesics, 030222 orthopedics, Shoulder Joint, business.industry, 030229 sport sciences, General Medicine, Arthroplasty, Surgery, Treatment Outcome, medicine.anatomical_structure, Arthroplasty, Replacement, Shoulder, Quality of Life, Shoulder Fractures, Physical therapy, Female, business, Follow-Up Studies

الوصف: Background This study investigated early functional outcome, quality of life, and the level of independency in elderly patients after primary reverse shoulder arthroplasty (RSA) for complex fractures of the proximal humerus. Methods This was a prospective case series that included 33 patients, aged ≥70 years, with a high level of independency who received RSA for complex fractures of the humerus (Orthopaedic Trauma Association B2/C) from January 2012 to April 2014. Results Level of independency, quality of life (Short Form 36 Health Survey score), early functional outcome (Constant-Murley score, Disabilities of the Arm, Shoulder and Hand Outcome Measure), and pain medication (World Health Organization grading) were obtained at the 6-month follow-up and 1 year after surgery. The Constant-Murley score was 64 ± 14 after 6 months and 71 ± 12 at 1 year (P

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8fa57213c0203f664ba17443d238d2c1Test
https://doi.org/10.1016/j.jse.2017.01.021Test

المؤلفون: Alex Dommann, Christoph Meier, Corina Dommann-Scherrer, Peter Wahl, Richard Cook, Mara Büchner

المصدر: Journal of the Mechanical Behavior of Biomedical Materials. 115:104304

مصطلحات موضوعية: Reoperation, Small diameter, Arthroplasty, Replacement, Hip, Biomedical Engineering, Total hip replacement, Dentistry, 02 engineering and technology, Prosthesis Design, Biomaterials, 03 medical and health sciences, 0302 clinical medicine, Bearing surface, Humans, Medicine, Direct analysis, Aged, Inlay, business.industry, 030206 dentistry, Metal debris, 021001 nanoscience & nanotechnology, Prosthesis Failure, Mechanics of Materials, Metal-on-Metal Joint Prostheses, Female, Hip Prosthesis, Anterior approach, 0210 nano-technology, business, Total hip arthroplasty

الوصف: Adverse reaction to metal debris (ARMD) is an issue in metal-on-metal (MoM) total hip replacements (THR). It mainly affects large-head MoM THR, whereas 28–32 mm MoM pairings are associated with low long-term revision rates. However, the bearing surface is not necessarily the only cause of metal debris. This report documents with advanced analysis of the retrievals a particular cause of trunnionosis in late failure of a small diameter MoM THR and illustrates the importance of cleaning of the taper when seating the head in THR. A 65-year-old patient was revised due to ARMD 16 years after small diameter MoM THR. Debridement and exchange of the inlay and the head had been performed through an anterior approach. While the cup and the outer surface of the head were accessible to direct analysis by an optical coordinate measuring machine, the female taper had to be analysed indirectly by measuring an imprint. Wear from the cup and the head was within expected low ranges. The analysis of the female taper identified bone fragments, which contributed to trunnionosis. Failure due to ARMD after MoM THR is not necessarily caused by the bearing, but can be due to trunnionosis. Bone fragments within the taper contact in this case highlight the importance of meticulous cleaning of the taper before seating the head, to avoid trunnionosis.

وصف الملف: text

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::449d13e55eeec69da48be183c96b758dTest
https://doi.org/10.1016/j.jmbbm.2020.104304Test

المؤلفون: Christoph Meier, Emanuel Benninger

المصدر: Injury. 48:615-620

مصطلحات موضوعية: Male, Humeral Fractures, medicine.medical_specialty, Humerus fracture, Deltoid curve, Fracture Fixation, Internal, 03 medical and health sciences, 0302 clinical medicine, Peripheral Nerve Injuries, Deltoid muscle, Cadaver, medicine, Humans, Minimally Invasive Surgical Procedures, Humerus, 030212 general & internal medicine, Muscle, Skeletal, Radial nerve, General Environmental Science, 030222 orthopedics, business.industry, Brachialis muscle, Anatomy, medicine.disease, Tendon, Surgery, medicine.anatomical_structure, General Earth and Planetary Sciences, Female, Radial Nerve, Axillary nerve, business, Bone Plates

الوصف: Introduction Minimally invasive lateral placement of plates on the humerus may be associated with a risk of injury to the radial nerve. Whereas this potential complication has been investigated in several studies, there is no data regarding potential injuries to the distal insertion of the deltoid muscle when the plates are passed distally in a submuscular tunnel. Methods Minimally invasive plate placement was performed on eight arms in fresh cadavers. A lateral deltoid split approach was made and the plates were introduced in an antegrade submuscular manner from proximal to distal. A lateral distal incison was made to adjust the position of the plate at the lateral aspect of the humerus without formal exploration of the radial nerve. The arms were dissected to identify the seven intramuscular tendons of the deltoid and their insertions at the humerus. The position of the plate and its relation to the intramuscular tendons of the deltoid was explored. Furthermore, potential injuries to the axillary and radial nerve were investigated. Damage to the brachialis muscle its interference with plate positioning were explored. Results The distal deltoid insertion was affected in all eight examined arms. The two most anterior and two most posterior segments were intact in all. In two arms, the third intramuscular tendon was perforated. In three specimens, the insertion of the fourth segment was damaged. The fifth segment was partially disrupted in three arms. Overall, injuries to the intramuscular tendons were limited to one tendon in all arms. Partial brachial muscle entrapment underneath the plate was observed in four specimens. The axillary nerve was not damaged in any of the examined arms. The radial nerve was entrapped between plate and humeral shaft in one case. Conclusions Lateral plate placement in MIPO technique damages central parts of the distal deltoid muscle insertion. However, the most anterior and posterior tendons are not involved and the clinical significance on muscle function remains unclear. Introduction of the plate without prior distal incision and elevation of the brachial muscle may be associated with partial entrapment of the brachial muscle and a higher risk of injuring the radial nerve. Level of evidence Experimental study.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::916ab6fa42b792aaae72e994f85be246Test
https://doi.org/10.1016/j.injury.2017.01.026Test

المؤلفون: Chi Ho To, Alina Giger, Rachel Ka Man Chun, Selim Orgül, Philippe C. Cattin, Peter Maloca, Christoph Meier, Tiziano Ronchetti, Christoph Jud, Boris Považay, Hendrik P. N. Scholl, Quan Liu

المصدر: PLoS ONE, Vol 14, Iss 6, p e0218776 (2019)
PLoS ONE

مصطلحات موضوعية: Male, genetic structures, Computer science, 01 natural sciences, 0302 clinical medicine, Healthy volunteers, Medicine and Health Sciences, Myopia, Segmentation, Longitudinal Studies, Child, Visual Impairments, Ground truth, Multidisciplinary, Applied Mathematics, Simulation and Modeling, Statistics, Healthy Volunteers, medicine.anatomical_structure, Research Design, Physical Sciences, Medicine, Female, Anatomy, Algorithms, Tomography, Optical Coherence, Research Article, Adolescent, Ocular Anatomy, Science, Research and Analysis Methods, Retina, 010309 optics, 03 medical and health sciences, Imaging, Three-Dimensional, Ocular System, 0103 physical sciences, medicine, Humans, Models, Statistical, Choroid, business.industry, Biology and Life Sciences, Pattern recognition, Ophthalmology, 030221 ophthalmology & optometry, Eyes, Similarity Measures, Human eye, Artificial intelligence, business, Head, Mathematics

الوصف: Monitoring subtle choroidal thickness changes in the human eye delivers insight into the pathogenesis of various ocular diseases such as myopia and helps planning their treatment. However, a thorough evaluation of detection-performance is challenging as a ground truth for comparison is not available. Alternatively, an artificial ground truth can be generated by averaging the manual expert segmentations. This makes the ground truth very sensitive to ambiguities due to different interpretations by the experts. In order to circumvent this limitation, we present a novel validation approach that operates independently from a ground truth and is uniquely based on the common agreement between algorithm and experts. Utilizing an appropriate index, we compare the joint agreement of several raters with the algorithm and validate it against manual expert segmentation. To illustrate this, we conduct an observational study and evaluate the results obtained using our previously published registration-based method. In addition, we present an adapted state-of-the-art evaluation method, where a paired t-test is carried out after leaving out the results of one expert at the time. Automated and manual detection were performed on a dataset of 90 OCT 3D-volume stack pairs of healthy subjects between 8 and 18 years of age from Asian urban regions with a high prevalence of myopia.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f1910050a638edcd1b255945f50ae8a9Test
https://doaj.org/article/58fd4c8a5b574badb8d60906f13423a2Test