Niels Hammer

Niels Hammer
Medical University of Graz · Macroscopic and Clinical Anatomy

Professor

About

271
Publications
49,212
Reads
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2,228
Citations
Introduction
Niels Hammer chairs the Department of Macroscopic and Clinical Anatomy, Medical University of Graz, Austria. He is co-affiliated with the Department of Orthopedic and Trauma Surgery of the University Hospital of Leipzig and the Fraunhofer IWU, Dresden, Germany. His research is on Musculoskeletal Biomechanics, Clinical Anatomy, Tissue Engineering, Emergency Medicine and Surgery. Dr Hammer is furthermore the president of the Austrian Society of Anatomy (GANÖ).
Additional affiliations
July 2019 - August 2019
Technische Universität Chemnitz
Position
  • Virtual Reality and Biomechanics
July 2018 - present
March 2018 - present
University of Leipzig
Position
  • Biomechanics

Publications

Publications (271)
Article
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Background Overall life expectancy continues to rise, approaching 80 years of age in several developed countries. However, healthy life expectancy lags far behind, which has, in turn, contributed to increasing costs in healthcare. One way to improve health and attenuate the socio-economic impact of an aging population is to increase overall fitness...
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In acetabular dysplasia, the cartilaginous roof on the acetabular side does not fully cover the femoral head, which may lead to abnormal stress distribution in both the femoral head and pelvis. These stress changes may have implications to the adjacent sacroiliac joint (SIJ). The SIJ has a minimal range of motion and is closely coupled to the adjac...
Preprint
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Purpose Elastic knee sleeves are often worn following anterior cruciate ligament reconstruction but mechanisms underlying observed changes in movement patterns are still unclear. The aim of this study was to determine the immediate and 6-week effects of wearing a knee sleeve on ground reaction forces (GRF) and knee joint power during a step-down ho...
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Improved surgical procedures and implant developments for ligament or tendon repair require an in-depth understanding of tissue load-deformation and fatigue properties. Cyclic testing will provide crucial information on the behavior of these materials under reoccurring loads and on fatigue strength. Sparse data are available describing soft tissue...
Article
Surgical resection of chest wall tumours may lead to a loss of ribcage stability and requires reconstruction to allow for physical thorax functioning. When titanium implants are used especially for larger, lateral defects, they tend to break. Implant failures are mainly due to specific mechanical requirements for chest-wall reconstruction which mus...
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The alteration in mechanical properties of posterior pelvis ligaments may cause a biased pelvis deformation which, in turn, may contribute to hip and spine instability and malfunction. Here, the effect of different mechanical properties of ligaments on lumbopelvic deformation is analyzed via the finite element method. First, the improved finite ele...
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In 1992, Walter Thiel described and embalming method that rendered ‘lifelike’ tissues. Over the last 30 years, the Thiel method has been introduced worldwide for medical training and scientific purposes. This review examines research which can be linked to the use of Thiel embalming. A systematic review was performed to identify articles published...
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Purpose To project the distance between the tip of the greater tubercle (GT), respectively, the proximal border of the tip of the coracoid process (CP) and the entry point of the coracobrachialis by the musculocutaneous nerve (MCN) proportionally onto the humeral length. Methods Sixty-six upper extremities were included in the study. The distance...
Article
Background: The subscapularis muscle, which is part of the rotator cuff, is located anterior to the shoulder. In anterior approaches to the shoulder, its supplying nerves are at risk of iatrogenic injury, which may cause postoperative complications. It is unclear whether there is any nerve-free zone in which a subscapularis split can be performed...
Preprint
Background: The subchondral lamella of the sacroiliac joint (SIJ) auricular surface is morphologically inconsistent, varying inter-individually and side-dependently. These variations have been well documented, however, the morpho-mechanical relationship to sacroiliac joint dysfunction (SIJD) remains unstudied to date. Here, the bone mineralisation...
Article
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Background Elastic knee sleeves are often worn following anterior cruciate ligament reconstruction (ACLR) but their effects on movement patterns are unclear. Aim To determine the immediate and six-week effects of wearing a knee sleeve on biomechanics of the knee during a step-down hop task. Methods Using a cross-over design, we estimated sagittal...
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An enlarged anastomosis connecting the vascular territory of the external iliac and the obturator artery may replace most or all of the latter. This relatively common vascular variation, known as Corona mortis, can lead to death in the worst-case scenario if injured. Despite being well-known, exact anthropometric data are lacking. The purpose of th...
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Bovine bone grafts (BBX) require protein removal as part of the manufacturing process to reduce antigenicity and, in consequence, to be safely used in humans. Deproteinisation may have direct effects on the characteristics of the bone material and on in vivo material performance. This research aimed to comprehensively study the physicochemical and...
Article
Background The anterior interosseous nerve (AIN) is a terminal motor branch of the median nerve innervating the following three muscles from proximal to distal: Flexor pollicis longus (FPL), the radial half of flexor digitorum profundus (FDP), and the pronator quadratus (PQ). The aim of this study was to define the course of the AIN within the PQ t...
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Zusammenfassung Beim Primary Survey des nichttraumatologischen Schockraummanagements kritisch kranker Patienten dient das ABCDE-Schema zur sofortigen Erkennung und Therapie vitaler Gefährdungen. „B-Probleme“ gehen mit einer Störung der Atmung einher und bedürfen einer sofortigen Behandlung. Die Pathogenese von „B-Problemen“ ist gerade im nichttraum...
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Rifles are often involved in violent deaths such as homicide and suicide. Consequently, expert knowledge and experimental forensic investigations are important to clarify the nature of ballistic trauma when applied to the human head and neurocranium. This study investigated differences in entrance wound morphology with Synbone® spheres which are de...
Preprint
Background Elastic knee sleeves are often worn following anterior cruciate ligament reconstruction (ACLR) but their effects on movement patterns are unclear. Aim To determine the immediate and 6-week effects of wearing a knee sleeve on biomechanics of the knee during a step-down hop task. Methods Using a cross-over design, we estimated sagittal pla...
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Background and Objectives: The foot comprises of active contractile and passive connective tissue components, which help maintain stability and facilitate movement during gait. The role of age- or pathology-related degeneration and the presence of fat within muscles in foot function and pain remains unclear. The existence of fat has to date not bee...
Preprint
The sacroiliac auricular surface is morphologically variable. The impact of morphology variations on subchondral mineralization distribution has not been investigated. Sixty-nine subject datasets were subjected to CT-osteoabsorptiometry for chronic loading visualization. Auricular surface morphologies were sorted into three types based on posterior...
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BACKGROUND Sacrectomy carries significant risk of bleeding; however, specific risk factors, apart from medical comorbidities and tumor type, for this life-threatening complication remain unclear. This study describes two cases of massive bleeding, including one death during sacrectomy attributable to adherence of the internal iliac vein (IIV) and i...
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Glial fibrillary acidic protein (GFAP) is a well-established astrocytic biomarker for the diagnosis, monitoring and outcome prediction of traumatic brain injury (TBI). Few studies stated an accumulation of neuronal GFAP that was observed in various brain pathologies, including traumatic brain injuries. As the neuronal immunopositivity for GFAP in A...
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Objectives Conventional autopsies remain the gold standard of postmortem healthcare quality assurance and help gathering extended knowledge on diseases. In answer to constantly declining autopsy rates non- or minimally invasive autopsy methods were introduced. Ultrasound is a well-established tool for imaging commonly used in clinical practice. Thi...
Article
Introduction The anatomical position of the inferior alveolar artery (IAA) within the mandibular canal and in relation to the substructures of the neurovascular mandibular bundle has been sparsely described to date. More detailed information on the exact IAA position would be beneficial for both dental and maxillofacial surgical procedures to minim...
Article
Background and Objectives: Vascular variations appear as morphologically distinct patterns of blood diverging from the most commonly observed vessel patterns. The facial artery is considered to be the main vessel for supplying blood to the anterior part of the face. An anatomical understanding of the facial artery, its course, its topography, and i...
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Background and Objectives: Vascular variations appear as morphologically distinct patterns of blood diverging from the most commonly observed vessel patterns. The facial artery is considered to be the main vessel for supplying blood to the anterior part of the face. An anatomical understanding of the facial artery, its course, its topography, and i...
Article
Citation: Siwetz, M.; Turnowsky, N.; Hammer, N.; Pretterklieber, M.; Wree, A.; Antipova, V. A Rare Case of Facial Artery Branching-A Review of the Literature and a Case Report with Clinical Implications. Medicina 2021, 57, 1172. https://doi.
Article
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Diagnosing traumatic brain injury (TBI) from body fluids in cases where there are no obvious external signs of impact would be useful for emergency physicians and forensic pathologists alike. None of the previous attempts has so far succeeded in establishing a single biomarker to reliably detect TBI with regards to the sensitivity: specificity rati...
Article
Obtaining biomechanical properties of biological tissues for simulation purposes or graft developments is time and resource consuming. The number of samples required for biomechanical tests could be reduced if the load-deformation properties of a given tissue layer could be estimated from adjacent layers or if the biomechanical parameters were unaf...
Article
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Zusammenfassung Im Rahmen des nichttraumatologischen Schockraummanagements zur Versorgung kritisch kranker Patienten werden akute Störungen der Vitalfunktionen rasch detektiert und behandelt. Beim „primary survey“ (Erstversorgung) dient das etablierte ABCDE-Schema der strukturierten Untersuchung aller relevanten Vitalparameter. Akute Störungen werd...
Article
Objectives Pregnancy-related pelvic girdle pain (PPGP) contributes to significant prenatal and postpartum impairments; however, various clinical practices exist around the conservative treatment of this condition. This study sought to reach a consensus on the essential components of PPGP management through an international Delphi survey of experts...
Article
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Background Rehabilitation following anterior cruciate ligament (ACL) reconstructions is based mainly on comprehensive progressive exercise programmes using a multi-dimensional approach. Elastic knee sleeves may be useful adjuncts to rehabilitation. The aim of this study was to determine the immediate and 6-week effects of wearing a knee sleeve on p...
Article
Full-text available
A new metric for the quantitative and qualitative evaluation of bone stiffness is introduced. It is based on the spectral decomposition of stiffness matrix computed with finite element method. The here proposed metric is defined as an amplitude rescaled eigenvalues of stiffness matrix. The metric contains unique information on the principal stiffne...
Article
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Background and objective: Capturing the population variability of bone properties is of paramount importance to biomedical engineering. The aim of the present paper is to describe variability and correlations in bone mineral density with a spatial random field inferred from routine computed tomography data. Methods: Random fields were simulated...
Article
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A single, specific, sensitive biochemical biomarker that can reliably diagnose a traumatic brain injury (TBI) has not yet been found, but combining different biomarkers would be the most promising approach in clinical and postmortem settings. In addition, identifying new biomarkers and developing laboratory tests can be time-consuming and economica...
Article
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Background: Postoperative analgesia after knee arthroplasty forms a basis for an optimal range of motion after surgery. Femoral nerve blocks are established as a sensory nerve blockade but at the expense of quadriceps weakness delaying postoperative mobilization. The adductor canal block (ACB) similarly provides sensory blockade but preserves quad...
Article
We have read with delight the systematic review on the innervation of the hip capsule by Meheux et al.1 The innervation of the hip seems a topic of broad interest of contemporary research, and the findings derived from this research impacts a large number of patients undergoing hip replacement surgery, which is sometimes referred to as the “operati...
Article
Within the framework of nontraumatic resuscitation room management for the care of critically ill patients, acute disturbances of vital functions are quickly detected and treated. In the primary survey, the established ABCDE (airway, breathing, circulation, disability, and exposure) approach is used for the structured examination of all relevant vi...
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It is unclear whether plantar and posterior heel spurs are truly pathological findings and whether they are stimulated by traction or compression forces. Previous histological investigations focused on either one of the two spur locations, thereby potentially overlooking common features that refer to a uniform developmental mechanism. In this study...
Article
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Objective: Fear of dental procedures is a common barrier to effective dental care. A promising technique to overcome dental anxiety is needle-free jet injection, which involves delivering local anaesthetic as a high-speed jet capable of penetrating the oral mucosa without a needle. Previous efforts have used loud, uncontrolled injectors designed fo...
Article
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Realistic biomechanical models of the human head should accurately reflect the mechanical properties of all neurocranial bones. Previous studies predominantly focused on static testing setups, males, restricted age ranges and scarcely investigated the temporal area. This given study determined the biomechanical properties of 64 human neurocranial s...
Article
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Background: Sacroiliac joint arthrodesis is an ultima ratio treatment option for sacroiliac joint dysfunction. Fusion drastically reduces sacroiliac joint movement providing long-lasting pain-relief associated with tension-relief to the innervated sacroiliac joint structures involved in force closure. Objectives: To display the bone mineralizati...
Preprint
Full-text available
A new metric for the quantitative and qualitative evaluation of bone stiffness is introduced. It is based on the spectral decomposition of stiffness matrix computed with finite element method. The here proposed metric is defined as an amplitude rescaled eigenvalues of stiffness matrix. The metric contains unique information on the principal stiffne...
Article
Full-text available
Sacroiliac joint dysfunction (SIJD) is an underappreciated source of back pain. Mineralization patterns of the sacroiliac (SIJ) subchondral bone plate (SCB) may reflect long-term adaptations to the loading of the joint. Mineralization densitograms of 27 SIJD patients and 39 controls, were obtained using CT osteoabsorptiometry. Hounsfield unit (HU)...
Article
Background The sacroiliac joint fixation is the last resort for patients with prolonged and severe joint pain. Although the clinical results of anterior fixations are conclusive, there exist several inevitable drawbacks with the surgical method such as the difficulty performing the surgery due to the presence of many organs. The posterior fixation...
Article
Purpose: A broad body of risk factors exists, predisposing the onset of DDH. Literature is sparse on the subject of combining these risks into a single integrated concept. Revisiting microscopic anatomy of the growing hip joint may help determine such concepts. Methods: Based on knowledge derived from contemporary hip sonography, it has been shown...
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Current treatments of plantar fasciitis are based on the premise that the Achilles tendon (AT) and plantar fascia (PF) are mechanically directly linked, which is an area of debate. The aim of this study was to assess the morphological relationship between the AT and PF. Nineteen cadaveric feet were x-ray imaged, serially sectioned and plastinated f...
Article
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Detailed understanding of the innervation of the hip capsule (HC) helps inform surgeons’ and anaesthetists’ clinical practice. Post-interventional pain following radiofrequency nerve ablation (RFA) and dislocation following total hip arthroplasty (THA) remain poorly understood, highlighting the need for more knowledge on the topic. This systematic...
Article
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There is much debate within the forensic community around the indications that suggest a head injury sustained by a child resulted from abusive head trauma, rather than from accidental causes, especially when a fall from low height is the explanation given by a caregiver. To better understand this problem, finite element models of the paediatric he...
Preprint
Full-text available
Background and Objective: Capturing the population variability of bone properties is of paramount importance to biomedical engineering. The aim of the present paper is to describe variability and correlations in bone mineral density with a spatial random field inferred from routine computed tomography data. Methods: Random fields were simulated by...
Article
Full-text available
The site-dependent load-deformation behavior of the human neurocranium and the load dissipation within the three-layered composite is not well understood. This study mechanically investigated 257 human frontal, temporal, parietal and occipital neurocranial bone samples at an age range of 2 to 94 years, using three-point bending tests. Samples were...
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A detailed knowledge on the exact morphology of pelvic injuries provided crucial information in understanding the mechanisms of injury and has influence on the natural course and subsequent mortality. However, forensic medical literature investigating pelvic fractures in detail is scarce to date. This case series aims to compare the accuracy in det...