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Biomedical subjects

H Clement

Publications and source records attributed to H Clement.

At least 19 recordsLinked to original sources

[Sonoanatomy of the muscles and fascia spaces of the pectoral regions].

BACKGROUND: Aim of the study was to work out a reliable method for the ultrasonographic evaluation of the pectoral region. METHODS: The study was performed in 20 cadaver specimens and 20 healthy volunteers as well as in 10 patients with disorders of the pectoral region. RESULTS: For examination of the pectoralis major muscle, the landmark for the positioning of the ultrasound transducer was found to be the lateral border of the anterior axillary fold in the direction of the tip of the coracoid process. Tilting the probe medially, the fibres of the pectoralis major muscle become visible in longitudinal alignment. The main part of the clavicular portion of the pectoralis major muscle can be visualised by moving the probe parallel to this position. Tilting the probe downwards, both the internal part of the clavicular portion, the sterno-costal and the abdominal portion are evaluated. For examination of the pectoralis minor muscle, the probe is positioned between the tip of the coracoid process and the sternal angle. Thus the whole muscle can be examined with a single sweep of the transducer. In all the specimens, probands and patients of our group, both muscle, fascias and pathological lesions could be clearly depicted. SUMMARY: Based on the introduction of standard examination planes, the pectoral region can be evaluated in detail using ultrasonography. Lesions and pathologic changes can be reliably appointed to individual anatomical structures.

Fascia↗

In-medium isovector piN amplitude from low-energy pion scattering.

Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni, and Zr have been measured as part of a study of the pion-nucleus potential across the threshold. The "anomalous" repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an empirical on-shell energy dependence.

Journal Article↗

[Ultrasound detection of dislocation of the ulnar nerve from the sulcus of the elbow joint].

BACKGROUND: Chronic ulnar nerve subluxation out of the sulcus in the elbow region may be a rare reason for undefined chronic disorders in the medial elbow aspect. METHODS: We report two cases: A 38 years old male patient reports recurrent painful disorders including paresthesia of the 4th and 5th fingers. A 12 years old boy shows a palpable band in the medial elbow region without pain. RESULTS: In both patients, the ulnar nerve was completely identified, both in transverse and longitudinal planes. Sonomorphology and echogeneity were the same as in the controlateral limb. Ulnar nerve subluxation could be diagnosed in elbow joint flexion, in both cases. CONCLUSION: Dynamic ultrasonographic examination is able to diagnose and document ulnar nerve subluxation and determine further (surgical) treatment.

Adult↗

Exclusive measurement of the pp --> pppi(+)pi(-) reaction near threshold.

The pp-->pp pi(+) pi(-) reaction has been measured exclusively near threshold at CELSIUS. The total cross sections are nearly an order of magnitude lower than expected from previous inclusive measurements. The differential cross sections reveal pp-->pp(*)(1440)-->pp sigma = pp(pi(+)pi(-))(I = l = 0) as the dominant process as well as significant contributions from p(*)-->Delta(++)pi(-)-->psigma. The observed anisotropy in the proton angular dependence is consistent with heavy-meson exchange. In the invariant mass spectra, no narrow structures of statistical relevance (3sigma) are found.

Journal Article↗

[Ultrasonography in trauma].

The aim of this paper is to report on the possibilities of ultrasonography of the musculoskeletal system following traumatic injuries. Subsequent to clinical and radiologic examination, ultrasonography is able to confirm the primary diagnosis by dynamic comparison with a minimal expenditure of time and costs. The size, extent, and anatomic topography of tissue lesions are depicted. This paper focuses especially on the diagnosis of fluid within joints and soft tissues, the identification of foreign bodies, the diagnosis and follow-up of fractures, the diagnosis of infections (possibility of sonographically guided puncture), and musculotendinous injuries. Furthermore, the use of ultrasonography for the evaluation of postoperative pain and complications, the preoperative planning of metal removals, and its performance during spinal surgery are discussed. This paper deals with indications and technical tips for sonography as well as methodological limitations and sources of error in the evaluation of ultrasonographic findings.

Adult↗

[Ultrasound diagnosis in knee and foot trauma].

Subsequent to clinical and radiologic examination, ultrasonography is an important diagnostic method in knee and foot trauma, especially to assess pathologic conditions of the periarticular soft tissue. The main indications for ultrasonographic assessment of the knee region are fluid conglomerations, injuries of tendons, ligaments, and muscles, and vascular diagnosis. The indications for ultrasonography in the foot region are diagnosis of foreign bodies, dislocation of the peroneal tendons, lesions to the flexor and extensor tendons, and osseous capsular and ligamentous avulsions. Changes of the soft tissues include articular effusion, fluid conglomeration, ossification, and vascular lesions. Fractures involve the base of the fifth metatarsal, navicular and sesamoid bones, and epiphysiolysis. Rare indications are the search for free articular bodies and free air and the depiction of cartilaginous lesions and fractures of the knee region.

Foot Injuries↗

[Ultrasound diagnosis in shoulder trauma].

In cases of injuries to the shoulder region, ultrasonography is an ideal supplement to clinical and radiologic examination, including dynamic functional evaluation. The advantages of the method in children and adults are mainly the reduction of conventional radiographs and thus a minimum exposure to radiation. Despite the growing experience of clinicians and the development of high-resolution sonographic technology, primary conventional radiology cannot be dispensed with. Moreover, sonographic examination is rather time-consuming. Evaluation of the subacromial space and the glenohumeral joint itself is impossible in adults, and diagnosis of lesions to the labrum and the articular capsule requires a great deal of experience on the part of the clinician. Ultrasonography has gained increasing importance in the evaluation and follow-up of shoulder trauma in adults and children.

Adult↗

[Ultrasound diagnosis of the Achilles tendon].

Due to the superficial position of the Achilles tendon and the development of high-resolution probes with 7.5, 10, and more MHz, which allow the exact depiction of even very small structures, ultrasonography is the method of choice for the diagnosis of acute and chronic Achilles tendon disorders. Using sonography, both chronic achillodynia (disorders of the tendon itself, peritendinous tissue, bursa, and insertion of the tendon at the calcaneus) and ruptures of the Achilles tendon are exactly diagnosed. By sonographic examination, depiction of changes of the tendon itself (rupture, calcification, thickening) and evaluation of the peritendinous soft tissue with dynamic assessment of the gliding sheath are possible. The risk for the less experienced clinician using ultrasonographic assessment of the locomotor system is not to miss pathologic findings, but to overestimate them, due to artifacts. Sufficient knowledge of ultrasound physics as a reason for typical artifacts and the use of a standardized examination technique are necessary. However, by using high-resolution small ultrasound probes, the depiction of "problem areas" (e.g., musculotendinous junction, insertion of the tendon on the calcaneus) has become easier and more accurate.

Achilles Tendon↗

[Ultrasound diagnosis in hip trauma].

The Question is: What are the indications for ultrasonography of the hip joint following trauma, except the investigation in children, and in which cases does ultrasonography provide a useful improvement within the diagnostic cascade? Considering the limitations in evaluation of boney structures and also soft tissues (due to anatomic topography) and if CT and MRI is not available, the moin indications are: Suspected soft tissue lesions (articular effusion, bursitis, muscle tears etc.) and vascular disorders (deep venous thromboses, vascular tears and occlusions). Both in preoperative planning and in postoperative follow up, ultrasonography provides useful information (e.g. after shunt surgery or as a screening method for venous thrombosis). There is also tho option for sonographically guide punction, drainage or even treatment (e.g. block anaesthesia). Performed by an experienced clinician, ultrasonography of the hip joint has a lot of indications to gain quick information. Using this non-invasive technique, demanding and invasive diagnostic investigations (for example phlebography) may even by saved.

Adult↗

[Ultrasonographic imaging of pneumarthrosis of the knee joint--case report and experimental cadaver study].

In case of penetrating injuries near to the knee joint showing only a small skin lesion and no damage to tendons and neuro-vascular structures, opening of the joint cavity has to be taken into consideration. Besides surgical revision of the penetration canal, radiological depiction of free intraarticular air may be useful. We report the cases of two patients, who suffered from intraarticular effusion and pain two, respectively three days after a penetrating injury. In both of them, free intraarticular air in the suprapatellar region could be depicted by ultrasonographic assessment. Subsequent evaluation of radiographs showed intraarticular air already being there at the day of admittance. Performing an experimental study in fifteen cadaver knee joint specimens, the reliability of this technique was evaluated and documented. Using an injection needle, air was insufflated into the knee joints with or without previous instillation of fluid. Afterwards sonographic assessment was performed using 7,5 - 13 MHz linear probes and Siemens (Elegra) equipment. Ultrasonographic detection of pneumarthrosis of the knee joint was possible early and reliably in both of the patients reported. With sufficient experience of the clinician and adequate equipment, even singular intraarticular air blisters are detectable, especially in cases of concomitant intraarticular effusion. By ultrasound it was possible to detect pneumarthrosis with at least 0,5 ml, by X-ray with at least 2 ml. Ultrasonography proved to be a reliable diagnostic tool for the detection of free intraarticular air within the knee joint. This fact should be considered in the differential diagnosis of unclear knee joint disorders after penetrating injuries.

Adult↗

Musculo-tendinous junction of the flexor carpi ulnaris muscle. An anatomical study.

The aim of the study was to evaluate the occurrence of the anatomical variations of the musculotendinous junction of the flexor carpi ulnaris (FCU) muscle and the variations of its insertion onto the pisiform. One hundred cadaver specimens preserved according to Thiel's method were assessed. Following careful dissection, the distance between the musculotendinous junction and the pisiform and the width of the muscle belly were determined. Three typical anatomical variations were found: 1) a large muscle belly running distally almost to the insertion onto the pisiform; 2) the muscle belly ending more proximally, with some large fibres running parallel to the tendon and almost reaching the pisiform; 3) the musculotendinous junction ending more proximally, with only single fibres continuing distally. The length of the tendon was greater than 10 mm. A number of variations of the distal region of FCU were observed. The presence of muscle fibres almost reaching the insertion point onto the pisiform have to be considered when interpreting MRI or ultrasound findings of this region.

Aged↗

[Ultrasound identification and size determination of the palmaris longus tendon].

Since the palmaris longus tendon is subject to a wide range of anatomical variations (in 10% of the cases, aplasia is observed), the identification and determination of its length and thickness is of importance for the pre-operative planning of ligament reconstructive surgery. Thirty healthy volunteers aged between 6 and 50 years were examined using high-resolution 10-12 MHz US probes. We determined the length and thickness of the tendon, and its relationship to the median nerve in the distal region of the forearm. Thanks to the dynamic nature of the examination and the typical tendinous echo structure, the palmaris longus tendon was accurately identified by US in both children and adults. Ultrasonography is highly suitable for the identification of the palmaris longus tendon and aids the pre-operative planning of ligament reconstructions.

Adolescent↗

[Ultrasound anatomy and pathology of the elbow joint in the child and in the adult].

The aim of this study was to evaluate the sonographic anatomy of the elbow joint in children and adults and to point out the indications for an ultrasound examination after elbow joint trauma. The study was carried out using isolated joint specimens, muscle specimens and cadaver limbs. Additionally, a clinical trial was performed using high-resolution ultrasound probes (7.5-12 MHz). When assessing standard sections, one has to consider both the position of the elbow joint in the frontal plane and the position of the forearm during pro- and supination. The outstanding advantage of this method, especially in children, is the possibility of a dynamic examination with evaluation of the articular cartilage and with a comparison to the healthy contralateral elbow joint.

Adult↗

[Ultrasound anatomy of the foot with high frequency transducers].

To show the possibilities of imaging diagnostic procedures using high and extremely high resolution ultrasonic probes we investigated the anatomic structures of the foot. We examined 10 cadaver feet of the anatomic institute and in a clinical trial 20 healthy patients with 10 to 20-MHz-probes and could identify correctly single tendons and ligaments even in the toe region. Especially the possibility of dynamic examination had to be mentioned beside the other advantages of ultrasound diagnostic (saving of expenses, lack of radiation, side-to-side comparison).

Adult↗

[Ultrasound fracture diagnosis--an experimental study].

Thanks to the increasing use of ultrasonography in the diagnostic evaluation of the musculoskeletal system, and the development of high-resolution ultrasonic transducers with ever better image quality, as well as the greater general trend towards non-invasive techniques, the use of ultrasonography in the diagnosis and follow-up of fractures would appear to make good sense. The aim of the present experimental study was, therefore, to identify the typical acoustic pattern of fractures and areas of bone impression and defects, while taking account of possible sources of error due to artefacts. Experiments were carried out on cadaver bones immersed in a water bath, using 7.5 and 10 MHz linear transducers. Depending on its size, the bony defect is represented by an interruption of the cortical echo, or a dorsal band of echoes limited to the fracture zone. Of interest is the fact that fractures and bony defects are not represented as such when the transducer is directed parallel to the line of the fracture or the impression area. Particular attention needs to be paid to the numerous artefacts occurring at the margins of the fracture. In summary, it may be noted that using resolution transducers under standardised experimental examination conditions, cortical interruptions of not less than 1 mm can be identified.

Artifacts↗