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Biomedical subjects

M Steinlechner

Publications and source records attributed to M Steinlechner.

29 records · Page 2Linked to original sources
PubMed1998

Metal pins fired from unmodified blank cartridge guns and very small calibre weapons--technical and wound ballistic aspects.

Blank cartridge guns are generally regarded as being harmless and are not considered to be firearms in most countries. A comparison of the legal situations in Germany and Austria concerning weapons is given. There have been several reports of serious injuries and even fatalities due to these weapons. Ballistic experiments show that even unmodified blank cartridge guns and very small calibre weapons can fire wire nails and can inflict potentially fatal injuries even at distances of 50 cm. Two serious injuries inflicted by metal pins fired from a blank cartridge gun and a very small calibre weapon are reported. These cases suggest that such weapons should also be considered handguns in the legal sense.

Aged↗
PubMed1998

The interosseous membrane and its influence on the distal radioulnar joint. An anatomical investigation of the distal tract.

From the interosseous membrane of the forearm a tract extends to the dorsal capsule of the distal radioulnar joint. The structure and function of this tract have been investigated. The tract originates from the radius 22 mm proximal to the distal dorsal corner of the sigmoid notch. Central fibres are attached there with fibrous cartilage and superficial bundles mix with the periosteum. The tract is 8 mm wide, 31 mm long and 1 mm thick. Distally it inserts at the capsule of the distal radioulnar joint between the tendon sheaths of extensor digiti minimi and extensor carpi ulnaris. Deep fibres insert directly at the triangular fibrocartilage. The tract of the interosseous membrane is taut in pronation and loose in supination. It strengthens the dorsal capsule of the distal radioulnar joint. During pronation the tract protects the ulnar head in a sling. Its attachment at the triangular fibrocartilage influences the distal radioulnar joint. Its insertion at the triangular fibrocartilage and the support of the weakest part of the dorsal capsule are of interest.

Aged↗
PubMed1997

Camphor ingestion for abortion (case report).

The case of a 16-year-old girl who ingested 30 g of camphor dissolved with 250 ml wine to induce abortion is reported. The girl started vomiting 45 min after ingestion, which may have saved her life. Camphor is present in a number of over-the-counter medications, mainly for external application, and is readily available in drugstores. The substance is highly toxic and rapid in onset. The reported human lethal dose is 50 to 500 mg kg-1. Camphor ingestion may lead to abortion because camphor crosses the placenta and fetuses lack the enzymes to hydroxylate and conjugate with glucuronic acid. The girl was charged with intended abortion.

Abortion, Illegal↗
PubMed1995

Subchondral bone density in the human elbow assessed by computed tomography osteoabsorptiometry: a reflection of the loading history of the joint surfaces.

The functional adaptation of bone tissue to the mechanical stresses acting on it has been convincingly established. This association should apply as well to the subchondral bone, reflecting the long-term distribution of stress over the joint surfaces. Thirty-six specimens of the human elbow joint were investigated by computed tomography osteoabsorptiometry in order to assess the distribution of the subchondral mineralization. The distal surfaces usually were more highly mineralized than the proximal components of the joint, whereas the humeroulnar and the humeroradial parts exhibited a similar degree of mineralization. The fovea of the radial head always showed a central density maximum, and the trochlear notch usually presented a bicentric distribution pattern, with maxima beneath the ventral and dorsal regions of the articular surface. The different patterns of subchondral mineralization were shown to reflect the loading history of the overlying articular surfaces, which is determined mainly by geometrical factors. The flatter socket of the humeroradial joint leads to central load transmission, but the deeper socket of the humeroulnar joint will, by contrast, give rise to bicentric stress distribution.

Absorptiometry, Photon↗
PubMed1994

Ultrasono-anatomy for evaluation of the local lymphatic groups of the mamma.

Sonography has been established as an important adjunct to current diagnostic techniques for the assessment of mammary lymph nodes. Although this method is widely used, no reproducible standard procedure which is equally applicable to the examination of all relevant lymphatic groups has been developed to date. Healthy subjects (n = 50) were examined in an attempt at defining sonographic scanning levels for optimum visualization of anatomic reference landmarks. Images were acquired with a 7.5-MHz linear-array transducer. Anatomic cross-sections of the same level as imaged by sonography were used to identify important details. Unique structures close to the lymph nodes could be identified by sonography, it was not possible, however, to differentiate normal lymph nodes. The correct assessment of lymph drainage areas is therefore possible only if the sonographic level is clearly defined and if the examiner is familiar with the topographic relationships between the depicted structures. By presenting a reproducible examination technique as well as anatomic details, this study aims at avoiding false interpretations and increasing the efficacy of sonographic exploration. The authors believe that this simple and hardly time-consuming technique can contribute to a comprehensive evaluation of the lymph drainage areas of the breast.

Adult↗
PubMed1994

Stress distribution in the trochlear notch. A model of bicentric load transmission through joints.

In 16 cadaver humeroulnar joints, the distribution of subchondral mineralisation was assessed by CT osteoabsorptiometry and the position and size of the contact areas by polyether casting under loads of 10 N to 1280 N. Ulnas with separate olecranon and coronoid cartilaginous surfaces showed matching bicentric patterns of mineralisation. Under small loads there were separate contact areas on the olecranon and coronoid surfaces; these areas merged centrally as the load increased. They occupied as little as 9% of the total articular surface at 10 N and up to 73% at 1280 N. Ulnas with continuous cartilaginous surfaces also had density patterns with two maxima but those were less prominent, and in these specimens the separate contact areas merged at lower loads. The findings indicate a physiological incongruity of the articular surfaces which may serve to optimise the distribution of stress.

Aged↗
PubMed1993

Cartilage degeneration in the human patellae and its relationship to the mineralisation of the underlying bone: a key to the understanding of chondromalacia patellae and femoropatellar arthrosis?

According to the literature subchondral bone plays a significant role in the transmission of load through joints and in the pathogenesis of osteoarthrosis. Therefore the degeneration of the articular cartilage was investigated in the patellae from 30 dissecting-room specimens and of 20 patients, previously submitted to arthroscopy, and subchondral mineralisation of their underlying bone was at the same time assessed by means of CT osteoabsorptiometry. Lateral cartilage lesions were localised over highly mineralised subchondral bone; these appear to be due to long-term stress. They were mainly found in the older specimens and showed a high rate of progression with increasing age. Medially localised cartilage lesions, on the other hand, were situated in a transitional region between moderate and slight subchondral mineralisation; they may be caused by infrequent stress peaks and by shear stress in the articular cartilage, the very medial part of the joint being deprived of mechanical stimulation for much of the time. These lesions were to be found predominantly in the younger specimens and showed little progress with advancing age. Patients with lateral cartilage degeneration exhibited higher, patients with medial chondromalacia patellae lower mineralisation than normals. Their density patterns therefore indicate a different mechanical pathogenesis of the cartilage lesions in the lateral and medial facet. It could be shown that CT osteoabsorptiometry allows an assessment of the mechanical situation, present in individual femoro-patellar joints, and that this situation is highly relevant for the pathogenesis of patellar cartilage degeneration.

Absorptiometry, Photon↗
PubMed1993

[Determining normal ultrasound values of the supra- and infraspinatus muscles].

Sonographic investigations concerning thickness of tendons (in longitudinal sections) and muscles (in resting position and isometric contraction) were performed on 60 volunteers without shoulder complaints. Increase in muscle thickness within isometric contraction did not depend on thickness in resting position. There was no side difference in tendon thickness. Since the observed values (median 4-5 mm) were far below measurements cited in the greater part of literature, we tried to verify our data by sonographic and anatomic examination of shoulders of corpses. We conclude that, by standardising, thickness measurement of tendons and muscles might become more important in diagnosis of shoulder complaints.

Adult↗
PubMed1993

[Areas of contact in human humero-ulnar joints as a function of pressure, their connection through subchondral mineralization and joint surface morphology of the incisura trochlearis].

Evaluation of the stress distribution in joints can be obtained directly from contact areas and pressure forces, and also indirectly from the functional adaptation of the connective tissues. Therefore 8 human humero-ulnar joints, fixed in formalin, were examined for size and position of contact areas (polyether casting/Vidas image analyser) and their dependence upon the joint forces (Zwick material testing machine). The distribution of subchondral mineralisation was assessed, using CT osteoabsorptiometry. Depending on the joint force, the contact areas increase from about 10% of the total surface (20 N) to approximately 60% (1280 N). With weak forces they are localised ventrally and dorsally in the joint, with more powerful forces they run together centrally. With a divided articular surface they join at about 160-640 N, with a continuous surface, at about 40-80 N. Divided joint surfaces show a bicentric mineralisation pattern of the subchondral bone with ventral and dorsal maxima. Continuous surfaces, on the other hand, usually show central maxima. Both the mineralisation pattern and the position of the contact areas suggest a physiological incongruity of the humero-ulnar joint surfaces, which vanishes with increasing pressure due to viscoelastic deformation of articular cartilage and subchondral bone. More marked incongruity is postulated for the divided surfaces than for the others. The consequent peripheral transmission of pressure seems to involve a functional principle, which, present in several human joints, leads to both optimal distribution of the stress and better nutrition of the articular cartilage.

Aged↗
PubMed1993

[Mechanical stress and subchondral mineralization of the human elbow joint. A CT-osteoabsorptiometric study].

We examined 21 elbow joints (age 60-97 years; mean 79 years) that had been fixed in 3.7% formalin. The articular surface of the trochlear notch was completely divided in 10 cases, undivided in 5, and only partially divided in the medial aspect of the joint surface in 6. Subchondral mineralisation was investigated by means of CT osteoabsorptiometry (Müller-Gerbl et al. 1989) on sections 2 mm apart with a Siemens Somatom SF CT scanner. Two-dimensional reconstruction of the surface distribution was achieved by dividing it into 8 Hounsfield ranges (< 300 HU > 900 HU) and using a joint template. Higher values for the subchondral mineralisation are usually found in the distal and medial parts of the joint, indicating greater stress there. Whereas the radial head and the capitulum show a distribution pattern with mineralisation falling off more or less concentrically from the centre outwards, the trochlea and trochlear notch are often poorly mineralised in the centre. There is one maximum on the proximal and one on the distal aspect of the joint surface. Such "two-peak" distribution patterns are more often found when there is complete central division of the articular cartilage of the trochlear notch than when it is continuous. In the latter case, a more central localisation of higher subchondral density is common. In the humero-radial part of the joint, the mineralisation pattern suggests central pressure transmission, probably a result of the fovea capitis radii being slightly less curved than the opposing capitulum.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗