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Biomedical subjects

H Witte

Publications and source records attributed to H Witte.

115 records · Page 7Linked to original sources
PubMedDate not supplied

[The lumbar ligamentum flavum. Anatomic characteristics with reference to microdiscotomy].

One important step in lumbar discotomy is the safe penetration and exact partial removal of the Lig. flavum. This is a crucial prerequisite for the selective and gentle removal of prolapsed and sequestrated intervertebral disc tissue. Extensive lancing of the Lig. flavum should be avoided, to minimize intraoperative and postoperative complications, such as injuries to the nerves and the Dura mater, instabilities, bleeding and scarring. As there has up to now been insufficient information on the anatomy of the Lig. flavum especially regarding microdiscotomy, an analysis of the Ligg. flava L2/L3 to L5/S1, guided by this aim, was carried out on 36 corpses kept in formaline (16 f, 20 m; 52-78 y). Preparations showed the lumbar Ligg. flava to be embodied in the Foramina interarcualia in a characteristic configuration. There also proved to be defined insertion areas on the laminae of the vertebral arches, which must be taken into consideration during the operative exposure. The Lig. flavum rises from the cranial vertebral arch from the ventral surface of the lamina (6.8 mm) whilst the insertion area on the caudal lamina covers the dorsal and the ventral surface. The extent at the ventral surface is 2.2 mm in average. Taking the insertion proportions into account we would suggest the Lig. flavum to be divided as follows: Pars interspinalis, which clearly differs from the Lig. interspinale (and from the M. interspinalis), and which houses venous anastomoses in its dorsal, ridge-shaped extension. Pars interlaminaris, which starts at the laminae and constitutes the target area for flavotomy in its lateral section, and Pars capsularis, which merges into the capsular structures of the facets. In all levels examined, there proved to be dorso-ventrally a typical change in the direction of the course of the fibres in the Pars interlaminaris. Whilst the direction of the fibres dorsally is oriented cranio-medially to caudo-laterally at an angle between 15 degrees and 30 degrees to the median line, the ventral fibres of the Lig. flavum are strictly aligned cranio-caudally. The changes in the directions of the fibres are continuous with the fibres being very closely intertwined, without there being any spatium at all. The texture of the Lig. flavum is, therefore, a mirror image of that of the autochthonuous muscular system of the back, even if the overlapping angle area is considerably smaller. The different segment levels show a segment-specific thickness profile. The analysis has provided anatomic information about the Ligg. flava L2/L3 to L5/S1. These data represent important prerequisites for a selective, gentle and safe intraoperative procedure for discotomy.

Aged↗
PubMedDate not supplied

[Shape transformations of the lumbar spine in relation to passive extension of the lower extremities in the sagittal level].

PROBLEM: The interdependencies between movements of the thighs and the lumbar vertebral shape are of high practical interest. Which are the normals of this phenomenon? METHOD: In an experiment on 107 volunteers without before known spinal disorders and complaints of back pain (47 f, 60 m, 17 a-30 a), the interdependencies between movements of the thighs in the sagittal and the lumbar back profile were analysed. Hip joint movements were provoked by a lift jack, elevating the feet to the volunteers, which sat on a bicycle chair. The hip joint flexion was measured by a Zebris CMS 50. The sagittal profile of the lower back was sensed by a comb of steel needles with low friction support. RESULTS: At 30 degrees of hip flexion, 68% of the volunteers demonstrated a kyphotic, 17% a straight and 15% a lordotic lumbar shape. Starting at 90 degrees of hip flexion, "definitively kyphosating movements" of the lumbar motion segments occur. At the end of the motion, 89% of the volunteers had a kyphotic, 3% a straight and 8% a lordotic lumbar configuration. Each 2 degrees of additional hip joint flexion caudo-cranially one more lumbar motion segment is recruited for the definitive kyphosation of the lumbar spine. CONCLUSIONS: Instead of a "physiological shape of the lumbar spine" its "physiological function" or its "physiological interaction between shape und function" should be in the focus of future discussions. In the sitting, hip joint flexion leads to a coupled motion of the thighs, the pelvic girdle and the lumbar vertebral column with the consequence of a kyphosation of the lumbar back shape.

Adolescent↗
PubMedDate not supplied

[Landing after jumps--wrong technique promotes spondylolysis].

The double-S-shape of the vertebral column usually is explained to be an adaptation to the functional requirements of axial shock absorption. We investigated the effects of axial impacts on the coupled motions of the pelvic girdle and the vertebral column. In contrast to the predictions of the bending spring model, in the first few miliseconds after impact induction the vertebral column shows a tendency of lumbal straightening. This effect may be one reason for high stresses in the vertebral arches, promoting spondylolysis and spondylolisthesis. In sports, high axial impact loads, especially provoked by wrong landing techniques after jumps, should be avoided.

Adaptation, Physiological↗
PubMedDate not supplied

A model for evaluating the stressed patient in the family practice setting.

Family physicians frequently encounter patients with stress-induced medical and psychological problems. When the symptoms are severe, or the mechanisms are vague, it is often useful to perform a detailed medical, behavioral, and psychological evaluation in order to initiate effective therapy. This paper illustrates a model for evaluating stress-related and other psychosomatic problems in a family practice.

Adult↗
PubMedDate not supplied

[Epiduroscopy with access via the sacral canal. Some constructional equipment requirements from the anatomic and biomechanical viewpoint].

To ensure optimal mechanical functioning of the vertebral column, intact symmetry of its bony and muscular elements is mandatory. With this in mind, the need to reduce the invasiveness of spinal surgery is even greater than that applying to surgery in general. To avoid bony or muscular damage during surgery, in particular in the case of the segments L4/L5 and L5/S1-which are particularly prone to intervertebral disc rupture-laser discotomy procedures, with introduction of instruments via the sacral canal during epiduroscopy are presently being developed. Preliminary experiments on human corpses have demonstrated the practicability of the technique, but specially designed instruments have yet to be developed for use in patients. In an attempt to define the conditions of important for the design of the instrument, we have carried out a morphometric analysis of 100 sacral bones (56 females; 44 males). The configuration of the sacral canal is described in quantitative terms, and the results used to determine the diameters and curvatures of the instruments needed for laser discotomy.

Aged↗