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Biomedical subjects

G Ittner

Publications and source records attributed to G Ittner.

14 recordsLinked to original sources
PubMed2003

Constant mineralization density distribution in cancellous human bone.

The degree of mineralization of bone matrix is an important factor in determining the mechanical competence of bone. The remodeling and modeling activities of bone cells together with the time course of mineralization of newly formed bone matrix generate a characteristic bone mineralization density distribution (BMDD). In this study we investigated the biological variance of the BMDD at the micrometer level, applying a quantitative backscattered electron imaging (qBEI) method. We used the mean calcium concentration (Ca(Mean)), the most frequent calcium concentration (Ca(Peak)), and full width at half maximum (Ca(Width)) to characterize the BMDD. In none of the BMDD parameters were statistically significant differences found due to ethnicity (15 African-American vs. 27 Caucasian premenopausal women), skeletal site variance (20 ilium, 24 vertebral body, 13 patella, 13 femoral neck, and 13 femoral head), age (25 to 95 years), or gender. Additionally, the interindividual variance of Ca(Mean) and Ca(Peak), irrespective of biological factors, was found to be remarkably small (SD < 2.1% of means). However, there are significant changes in the BMDD in the case of bone diseases (e.g., osteomalacia) or following clinical treatment (e.g., alendronate). From the lack of intraindividual changes among different skeletal sites we conclude that diagnostic transiliac biopsies can be used to determine the BMDD variables of cancellous bone for the entire skeleton of the patient. In order to quantify deviations from normal mineralization, a reference BMDD for adult humans was calculated using bone samples from 52 individuals. Because we find the BMDD to be essentially constant in healthy adult humans, qBEI provides a sensitive means to detect even small changes in mineralization due to bone disease or therapeutic intervention.

Adult↗
PubMed1997

[Replacement of the anterior cruciate ligament by cold preserved bone-cruciate ligament-bone allotransplants. An experimental study in the sheep].

One ACL in each of 17 mature sheep was replaced with a deep-frozen bone-an ACL bone allograft. Allografts were obtained from skeletally mature sheep using a standard aseptic technique and stored deep frozen for at least 6 days (mean 21 days). Macroscopical, biomechanical, and histological changes were evaluated 12, 24, and 52 weeks following implantation. At autopsy all allograft ligaments were present and demonstrated no evidence of infection or immune reaction. We found slight arthrotic changes in 3 knees after 12 weeks, in 4 knees after 24 weeks, and in 3 knees after 52 weeks. Twelve weeks after the operation the maximum load of the allografts was 17.5% of the contralateral controls and increased to 20.9% after 24 weeks and to 32% of controls after 52 weeks. Ligament stiffness in the linear region also increased from 18.9% of control (12 weeks) to 32.5% after 52 weeks, whereas maximum load decreased from 112.2% of controls (12 weeks) to 98% of controls (52 weeks). Histologically, the allografts progressively matured with time, becoming nearly identical to normal ligaments at 52 weeks.

Animals↗
PubMed1992

[Power stapling in trauma surgery. An improvement of trauma surgery technique?].

Power staple fixation of fracture fragments represent an enrichment of technological possibilities in adaptive osteosynthesis. We gained some experience with a variety of indications. The advantage of this method can be seen in the simple and fast way of application. Observing limited indications excellent results can be achieved.

Fracture Fixation, Internal↗
PubMed1990

[Sonography of the skeletal muscles using high-frequency ultrasound probes].

8 musculi graciles of human cadavers were examined sonographically by means of high-frequency ultrasound probes (10 MHz) to evaluate the echo texture of skeletal muscles. It could be shown that the smallest structures of skeletal muscles that may be differentiated sonographically are the primary bundles. In addition, 100 patients with clinically suspected muscular trauma and 8 patients with neuromuscular diseases were examined via high-frequency ultrasound probes (10 or 7.5 MHz). The typical signs of muscle tears and neuromuscular diseases in relation to normal sonomorphology are discussed. The special value of the method in these indications is emphasised.

Humans↗
PubMed1989

[Percutaneous embolization of retroperitoneal hemorrhages in pelvic fractures].

Pelvic fractures may lead to severe retroperitoneal bleeding. Percutaneous catheter embolisation has become an increasingly important therapeutic alternative to surgical intervention. Most studies dealing with this problem have been small and we have attempted to evaluate the method on the basis of our own experience and a review of the literature. The success rate of percutaneous embolisation appears to be about 94%. The use of blood transfusion dropped from an average of 25.7 units before embolisation to an average of 6.5 units after embolisation. In spite of this, mortality in these patients remains high at 43.3% because of the serious additional injuries. The advantages and disadvantages of various embolising materials are discussed and various techniques of percutaneous embolisation are described.

Adult↗
PubMed1989

Fractures of the posterior tibial margin: their role in the prognosis of malleolar fractures.

One hundred forty-two patients with malleolar fractures were followed up for an average of 5.7 years postoperatively. In 80 cases (56.4%) we found no lesion of the distal articular surface of the tibia; 62 patients (43.6%) had a fracture of the posterior tibial margin. Both groups were closely matched with regard to fractures of the lateral and medial malleolus. The long-term results were significantly poorer when a fracture of the posterior tibial margin was additionally present, even in cases with a small marginal fragment of the lip of the tibia. Further, we found a clear relationship between the articular involvement and the incidence of post-traumatic osteoarthrosis in cases with no additional osteosynthesis of the fragment. In cases of larger fragments, the long-term results after anatomic reduction and additional osteosynthesis were on the whole far better than in cases treated conservatively.

Adult↗
PubMed1989

[Surgical management of dislocated patellar fractures--therapy and results].

Between 1976 and 1985, 96 patients with 97 fractures of the patella have been operated at the 2nd Department of Trauma Surgery, University of Vienna. According to the radiographs the fractures were classified in nine apical fractures (9.3%), 34 transverse fractures (35.1%), two longitudinal fractures (2.1%), three star-like fractures (3.1%), 25 multifragment fractures (25.8%) and 24 comminuted fractures (24.7%). The methods of operation employed are: In 34 patients standard circumferential wiring, in 43 patients tension-band wiring either alone or combined with Kirschner-wires and in 13 patients partial patellectomie. One fracture was fixed with a screw alone. 47 patients with 48 fractures were followed up clinically and radiologically three to nine years postoperatively. The overall results were in 16 cases excellent, in 23 cases fair and in nine cases poor. The possible surgical procedures of the various forms of fractures are discussed referring to their longterm results.

Adolescent↗
PubMed1989

[Treatment of fresh subcutaneous flexor tendon rupture of the distal joint of long fingers with temporary bone wire arthrodesis].

Drop-finger at the distal joint or mallet-finger from injury occurs because of the extensor apparatus is so much weaker than the flexor tendon that it breaks under strain. We report on 100 cases treated by internal splinting with longitudinal applied Kirschner wire in the distal and middle phalanx of the finger. It affords an absolute immobilisation of the distal interphalangeal joint in slight hyperextension with relaxation of the extensor apparatus. The wire was removed after six weeks. The results evaluated in 76 patients by follow-up four to 84 months were classified as excellent in 86.8% (full range of motion), good in 11.9% (loss of motion 5 to 15 degrees), and poor in 1.3% (loss of motion more than 15 degrees). The excellent and good results emphasize that internal splinting in ruptures of the extensor apparatus near the distal interphalangeal joint.

Adolescent↗
PubMed1986

[Conservative therapy of forearm fracture in the growth stage with special reference to the correlation of roentgenologic course, objective and subjective total results].

143 out of 310 patients in the age of one to 18 years suffering from forearm-shaft-fractures could be followed up at the 2nd Department of Traumatology, University of Vienna, out of a period between 1978 and 1983. A correlation between radiologic follow-ups and objective/subjective findings was achieved by means of the WAMASTAT/SAS program at the Institute of Medical Computer Sciences. With the aid of computer diagrams of the angulation of fracture-dislocation awaited restrictions of movement can be anticipated. Corrective reductions performed in time can prevent disalignment and improve long-term follow-up results.

Adolescent↗
PubMed1986

[Experiences using the rotation femur head prosthesis in the treatment of medial femoral neck fractures in geriatric patients].

We report upon 167 fractures of the medial femoral neck (166 patients aged 82 years on average) that were treated by hemialloarthroplasty (trunnion hip prosthesis Allo-Pro). 94 patients were followed-up from three to 53 months (average 18 months) postoperatively. 67 patients regained their full physical activity. This operative technique is indicated in fractures with high risk of femoral head necrosis and in patients with reduced physical conditions. We see the advantage of hemialloarthroplasty in the relatively small operative trauma and the possibility of early mobilization.

Aged↗
PubMedDate not supplied

[Treatment of flake fracture of the talus].

This is a report on 18 osteochondral lesions of the talar dome after sprained ankles and ruptured lateral collateral ligaments of the ankle. They were classified according to Berndt & Harty. The treatment of choice in recent flake fractures is the reduction and glueing with fibrine. Very good results were obtained according to Weber. The recommended treatment of ancient flake fractures frequently occurring to elder patients is the removal of the fragment and the drilling of the subchondral bone.

Adolescent↗
PubMedDate not supplied

Modulation of the migration and chemotaxis of PMN cells by hyaluronic acid.

Hyaluronic acid (HA) has a dose-related inhibiting effect on the migration and chemotaxis of polymorphonuclear leucocytes (PMN) in vitro. These effects were measured with a new indirect quantitative assay. On average 1 mg HA/ml causes an inhibition to about 80% of the control (spontaneous migration). This effect increased progressively with an increasing HA concentration, and with 4 mg HA/ml only about 19% of the PMN were able to migrate in the in vitro system. Similar results were obtained in the presence of a potent chemotactic factor (leukotriene B4 [LTB4]). In the mean 1 ng LTB4/ml alone stimulated the chemotaxis of PMN by a factor of 3 compared to the spontaneous migration. The highest HA concentration (4 mg/ml) reduced the number of migrating PMN cells to about 17%. From these experiments it may be concluded that the HA in the synovial fluid of the healthy joint has a protective effect against the invasion of PMN cells. This functions is disturbed in inflamed joints by the decrease in the HA concentration and possibly by its depolymerization. The intraarticular application of high molecular weight HA might be an important therapeutic regimen to restore the natural barrier against PMN migration, also in the presence of chemotactic factors and could therefore be helpful for interrupting the inflammatory cascade.

Arthritis↗