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Biomedical subjects

G Jentschura

Publications and source records attributed to G Jentschura.

At least 19 recordsLinked to original sources
PubMed1981

The effects of mechanical factors on bio-compatibility tests.

Evaluation of materials for bone and joint replacement has led to contradictory results in a number of cases: some researchers have reported the formation of good load-bearing bone structures along the surface of a particular material, e.g. dense, high strength Al2O3-ceramics, others found the same material encapsulated by soft tissue. Considering the results of various animal experiments and the evaluation of clinical follow-up studies, it can be shown that many of these conflicting observations are due to different biomechanical conditions at the site of examination. Failure to consider the local load situation at the interface between the implanted specimen and the bone tissue can lead to misleading statements about the possible applications of a material.

Animals↗
PubMed1981

[Early results of operative treatment of scoliosis using the anterior derotation spondylodesis technique (VDS-Zielke) (author's transl)].

The paper presents early results of 25 surgical procedures for scoliosis using the instruments and implants of the anterior derotation spondylodesis (VDS-Zielke). The series included 10 dorsal, 3 dorso-lumbar and 12 lumbar curves, whereby up to 8 vertebral bodies were fused. The average postop. follow-up time was 25 months (8--45 months). The average degree of correction was 51 p.c. Emphasis is layed on the fact that aetiology and severity of the scoliotic curves was extremely heterogeneous. Besides excellent corrective potentials of the VDS for scoliosis, this technique offers possibilities for correction of cyphosis or lordosis as well. The results are described and documented in detail. The author puts much emphasis in describing special techniques for correcting lordosis or cyphosis as well as scoliosis in the same patient. The analysis of the results presented shows good indications for VDS in dorso-lumbar and lumbar scoliosis, congenital scoliosis of the dorso-lumbar area and thoracic lordo-scoliosis. For the indications outlined the possibilities of the VDS are superior to any other operative technique for scoliosis (Dwyer, Harrington). The rate of complications can be kept low through good selection of cases, excellent surgical technique and postoperative intensive care.

Adolescent↗
PubMed1979

Direct anchorage of Al2O3-ceramic hip components: three years of clinical experience and results of further animal studies.

The biocompatibility of high-purity dense Al2O3-ceramics had been shown to open the possibility of direct cement-free anchorage of joint endoprostheses. Three years of clinical experience with ceramic-metal composite total hip prostheses confirm the biomechanical design criteria used for the acetabular components. They also allow for additional conclusions regarding the reaction of bone tissue towards a bioinert implant. Further research activities are directed towards a solution for biomechanically stable anchorage of the femoral component of hip prostheses.

Aged↗
PubMed1978

[A new technique for socket implantation into dysplastic acetabula (author's transl)].

This report presents a new technique of socket implantation into the dysplastic acetabulum. A major part of the resected femoral head serves as the so-called intra acetabular femoral head graft and is screwed into the lateral part of the original acetabulum. By this technique it is possible to achieve a complete bony reconstruction of the dysplastic acetabulum into which a square shaped small ceramic socket can be easily implanted using few especially designed instruments. After the description of the operative technique this report presents the clinical results of this procedure based on 11 personal cases. Finally the technical, biomechanical and biological advantages of this implantation technique are discussed in view of other similar methods described recently.

Acetabulum↗
PubMed1978

[The relevance of histological results for the evaluation of materials for bone replacement (author's transl)].

Different groups have observed and reported deviating tissue reactions for the same material for bone replacement: for the "bioinert" Al2O3-ceramic close bone contact is mentioned, others report about a soft tissue layer adjacent to the implant; for the "bioactive" glass ceramic interfaces capable to transmit considerable shear forces are described, others found no interface bonding.--The analysis of the results of animal experiments and the evaluation of clinical follow-up studies show that these discrepancies had been caused by the differences of the biomechanical situations in the examined interfaces. It is pointed out that the negligence or not mentioning of the load pattern at the site of examination can lead to misinterpretations about the possibilities and limits of applicability of biomaterials.

Aluminum Oxide↗
PubMed1978

[Chriotherapy].

Explore the source record for details and available documents.

Chiropractic↗
PubMed1976

Evaluation of a bioglass-coated Al2O3 total hip prosthesis in sheep.

A bioglass-coated fully dense alumina total hip was evaluated in sheep without using polymer bone "cement." After 3 months following surgery, both the acetabular cup and femoral stem component were firmly attached to bone. Histologic and radiographic analysis of the bone-implant interface showed regions of woven and even lamellar bone formation where high load transmission occurred. In regions of low loading or poor fit, a pseudosynovial fibrous lining was present.

Acetabulum↗