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Biomedical subjects

W Mutschler

Publications and source records attributed to W Mutschler.

At least 145 records · Page 8Linked to original sources
PubMed1988

[Accomplishments of tumor surgery in tumors of bone].

Progress in the difficult field of bone tumor surgery is based on team work (centers for oncology) and knowledge of radical oncological surgery and compartment resection. Each resection results in defect of bone and/or soft tissue. Increased possibilities are provided by new implants and intraoperatively custom-made prosthesis when combined with biological procedures (muscles, vessels, nerves), especially the preservation of function and weight-bearing capacity of the extremity by bone transplantation.

Amputation, Surgical↗
PubMed1987

[Surgical therapy of pelvic tumors].

Results in 72 patients with primary tumors of the pelvis and in 140 patients with metastases are reported. Classification, localization, type of resection and reconstruction including bone grafts, osteosynthesis and internal hemipelvectomy are described. In benign and low grade malignant bone tumors continuity resections and pelvic reconstructions give good oncological and functional results. In high grade malignant bone tumors and soft tissue sarcomas the 5-years-survival rate is only 37% respectively 19%. Metastases of the pelvis and proximal femur are treated by combinations of metal implants and bone cement as well as by different types of total hip prostheses.

Adult↗
PubMed1986

[Resorbable implants for refixation of osteochondral fragments in joint surfaces].

Resorbable pins made of solid polydioxanone (PDS) were tested for refixation of osteochondral fragments. In both medial femoral condyles of sheep osteochondral fragments were chiselled and refixed by 3 PDS pins. After 3 months the sheep were sacrificed and healing of the fragments investigated histologically and biomechanically. Fragment dislocation was not seen in any of the cases and the cartilage surface could be described as normal. The strength of the bone healing zone reached 80% of the strength of the normal bone. The contact surface between fragment and subchondral bone showed complete bony healing. Only the border of the cartilage flake was still visible. The PDS pins had not been completely biodegraded after 3 months.

Animals↗
PubMed1985

Bone healing stimulated by plasma factor XIII. Osteotomy experiments in sheep.

Sheep had their right metatarsals osteotomized midshaft and stabilized by plate and screws. One group was injected with 1250 units of Factor Thirteen for 9 days postoperatively, and a control group received placebo injections. After 8 weeks, the bones were evaluated biomechanically, histomorphologically and by densitometry. The bones of the treated group had a significantly higher tensile strength than the bones of the control animals. The correlation of biomechanical and morphological results demonstrated that the tensile strength increased with an increasing number of osteons crossing the osteotomy gap. The hydroxyapatite content of the bone healing zone was 7.3 per cent higher for the treated bones than for the control bones.

Animals↗
PubMed1984

Experimental studies on the pathogenesis of ochronotic arthropathy. The effects of homogentisic acid on adult and fetal articular chondrocyte morphology, proliferative capacity and synthesis of proteoglycans in vitro.

Lapine adult and fetal articular chondrocytes in monolayer culture were employed as an experimental model for studying the effects of homogentisic acid on chondrocyte morphology, proliferation and synthesis of proteoglycans. Concentrations of homogentisic acid in the range from 0.1 to 100 micrograms/ml were investigated and a cytotoxic effect was detected with concentrations of 5 micrograms/ml and above. Thus, with adult articular chondrocytes this effect was seen between 36 and 48 h of subculture with 5 micrograms/ml or more of homogentisic acid present from the beginning of subculture. In fetal articular chondrocyte cultures a concentration of 1 microgram/ml elicited a statistically significant reduction (13%) in cell proliferation without altering sulphated macromolecular synthesis. Experiments with 3H-thymidine autoradiography to measure the pulse labeling index (LI) in fetal chondrocytes in vitro showed that the 5 micrograms/ml concentration of homogentisic acid present for 21 h from the beginning of subculture gave a LI of 2%, compared with 25% for controls. Thus, homogentisic acid can reduce chondrocyte proliferative capacity before morphological alterations can be detected by light microscopy. No significant alterations in the synthesis of proteoglycans were detected at concentrations below the cytotoxic level. The homogentisic acid-induced cytotoxicity and reduction of proliferation in chondrocytes represents a possible pathway by which cartilage is damaged in ochronotic arthropathy.

Animals↗
PubMed1982

[Results of treatment of tumors and metastases of the pelvis and proximal femur].

A retrospective study of 293 primary tumors and 244 metastases of the pelvis and proximal femur allows the following conclusions. Benign tumors are treated by curettage whereas low-grade malignant tumors have to be resected "en bloc". In high-grade malignant pelvis tumors, total internal hemipelvectomy with replacement of half of the pelvis has been used with success. Metastases are treated by total hip prosthesis or a combination of bone cement and osteosynthesis. On the whole early lethality is low, local complications are acceptable and most of the patients are able to walk.

Adolescent↗
PubMed1982

[Chondropathia patellae--preoperative and postoperative demonstration of the patellar structure in plain roentgenography (author's transl)].

The study is based on 86 patients surgically treated for chondromalacia patellae, who in a 2 year follow-up were controlled by défilé-radiographs and clinical examination. While there was an improvement of all clinical symptoms examined, no significant change in the radiologic appearance of the patellar structure was observed as compared with the pre-operative status. This includes that neither significant changes indicating development of arthrosis nor aggravation of pre-existing arthrotic lesions could be found. However, it is commonly suggested from roentgenographic findings with type 3 lesions, that severe chondromalacia patellae may be precursor of osteoarthrosis.

Cartilage Diseases↗
PubMed1981

Quantitative investigations on newly-built bone and defects. Its time-dependent changes of morphological and biomechanical properties.

Bone growth in drillholes in sheep tibiae were examined morphologically and biomechanically after 4, 6, 9, and 12 weeks. Selected bone specimens were removed from the defective areas and used to determine the strength and, with the aid of microradiographs, the volume of new bone. Strength as well as volume of new bone increased in the defects within the healing time. However, the strength of the newly-formed bone reached only 20% of the strength of normal cortical bone. This is caused by the random structure of new bone which, despite the repair of the defect and the nearly normal mineralization, is not yet adapted to the adjacent normal cortical bone.

Animals↗
PubMed1981

[Plain film appearances of chondropathia patellae. Morphological changes after surgical treatment (author's transl)].

The localised patella defects in our material of 90 patients were largely unchanged up to nine months after surgical treatment. Persistence of soft tissue swelling round the knee correlates with continuing pain. In some cases there has been remineralisation of the patella, which can be regarded as a stage in healing. Unchanged or deteriorating radiological findings may be associated with clinical improvement or deterioration.

Humans↗