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Biomedical subjects

A Härle

Publications and source records attributed to A Härle.

At least 19 recordsLinked to original sources
PubMed1991

[Infection of knee endoprosthesis].

In knee arthroplasties, infection was and still is the most decisive factor with respect to the end result. Control of infection without removal of the endoprosthesis can be achieved only when an early revision is performed in the first 6 weeks after the arthroplasty. Half-hearted antibiotic medication alone is an unsuitable remedy. Therefore, an infection must be diagnosed without delay and followed up by decisive management. Clinical and laboratory data must be considered together and must supplement each other. Late infections need temporary or permanent removal of the endoprosthesis as a prerequisite for getting rid of the infection. Reimplantation and arthrodesis should be done in a two-stage procedure after the infection is healed. Reimplantation should be restricted to cases in which the infection is definitely under control and in which there is a good bone stock. Arthrodesis is still the treatment of choice, especially in patients with bony defects in the metaphysis of the femur and tibia. Arthrodesis also needs good soft tissue cover, and to prevent a reinfection in this dangerous area we suggest the use of antibiotic-releasing bone plates for stabilisation. External fixation has a high percentage of pintrack infections and often cannot be applied long enough; thus non-unions are the logical consequence.

Adult↗
PubMed1991

Treatment of infected arthrodesis of the ankle.

In arthrodesis of the ankle joint the use of external fixation can cause severe problems owing to pintrack infections. As long as infection is active, bony consolidation of the arthrodesis is delayed. In the potentially infected area a normal internal osteosynthesis is risky. Our treatment rationale comprises a two-stage procedure with treatment of infection first by implant removal, thorough debridement and implantation of Septopal beads and then secondary internal stabilization with an antibiotic-releasing bone plate. Of the 42 cases amputation had to be performed in 3; of the remaining 39, infection was cured long-term in 36. In all 39 a stable bony fusion was achieved.

Aged↗
PubMed1991

Management of wound sepsis after spinal fusion surgery.

In wound sepsis after spinal surgery a first attempt to control infection without removal of the implants is justified, as implant removal after correction of scoliosis and kyphosis and in reduction of slipped vertebrae would often cause instability of the segments operated on. If the first revision is not successful, a second should not be delayed too long. Sometimes partial removal of the implants may be sufficient for infection control, thus maintaining a certain stability. We use local antibiotic treatment with Septopal chains, as suction irrigation sometimes is complicated by secondary bacterial contamination. By applying this treatment rationale we were able to control infection in 50 out of 53 patients with wound infection.

Adolescent↗
PubMed1989

The proliferation behavior of bone tumors investigated with the monoclonal antibody Ki-67.

Specimens of several tumor entities at various grades of malignancy were selected from the Bone Tumor Registry of Westphalia for an immunohistological study of their proliferation behavior. Using the monoclonal antibody Ki-67 directed against a nuclear antigen present in all active phases of the cell cycle (G1, S, G2, and M), we were able to demonstrate the growth fractions in tissues with an atypical rate of proliferation, implying an increased risk of malignant transformation. In the 97 cases examined we found a good correlation of the biological proliferation behavior with the expression of the nuclear antigen Ki-67. Moreover, our immunohistological results are comparable with the data from the same tumor entities obtained by other methods such as flow cytometry and autoradiography. Thus the monoclonal antibody Ki-67 provides an excellent marker for labeling the growth fraction in a human tissue. Its practical impact lies in the differential diagnostic analysis of the proliferation rate in a given tumor and its possible grading, and in pre- or posttherapeutic monitoring of patients and the establishment of a prognosis.

Adolescent↗
PubMed1989

Flow cytometric DNA analysis of bone tumors.

Flow cytometric DNA analysis was performed in a total of 203 bone tumors, benign and malignant. In more than 80% of cases the material studied was paraffin-embedded tumor tissue, mainly from the archives of the Bone Tumor Registry of Westphalia in Münster. Compared with ethanol-fixed fresh tumor samples, the variation coefficient in DNA histograms of the stored material was increased by a factor of 1.2-1.5, which means that resolution was decreased and that, in many cases, accurate cell cycle analysis was not feasible. However, the results of cell cycle analysis in bone tumors, even if performed on optimally fixed specimens, have to be evaluated with caution and full reference to the corresponding histological slides, since these histograms are apt to show various superpositions from the inflammatory infiltrate. The assessment of DNA ploidy is unimpaired if, in agreement with most researchers today, deviations smaller than +/- 10% from the diploid standard are still defined as DNA diploid, peridiploid, or pseudodiploid. The coefficient of variation should be kept as low as possible. If it is between 10% and 15%, the near-diploid stemlines with DNA indices of 0.9 or 1.1 may be hard to delineate. On account of the particularly marked regressive changes, the resolution of DNA histograms was most strongly impaired in chondromatous tumors, whereas it was mostly excellent in highly cellular viable tumor tissue, such as that from Ewing's sarcoma or osteoblastoma. On the whole, there was a distinct correlation between DNA ploidy and the biological behavior of bone tumors (Table 8). The highest rates of DNA aneuploidy were found in highly malignant OSs (18/21) and FSs (14/16), thus reflecting their poor prognosis. Of six juxtacortical OSs, three well-differentiated parosteal OSs and two periosteal OSs were DNA diploid, whereas one highly malignant surface OS and five highly malignant extraskeletal OSs, all DNA aneuploid, corresponded fully to the medullary OSs. Judging by preliminary results, adjuvant preoperative chemotherapy (COSS 80/82: Bösing et al. 1987) may reduce the rate of DNA aneuploidy and, consequently, of stem cell heterogeneity in general. A selective destruction of those stemlines that respond particularly to chemotherapy appears probable. In contrast to their high malignancy, Ewing's sarcomas showed an unexpectedly low proportion of DNA aneuploid stemlines (14/24). The comparatively favorable prognosis of MFH of bone is reflected in a lower rate of aneuploidies (2/10), which is also rather low (probably too low) when compared to our own data from soft tissue MFH (9/19).(ABSTRACT TRUNCATED AT 400 WORDS)

Bone Neoplasms↗
PubMed1989

Immunohistochemical investigation of chordomas: histogenetic and differential diagnostic aspects.

Chordomas are rare tumors of neuroectodermal origin and often show a very heterogeneous histological picture. In a combined histochemical and immunohistochemical study of 32 chordomas collected in the Bone Tumor Registry of Westphalia we were able to show that the immunoreactivity of the cells in both chordoma and notochordal structures are in close relationship with the extracellular matrix and depends more on the metabolic activity of these cells than on the origin of the cells of the neuroectoderm. All tumor cells show a bimodal immunoreaction with cytokeratin and vimentin, as well as a strong immunoreaction with the oncofetal markers CEA and AFP. The differentiation of chordomas from other malignant tumors, mainly the myxoid variant of chondrosarcoma, may cause major difficulties, especially if only a little biopsy material is available. Here we can see that in tumors with bimodal immunoexpression of vimentin and cytokeratin, as can be found in chordomas, the further use of antibodies offers a reliable differential diagnostic tool. The positive reaction of chordomas with all epithelial tumor markers offers a clear differentiation from chondrosarcomas, which, unlike chordomas, do not express cytokeratin. The identification of a marker profile by employing common antisera is of major value in the differentiation of chordoma from other epithelial or mesenchymal tumors.

Adult↗
PubMed1989

The cytogenesis of macrophages and osteoclast-like giant cells in bone tumors with special emphasis on the so-called fibrohistiocytic tumors.

Recent investigations have suggested that osteoclasts and osteoblasts belong to different cell systems: osteoclasts originate from hemopoietic stem cells, most probably via precursors of the mononuclear phagocyte system. Osteoblasts, however, arise from local mesenchyme. The present classification of bone tumors issued by the WHO, however, is still based on the assumption of osteoclasts and osteoblasts being merely different manifestations or differentiations of the same basic cell type. Consequently, histiocytes or macrophages as well as osteoclast-like giant cells are interpreted in most bone tumors as an autochthonous component of the tumor. In the present study, this theory is contradicted by histological immunohistological, electron microscopic, and autoradiographic-electron microscopic results on a larger number of osteosarcomas, chondromas, chondrosarcomas, chondroblastomas, aneurysmal bone cysts, giant cell tumors of bone, malignant fibrous histiocytomas, fibrosarcomas, desmoplastic fibromas, Ewing's sarcomas, fibrous dysplasias, nonossifying fibromas, and malignant hemangioenkdotheliomas of bone. In order to elucidate the role of macrophages and osteoclast-like giant cells, different monoclonal antibodies were applied to bone tumor specimens as markers of mononuclear macrophages and giant cells. The concept of what is called fibrohistiocytic tumors should be reconsidered. Immunohistological studies have shown that in malignant fibrous histiocytoma as well as in giant cell tumors of bone only a certain portion of macrophages will react with the highly specific antibodies, whereas the majority of tumor cells are negative. This finding alone suggests that the infiltration of macrophages is a reactive phenomenon. It is in agreement with earlier autoradiographic and electron microscopic investigations on giant cell tumors of bone, confirming that only the fibroblast-like tumors are actually proliferating. These data were verified in the present study with the aid of double labeling immunohistological techniques, using antibodies against mature tissue macrophages and others against a proliferation-associated nuclear antigen. Only the fibroblast-like cells, which do not react with the macrophage-specific antibody, will express the proliferation-associated nuclear antigen. Analogous results were obtained in malignant fibrous histiocytoma. We may infer from these results that the majority of these tumors must be neoplasms of local mesenchyme, mostly in fibroblastic differentiation, while the considerable number of macrophages is seen as a reactive phenomenon.(ABSTRACT TRUNCATED AT 400 WORDS)

Bone Neoplasms↗
PubMed1989

Infection management in total hip replacement.

Early diagnosis and determined management of infection after hip replacement are the prerequisites for good end results. Infections that manifest themselves during the first 6 weeks after a prosthetic implant can be mastered by local debridement. The implant can thus be saved, and the functional performance as well. Infections that appear after this 6-week period may require temporary removal of the implant in order to control the infection. When the clinical aspects and laboratory data indicate the infection is under control, the hip endoprosthesis can be reimplanted with a very low rate of recurrence. The method applied for removal of implants and bone cement is of utmost importance for the final results, and a extremely diligent surgical technique is the basis for long-term management of infection and good functional performance. Resection arthroplasty is not the treatment of choice anymore for infected hip prostheses and should be restricted to special cases.

Aged↗
PubMed1989

Ultrasonography of the hip for Perthes' disease.

The incidence of intracapsular hip-joint effusion in the initial stage of Perthes' disease is unknown. Recent experimental data demonstrated intracapsular hip-joint tamponade followed by necrosis of the femoral head. Ultrasonographic screening of children with "irritable hip syndrome" may reveal a ventral capsular distension as the decisive morphological criterion of hip-joint effusion. The patient is treated by aspiration of the effusion, bed rest, and nonsteroidal anti-inflammatory drugs. The noninvasive and nonionizing ultrasonographic technique permits the identification of a persisting hip-joint effusion by consequent serial follow-up. The suspicion of Perthes' disease can be confirmed by radiography, scintimetry, or, moreover, by magnetic resonance. On the other hand, hypertrophic synovial tissue stopping up the articular cavity and producing weak echos can be demonstrated in patients with a severe course of the disease. The importance of the sonographic diagnosis "ventral capsular distension along the femoral neck" for the prognosis and therapy of Perthes' disease should be investigated. Hips with intracapsular effusion should not be immobilized in extension and/or mild traction, as a relation between high intracapsular pressure and the position of the extended hip is known.

Child↗
PubMed1989

Two-stage therapy in the treatment of sacral tumors.

Sacral tumors are rare and may be clinically overlooked for a long period, because the symptoms and signs are often mild and non-specific. This led to frequent errors in clinical diagnosis and a long delay between the onset of symptoms and treatment. On presentation the lesions frequently expanded the anterior cortex, however, in most patients the periosteum of the sacrum and the presacral fascia form an unbroken barrier for a tumor. The pelvic viscera are not infiltrated by the tumor until late. Wide excision is difficult and often causes urogenital and/or anorectal dysfunction, but preserving the sacral nerve roots often leads to local recurrence. Surgical wide excision with a combined anterior-posterior approach is considered the treatment of choice for large lesions with significant anterior intrapelvic extension. This paper reports data resulting from the treatment of five large sacral tumors with comments on the results.

Adult↗
PubMed1989

[Parosteal osteosarcoma as a cause of chronic knee pain in an athlete].

The present case of a rare, however existing disease, which remained undetected for years, is to underline the necessity of diligent diagnosis. We report about a 23-year-old football player who complained about permanent pain in the right knee from the age of 13. In spite of repeated sports- and orthopedic-specific examinations correct diagnosis could only be established eight years after the onset of the symptoms. Differential diagnosis and the present mode of the therapy of this tumor close to the knee joint are demonstrated.

Adult↗
PubMed1989

[The value of nuclear magnetic resonance tomography in staging of bone and soft tissue sarcomas].

The prognosis of survival in bone and soft-tissue sarcomas is definitely correlated with compartmental tumor extension at the time of surgery and with the surgical margins achieved by resection. Preoperative planning and selection of an adequate surgical treatment procedure require a maximum of information on the tumor size, compartmental extension, proximity to the physis, skin layers, and the vessels and nerves. This information is indispensable and can only be obtained by a combination of several diagnostic investigations, MRI being of utmost importance. Whereas CT is superior in illustrating the bone structure, MRI outclasses CT in outlining the intraosseous tumor extension and the extraosseous tumor components. The latter aspects are especially important in planning and performing tumor resection. With the combined use of gradient echo sequences and Gadolinium DTPA with MRI, appreciation of the tumor margin and response to polychemotherapy may be possible in the future.

Bone Neoplasms↗
PubMed1988

[Efficient use of flash sequences in the staging of bone and soft tissue tumors].

Delineation of neoplasms from normal tissue is possible using Flash sequences. These sequences prove useful in preoperative staging of bone tumours and soft tissue tumours. However, contrast between neoplastic and surrounding normal tissue is lower than in optimal selected spin-echo sequences. Flash-90 sequence is superior to Flash-10 sequence in the demonstration of intraosseous extension of predominantly sclerotic, calcified and purely fibrous tumours. In contrast, Flash-10 sequence proves superior for the demarcation of osteolytic tumours with minimal fibrous tissue content. Delineation of extraosseous tumour masses against muscle can best be achieved using Flash-90 sequence after intravenous administration of Gadolinium-DTPA. Flash-90 sequence enables sharp demarcation of extraosseous masses of bone tumours against surrounding fat, whereas Flash-10 sequence proves useful in the delineation of non-lipomatous soft tissue tumours against normal fat.

Bone Neoplasms↗
PubMed1988

[Cystic parosteal osteosarcoma. A case treated by resection].

A parosteal sarcoma in a twelve-year-old girl is described in which a large cystic lesion developed at the centre of the lower femoral metaphysis. Treatment was by extensive resection and reconstruction with an allograft in two stages. There was an excellent result after seven years. Only one other case was found in a review of the literature of slowly growing primary malignant tumours.

Child↗