Denervation deprives the heart of its normal adrenergic and cholinergic control via the sympathetic and parasympathetic pathways. In a heart which is blood supplied by a donor animal of the same species, normal contractility is maintained, probably by blood borne catecholamines or possibly by unknown inotropic agents of the donor. A heart receiving blood oxygenated by isolated lungs is in a state of failure. Substitution of blood by a cell and protein free solution diminishes oxygen availability in cardiac muscle, both in the perfused and bathed preparation. In the unphysiological environment, myocardial cells lose K+ and gain Na+. Under best possible conditions of oxygen supply but in a later stage of perfusion, contractility during rhythmical stimulation is depressed more at lower than at higher rates. Frequency potentiation and the inotropic effectiveness of noradrenaline is more pronounced in vitro than in situ. In excised papillary muscles and ventricular and atrial strips, the disarrangement and a more or less severe lesion of individual fibres accelerates the decay in mechanical performance. The role of endogenous catecholamines for the maintenance of normal contractility in situ and in vitro is still a matter of discussion.

Animals↗

PubMedDate not supplied

Frequency-potentiation in the human myocardium.

Explore the source record for details and available documents.

Adams-Stokes Syndrome↗

PubMedDate not supplied

[Etiology of early loosening after aseptic cup replacement using allogenic bone blocks and cement-free press-fit cups].

PURPOSE: There are two problems using structural allografts in revision total hip surgery. The long-term stability of bulk allografts and the intraoperative primary stability of the graft and implant limit the success of this revision philosophy. The purpose of this study was to analyse the reasons of early loosening of cementless cups after reconstruction with bulk allografts. METHOD: In a retrospective study 78 revisions were analysed radiologically. The preoperative stage of bone destruction, the size of allografts, the implant-allograft coverage, and the position of implants were analysed in X-ray series. RESULT: There were 12 (15.3%) cases with aseptic and 5 (6%) cases with septic cup loosening, after revision surgery, with an average follow-up of 37 (25-84) months. All of these failures were registered in the first 12 months postoperatively. Large bone defects and an implant-allograft coverage of more than 50% are significant (p < 0.001) risk factors of early aseptic loosening. CONCLUSIONS: It is important to give careful attentions to primary stability, especially in revision total hip arthroplasty using structural allografts and cementless cups. For primary stability as well as secondary stability a stable fixation with as large as possible areas of contact between implant and living bone is necessary. The limit of the method (allograft and cementless cup) is to be seen in stage 2B according Paprosky (1990). In larger defects alternative reconstruction methods have to be used.

Acetabulum↗

PubMedDate not supplied

[ROBODOC--a path into the future of hip endoprosthetics or an investment error?].

GOAL: The Orthopaedic Department of Martin-Luther-University has been using computer-guided, robot-assisted surgery in cementless total hip arthroplasty since June 1997. The goal of the present paper is to critically evaluate the advantages and disadvantages of the ROBODOC system when using two different femoral components and the employment of the system in orthopaedics in general. METHOD: Between June 1997 and August 1999 87 procedures have been performed using the ROBODOC system. 48 ABG stems and 39 OSTEOLOC stems manufactured by HOWMEDICA were used. The results are based on a prospective study. RESULTS: The main advantage of the system is the excellent three-dimensional preoperative planning and the precise execution of the preoperative plan during surgery. Problematic situations of the proximal femur can be evaluated and the optimal position of the femoral component can be guaranteed. Investigations on cadaver femurs showed significant differences in the bone-implant contact. The first results let us expect some advantage in congenital and acquired femoral deformities. CONCLUSION: The ROBODOC system has to be critically considered as an alternative to hand implantation. In our opinion, it should be used only under certain circumstances considering the current technical progress. Only in these cases the potential of the system can be used beneficially.

Arthroplasty, Replacement, Hip↗

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[Knee endoprosthesis implantation in hemophiliac arthropathy: results, problems and complications].

AIM OF STUDY: In the final stages of haemophilic arthropathy of the knee joint, the preservation of walking ability is only possible by joint replacement. Fibrotic ancylosis and severe deformities, being mostly bilaterally, make the joint reconstruction difficult and impair the results. The purpose of this study was to evaluate the results of total knee replacement (TKR) in haemophilia. METHODS: From 1990 to 1998, 14 TKR in 7 patients with severe haemophilia were performed. The mean age at operation was 47.3 years (range, 27-62 years). The mean follow-up period was 3.7 years (range, 1-7 years). The TKR was performed bilaterally at the same time in 6 cases. In 1 case, the bilateral TKR was done one after another with 6 months interval. In 10 knee joints, an unconstrained or semi-constrained surface replacement system was used. In 4 joints, a hinged prosthesis was required. RESULTS: The range of motion (extension-flexion) was improved from 0-23-69 degrees preoperatively to 0-4-88 degrees at follow-up. The mean HSS Score increased from 34.5 points preoperatively to 77.9 points at follow-up. Perioperatively, no haemorrhages or early infections were observed. In 1 case, 6 years postoperatively a late infection of the hinged knee prosthesis occurred. A two-stage-exchange of the prosthesis was performed. Aseptic loosenings of prosthetic components were not observed. CONCLUSION: The TKR in haemophilia is technically demanding and requires a consequent perioperative F-VIII or F-IX substitution. A bilateral simultaneous implantation is useful. The indication for TKR has to be strict because of the higher risks and requires a close cooperation with the haemostaseologist.

Adult↗

PubMedDate not supplied

[DNA flow cytometry of bone metastases of different primary tumors].

AIM: Some human tumors of different primary localization metastasize preferably into the bone. This concerns especially kidney, breast, prostate and lung cancer. So far, the reason for this specific pattern of metastazing could not sufficiently be clarified. The aim of the study was the search for mutuality in the results of the DNA analysis of bone metastases of different primary tumors and their importance for prognosis and therapy. METHOD: In this study, the DNA content of 40 excised bone metastases of different primary localisation has been determined by flow cytometry. By means of the DNA distribution pattern, the percentage of tumor cells in the particular cell cycle phase as well as the respective ploidy condition have been calculated. RESULTS: Altogether, no preference of DNA diploid or DNA aneuploid stem cell lines could be found. Whether this can be applied for metastases of all primary tumors has not been clarified yet. The fact that, in 11 out of 12 tested cases of the same metastasis, DNA diploid as well as DNA aneuploid areas could be demonstrated, seems to be fundamental. CONCLUSION: There exist a high variability of the extent of dysregulation and the intensity of the growth of bone metastasis. This does not seem to be crucial for the preferable tendency to metastazise into the bone. Due to the often insufficient tumor amount for material extraction from different areas and the large amount of DNA diploid metastases after flow cytometry analysis there should be considered the additional use of pictorial analytical methods for the DNA ploidy and proliferation assessment. A knowledge of the intensity of the course and the degree of dysregulation of tumor cell proliferation of bone metastases is beneficial in order to estimate the prognosis and to design an individual therapy regime.

Adult↗

PubMedDate not supplied

[Surgical treatment and evaluation of prognostic factors in spinal metastases of renal cell carcinoma].

AIM: The aim of this study was the evaluation of surgical results and prognostic factors in spinal metastases of renal cancer. METHODS: 37 surgical patients with spinal metastases of renal cell carcinoma were retrospectively analysed. In 2 patients the cervical, in 16 patients the thoracic, in 4 patients the thoraco-lumbar and in 16 patients the lumbar spine was involved. RESULTS: In 11 cases (29.7 %) a combined posterior-anterior spondylodesis with vertebral body replacement, in 26 cases (70.3 %) a single posterior instrumentation was done. Perioperatively, 24 complications appeared, 4 of them were lethal. Postoperatively, the neurological situation was unchanged in 26 patients, dischanged in 4 patients and improved in 7 patients. The level of pain was unchanged in 10 patients, dischanged in 3 patients and improved in 24 patients. The mean postoperative survival was 13.6 months. For the postoperative survival the Karnofsky-Index and the Frankel-Score were univariate highly significant, the factors nutritional condition and latency between the primary tumor and the development of spinal metastases showed a lower significancy. No prognostical influence for the postoperative survival could be detected for the factors gender, age, localisation of the metastases, type of operation and the factor solitary/multiple metastases. The multivariate analyses did not attempt any of the univariate significant prognostic factors for the postoperative survival. The postoperative survival was significantly (p: 0.0030) influenced by postoperative adjuvant therapy (radio- and/or chemotherapy). The analysis of each adjuvant therapy form (i. e. chemo-, radio- and combined therapy) attempts this prognostic effect (p: 0.0229). CONCLUSION: In most patients with spinal metastases of renal cell carcinoma, the singular posterior intrumentation combined with a decompression is a sufficient therapy. To avoid posterior implant failure, in patients with a prognosticated survival of more than one year, a combined posterior-anterior spondylodesis with vertebral body replacement should be done. The prognostic influence of an adjuvant postoperative treatment in the present study must be interpreted in the context of this small, highly selected patient collective. Further standardized studies should be performed to evaluate the prognostic influence of an adjuvant therapy.

Adult↗

PubMedDate not supplied

[Results of shoulder hemiarthroplasty in patients with acute and old fractures of the proximal humerus].

STUDY-DESIGN: We report on a prospective study of 22 patients after shoulder hemiarthroplasty in acute and old proximal humerus fractures. METHOD: Nine patients with an acute and 13 with an old humerus fracture, in whom a hemiarthroplasty was performed have been evaluated clinically using the Constant score as well as radiologically on average 22 months postoperatively. RESULTS: The mean Constant score improved on 28 points (27 to 55). The improvement was especially distinct in the group with acute fractures. Sixteen of the twenty examined patients were painfree. Two patients reported sleeping disturbances due to pain. The ROM was improved, especially in forward elevation and abduction. In two patients with an old fracture the results were less satisfying. Major complications could not be observed. In five cases X-ray revealed an atrophy of the fixated fragments. Dislocations did not occur. Radiological changes of the glenoid, already seen preoperatively became more obvious. Some humeral components, inserted without cement, showed "densification lines". There were no clinical signs of loosening. CONCLUSION: By performing hemiarthroplasty pain relief can be achieved, especially in old fractures. The postoperatively achieved joint function mainly depends on the type of fracture as well as ist age. In cases with a destroyed glenoid we now prefer to perform a total arthroplasty. In our opinion, general cement use for shaft fixation is not necessary.

Adult↗

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[Comparison of roentgenological, macroscopic and histological degree of degeneration in varus gonarthrosis].

In 20 cases of varus gonarthrosis the degree of severity of osteoarthrosis was assessed preoperatively, intraoperatively and postoperatively for the medial and lateral compartments, respectively. The preoperative assessment was carried out on the basis of x-ray taken in an anterior-posterior and lateral view, whereas the intraoperative assessment was based on the recognizable macroscopic alteration of the femur and tibia. Following implantation of a total knee prosthesis, the resected osteocartilogical samples were assessed from a histological point of view. In the case of varus gonarthrosis there is a distinct difference in the degree of degeneration in the medial and lateral compartments. This difference becomes less noticeable if the assessment is carried out intraoperatively. The histological analysis shows that there are certainly differences between the compartments from a quantitative point of view but a late stage of osteoarthrosis was discernible both medially and laterally. From a histological point of view the radiological concept of the so-called "unicompartmental varus gonarthrosis" cannot be supported. In both compartments the osteoarthrotic process is more uniform than is to be expected.

Aged↗

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[Cerebellar hemorrhage as an early complication of spinal operations. 2. Case reports and review of the literature].

GOAL: The present paper investigates the etiology and pathogenesis of cerebellar hemorrhage after spine surgery. METHOD: This paper reports two patients in those this complication was seen. In respect to the current literature we discuss the etiology and pathogenesis of cerebellar hemorrhage due to spine surgery. RESULTS: Cerebellar hemorrhages represent a life-threatening situation. There are no reports in the literature about cerebellar hemorrhage as an early complication of intraoperative dura injuries in spine surgery. It seems that a bigger cerebrospinal fluid loss is responsible for the developing of cerebellar hemorrhages. The loss creates a pressure gradient from infratentoriell to site of lesion and also leads to mechanical stress on cerebellar blood vessels such as traction, tearing and kinking. CONCLUSIONS: Every condition after spine surgery with dura injuries and neurological deficits should be carefully evaluated and intracranial hypotension as well as hemorrhage should be ruled out.

Adult↗

PubMedDate not supplied

[Long-term outcome of Dega acetabulum-plasty].

The authors reviewed the results of Dega acetabuloplasty in developmental dysplasia of the hip performed simultaneously with intertrochanteric osteotomy (predominant derotation-varusosteotomy DVO). 74 hips in 55 patients were assessed at a follow-up of 7-17 years (mean 10 years). Measurements of the acetabulum and the head-acetabulum-relation were found to be normal or slightly pathologic in 80-93% of the hips. Values of the femoral head and neck were in the low normal percentage. Poor clinical and radiological outcome was caused by avascular necrosis of the femoral head or revalgisation after DVO. The rate of avascular necrosis after conservative treatment was 23.4%, the rate as a consequence of the operation was 5.4%. Therefore, we prefer at present the subtrochanteric osteotomy of the femur.

Acetabulum↗