Biomedical subjects

K-P Günther

Publications and source records attributed to K-P Günther.

18 recordsLinked to original sources

PubMed2006

Indications for total hip replacement: comparison of assessments of orthopaedic surgeons and referring physicians.

OBJECTIVES: To analyse differences of opinions on indications for primary total hip replacements (THRs) within and between groups of orthopaedic surgeons and the physicians who refer patients to them. METHODS: 22 orthopaedic centres in 12 European countries took part, resulting in a postal survey of 304 orthopaedic surgeons and 314 referring physicians. Each participant was asked to state what importance different domains (pain, functional impairment, physical examination and radiographs) have on their decision to recommend THR and to select the most appropriate level of severity of each symptom or sign for recommending THR. In addition, the participants were asked to prioritise other personal or environmental factors that affect their decision to undertake a THR. RESULTS: Rest pain, pain with activity and functional limitations were the most important criteria for THR, although range of motion and radiographic changes were of least importance. Both similarities and differences were observed within and between groups of surgeons and referring physicians in the overall approach to indications and the most appropriate level of severity of disease for recommending THR. Most surgeons agreed on severity levels in only 4 of 11 items and most referring physicians in only one. Between the groups, major differences occurred with regard to the importance of activities of daily living and the appropriate level of symptoms for THR. In general, compared with surgeons, referring physicians reported that the disease needed to be more advanced to warrant surgery. CONCLUSION: Currently, no consensus exists on objective indication criteria for THR. The observed differences between the gatekeepers (referring physicians) and surgeons can lead to variations and perhaps inequities in the provision of care.

Arthroplasty, Replacement, Hip↗

PubMed2006

[Revision of unicompartmental knee arthroplasty].

Despite the good midterm survivorship reported for unicondylar knee arthroplasty, an increase in revision surgery has to be expected due to increased replacement rates. The reasons for failure as well as distribution are different for unicondylar knee arthroplasty compared to total knee arthroplasty. The main reasons for revision are aseptic loosening and the progression of osteoarthritis. In most cases, unicondylar knee arthroplasty will be revised to total knee arthroplasty. To obtain good revision results, the cause of implant failure has to be analysed carefully. In the case of contained bone defects, the reconstruction can be supported with bone grafting. For those cases with uncontained defects, implants with augmentation and, in some cases, stem extensions are needed. The modularity of the revision implant should cover different intraoperative requirements.

Arthroplasty, Replacement, Knee↗

PubMed2005

Sports activities 5 years after total knee or hip arthroplasty: the Ulm Osteoarthritis Study.

OBJECTIVE: To analyse sports activities of patients with hip or knee osteoarthritis (OA) over lifetime, preoperatively, and 5 years after arthroplasty. METHODS: In a longitudinal four centre study, 809 consecutive patients with advanced OA of the hip (420) or the knee (389) joint under the age of 76 years who required total joint replacement were recruited. A completed questionnaire about sports activities at 5 year follow up was received from 636 (79%) of the 809 patients. RESULTS: Although most patients with hip (97%) and knee (94%) OA had performed sports activities during their life, only 36% (hip patients) and 42% (knee patients) had maintained sports activities at the time of surgery. Five years postoperatively, the proportion of patients performing sports activities increased to 52% among patients with hip OA, but further declined to 34% among those with knee OA. Accordingly, the proportion of patients with hip OA performing sports activities for more than 2 hours a week increased from 8 to 14%, whereas this proportion decreased from 12 to 5% among patients with knee OA. Pain in the replaced joint was reported by 9% of patients with hip and by >16% with knee OA. CONCLUSION: Differences in pain 5 years after joint replacement may explain some of the difference of sports activities between patients with hip and knee OA. Reasons for reduction of sports activities may include the increasing age of the patients, their worries about an "artificial joint", and the advice of their surgeon to be cautious.

Aged↗

PubMed2005

[Resurfacing arthroplasty of the hip].

Currently, an increase in resurfacing arthroplasty in the treatment of hip osteoarthritis--especially in young adults--can be observed. New bearing technologies (mainly metal-on-metal surfaces) show better tribologic results than historical designs (e.g. the Wagner cup). At present, it is unclear whether these modifications and a definitively low dislocation rate--due to the large head diameter--can be supported by further good clinical results. The quantity as well as the quality of the available investigations prevents a definite opinion at the moment. Appropriate clinical studies with documented radiographic follow-up are necessary to compare the outcome of these new implants with standard techniques.

Arthroplasty, Replacement, Hip↗

PubMed2005

Differences in the views of orthopaedic surgeons and referring practitioners on the determinants of outcome after total hip replacement.

In order to assess current opinions on the long-term outcome after primary total hip replacement, we performed a multicentre, cross-sectional survey in 22 centres from 12 European countries. Different patient characteristics were categorised into 'decreases chances', 'does not affect chances', and 'increases chances' of a favourable long-term outcome, by 304 orthopaedic surgeons and 314 referring practitioners. The latter were less likely to associate age older than 80 years and obesity with a favourable outcome than orthopaedic surgeons (p < 0.001 and p = 0.006, respectively) and more likely to associate age younger than 50 years with a favourable outcome (p = 0.006). Comorbidity, rheumatoid arthritis, and poor bone quality were thought to be associated with a decreased chance of a favourable outcome. We found important differences in the opinions regarding long-term outcome after total hip replacement within and between referring practitioners and orthopaedic surgeons. These are likely to affect access to and the provision of total hip replacement.

Adult↗

PubMed2004

[Hip resurfacing arthroplasty].

In comparison to stemmed total hip replacements, hip resurfacing offers advantages especially in joint stability and amount of femoral bone resection. After the poor results achieved with this concept that were mainly caused by failure of the materials used, reintroduction of the metal-on-metal bearing initiated a renaissance. This bearing, the cementless cup, and the improved surgical technique led to better short- to medium-term results. Revision and complication rates are now comparable to conventional total hip replacements. The functional capacity of the method is higher. Because long-term results are not available, however, questions remain, for instance, the consequences of the higher metal ion serum concentrations or the impossibility of changing the inlay when femoral revision becomes necessary.

Adolescent↗

PubMed2004

Severity and extent of osteoarthritis and low grade systemic inflammation as assessed by high sensitivity C reactive protein.

BACKGROUND: Although osteoarthritis (OA) is thought to derive from defective chondrocyte metabolism and thus inherently lack the large scale systemic response of rheumatoid arthritis, there is increasing interest in the acute phase proteins in OA. OBJECTIVE: To assess the association between high sensitivity C reactive protein (hsCRP) and severity and extent of OA in patients with advanced hip and knee OA. METHODS: Preoperative hsCRP was measured in frozen serum samples from 770 consecutive patients with hip or knee joint replacement due to advanced OA recruited between 1995 and 1996. Pain was measured by a visual analogue scale and the Western Ontario and McMaster Universities OA index (WOMAC). The extent of OA in different joints was assessed clinically and radiographically. RESULTS: The (geometric) mean hsCRP was 2.5 mg/l among all patients. Severity of pain was associated with mean hsCRP (adjusted elevation highest v lowest quintile = 35%, p = 0.01) after controlling for known or suspected predictors of hsCRP, including age, smoking, and body mass index. Neither the bilateral nor the generalised extent of OA, nor any of the dimensions of the WOMAC were associated with mean hsCRP levels. CONCLUSIONS: Severity of pain, but not extent of OA, was associated with hsCRP levels in this group of patients with advanced OA. Longitudinal studies with repeated assessments of hsCRP and pain are needed to assess the possible value of hsCRP for monitoring or predicting the clinical course of OA.

Acute Disease↗

PubMed2003

[Anterior knee pain in children and adolescents. Diagnosis and conservative treatment].

Anterior knee pain is a common problem in childhood and adolescence with a prevalence of 4-30% in regional surveys. Although different etiologic theories are discussed in a large number of published studies, most cases are probably attributed to lower extremity malalignment, muscular imbalance, or physical overactivity (or even a combination of all three). Thorough clinical investigation should result in a definition of relevant static or functional problems as underlying causes of the disease. Radiographic analysis is mainly performed to exclude severe pathology (i.e., malignancies), as the correlation between described morphometric variables and clinical problems is weak. Prior to therapeutic recommendations, the benign natural course of the disease should be discussed with patients and their parents. In a large number of published studies with different conservative treatment protocols, positive results for many regimens are reported. The size,however, is not always large enough to prove superior outcome when compared to the natural course of the disease. There is also no evidence to support the superiority of one physiotherapy intervention over others.

Adolescent↗

PubMed2003

International variation in hip replacement rates.

OBJECTIVES: To summarise epidemiological data on the frequency of hip replacements in the countries of the developed world, especially in countries of the Organisation for Economic Cooperation and Development (OECD), and to investigate whether missing consensus criteria for the indication for total hip replacement (THR) result in different replacement rates. METHODS: Country-specific hip replacement rates were collected using the available literature, different data sources of national authorities, and estimates of leading hip replacement manufacturers. RESULTS: According to administrative and literature data sources the reported crude primary THR rate varied between 50 and 130 procedures/100000 inhabitants in OECD countries in the 1990s. The crude overall hip implantation rate, summarising THR, partial hip replacement, and hip revision procedures, was reported to range from 60 to 200 procedures/100000 inhabitants in the late 1990s. Moreover, large national differences were seen in the relationship between total and partial hip replacement procedures. CONCLUSION: The reported differences in hip replacement rates in OECD countries are substantial. They may be due to various causes, including different coding systems, country-specific differences in the healthcare system, in total expenditure on health per capita, in the population age structure, and in different indication criteria for THR.

Age Factors↗

PubMed2002

Adsorption and release properties of growth factors from biodegradable implants.

The present investigation was performed to study the adsorption behavior of growth factors and their release characteristics from biodegradable implants in an in vitro study. We investigated the stability of growth factors administered on various scaffolds. We used porous tricalcium phosphate ceramics (alpha-TCP), a neutralized glass-ceramics (GB9N), a composite (polylactid/-glycolid/GB9N), and solvent dehydrated human bone as carriers. Block shaped scaffolds (sized: 7 x 7 x 10 mm) were loaded with 5 microg of either bone morphogenetic protein (rxBMP-4), basic fibroblast growth factor (rh-bFGF), or vascular endothelial growth factor (rh-VEGF) solved in 150 microL PBS. The growth factors were labeled with Iodine125 (I-125) for detecting the adsorbed and released amount of growth factors by counting the samples for total I-125 activity. We observed that the adsorption of these growth factors seems to depend on two different parameters: first on the nature of the tested material, and second on the growth factors on their own. The release kinetics of the growth factors from the biodegradable implants can be described as a two phase process-a very rapid release during the first hours by an elution of not adsorbed protein, followed by a specific release, which depends upon the chemical/physical interaction of the material and the growth factor used. Analyzing the eluted proteins on SDS-PAGEs rh-VEGF was degraded into a smaller fragment with a size of around 15 kDa, while rxBMP-4 and rh-bFGF showed a complete degradation into fragments smaller than 3 kDa after more than 3 days. Although this in vitro study suggests that biodegradable implants might be successfully used as carriers for osteogenic growth factors, the different release kinetics as well as the alteration of their molecular structure including loss of biological activity should be considered.

Absorbable Implants↗

PubMed2002

Vascular endothelial growth factor stimulates chemotactic migration of primary human osteoblasts.

Recent studies have indicated a critical role for vascular endothelial growth factor (VEGF) during the process of endochondral ossification, in particular in coupling cartilage resorption with bone formation. Therefore, we studied the chemoattractive and proliferative properties of human VEGF-A on primary human osteoblasts (PHO) and compared these data with the effects of human basic fibroblast growth factor (bFGF) and human bone morphogenetic protein-2 (BMP-2). Furthermore, initial experiments were carried out to characterize VEGF-binding proteins on osteoblastic cells possibly involved in the response. For the first time, to our knowledge, we could demonstrate a chemoattractive effect of VEGF-A, but not VEGF-E, on primary human osteoblasts. The effect of VEGF-A was dose-dependent and did not reach a maximum within the concentration range tested (up to 10 ng/mL). The maximal effect observed was a chemotactic index (CI) of 2 at a concentration of 10 ng/mL. bFGF and BMP-2 exhibited maxima at 1.0 ng/mL with CI values of 2.5 and 2, respectively. In addition to its effect on cell migration, VEGF-A stimulated cell proliferation by up to 70%. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed the expression of VEGF receptors VEGFR-1 (Flt-1), VEGFR-2 (Kdr), and VEGFR-3 (Flt-4), as well as neuropilin-1 and -2. An in vitro kinase assay failed to demonstrate activation of VEGFR-2 upon stimulation with either VEGF-E or VEGF-A, consistent with the idea that the effect of VEGF-A on primary human osteoblasts is mediated via VEGFR-1. Taken together, our data establish that human osteoblasts respond to VEGF-A, suggesting a functional role for this growth factor in bone formation and remodeling.

Aged↗

PubMed2002

Lipofection of rabbit chondrocytes and long lasting expression of a lacZ reporter system in alginate beads.

OBJECTIVE: Our aim was to investigate the maintenance of the transfection status of non-viral transfected chondrocytes in an alginate culture system. DESIGN: Chondrocytes harvested from rabbit knees were isolated by sequential digestion and cultivated in monolayer culture. At 60-70% cell density, chondrocytes were transfected with different transfection systems (FuGENE6, CaCl2, Lipofectin). A lac Z expression vector (pcDNA 3.1/Myc-His+ lacZ) was used as a reporter system. In order to improve transfection rates, hyaluronidase (4 U/ml) was used prior and during the transfection procedure. Thereafter, transfected cells were either kept in monolayer culture or embedded in alginate beads and kept in culture for up to the next 30 weeks. RESULTS: Transfection efficiency was maximal using FuGENE6TM/DNA at a ratio of 3:2 and hyaluronidase (4 U/ml). Transfection efficiency reached up to 40.8% (+/- 3.2%) after 36 h. In alginate beads lac Z positive cells declined to 8.5% +/- 3.3% after 4 weeks and to 4.6% +/- 3.2% after 12 weeks of culturing. After 30 weeks 3% of chondrocytes still expressed lac Z. In contrast, during culturing in monolayer, no lac Z expression was detectable after 4 weeks. Differentiation status of the chondrocytes was confirmed by histology and immunohistochemistry methods. CONCLUSIONS: After successful gene transfer to rabbit chondrocytes the alginate system made it possible to culture lipofected chondrocytes phenotypically stable. Genetically engineered chondrocytes express the lac Z reporter gene over a period of at least 30 weeks. This transfection and culture system provides a promising tool to further investigate the over-expression of growth factors and enzyme inhibitors.

Alginates↗

PubMedDate not supplied

[Modern carbon fibre orthoses in the management of polio patients--a critical evaluation of the functional aspects].

AIM: Evaluation of practicability and functional benefit with modern carbon fibre knee ankle foot orthoses in polio patients. METHODS: In a retrospective analysis, fifty-five (55) polio patients between the ages of 42 and 80 years who had been provided with a carbon fibre orthoses for a minimum of three months, were asked about their acceptance as well as changes in functional capacity and comfort. RESULTS: Clear improvements were shown in walking, sitting and automobile driving as well as comfort and dressing/undressing of the orthoses. Through the use of these new orthoses, the maximum walking distance increased significantly--at least partially due to less weight (40%). 95% of all treated patients were very satisfied or satisfied. CONCLUSION: The use of carbon fibre material in the orthotic treatment of polio patients seems to be supported by the positive results of our study.

Activities of Daily Living↗

PubMedDate not supplied

[Evidence-based medicine in orthopedics - a sensible or unnecessary addition to clinical routine? Part 1: the diagnostics tool].

AIM: The methods of evidence based medicine (EBM) are recommended to solve problems in day-to-day routine. Aim of this article is to demonstrate the practicability of this procedure for the diagnostic module. METHODS: Within a teaching session in our department 20 participants guided by an extern al EBM teacher validated the results of an article according to the EBM criteria concerning the module "diagnosis". We demonstrate what EBM can contribute to solve day-to-day clinical problems and discuss the six formal steps for the implementation of EBM into day-to-day practice. 1) To transform the clinical problem into an answerable 4-part question. 2) To answer this question based on your internal evidence. 3) To search for external evidence to answer this question. 4) To critically appraise the evidence found with respect to its validity, importance and applicability. 5) To integrate the appraised external evidence into your existing internal evidence in order to come to a new decision if the additional new external evidence is convincing. 6) To assess the benefit which was gained for the patient. RESULTS: Statistical tests to evaluate the relevance and validity of the chosen article were performed. The following data were determined: sensitivity, specifity, pretest probability, posttest probability, likelihood ratio, positive predictive value, negative predictive value. CONCLUSION: In conclusion we show that EBM can help to solve day-to-day clinical problems, because the structured analysis of concrete questions can lead to a validation of the literature.

Clinical Competence↗

PubMedDate not supplied

[Evidence-based medicine in orthopaedics - a sensible or unnecessary addition to clinical routine? Part 2: the therapy tool].

AIM: In the second part of our project to implement evidence-based medicine into day-to-day clinical practice the module therapy is presented. METHODS: Within a teaching session in our department 20 participants guided by an extern al EBM teacher validated the results of an article according to the EBM criteria concerning the module therapy. To work with this module formal procedures are necessary, too. RESULTS: Statistical tests to evaluate the relevance and validity of the chosen article were performed. The following data were determined: relative risk reduction, absolute risk reduction, number needed to treat. CONCLUSION: In conclusion we can show, that EBM can help to solve day-to-day clinical problems, because the structured analysis concerning valid answers to concrete clinical problems is possible.

Clinical Competence↗

PubMedDate not supplied

[Midterm results after treatment of liposarcoma in the extremities].

PURPOSE: In this retrospective analysis, survival time, local recurrence and rate of metastasis were appraised in patients with primary liposarcoma of the extremities depending upon the applied primary and adjuvant therapy procedures. Furthermore, we compared the representativity of histological results of the biopsy with the final histology of the resected tumour. MATERIAL AND METHOD: Between 1990 and 1998, 27 patients were surgically treated who suffered from a primary liposarcoma of the extremities. At the mean follow-up time of 62.4 months (39-141 months) postoperative survival rate, rate of metastasis and local recurrence were determined. The results were analysed with regard to intraoperative resection distance, tumour size and localisation as well as histological classification of previous biopsy and finally resected tumour. The influence of radiotherapy on the results was also determined. RESULTS: In 5 patients (18.5%) the amputation and in 22 cases (81.5%) the limb sparing resection of the liposarcoma was performed. 6 patients underwent a marginal resection and one patient an intralesional resection. At follow-up we observed a local recurrence rate of 22.2% (n = 6) and a survival rate of 74.1%. 18.5% of the patients had metastases. After adjuvant radiotherapy three patients (50%) showed local recurrence after marginal resection. In only 8 cases (29.6%) the results of primary biopsy and final tumour classification (entity, subtype and grading) were identical. CONCLUSION: The development of metastases (often pulmonary) and local recurrences even after long tumour-free interval makes adequate follow-up investigations mandatory in liposarcoma patients. With regard to the problems in assessing liposarcoma biopsies, MRI-orientated biopsies from several tumour areas via one biopsy approach are recommended.

Adult↗

PubMedDate not supplied

[Functional results after surface replacement of the hip: comparison between dysplasia and idiopathic osteoarthritis].

AIM: To determine if there are differences in function after resurfacing arthroplasty of the hip in patients with primary osteoarthritis compared to patients with secondary osteoarthritis due to developmental dysplasia of the hip. METHOD: In a controlled prospective study of Birmingham Hip Resurfacing (BHR) we included all patients with primary osteoarthritis (n = 54, average age 48.4 years) and osteoarthritis due to high grade dysplasia (Eftekhar B, n = 34, average age 55.8 years). Standardized clinical (Harris hip score) and radiographic examinations were performed 6 weeks, 3 months and 6 months and then every year after the operation. RESULTS: All patients could be followed up to 1.5 years (1-4 years) after surgery. The average Harris hip score improved to 82-95 points in both groups 3 months postoperatively. Statistically significant differences could be found in the subscales "function" and "limp", where patients with dysplastic hips showed somewhat lower results after 6 (function) to 12 weeks (limp) postoperatively. This is probably attributable to extended non-weight-bearing after acetabular reconstruction in these cases, as the difference disappeared with full weight-bearing. Radiographically determined neck-shaft angles are slightly higher in dysplastic hips (142 degrees versus 135 degrees ), but we did not recognize any significant differences in implant positioning. CONCLUSION: The short- to mid-term results showed no clinically relevant functional differences after surface replacement in patients with primary osteoarthritis of the hip and patients with secondary osteoarthritis due to higher grade dysplasia. Long-term observation is necessary, however, to determine if these positive functional results are reflected by appropriate radiographic survival.

Adult↗

PubMedDate not supplied

[Total hip arthroplasty in congenital dysplasia of the hip: follow-up of a small-dimensioned, cemented straight stem].

AIM: The aim of this study is to report the survival and mid-term results including patient-relevant outcome measures with a small-sized cemented stem (CDH-stem) for the treatment of coxarthrosis secondary to developmental dysplasia of the hip. METHOD: 33 total hip replacements were performed with the CDH stem, 29 of which (88 %) were included in the follow-up after an average of 7.6 years. According to the classification system of Hartofilakidis et al., 10 hips were classified as type 1, 15 as type 2, and 3 as type 3. Survival was predicted using Kaplan-Meier survivorship analysis with revision as the end point. Results were assessed using the Harris hip score, as well as the WOMAC and SF-36 as patient-relevant outcome measures. RESULTS: Survival at thirteen years was predicted to be 92.4 % for the stem and 87.6 % for the varying acetabular implants used. At the time of the final follow-up, the average Harris hip score was 82.45 points. The global WOMAC index averaged 2.1, the average SF-36 score was 66.2 points. CONCLUSIONS: The data support the use of a small-sized cemented stem in small femora for total replacement of the dysplastic hip. To the best of our knowledge, this is the first study utilising the well validated WOMAC and SF-36 as patient-relevant outcome measures in this subgroup of patients.

Aged↗