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Biomedical subjects

S Fickert

Publications and source records attributed to S Fickert.

7 recordsLinked to original sources
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

[Obesity and arthritis].

An increasing prevalence and incidence of osteoarthritis especially in aging populations results in different socioeconomic problems. Recent studies have shown an association between osteoarthritis and overweight especially for knee and hip joints. The mechanisms responsible for the destruction of joints are still unknown, however. Obesity and overweight can lead to higher force transmission on joints at least in lower extremities, but mechanical factors hardly explain the association between overweight and hand osteoarthritis shown in different studies. There may be additional metabolic effects responsible for cartilage destruction, but distinct mechanisms have not been demonstrated up to now. They would, however, support preventive measures as well as therapeutic approaches.

Causality↗
PubMed2003

Identification, quantification and isolation of mesenchymal progenitor cells from osteoarthritic synovium by fluorescence automated cell sorting.

OBJECTIVE: Identification, quantification and isolation of subpopulations with characteristics of mesenchymal progenitor cells (MPC) from the synovial membrane (SM) from patients with osteoarthritis (OA). METHOD: Cells from the SM of patients with end stage OA who underwent total knee joint replacement were enzymatically isolated. One aliquot was directly analyzed by fluorescence automated cell sorting (FACS) using various combinations of surface markers of bone marrow MPC (CD9, CD44, CD54, CD90, and CD166). Remaining cells were cultivated on plastic, expanded over several passages, analyzed by FACS again and tested for their osteo- and chondrogenic potential. The differentiation was analyzed by immuno-/histochemistry and by RT-PCR for the expression of lineage related marker genes. RESULTS: Using FACS analysis we could show that the relative proportion of subpopulations expressing triplicate combinations of CD9, CD44, CD54, CD90 and CD166 in the SM from OA patients varies between 3 and 10%. Upon cultivation their relative amount markedly increased to values between 24 and 48%. Within the heterogeneous cell populations it was possible to induce osteogenic and chondrogenic differentiation. Initial sorting for CD9/CD90/CD166 triplicate positive cells proved that this subpopulation contains cells with multipotency for mesenchymal differentiation and thus characteristics of MPC. CONCLUSION: Our results show that SM from OA patients contains cells that express typical combinations of MPC surface markers and have the potency of osteogenic and chondrogenic differentiation. Their relative enrichment during in vitro cultivation and the possibility of cell sorting to get more homogenous populations offer interesting perspectives for possible future therapeutic applications.

Aged↗
PubMed2001

Total condylar knee arthroplasty: a long-term followup.

Between July 1977 and December 1983, 80 patients underwent 120 arthroplasties using a total condylar knee prostheses. Forty-one patients (68 knees) died and 13 patients were lost to followup. Twenty-six patients with 34 total condylar replacements were available for clinical followup. During the followup, 10 knees in nine patients (8.3%) from the overall 80 patients (120 knees) underwent revision; three (four knees) for aseptic loosening, one for periprosthetic fracture, three for infection, and two patients underwent revision for pain. Three revisions (three patients) occurred in the group of 26 patients available for followup. The average age of this group of patients at followup was 78 years (range, 53-94 years). There were 10 men and 16 women. Considering the high mean age of the patients in the series and patients' overall health status, the clinical results were extremely good. Kaplan-Meier analysis showed a survivorship of 91% at 23 years followup, considering revision as an end point. Although there have been several changes in total knee replacement designs, materials, and implantation techniques, the long-term outcome of the original total condylar knee prosthesis is excellent.

Adult↗
PubMed1999

Immunohistological analysis of cytokine expression in human osteoarthritic and healthy cartilage.

OBJECTIVE: To investigate osteoarthritic cartilage in comparison to normal cartilage in humans for the presence of the most relevant cytokines/growth factors known to be important for degradation and formation of new cartilage. METHODS: Cartilage from knee or hip joints was obtained from 10 patients with osteoarthritis (OA) and from 7 age matched control patients with intact cartilage. Additionally, normal cartilage from 2 young patients (12 and 17 years old) was obtained after knee traumas. Immunohistological staining of cartilage sections was performed using antibodies for the following cytokines/growth factors: tumor necrosis factor alpha (TNF-alpha), interleukin 1alpha (IL-1alpha), IL-1beta, interferon-gamma, IL-6, IL-4, IL-10, transforming growth factor beta1 (TGF-beta1), insulin-like growth factor I (IGF-I), IGF-II, platelet derived growth factor AA (PDGF-AA), and PDGF-BB. RESULTS: Immunohistochemical stainings were positive for all cytokines in OA cartilage, while only a faint or no staining was found in healthy cartilage. Activated chondrocytes expressing most of the cytokines were located in the middle and partly in the lower layer of cartilage, with the exception of IGF-I, which was expressed exclusively in the upper cartilage layer close to the surface. More chondrocytes stained positive for TNF-alpha than for IL-1, and expression of the degrading cytokine TNF-alpha was inversely correlated to the expression of the regulatory cytokines IL-4, IL-10, and TGF-beta. CONCLUSION: The most relevant cytokines known to be involved in cartilage metabolism are produced by chondrocytes themselves. They are upregulated in OA cartilage, suggesting that they serve some regulatory function and could be a target for future treatment.

Adolescent↗
PubMedDate not supplied

[Predictors of tibial head transposition in the therapy of varus knee osteoarthritis].

PURPOSE: The aim of this study was to find predictors for the clinical outcome in patients who underwent a high tibial osteotomy (HTO). METHOD: Between 1984 and 1996 a high tibial valgus osteotomy was performed in 155 patients with genu varum. 133 HTO patients were available for follow-up at an average postoperative time of 9.3 +/- 3.0 years. The degree of osteoarthritis was evaluated by radiological (Kellgren) and arthroscopic scoring systems (Outerbridge). Survival time of HTO was estimated using Kaplan-Meier survivorship analysis. RESULTS: The survival rate of HTO was 95 % after 5 years and 77 % after 10 years. In the medial compartment of knee joints with a preoperative Outerbridge stage III/IV or Kellgren stage III/IV the survival rate of HTO was significantly lower when compared to stages 0/I/II (p < 0.05). Age, sex, tibial malalignment and severity of osteoarthritis in the lateral compartment had no influence on survival rates. The pre-postoperative comparison of radiologically visible signs of osteoarthritis showed mainly either no (46.5 %) or only small (50.5 %) progression. We found that patients who underwent a HTO had good and very good clinical outcomes. CONCLUSION: We identified severity of preoperative radiological osteoarthritis and intraoperative chondromalacia as predictors of survival rate.

Female↗