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Biomedical subjects

C Perka

Publications and source records attributed to C Perka.

At least 19 recordsLinked to original sources
PubMed2006

[Axial correction in knee revision arthroplasty].

Implant malalignment is a major cause for early loosening, increased wear, painful limitation of motion, and patient dissatisfaction in total knee arthroplasty. Validated diagnostic algorithms and a deeper understanding of the pathological mechanisms underlying functional deficits and pain resulting from malalignment explain the increasing number of revision operations on unloosened prostheses, which are now nearly as common as revisions for implant loosening. Common reasons are component malpositioning are a shifted joint line, or a non-physiological patella position. The success of any revision procedure basically depends on: (1) correct component positioning, (2) equal and symmetrical flexion and extension gaps, (3) restoration of joint line, and (4) a physiological patella height. The adequate grade of implant constraint has to be determined intra-operatively. A higher loosening rate of constrained implants as well as increased wear and painful limitation of motion in case of instability have to be taken into account. In the present work, a diagnostic and therapeutic algorithm for malalignment of knee prostheses is presented.

Algorithms↗
PubMed2006

[Variance of identification of femoral epicondyles in navigated total knee arthroplasty].

BACKGROUND: The aims of this study were the quantification of the accuracy of registration of the epicondylar axis (EA) in navigated total knee arthroplasty (TKA) and the identification of presumed factors influencing this accuracy. METHODS: A total of 32 navigated TKAs were performed and the surgical EA registered. Postoperatively, the difference from the surgical EA determined by computed tomography was calculated. Presumed factors influencing the accuracy were sex, preoperative malalignment, stability and range of motion, operated side, body mass index, and component size. RESULTS: The absolute error was calculated to be 1.4+/-1.3 degrees . Alignment according to the intraoperatively defined axes would have resulted in three outliers (>3 degrees malalignment). The operated side was the only factor showing a significant effect on the accuracy. The absolute error in left knee joints was calculated to be 0.9+/-0.7 degrees (max. 2.4 degrees ) and in right knee joints to be 2.0+/-1.5 degrees (max. 5 degrees, p=0.021). CONCLUSIONS: The surgeon stood on the patient's right side in every case, so that right knee joints were operated from the lateral and left ones from the medial side. A medial position of the surgeon to the knee joint during registration of EA is recommended because it results in a higher accuracy than a lateral position.

Arthroplasty, Replacement, Knee↗
PubMed2006

[Reduction of arthrosis associated knee pain through a single intra-articular injection of synthetic hyaluronic acid].

AIM: Conventional hyaluronic acids need three to five injections for therapeutic success, whereas Durolane), a synthetic hyaluronic acid, needs only a single injection. Clinical outcome using Durolane should be compared with the results of studies using hyaluronic acids or glucocorticoids. METHOD: Fifty patients with primary gonarthrosis stages I-III (Kellgren Score) were investigated for knee function, pain intensity, and quality of life. The knee and osteoarthritis outcome score (KOOS), visual analogue scale (VAS), and European quality of live score (EQ-5D), as well as motion of the knee were measured. Patients were investigated before, and 2, and 24 weeks after injection. RESULTS: Two weeks after injection, the subjective function of knee and quality of life had increased significantly. In the following 22 weeks, all parameters increased significantly (quality of life and activity +19%; range of motion active 109 vs. 115 degrees ; pain, 55 vs. 41 mm (VAS); all p<0.01). CONCLUSION: We conclude that a single injection of Durolane can reduce arthrosis associated knee pain sufficiently. Our data are comparable with those published in clinical studies using other hyaluronic acids. The effects of Durolane are delayed but more sustained compared than those found for glucocorticoids. Because of the single injection, we see an advantage in using Durolane compared to other conventional hyaluronic acids and glucocorticoids.

Activities of Daily Living↗
PubMed2006

Proposal for a histopathological consensus classification of the periprosthetic interface membrane.

AIMS: The introduction of clearly defined histopathological criteria for a standardised evaluation of the periprosthetic membrane, which can appear in cases of total joint arthroplasty revision surgery. METHODS: Based on histomorphological criteria, four types of periprosthetic membrane were defined: wear particle induced type (detection of foreign body particles; macrophages and multinucleated giant cells occupy at least 20% of the area; type I); infectious type (granulation tissue with neutrophilic granulocytes, plasma cells and few, if any, wear particles; type II); combined type (aspects of type I and type II occur simultaneously; type III); and indeterminate type (neither criteria for type I nor type II are fulfilled; type IV). The periprosthetic membranes of 370 patients (217 women, 153 men; mean age 67.6 years, mean period until revision surgery 7.4 years) were analysed according to the defined criteria. RESULTS: Frequency of histopathological membrane types was: type I 54.3%, type II 19.7%, type III 5.4%, type IV 15.4%, and not assessable 5.1%. The mean period between primary arthroplasty and revision surgery was 10.1 years for type I, 3.2 years for type II, 4.5 years for type III and 5.4 years for type IV. The correlation between histopathological and microbiological diagnosis was high (89.7%), and the inter-observer reproducibility sufficient (85%). CONCLUSION: The classification proposed enables standardised typing of periprosthetic membranes and may serve as a tool for further research on the pathogenesis of the loosening of total joint replacement. The study highlights the importance of non-infectious, non-particle induced loosening of prosthetic devices in orthopaedic surgery (membrane type IV), which was observed in 15.4% of patients.

Adult↗
PubMed2005

Stabilisation of periprosthetic fractures with angular stable internal fixation: a report of 13 cases.

INTRODUCTION: Periprosthetic fractures of the femur present a challenging surgical problem. The aim of this study was to retrospectively evaluate the outcome of periprosthetic fractures stabilised with an angular stable, less invasive stabilisation system (LISS). PATIENTS AND METHODS: Thirteen patients (ten total hip-, two total knee-, one total hip- and knee-arthroplasty) with periprosthetic fractures were treated with the LISS internal fixator (in ten cases minimal invasive). Six patients had previous operations due to periprosthetic fractures. The average follow-up period was 20 months, follow-up rate 85%. RESULTS: All fractures showed radiographic fracture healing without implant loosening. Except one patient, all patients had returned to their pre-operative activity level. No early post-operative complications were seen. There was one implant failure after 4 months and two cases of malunion. CONCLUSION: The cases showed the internal fixator to be effective for the stabilisation of periprosthetic fractures, even in cases of poor bone quality with good functional outcomes. The internal fixator, with the option of minimal invasive application, is the preferred method of osteosynthesis in periprosthetic fractures.

Accidental Falls↗
PubMed2005

[Periprosthetic fractures after total knee joint arthroplasty].

Periprosthetic fractures of the femur, tibia and patella are being registered with increasing frequency due to the rising numbers of total knee replacements. Depending on the site of the fracture, apart from mere traumatic mechanisms, implant specific parameters and implant loosening may represent the main causes of periprosthetic fracture. Moreover, general risk factors promote the manifestation of a periprosthetic fracture. Nowadays, valid classifications are available to categorize periprosthetic fractures of the femur, tibia and patella, and to create the basis for specific decision-making in choice of treatment. Despite a wide field of treatment options, the actual functional outcome after therapy and the high rates of complications imply that an adequate analysis of the fracture etiology and the corresponding transfer into an individualized treatment concept offer the chance of functional restoration of the patient similar to the pre-fracture state.

Arthroplasty, Replacement, Knee↗
PubMed2005

Endothelin-1 is secreted after total knee arthroplasty regardless of the use of a tourniquet.

Early infections and wound healing disorders after implantation of a total knee replacement occur regardless of the intraoperative use of a tourniquet. The biochemical regulatory processes responsible for the disturbances in microcirculation and thus the potential therapeutic options have yet to be elucidated. The hypothesis of the present paper was that endothelin-1 (ET-1), a mediator of microcirculation disturbances in parenchymatous organs, also is released after major operations on peripheral joints. The concentration of ET-1 in the plasma was determined preoperatively and at 10 postoperative time points (5 min-48 h) with (group A, n=10) and without the use of a tourniquet (group B, n=10). The ET-1 concentration achieved its maximum 6h after opening the tourniquet, which corresponded to 3.3 times the preoperative value. Without a tourniquet, the concentration maximum (2.9 times the baseline value) was achieved already 1.5 h after the end of the operation. However, the total amount of ET-1 secreted over 24 h was identical in both groups (p>0.5). We conclude that the tissue hypoxia resulting from the use of a tourniquet modulates ET-1 secretion, but that traumatization during the operation has a much stronger influence on the total amount secreted. ET-1 antagonists thus should be discussed for the drug prophylaxis of wound healing disorders, regardless of the use of a tourniquet.

Aged↗
PubMed2005

The management of necrosis-associated and idiopathic bone-marrow oedema of the proximal femur by intravenous iloprost.

Bone-marrow oedema can occur both in isolation and in association with necrosis of bone, but it has not been shown whether each respond to the same methods of treatment. We treated 16 patients with isolated oedema and 17, in which it was associated with necrosis of the proximal femur, with the prostacyclin derivative iloprost, which has been shown to be effective in the idiopathic form. The Harris hip score, the range of movement, the extent of the oedema as measured by MRI, pain on a visual analogue scale and patient satisfaction were recorded before and subsequent to treatment. In both groups, we were able to show a significant improvement (p < 0.001) in these observations during the period of follow-up indicating that iloprost will produce clinical improvement in both circumstances.

Adult↗
PubMed2005

Cementless stem fixation and primary stability under physiological-like loads in vitro.

Primary stability and in consequence osteointegration are commonly related to the stem anchorage but also to the complex musculoskeletal loading of the hip region. This study investigated the influence of metaphyseal and meta-diaphyseal anchorage on the primary stability of cementless stems under physiological-like loading in vitro. Metaphyseal and meta-diaphyseal anchoring stems (n=6 each) were implanted into composite femora. Musculoskeletal loads, validated by in vivo data (peak joint force 2348 N), were applied using a mechanical set-up. Interface movements were recorded by seven displacement transducers and primary stability was compared. Both stems exhibited similar movement patterns and principally moved distally with a retroversional twist. Although elastic movements were comparable, the metaphyseal stem exhibited higher plastic deformations than the meta-diaphyseal stem, particularly for the metaphyseal, medio-lateral and antero-posterior components. Under physiological-like loading, the metaphyseal stem allowed higher interface movements and tended to initially migrate faster than the meta-diaphyseal stem and then stabilized. Elastic movements were comparable and seemed to be less influenced by the anchoring concept than by the mechanical properties of the bone. The analyses emphasize the importance of metaphyseal bone in proximal anchorage and the necessity of an accurate canal preparation to prevent excessive initial migration.

Arthroplasty, Replacement, Hip↗
PubMed2004

[Molecular characterization of tissue-engineered articular chondrocyte transplants based on resorbable polymer fleece].

Three-dimensional arrangement and subsequent transplantation of chondrocytic cells in resorbable polymers has been shown to be a promising technique for the treatment of cartilaginous defects. Engineering of artificial cartilage tissue includes dedifferentiation of chondrocytes in monolayer culture, the use of biodegradable matrices and polymer scaffolds, and re-expression of chondrocytic marker genes in three-dimensional culture. The aim of this study was to characterize molecularly the phenotypic changes occurring with autologous cartilage tissue engineering. Human articular chondrocytes were isolated, cultured in medium containing human serum, and expanded up to passage 3. Chondrocytes were embedded in human fibrinogen and in polyglactin-polydioxanon fleeces and cultured three-dimensionally up to 4 weeks. Dedifferentiation of chondrocytes in monolayers and formation of cartilage tissue in vitro or after subcutaneous transplantation into nude mice was assessed by gene expression analysis of typical chondrocytic genes, histology, and immunohistochemistry. The expansion of chondrocytes with human serum resulted in the induction of type I and type III collagens, whereas cartilage-specific type II collagen, cartilage oligomeric matrix protein, cartilage link protein, and aggrecan were repressed and induced again after three-dimensional arrangement of chondrocytes in polyglactin-polydioxanon. Transplantation experiments documented the synthesis of proteoglycan and cartilage-specific type II collagen in vivo. Three-dimensional arrangement of human articular chondrocytes in resorbable polyglactin-polydioxanon fleeces supports chondrogenic differentiation and the formation of a hyaline-like cartilaginous matrix in vitro and in vivo.

Aged↗
PubMed2004

[Factors influencing perioperative morbidity and mortality in primary hip arthroplasty].

INTRODUCTION: In the present study we examined preoperative parameters that may identify patients at high risk for postoperative complications after endoprosthetic joint replacement. MATERIALS AND METHODS: The incidence of risk factors and perioperative complications in 628 primary hip arthroplasties (THA) (549 patients) was investigated in an unselected, retrospective study. Concomitant illnesses were found in 426 cases. Intra- and postoperative complications (93 specifically orthopedic and 42 common ones) were observed in 104 cases. RESULTS: High risk scores based on Lutz and Klose criteria, a prolonged operation time, and the number of previous operations were significantly correlated to the incidence of postoperative complications. In contrast, obese patients had a significantly lower rate of intra- and postoperative complications and a diminished perioperative blood loss. THAs performed under intubation anesthesia led to a higher blood transfusion volume. The patient's age and the kind and quantity of concomitant illnesses did not influence the perioperative complication rate. CONCLUSION: The complication rate of elective primary THAs is not dependent on risk factors suspected up to now such as advanced patient age or the kind and quantity of concomitant illnesses. High-risk patients can only be determined by complex scores, not by single parameters. Adiposity becomes a relevant economic factor only by dint of the prolonged operation time.

Adolescent↗
PubMed2003

Effects of fondaparinux compared with dalteparin, enoxaparin and unfractionated heparin on human osteoblasts.

The objective of the this study was to examine the effects of fondaparinux, a synthetic anticoagulant substance similar to heparin, on osteoblasts compared with previously used heparins. Its effects have been shown in clinical trials to be highly effective in thromboembolism prophylaxis. Unfractionated heparin (UFH), dalteparin, enoxaparin and fondaparinux were added to osteoblast cultures in the therapeutic range and two decimal powers above and below it in each case. The results showed that the mitochondrial activity and protein synthesis of osteoblasts treated with fondaparinux were significantly higher than in the other groups. Similar effects could be demonstrated for the matrix collagen type II content and calcification. In contrast enoxaparin, dalteparin and UFH lead to a significant decrease of matrix collagen type II content and calcification in concentrations equal or higher than the therapeutic one. No inhibitory in-vitro effects of fondaparinux on human osteoblasts could be demonstrated within the concentration range investigated (0.01-100 microg/ml). We conclude that fondaparinux can be used to avoid the heparin-related negative influence on osteoblast-dependent fracture healing and endoprosthetic implant integration.

Aged↗
PubMed2003

[Spontaneous patellar tendon rupture in a patient with Ehlers-Danlos syndrome].

The operative treatment of patellar tendon ruptures in patients with Ehlers-Danlos syndrome is complicated by the reduced mechanical properties of the tissue. These make it necessary to use, in addition to an end-to-end suture of the debrided tendon stumps and temporary stabilization by a McLaughlin cerclage, an additional augmentation, for example a Trevira band.

Ehlers-Danlos Syndrome↗
PubMed2002

Imaging of low-grade bone infection with a technetium-99m labelled monoclonal anti-NCA-90 Fab' fragment in patients with previous joint surgery.

Low-grade bone infection represents a serious clinical problem. Diagnostic options are often insufficient, yet the therapeutic implications of proven disease are important, especially in patients with prosthetic joint replacement. Technetium-99m labelled monoclonal anti-NCA-90 granulocyte antibody Fab' fragment (MN3 Fab') has been shown to be useful in bone and joint infection, but there are no data specifically referring to low-grade bone infection. We therefore analysed 38 scans in 30 consecutive patients (age range, 30-85 years; median age, 62 years) referred for suspected low-grade bone infection. There were 17 patients (21 scans) with total hip arthroplasty (THA), six with total knee arthroplasty (TKA), three who had undergone hip or knee surgery for trauma and five (seven scans) with resected hips and no endoprostheses (Girdlestone situations); one of these five patients had been investigated before with THA in situ and another prior to surgery for low-grade coxitis. There were no patients with rheumatoid arthritis as the underlying disease. Results were verified by means of bacteriological cultures, histopathological findings and/or follow-up and compared with the respective Zimmerli scores, which were used for clinical assessment of inflammatory activity. In one patient, the final diagnosis could not be established. One, 5 and 24 h after intravenous injection of up to 1.1 GBq of MN3 Fab', whole-body and planar scans were performed using a dual-head gamma camera. Scans were analysed visually and semiquantitatively adopting an arbitrary score ranging from 0 to 3. There were 13 true positive, 14 true negative and 10 false positive outcomes, yielding an overall sensitivity of 100%, an overall specificity of 58%, an accuracy of 73% and positive and negative predictive values of 57% and 100%, respectively. In patients with THA or TKA, accuracy was 81% and 80%, respectively, while it dropped to 43% in patients with Girdlestone situations owing to a high proportion of false positive findings (4/7) in this subgroup. Scintigraphic score was 1 in all of the false positive and in 11/13 true positive findings. The two remaining true positive findings displayed scintigraphic scores of 2 and 3, respectively. Scintigraphic and Zimmerli scores were loosely correlated (Spearman rho=0.38, P<0.05). Infection was excluded in 22/24 investigations with Zimmerli scores of <6. In this group, there were 13 scintigraphically true negative, nine false positive outcomes, and just two true positive outcomes. In 11/12 investigations with Zimmerli scores of 6 or 7, infection was verified and scintigraphic outcome was accordingly true positive, while the remaining patient was true negative. In conclusion, MN3 Fab' scintigraphy proved to be highly sensitive but not specific in diagnosing low-grade infections of the hip and knee regions in patients with previous joint surgery. The method seems reliable in excluding but not in proving the presence of infection. MN3 Fab' scintigraphy should not be applied in patients with Girdlestone situations. Assessment of infection using the Zimmerli score was more reliable than MN3 Fab' scintigraphy in this group of patients without rheumatoid arthritis as the underlying disease. Considering results from the literature concerning leucocyte scintigraphy, MN3 Fab' scintigraphy may be clinically useful in evaluating low-grade bone infection in THA and TKA patients with Zimmerli scores above 5 and concomitant rheumatoid arthritis or other inflammatory diseases.

Adult↗
PubMed2002

[Diagnosis and therapy of nodular tenosynovitis of the tendon sheath--case presentation].

A well-localized nodular mass near on a tendon is often the first clinical sign of a nodular tenosynovitis or so-called tenosynovial giant cell tumor of the tendon sheath. We report three cases of this rare tumor localized at the lower extremity, in correlation with clinical, radiographic and intraoperative findings. After the pathologic diagnosis was made, the patient in the first case decided not to have the tumor resected. This patient's postoperative course continues uneventfully without expansion of the tumor. In the second and third case, a surgical intervation was performed but both developed a local recurrence. A second operation with partial resection of the tendon was successfully performed. To the last follow-up 12 and 24 months after revisions, there were no signs of local recurrence. The review of the literature shows that treatment modalities for such lesions range from excisional biopsy to radiation therapy. The authors present their own experience with the MRI diagnosis and the therapy. Using well-defined histopathologic criteria, marginal resection is the treatment of choice. To prevent a local recurrence, partial resection of the tendon should be done during the primary surgery.

Adolescent↗
PubMed2002

[Results after anterior cruciate ligament revision surgery].

Revision surgery after failed anterior cruciate ligament reconstructions has increased tremendously. Reasons for revisions are persistent loss of motion, recurrent joint laxity, a painful knee or joint infections. In a retrospective study with a mean follow-up of 35.2 months 82 patients were examined after revision surgery. Time interval between primary and revision surgery, causes of revisions and treatment modalities were evaluated and compared to subjective, clinical and radiological parameters. In all cases a clinical improvement could be achieved. But results after revision operations are inferior to first reconstructions. The mean Tegner score improved after revision surgery from 2.4 to 4.6 points. The mean Lysholm score increased after secondary surgery from 54 to 76 points. The overall IKDC results of follow-up showed category A - 35.4 %, B - 39 %, C - 13.4 % and D - 12.2 % of the patients. A distinction between patients with preoperative isolated loss of motion and patients with isolated joint laxity seems useful. Revision operations with an improvement of joint mobility showed a higher subjective satisfaction, a lower rate of joint instability and better overall IKDC result compared to those with a high grade of preoperative joint laxity. Better results could be also achieved for early revision compared to late revisions and also for autologous grafts compared to alloplastic revision plasty. Transplant retaining procedures are only possible in selected cases and showed no clinical benefit compared to second revision of cruciate replacements. As a result of this study we conclude that early revision operation and the use of an autologous graft can be recommended but the surgeon has to be prepared to encounter many demanding technical problems.

Adolescent↗