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R Windhager

Publications and source records attributed to R Windhager.

At least 19 recordsLinked to original sources
PubMed2006

[Revision of tumour endoprostheses around the knee joint. Review and own results].

Revision of tumour endoprostheses around the knee joint is mainly caused by aseptic loosening and deep infection. Mechanical complications have been significantly reduced by improvements in prosthetic design. The rate of aseptic loosening after distal femur or proximal tibia replacement ranges from 10% to 45% depending on the time of follow-up and prosthetic design; the success rate after revision averages 75% at midterm follow-up. The rate of infection reported in the literature varies between 2.9% and 12%. One stage revision may be considered after acute infection without signs of loosening, after which a success rate of 77.8% can be expected. Two stage revision is mainly indicated in multi-resistant microorganisms as well as septic loosening, with a success rate of 75% after 5 years. Deep infection represents the most serious complication in long-term follow-up, often leading to amputation due to soft tissue problems after tumour resection. The authors were able to confirm the minimal decrease in MSTS score despite the large number of operations (15 patients: nine females, six males; median MSTS score 84%; mean 81%).

Aged↗
PubMed2006

Immunohistochemical and mutational analysis of PDGF and PDGFR in desmoid tumours: is there a role for tyrosine kinase inhibitors in c-kit-negative desmoid tumours?

AIM: To determine the platelet-derived growth factor (PDGF) alpha and beta status of desmoid tumours. Desmoid tumours are rare monoclonal neoplasms that appear to have no metastatic potential. Surgical resection and radiotherapy in the event of a positive surgical margin is the first-line treatment. Recurrences are frequent. Treatment results using non-steroidal anti-inflammatory agents, anti-oestrogen compounds and other agents such as Imatinib mesylate have been published. Therapy with Imatinib has been proposed as a therapeutic option, although in most reports desmoid tumours are reported to be c-kit-. METHODS AND RESULTS: We performed immunohistochemical analysis on 124 archived samples (85 patients) of desmoid tumours using antibodies to PDGFalpha, PDGFbeta, PDGFRalpha and PDGFRbeta. All desmoid tumours showed immunoreactivity with antibodies to PDGFalpha and PDGFRalpha, whereas with antibodies to PDGFbeta and PDGFRbeta no specific reaction could be detected. Mutational analysis of PDGFRalpha (exons 11, 12, 17 and 18) and PDGFRbeta (exon 12) on frozen material from 14 patients was performed, but no mutations leading to amino acid changes in the mature protein were identified. CONCLUSION: The absence of an activating mutation in a protooncogene does not exclude the efficacy of tyrosine kinase inhibitors through other possible mechanisms, and these might be a therapeutic option for patients with desmoid tumours in whom established local and systemic approaches fail to control the disease.

Adult↗
PubMed2006

Current concepts in gene therapy of the musculoskeletal system.

The purpose of this article is to review the remarkable progress in the field of musculoskeletal system gene therapy. Since the introduction of this concept 15 years much of the preclinical and clinical data have emerged. The original target, rheumatoid arthritis, has been subjected to clinical phase II efficacy protocol, and osteoarthritis gene therapy efficacy is being thoroughly investigated in various animal models. The most promising area of research in this field however, is the tissue repair, because it doesn't require prolonged period of gene expression, local delivery is reasonably simple and it avoids substantial risk associated with systemic delivery, and levels of gene expression don't need to be so finely regulated. Gene transfer is successfully being used to aid the repair and regeneration of bone, cartilage, ligament tendon, meniscus and intervertebral disc. Other potential applications of gene therapy in musculoskeletal system include osteoporosis, aseptic loosening, genetic diseases and tumors. Highly encouraging data gained from these studies have confirmed that gene therapy is a promising therapeutic solution to treat various musculoskeletal system disorders.

Genetic Therapy↗
PubMed2005

Immunohistochemical analysis of desmoid tumours.

BACKGROUND/AIMS: Although the standard treatment for desmoid tumours is complete surgical resection with wide margins, the optimal adjuvant treatment for recurrent or inoperable disease is unclear, often being based on sporadic immunohistochemical reports with a low number of cases. Therefore, a large immunohistochemical study was performed, to provide a theoretical basis for adjuvant treatment regimens. METHODS: One hundred and sixteen tissue samples from 80 patients (49 female, 31 male; mean age, 34 years; range, 0-83) with desmoid tumours (46 extra-abdominal, 21 abdominal, 13 intra-abdominal) were tested for oestrogen receptors alpha and beta, progesterone and androgen receptors, and somatostatin, in addition to HER2, cathepsin D, Ki-67, and c-KIT by immunohistochemistry. RESULTS: All samples were negative for oestrogen receptor alpha, HER2, and the progesterone receptor. Positive staining for the androgen receptor was found in six extra-abdominal cases. Staining for oestrogen receptor beta was positive in four extra-abdominal, two abdominal, and one intra-abdominal case. Staining for somatostatin was positive in six extra-abdominal, two abdominal, and one intra-abdominal case, and staining for cathepsin D was positive in all cases. Positive staining for Ki-67 was found in 14 extra-abdominal, three abdominal, and three intra-abdominal cases. C-KIT was detectable in one abdominal case only. CONCLUSIONS: The data from this immunohistochemical study show that the published effects of antioestrogens and imatinib mesylate in the treatment of aggressive fibromatoses may not be attributable to oestrogen receptor alpha or c-KIT expression.

Abdominal Neoplasms↗
PubMed2004

Intraoperative dissemination of tumour cells in patients with Ewing tumours detected by RT-PCR.

Using reverse transcriptase polymerase chain reaction (RT-PCR) we evaluated the occurrence of tumour-cell ribonucleic acid (RNA) in the blood during surgery in patients with Ewing tumours. The patients received irradiation and chemotherapy according to the protocol of the European Intergroup Cooperative Ewing Sarcoma Study (EICESS) 92. Blood samples were taken from 15 patients. Intra-operative dissemination was found during 2/8 resections but showed no relation to patient survival. At second-look biopsy, detection of tumour-cell RNA was associated with relapse and metastases in 3/4 patients. The results suggest that pre-operative treatment did not completely prevent dissemination of tumour cells during surgery of Ewing tumours.

Adolescent↗
PubMed2003

Dura resection in combination with en bloc spondylectomy for primary malignant tumors of the spine.

STUDY DESIGN: Resection of a primary malignant tumor of the bone with wide surgical margins has become the golden standard in oncological surgery. In the case of a spinal tumor with tumor invasion of the spinal canal, a wide resection could necessitate resection and subsequent replacement of part of the dura. SUMMARY OF BACKGROUND DATA: Dura replacement is a consequent surgical step in the treatment of primary malignant tumors of the spine. METHODS: We present the case of a 27-year-old male with a tumor of the dorsal elements of D6. After paraplegic symptoms, a laminectomy of D5 to D7 was performed and histologic examination revealed the presence of an osteosarcoma. After neoadjuvant polychemotherapy, a wide resection of the dorsal elements from D4 to D7 combined with a resection of the dorsal part of the dura was planned. Replacement of the dura was performed with Lyodura (B. Braun Melsungen AG, Melsungen, Germany). The spine was stabilized with an ISOLA instrumentation (Depuy International Ltd., Leeds, England). For wound closure, a pedicled latissimus dorsi flap and split skin graft were necessary. In a second step, ventral spondylodesis with Texas Scottish Rite Hospital instrumentation (Sofamor Danek, Memphis, TN) was performed. RESULTS: One hundred sixteen months after surgery the patient is alive without evidence of disease, is pain free, and has returned to his profession and life without any restrictions.

Adult↗
PubMed2003

[Measurement precision of sonography to evaluate movable meniscal bearings].

After resection of the ACL, the knee exhibits a paradoxical movement but the effect of this movement on function,wear, and implant survival in a meniscal bearing total knee replacement (TKR) is not known. Up to now, only radiological methods are described to measure the meniscal bearing's movement. We developed a method using ultrasound for analyzing MB motion. In an in vitro study we compared ultrasound of 5 MHz with 8 and 12 MHz, we studied the effect of malrotation on the projection of plain and digital radiographs, and compared ultrasound of 8 MHz with plain and digital radiographs. In all three methods the distance was measured between the anterior border of the tibial component and the anterior rim of the meniscal bearing. The accuracy and precision of 8 and 12 MHz were identical and statistically significantly more accurate than 5 MHz (p<0.01). Malrotation had a significant impact on the radiological projection. Neutral rotated radiographs and ultrasound of 8 MHz did not differ in accuracy and precision, but ultrasound was significantly more accurate than any radiograph with a malrotation of 1 degrees or more (p<0.001). We conclude that ultrasound of 8 MHz is an alternative to radiological methods for the measurement of meniscal bearings' motion.

Equipment Failure Analysis↗
PubMed2003

[In vivo assessment of mobility of meniscal bearings with ultrasound].

Clinical scores and fluoroscopically guided standard X-rays are still the golden standard for evaluating the outcome of total knee arthroplasty, but up to now there was no way to evaluate the function of mobile inlays except with digital fluoroscopy. We describe a new method using a flat 8-MHz ultrasound for the in vivo measurement of meniscal bearings (MB) with an accuracy and precision of 0.7 mm and 0.4 mm, respectively. In 73 knees with LCS classic total knee replacement, all of the medial (100%) and 71 of the lateral (97%) MB could be analyzed. The MB moved unhindered with an average total shift of 4.5 mm (range: 0.2-12.1) on the medial and 4.2 mm (range: 0.8-13.2) on the lateral side. A significant correlation was found between the active range of motion (ROM) of the knee joint and the medial MB's shift ( p=0.004) but not for the lateral MB ( p=0.114). Three knees had to be revised due to aseptic loosening (2) or excessive PE wear (1). No single parameter of the ultrasound analysis could be detected to be predictive for the MB's failure. Conventional ultrasound allows the analysis of MB function at low cost with an accuracy better than 1 mm. This method is an alternative to radiological methods and suitable for studies with larger numbers of patients followed over longer periods.

Arthritis, Rheumatoid↗
PubMed2003

[Surgical therapy of pelvis and spine in primary malignant bone tumors].

Despite standardization of surgical treatment of primary malignant tumors of the pelvis and spine, prognosis in these centrally located tumors still is inferior compared to those located in the extremities. This fact may be attributed to delayed diagnosis in many cases and the resulting increase in tumor volume as well as to difficulties of resection due to the anatomical situation. The frequency of local recurrence after resection of primary malignant tumors is reported to be between 4 and 41% and the 5-year survival rate below 40%. Whereas the latter has remained almost unchanged during the past 20 years, amputation has been replaced by limb-salvage surgery except for a minimal amount of less than 10%. For reconstruction, biological techniques are increasingly preferred to endoprosthetic replacement or use of bulk allografts because of the high complication rate. Even in the spine wide resections are feasible provided at least one lamina is healthy in order to prepare and save the neural structures without touching the tumor. Compared to the widely used technique of curettage, en bloc resection may provide a significantly better oncologic result with respect to local tumor control. Failure of the dorsoventral stabilization with delayed union is the most frequent complication of these challenging procedures. In order to improve the long-term prognosis of these groups of patients in the future, early diagnosis and immediate admission to a specialized tumor service has to be attempted.

Adolescent↗
PubMed2003

Osteosarcoma over the age of forty.

The European Musculo Skeletal Oncology Society (EMSOS) has carried out a retrospective review of patients over the age of 40 years with osteosarcoma. 481 patients from 12 centres or multicentric groups were included. 42 patients had osteosarcoma arising in Paget's disease, median survival was 9 months. Patients with axial or metastatic tumours also did badly whilst 41 patients with radiation-induced osteosarcoma had a prognosis paralleling conventional osteosarcoma matched for patient age and site of the tumour. 238 patients had high grade non-metastatic osteosarcoma and had a survival of 46% at 5 years. Older patients had less chemotherapy and fared worse. Osteosarcoma in the elderly is a curable condition and warrants intensive treatment with chemotherapy and surgical resection.

Adult↗
PubMed2003

Reduction of blood loss using high-dose aprotinin in major orthopaedic surgery: a prospective, double-blind, randomised and placebo-controlled study.

We have investigated in a prospective,randomised placebo-controlled study the effect of high-dose aprotinin on blood loss in patients admitted for major surgery (revision arthroplasty of the hip or knee, or for resection of a soft-tissue sarcoma). The mean intraoperative blood loss was reduced from 1957 ml in the control group to 736 ml in the aprotinin group (p = 0.002). The mean requirement for intraoperative homologous blood transfusion in the aprotinin group was 1.4 units (95% CI 0.2 to 2.7) and 3.1 units (95% CI 1.7 to 4.6) in the control group (p = 0.033). The mean length of hospital stay was reduced from 27.8 days in the control group to 17.6 days in the aprotinin group which was not statistically significant. The intraoperative use of aprotinin in major orthopaedic operations significantly reduced blood loss and the required amount of packed cells. It may result in in the length of hospital stay and costs.

Aged↗
PubMed2002

Peripheral osteoid osteoma. Is there still a place for traditional surgery?

We treated 106 patients with a peripheral osteoid osteoma by conventional surgical methods; 81 had curettage and 25 en-bloc resection. The rate of local recurrence after curettage was 12% and after en-bloc resection 4.5%. Postoperative fractures were observed in 3% after curettage and in 4.5% after en-bloc resection. We compared our findings with those reported in the literature after minimally invasive treatment and concluded that curettage can be regarded as the treatment of choice in patients in whom minimally invasive methods do not offer any advantage, for example, for subperiosteal tumours which are readily accessible, or when the diagnosis is unclear and further histological analysis is required.

Adolescent↗
PubMed2002

Revision of the Kotz type of tumour endoprosthesis for the lower limb.

In 251 patients over a period of 15 years an uncemented Kotz modular femoral and tibial reconstruction mega prosthesis was implanted after resection of a malignant tumour of the lower limb. Twenty-one patients (8.4%) underwent revision for aseptic loosening, again using an uncemented prosthesis, and five of these required a further revision procedure. The median follow-up time from the first revision was 60 months (11 to 168) and after a second revision, 33 months (2 to 50). The probability of a patient avoiding aseptic loosening for ten years was 96% for a proximal femoral, 76% for a distal femoral and 85% for a proximal tibial implant. At the time of follow-up all radiographs were assessed according to the International Symposium of Limb Salvage criteria. The first radiological signs of aseptic loosening were always seen at the most proximal or distal part of the anchorage stem at a mean of 12 months (4 to 23) after the first implantation. Using the Musculoskeletal Tumor Society score for evaluation, the clinical results showed a mean of 88% of normal function.

Adolescent↗
PubMed2002

Total vertebrectomy for primary malignant tumours of the spine.

Primary malignant tumours should be resected with wide margins. This may be difficult to apply to lesions of the spine. We undertook total vertebrectomy on seven patients, four males and three females with a mean age at operation of 26.5 years (6.3 to 45.8). The mean follow-up was 52.3 months. Histological examination revealed a Ewing's sarcoma in two patients and osteosarcoma, leiomyosarcoma, spindle-cell sarcoma, chondrosarcoma and malignant schwannoma in one each. In five patients, histological examination showed that a wide resection had been achieved. At follow-up there was no infection and a permanent neurological deficit was only seen in those patients in whom the surgical procedure had required resection of nerve roots. Despite the high demands placed on the surgeon and anaesthetist and the length of postoperative care we consider total vertebrectomy to be an appropriate procedure for the operative treatment of primary malignant lesions of the spine.

Adolescent↗
PubMed2001

Expression of insulin-like growth factor-I (IGF-I) in aneurysmal bone cyst.

The effects of insulin-like growth factor-I on bone tissue and its role in bone development have been extensively investigated, but there is little information on its role in the pathogenesis of aneurysmal bone cyst. Therefore, using the techniques of immunohistochemistry and in situ hybridization, the authors studied the expression of insulin-like growth factor-I in 19 specimens of aneurysmal bone cyst. Insulin-like growth factor-I or specific mRNA sequences encoding for insulin-like growth factor-I were detectable in all specimens tested and were mainly localized in multinucleate giant cells. In contrast, only insignificant levels of insulin-like growth factor-I expression were detectable in normal human bone tissue. Taken together with the previously reported role of insulin-like growth factor-I in the pathogenesis of giant cell tumor, the findings of this study suggest that insulin-like growth factor-I may play a role in the pathogenesis of aneurysmal bone cyst.

Adolescent↗
PubMed2001

A long-term review of the treatment of patients with Ewing's sarcoma in one institution.

AIMS: The treatment of patients suffering from Ewing's sarcoma has changed over the last three decades. We report the analyses, significant prognostic factors, interdisciplinary approach and development of therapy in one institution in Austria. METHODS: One hundred and forty-two patients treated for Ewing's sarcoma between 1949 and 1994 were reviewed. Median follow-up was 8.5 years. Fifty-six patients were treated between 1949 and 1980 (group 1), and 86 patients between 1981 and 1994 (group 2). Patients in group 1 were treated with polychemotherapy. Patients in group 2 were treated with a neoadjuvant CESS (Cooperative Ewing's Sarcoma Study) regimen. In group 1, 24 patients underwent biopsy only, 32 patients had a definitive operation, 48 patients received either radiation therapy only or additional radiation therapy compared with in group 2: 6, 80 and 44 cases, respectively. RESULTS: Five-year overall survival (OS) increased from 27% to 57%. Significant prognostic factors for OS were pre-operative metastases (P=0.0001), tumour location (P=0.0048), type of chemotherapy (P=0.002) and response to chemotherapy (P=0.0004). Chemotherapy (P=0.037), tumour location (P=0.0017) and metastases at diagnosis (P=0.0025) were significant. CONCLUSION: The most effective treatment of Ewing's sarcoma is chemotherapy.

Adolescent↗