Biomedical subjects

R Windhager

Publications and source records attributed to R Windhager.

At least 19 recordsLinked to original sources

PubMed1997

One-stage revision surgery for infected megaprostheses.

We have reviewed the results of one-stage revision surgery in 18 patients for infection of megaprostheses implanted after the resection of malignant bone and soft-tissue tumours. At a mean follow-up of 52.0 +/- 35.0 months (18 to 135) infection was eliminated in 14 of the 18 patients. The infection-free patients showed no abnormal tests for inflammation and had a mean Enneking score of 20.6 +/- 5.0 points (maximum 30 points). We suggest that one-stage revision without exchange of the anchorage parts is justified in patients with megaprostheses infected by antibiotic-sensitive micro-organisms.

Adolescent↗

PubMed1996

Vascular reconstruction for limb salvage in sarcoma of the lower extremity.

OBJECTIVES: To examine the patency and limb-salvage characteristics of vascular reconstruction in patients with sarcomas of the lower extremity who had been treated with limb-preserving resection and to examine patient survival during a long follow-up period. DESIGN: Retrospective cohort study. SETTING: University hospital, tertiary referral center. PATIENTS: From 1984 to 1992, 14 patients underwent limb-preserving resection of sarcomas in the proximal lower extremity, with 20 vascular reconstructions performed. OUTCOME MEASURES: Color Doppler scans documented patency of the vascular reconstructions. Clinical evaluation included functional results in terms of limb movement and quality of life. Local tumor control and systemic recurrence were examined by repeated radiologic examination. Overall survival as well as time and cause of death were assessed. RESULTS: A total of 13 patients had patent vascular grafts, while the venous graft became occluded in 1 patient. Limb function was rated as excellent or good in 9 patients, as fair in 3, as poor in 1, and could not be clinically estimated in 1. Postoperative thrombosis of the venous graft was detected in 3 patients and was effectively managed by thrombectomy in 2. Three patients underwent reoperation because of hematoma or complications caused by local infection. The tumor endoprosthesis had to be replaced in 3 patients. During follow-up periods that ranged from 15 to 132 months (mean, 55 months), 4 patients died. In all of these patients the cause of death was systemic recurrence in the lung. Two additional patients developed pulmonary metastases, but at the time of this report, they were still alive as long as 132 months after operative resection or chemotherapy. No local recurrence was found. CONCLUSION: Limb-preserving resection of sarcoma of the lower extremity can be performed with satisfactory function of the limb maintained, even if it becomes necessary to resect the femoral vessels. Autologous venous graft for vascular reconstruction is the treatment of choice. In spite of the high incidence of metastases, considerable long-term survival is possible.

Adolescent↗

PubMed1996

Recorticalization after bifocal internal bone transport in the double-plated sheep femur.

Distraction osteogenesis and bone remodelling after the end of bone transport were investigated in one femur each of six adult male sheep. A newly designed internal distraction device was used. A custom-made osteosynthesis plate was fixed on the lateral side of the femur, and two transporting plates driven by a transcutaneously inserted screwdriver moved two bone cylinders simultaneously over a 40 mm defect. An additional plate was applied ventrally to stabilize the device. Bone transport was begun 2 weeks postoperatively at 1 mm/day at each transporting plate until they came into contact. New bone formation within the distraction gaps was evaluated by computed tomography scans and was quantified at 4 and 6 months by dual energy x-ray absorptiometry as well as histomorphometry on polyfluorochrome-labelled undecalcified ground sections and microradiographs. At 4 months, all distraction gaps were bridged by abundant newly formed bone trabeculae, which were reduced and condensed to cortex-like layers of new bone at 6 months. Less new bone was always found under the lateral device than in the unplated medical and dorsal segments, but the amount of new bone under the ventral plate was comparable with that in the unplated regions. The results of this pilot study show that distraction osteogenesis can be achieved with an internal device such as this one and that recorticalization and restoration of a medullary canal occur despite the relatively rigid internal stabilization by the plates.

Animals↗

PubMed1996

Mobilization of tumour cells during biopsy in an infant with Ewing sarcoma.

UNLABELLED: Ewing sarcoma and the closely related peripheral primitive neuroectodermal tumour, recently referred to as Ewing tumour (ET), are characterised by unique gene rearrangements on chromosome 22. The breakpoints have been cloned and shown to fuse the Ewing sarcoma gene to one of two closely related ETS proto-oncogens, FLI-1 or ERG, which reside on chromosomes 11 and 21, respectively. The rearrangement results in the expression of specific hybrid transcripts which can be detected with high sensitivity by the reverse transcriptase polymerase chain reaction technique (RT-PCR) in primary tumours, blood and bone marrow. We report on a 7-month-old boy with a pelvic Ewing sarcoma in whom circulating tumour cells were identified in the peripheral blood during open tumour biopsy by RT-PCR. However, before and 6 days after surgery no tumour cells could be detected in the peripheral blood. CONCLUSION: The application of RT-PCR to monitor shedding of tumour cells during surgical intervention will help to evaluate if open biopsy potentially contributes to metastatic tumour cell spread.

Base Sequence↗

PubMed1996

Prevention of chemotherapy-induced anemia by the use of erythropoietin in patients with primary malignant bone tumors (a double-blind, randomized, phase III study).

BACKGROUND: Patients undergoing chemotherapy for treatment of malignancy frequently experience clinically significant anemia. Myelosuppressive chemotherapy impairs erythropoiesis, which may not fully recover between treatment cycles. Recombinant human erythropoietin (rHuEPO) has been effectively introduced in anemic patients suffering from chronic renal failure. The present study was designed to assess, first, whether rHuEPO treatment decreases transfusion requirements in chemotherapy-induced anemia and, second, whether high-dose rHuEPO application is safe. STUDY DESIGN AND METHODS: Thirty consecutive anemic patients (hemoglobin <11 g/dl) receiving combination chemotherapy for primary malignant bone tumors were studied in a prospective, double-blind, randomized, Phase III trial. Patients received chemotherapy according to one of two German protocols, depending on histologic diagnosis. All subjects enrolled were randomly assigned either to receive 600 IU of rHuEPO per kg of body weight intravenously twice a week or to receive a placebo during chemotherapy. To obtain comparable data, an observation period of 20 weeks was chosen. Twenty-nine patients fulfilled the criteria and were eligible for statistical evaluation. RESULTS: Transfusion requirements were significantly decreased from Week 8 of therapy (p<0.05) in the treatment group. Therapeutic benefits were even more evident with continuation of therapy (Week 12, p = 0.03; Week 16, p = 0.016; Week 20, p = 0.002). The blood required was 2.1 units of red cells in the treatment group and 8.4 units of red cells in the placebo group. All patients tolerated rHuEPO with no serious side effects. CONCLUSION: These findings suggest that rHuEPO is an effective and well-tolerated therapeutic option for decreasing the transfusion requirements in chemotherapy-induced anemia.

Adolescent↗

PubMed1996

Limb salvage in periacetabular sarcomas: review of 21 consecutive cases.

The oncologic and functional outcome was reviewed in 21 consecutive patients who underwent limb salvaging surgery for periacetabular sarcoma using a new surgical approach and different types of reconstruction between 1972 and 1990. Histologic diagnosis in 86% showed osteosarcomas, chondrosarcomas, and Ewing's tumors. Age ranged from 10.0 to 61.5 years (mean age, 32.9 years). The resection margin was wide in 15 patients but marginal in 2 patients and intralesional in 4 patients. All of the latter patients died of their disease. In all cases where 3-dimensional imaging was used, wide resection margins could be achieved, whereas this was possible only in 50% of the cases with conventional imaging techniques. Seven patients died of their disease 3 to 15 months after surgery, 2 died of chemotherapy induced sepsis, and 2 patients died perioperatively. At followup, 8 patients had no evidence of disease (mean, 57.6 months; range, 12-190 months), and 2 patients were alive with disease. Fourteen patients could be observed for at least 12 months (mean, 41.1 months) and were functionally evaluated according to Enneking's criteria. If extensive resection was necessary, the best results were found if the defect had been reconstructed with a custom made prosthesis. The results were only satisfactory after implantation of saddle prostheses and poor with allografts or when no reconstruction of the bone defect was done.

Acetabulum↗

PubMed1995

Effect of bone cylinder length on distraction osteogenesis in the rabbit tibia.

The viability and osteogenic potential of bone cylinders for bone transport was investigated in one tibia of 18 mature male New Zealand rabbits. The length of the bone cylinder was equal to or twice that of the diameter of the tibia. The cylinder was cut subperiosteally with an externally cooled oscillating saw from a lateral approach, after a specific unilateral external fixator had been applied. To simulate bone transport, one end of the cylinder was fixed to the distal bone stump by a cerclage wire and healing and revascularization was prevented by an interposed expanded polytetrafluoroethylene membrane. The periosteum was re-adapted and sutured, and distraction began 10 days postoperatively at 0.25 mm/12 hours for 22 days. New bone formation in the distraction gap was quantified by dual energy x-ray absorptiometry and by computer-assisted histomorphometry of polyfluorochrome-labeled undecalcified bone sections and corresponding microradiographs. In half of the animals with each size cylinder, osseous bridging occurred, so the findings on distraction osteogenesis are reported only for the remaining nine animals. Generally, centripetal mineralization of the gap with two distinct zones of ripening bone structures and a central radiolucent fibrocartilaginous zone could be distinguished. Neither absorptiometry nor histomorphometry showed significant differences in the overall amount of this new bone formation for the bone cylinders of two different lengths. However, osteogenesis was significantly greater at the proximal end than at the cylinder. New bone was formed predominantly from endosteal sites in the smaller cylinders and from periosteal sites in the larger cylinders. Histologically, there was complete necrosis of both sizes of cylinders, followed by revitalization through newly formed vascular channels.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1995

Extendable tumour endoprostheses for the leg in children.

From 1986 to 1991 we fitted 20 children with endoprostheses after resection of malignant bone tumours of the leg; six have reached skeletal maturity and are the subject of this study. Reconstruction of defects in growing limbs in which the eventual shortening can be predicted requires the use of extendable prostheses. The mean age at operation was 11 years (9.2 to 13.7) and the average follow-up period was 6.3 years (4.3 to 7.6). The diagnosis was osteosarcoma in five patients and Ewing's sarcoma in one. All tumours were Enneking stage-IIB. When seen for follow-up all patients were free from disease. The extendable implants used included the Pafford-Lewis prosthesis and the Kotz Modular Femur Tibia Reconstruction system with a compatible, newly-designed growth module. Telescope-like elongation of the prostheses was performed by insertion of a screwdriver through a small skin incision. Active epiphyseal growth in the adjacent growth plate was preserved by using prosthetic stems with a smooth surface. The mean length gained was 13.15 cm (4.5 to 19.5) requiring 53 planned procedures. Seven revision operations were necessary for complications. Functional evaluation showed excellent and good results in all cases. Stress-shielding at the site of anchorage of the prosthesis was more pronounced than in adults. Implantation of extendable endoprostheses in children provides a reasonable alternative to rotationplasty, but limb salvage requires more operations.

Adolescent↗

PubMed1995

Resection-replantation for primary malignant tumours of the arm. An alternative to fore-quarter amputation.

We describe a method of partial limb salvage for the treatment of large primary malignant tumours of the arm. The tumour-bearing area is resected as a cylindrical segment and the distal arm is then replanted with the necessary shortening. The method is suitable for stage-IIB tumours with or without neurovascular involvement which, because of their extent, could otherwise be adequately treated only by amputation. From 1987 to 1992 we used this method in 12 patients with primary malignant bone or soft-tissue sarcomas. Wide resection margins were achieved in all, but six patients died from their disease at a mean of 21.5 months (6 to 48), none with any local recurrence. Five patients have no evidence of disease at a mean follow-up period of 52.2 months (22 to 78), and one was lost to follow-up at 48 months postoperatively when there was no evidence of disease. The results of the functional evaluation of ten patients with a follow-up of over ten months were excellent in one, good in six and fair in three, by the criteria of Enneking (1987). Recovery after nerve reconstruction was satisfactory in all cases with sensation S3 or higher and motor function M2+ or higher. Detailed evaluation of hand function on the Millesi score rated only 22% (9.6% to 33.7%) as compared with the contralateral side, but the patients were satisfied and refused further operations for the improvement of function. These oncological and functional results allow us to recommend resection-replantation as a valuable alternative to amputation for the treatment of primary malignant tumours of the arm.

Adolescent↗

PubMed1995

[Aneurysmal bone cysts].

An aneurysmal bone cyst is a tumor-simulating bone lesion, the etiology of which is still unclear and probably inhomogeneous. This type of lesion is mainly observed during the second decade of life and is rarely diagnosed beyond the age of 30 years. It is characterized by hollow spaces consisting of several compartments filled with blood and partially divided by septs consisting of spindle-cell tissue with ample multinuclear giant cells and frequent reactive new bone formation. The locations of preference are the metaphyses of the long bones, the spine and flat bones; however, they can appear in every sort of bone. The radiological picture is characterized by osteolytic expansion of the bone with more or less distinct formation of trabeculae. In the CT image we can often find fluid formation; in MRT images alteration of signals can also be seen, indicating former or fresh bleeding. The primary aneurysmal bone cyst should be distinguished from its secondary counterpart; the latter one is occasionally found in giant cell tumors, chondroblastomas, chondromyxoid-fibromas, osteoblastomas, but also in osteosarcomas. When planning biopsy or therapy, this possibility should be also taken into account. The therapy of choice consists of accurate curettage and autologous or allogenous bone transplantation. To avoid recurrences, curettage should be followed by adjuvant therapy with phenol or cryotherapy. When there are extensive recurrences that can no longer be treated by the surgical method described above, embolization of the nutrient vessels may be curative.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

The intraosseous ganglion. A clinical-pathological report on 42 cases.

In this study we report on the clinical, radiological and pathologic data of 42 intraosseous ganglia which had been verified histologically. Of the patients, 26 were male and 16 female. Their mean age was 41.8 years (range 20-71 years). Exclusively solitary ganglia were included in this study; mainly they were located within the lower extremity. In most cases (n = 12), the malleolus medialis was involved. In 40 patients, treatment consisted of curettage, in 39 cases in combination with autologous or homologous bone grafting. In 2 cases, a resection was performed. No local recurrence was observed. Etiology and pathogenesis are discussed.

Adult↗

PubMed1994

Variability of EWS chimaeric transcripts in Ewing tumours: a comparison of clinical and molecular data.

Ewing tumours (ET), including Ewing's sarcoma and peripheral primitive neuroectodermal tumour, are well characterised at the molecular level by a unique chromosomal rearrangement which fuses the EWS gene to one of two closely related ETS proto-oncogenes, FLI-1 or ERG. Expression of the resulting chimaeric transcripts can be readily detected by reversed transcriptase polymerase chain reaction (RT-PCR). This approach led to the identification of a number of different exon combinations at the junction site of coding sequences. The physiological consequences of the observed variability in the hinge region of EWS chimaeric proteins are not known. We have analysed tumour-derived material from 30 ET patients with well-documented clinical course (18 with localised and 12 with metastatic disease at diagnosis) for the presence of EWS/FLI-1 or EWS/ERG RNA. Karyotypes were obtained in 21 out of 27 cases and analysed by routine cytogenetics. A chromosome 22 rearrangement was demonstrated in 18 cases (67%). In contrast, RT-PCR revealed the presence of chimaeric transcripts in 28 tumours (93%), with fusions of EWS exon 7 to FLI-1 exons 6 (19/28), 5 (4/28) and 7 (1/28). In addition, EWS/FLI-1 exon combinations 10/5 and 9/4 were observed in one case each. In the last tumour, the presence of at least four additional splicing variants corresponding to fusion of EWS exon 7 to FLI-1 exons 4, 6, 8 and 9 was demonstrated. Two tumours expressed EWS/ERG fusion transcripts involving EWS exon 7 and ERG exon 6. In this study, EWS/FLI-1 exon combinations 7/6 (type I) predominated over 7/5 (type II) in localised ET (14 versus 1) and were more abundant in tumours affecting the long bones (9 versus 0), whereas in central axis tumours and metastatic disease there was only little difference in the frequency of the two types. So far, no correlations between different chimaeric EWS transcripts and any other clinical parameters have been identified.

Adolescent↗

PubMed1994

Preoperative staging of osteosarcoma: efficacy of MR imaging in detecting joint involvement.

OBJECTIVE: Selecting the appropriate surgical procedure for treatment of patients with osteosarcoma requires accurate preoperative evaluation of tumor extent. Establishing the presence or absence of joint involvement is particularly important. Accordingly, we studied the efficacy of MR imaging for detecting joint involvement in 46 patients with osteosarcoma around joint spaces. SUBJECTS AND METHODS: Preoperative MR examinations were performed in 46 consecutive patients with osteosarcoma whose tumors were located around the knee (n = 33), the hip (n = 8), or the shoulder (n = 5). T2-weighted and unenhanced and contrast-enhanced T1-weighted spin-echo MR images were obtained for all patients. We assessed the presence or absence of tumor invasion of the intracapsular-intrasynovial joint space, either by disruption of the joint capsule or by intraarticular destruction of the cortical bone and articular cartilage or the intracapsular-extrasynovial cruciate ligaments of the knee. All patients subsequently had surgery. The MR findings were correlated with findings from macroscopic and microscopic pathologic examinations. RESULTS: All 10 patients who subsequently proved to have tumor involvement of the joint were correctly identified (sensitivity, 100%). The tumor involved the knee joint in seven patients, the hip joint in two, and the shoulder joint in one. However, the MR diagnosis was false-positive in another 11 patients who did not have joint involvement at surgery (specificity, 69%). In the knee, MR imaging was more accurate in identifying tumor extension to the cruciate ligaments than to the intrasynovial joint space. Post-contrast T1-weighted images were most useful in detecting joint involvement. CONCLUSION: MR imaging is highly sensitive for detecting joint invasion of osteosarcoma. However, false-positive diagnoses may lead to overstaging of tumor and result in unnecessarily radical surgical procedures.

Adolescent↗

PubMed1994

Gait after knee arthroplasty for femoral tumor. Foot pressure patterns recorded in 20 patients.

We evaluated pressure distribution patterns under the feet during gait in 20 patients after resection of malignant bone tumor and endoprosthetic replacement of the distal femur. In all cases, a modular cementless, hinged prosthesis had been used. The examination was performed after 4 (1-6) years. Shortened contact phase, decreased peak pressure, and reduced force-time integral during gait analysis were observed on the operated side. Peak pressure in the heel and the toe regions was decreased and the load (force-time integral) in the metatarsal heads and the big toe regions was reduced. There was a positive correlation between load under the foot and knee extension strength, measured isokinetically.

Adolescent↗

PubMed1993

Knee function after operation for malignancy of the distal femur. Quadriceps muscle mass and knee extension strength in 21 patients with hinged endoprostheses.

We evaluated quadriceps muscle mass and knee extension strength in 21 patients after resection and endoprosthetic replacement of the distal femur for malignant bone tumor. In all cases, a modular cementless, hinged prosthesis had been used. The mean follow-up period was 4 (2-9) years. Muscle mass was measured ultrasonographically, and strength isokinetically with a Cybex 6000 dynamometer. All the data for the operated side are given as percentage of the non-operated side. The average quadriceps mass was 48 (27-70) percent. The average peak torque was 31 (14-48) and 36 (18-55) percent at the speed of 30 degrees/s and 90 degrees/s, respectively. The reduction in extension strength became greater with increasing flexion. There was a moderate correlation between muscle mass and muscle strength. Most of the patients who had kept more than 40 percent of the quadriceps mass had more than 30 percent peak torque. Patients with excellent function (Enneking 1987) had more quadriceps muscle mass and higher strength than those that were merely good with the borderline at about 40 percent muscle mass.

Adolescent↗

PubMed1993

[The radiologic clinical picture of primary bone lymphoma].

Primary lymphoma of bone is a rare form of non-Hodgkin lymphoma which involves a single bone and has a relatively good prognosis following radiation therapy. We observed 17 histologically verified cases and found 97 cases in the literature. This rare tumour may occur at any time in adults and usually affects the metaphyses of long bones. It produces osteolytic changes and usually only mild periosteal reactions. Radiologically as well as histologically, differentiation from other highly malignant bone tumours is extremely difficult and sometimes impossible. A correct diagnosis can only be made from an accurate knowledge of the radiological appearances, localisation of the tumour and age of the patient.

Adolescent↗

PubMed1992

Polygonal triple osteotomy of the pelvis. A correction for dysplastic hip joints.

A new triple osteotomy, polygonal pelvic osteotomy (PPO), is described for use in dysplastic hips. The hip joint must be congruous with a centre-edge (CE) angle between +20 degrees and -10 degrees. Templates are used before and during operation which allow precise correction of the position of the acetabulum. The geometry of the osteotomy and a special compression plate achieve sufficient stability to permit early mobilisation. Surgery is indicated in adolescents and young adults if pain persists for at least two months. The surgical exposure, operative technique and postoperative management are presented, with the two-year results in nine cases.

Acetabulum↗

PubMed1991

Chiari pelvic osteotomy for osteoarthritis secondary to hip dysplasia. Indications and long-term results.

Of 142 Chiari pelvic osteotomies for osteoarthritis in dysplastic hips, most performed by Chiari himself, we were able to review 82 and obtain information about 18 by questionnaire. All patients were over 30 years of age at operation; follow-up averaged 15.5 years. Twenty hips had undergone secondary total hip replacement. The outcome was good in 75%, fair in 9% and poor in 16%. High osteotomies all gave good results, and the result also depended on adequate medialisation. Statistics were worse for patients over 44 years of age at the time of operation. For osteoarthritis secondary to hip dysplasia, the Chiari pelvic osteotomy is an alternative procedure to early hip replacement. In contrast to intertrochanteric osteotomy, it has the advantage of facilitating the implantation of an acetabular prosthesis should arthroplasty become necessary at a later stage.

Adult↗