Biomedical subjects

R Windhager

Publications and source records attributed to R Windhager.

80 records · Page 5Linked to original sources

PubMedDate not supplied

[Widening of the sub-acromial space using a wedge osteotomy of the scapular spine. Anatomical bases, measurements on the preparation, studies of the kinematics of the acromion movements on a computer model].

We describe the theoretical principles of a new kind of decompression of subacromial impingement syndrome by means of a wedge osteotomy at the transition between acromion and spine of the scapula. The operation on cadaver bone and the simulation of acromion movement in a computer model demonstrate an increase of subacromial space more than 1 cm after wedge excision with cranial base of 5 mm and ventral base of 3 mm. After the excision of an anterior based wedge the resection of the coracoacromial ligament is not necessary. An angle between 50 and 60 degrees from mediocranial to laterocaudal referred to the transverse plane has been calculated as optimal. We regard the sparing of the abducting parts of deltoid muscle, the better approach to the cuff with the possibility to mobilize the supraspinate muscle in cases of greater cuff-tears and the possibility to obtain a smooth undersurface of the acromion as further advantages of this procedure. Further biomechanic experiments will be necessary to optimize osteosynthesis.

Acromion↗

PubMedDate not supplied

[The incidence of recurrence in phenol treated and non-phenol treated bone cavities following intralesional resection of non-malignant bone tumors].

Between 1955 and 1986 intralesional excisions were performed at Vienna University Orthopedic Clinic on 103 patients suffering from aneurysmatic or juvenile bone cysts, chondromyxoid fibromas or giant cell tumors. In 31 patients phenol was applied to the wall of the bone cavity after this had been carefully curetted or fraised. The chemical cauterization effect is intended to destroy any remaining tumor cell remnants. The cavity is then filled with autologous or homologous spongiosa. In a total of 72 nonphenolized bone cavities there were 21 recurrences (29.1%). By using phenol following intralesional excision of nonmalignant bone tumors in 31 patients the recurrence rate was significantly lowered (3 recurrences - 9.7%).

Adolescent↗

PubMedDate not supplied

[The incidence of recurrence of intra- and extra-lesional operated metastases of long tubular bones].

Using a collective of 54 patients with 76 operated metastases of long bones in carcinoma of the breast and kidney the frequency of local recurrence after intralesional and extralesional (marginal, wide, radical) resection was investigated. 57 operations were done intralesional, 19 extralesional. Local recurrence was seen in 50.8% in the intralesional group on the other hand in only 15% in the extralesional group (p 0.007). Relief of pain was similar in both groups. The postoperative range of motion had worse results after extralesional resection and endoprosthetic replacement. There was no difference between both groups in the manifestation of further metastases.

Adult↗

PubMedDate not supplied

[Surgical treatment of Osgood-Schlatter disease].

18 patients (20 knee joints) were operated for Osgood-Schlatter disease. 12 patients (14 knee joints) had a follow-up of 2.4 years (0.5-13.5) after operation. The informations of the other patients were taken from our clinical data. 1 month (0.5-24) after operation 13 patients (15 knee joints) were painfree. In 5 cases there were still complaints, but 3 of them were improved by operation. One patient, who was operated on both knees, had no change after operation. The failures are analysed and interpreted concerning their pathogenesis. With help of our results the different operation methods of the literature are discussed.

Adolescent↗

PubMedDate not supplied

[Minimal metastatic and minimal residual disease in patients with Ewing tumors].

At least 95% of Ewing tumors (ET) are characterized by an EWS-gene rearrangement with either FLI-1 or ERG and by extraordinary high MIC2/CD99 expression. Both features can be used for the specific identification of tumor cells, which might also be present in blood and bone marrow in minimal metastatic or minimal residual disease. We report the establishment of sensitive ET cell detection methods based on these characteristics. Preliminary results of 14 patients are given and two cases are reported in detail. 6/14 patients showed RT-PCR positivity in the bone marrow whereas in 8/14 patients ET cells could be detected by immunofluorescence. Only in 2 patients, one at diagnosis and one at relapse, tumor cells were detected in blood samples by RT-PCR. Peripheral blood stem cells of 5 patients showed no contamination with ET cells. The versatility of the immunocytochemical approach as compared to the RT-PCR analysis is discussed in order to explain the discrepancies between the results obtained with the two detection methods.

Adolescent↗

PubMedDate not supplied

[The EWS gene rearrangement in Ewing tumors: key to the disease].

The family of Ewing tumors (ET) is characterised by a unique gene rearrangement which is represented by a translocation t(11;22) (q24;q12) or a deletion del 22q12 in most cytogenetically analysable cases. The recent cloning of the underlying gene fusion provides the basis for the diagnostic detection of minimal amounts of residual tumor cells at resection margins, in blood and bone marrow. In addition, the very first steps in ET tumorigenesis can be studied on a functional basis. In this study, a variety of fusion products were identified with a sensitivity of 10(-6) by means of RT-PCR. In 20 of 22 ET, a gene rearrangement was identified which resulted in the substitution of the effector domain of one of the closely related DNA-binding oncogenes, FLI-1 or ERG, by the transactivating domain of a new gene, EWS. Presumably, the oncogene and consequently its target genes are activated by this type of translocation. If the EWS domain was replaced with a transcriptionally irrelevant domain by transfection of a recombinant gene into ET cells, competition with the endogenous chimeric oncogene-product for DNA-binding was observed resulting in a partial growth inhibition. Activation of FLI-1 has been previously shown to occur as a primary event in Friend virus induced mouse erythroleukemia. During progression of this disease, inactivating p53 mutations have been observed frequently. In contrast, such aberrations were found to be extremely rare in ET.

Adolescent↗

PubMedDate not supplied

[Incidence of recurrence of aneurysmal bone cysts following surgical treatment and adjuvant therapy with phenol].

Between 1966 and 1991, at the Department of Orthopaedics 34 patients with a mean age of 15.7 years (range 7-46 years) underwent surgery because of aneurysmatic bone cysts. Mean follow-up was 11 years (range 1-26.3 years). We observed a total rate of recurrence of 11.8%. In a group of 9 patients who received local phenol therapy after curettage and bone transplantation no recurrence was observed. The different surgical and conservative methods of treatment are discussed also with respect to rates of recurrence stated in the literature.

Adolescent↗

PubMedDate not supplied

Patellar resurfacing in tumor endoprosthesis: a study in regard to power transmission.

Relation between quadriceps muscle mass and knee extension strength was investigated after resection of malignant bone tumor and endoprosthetic replacement of the distal femur in 19 patients with patellar resurfacing (Group A) and 16 patients without resurfacing (Group B). In all cases, a modular cementless, hinged prosthesis had been used. Age and follow-up period were comparable in the 2 groups. Muscle mass was measured ultrasonographically and strength was evaluated isokinetically. All the data on the operated side are given as percentage of the non-operated side. There was a positive correlation between muscle mass and strength in both groups. By linear regression analysis, a slightly lower value of strength was predicted in the unresurfaced group than in the resurfaced group. Analysis of covariance revealed that the influence of patellar resurfacing on strength was significant. This factor should also be considered in making a decision about patellar resurfacing with a tumor endoprosthesis.

Adolescent↗