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R Stangl

Publications and source records attributed to R Stangl.

At least 19 recordsLinked to original sources
PubMed2006

[Norian SRS augmentation in revision of acetabular cup of total hip arthroplasty. A follow up of six patients].

This article reports on bony acetabular reconstruction combined with load-bearing cementation of the acetabular components in revision hip arthroplasty. In six cases bone defects were filled with osteoconductive cement Norian SRS--if needed after cancellous bone grafting. Thereupon the primary load stable cementation of an acetabular reconstruction ring or an acetabular basket was done in combination with cementation of an inlay. Patients were examined according to the scores of Harris and Merle d'Aubigné. The patient's satisfaction was used as another criterion and X-rays were taken upon consent. Four of five patients included in the evaluation achieved good or excellent results.

Acetabulum↗
PubMed2005

Bone-implant interface shear modulus and ultimate stress in a transcortical rabbit model of open-pore Ti6Al4V implants.

This experimental study on laser-textured implants aimed to evaluate periimplant bone elasticity and ultimate stress of the bone-implant interface in a rabbit femur model. After randomization, two cylindrical Ti6Al4V samples (3.5 mm wide, 5.5 mm long) were transcortically implanted in each femur of 15 female New Zealand White Rabbits. Polished implants had been laser-textured with 100, 200, and 300 microm diameter pores, and another corundum blasted implant was additionally textured with 200 microm pores. Twelve weeks into the experiment, a modified push-out test was performed. The median shear modulus indicating the elasticity of the periimplant bone was 41.12 MPa for the proximal implant location and 25.38 MPa for the distal, without evidence for significant differences between implant types. Taking into account the median ultimate shear stress for 200 microm implants with and without corundum blasting, no significant difference could be demonstrated. However, for blasted 200 microm implants a statistically significant (p<0.025) relative gain in ultimate shear stress of 41% and 17% was proven in comparison with 100 and 300 microm implants, respectively. Non-blasted 200 microm implants reached 48% relative gain in respect of 100 microm samples.

Alloys↗
PubMed2005

The composite vastus medialis-patellar complex osseomuscular flap as a salvage procedure after complex trauma of the knee--an anatomical study and clinical application.

BACKGROUND: In the setting of severe perigenicular trauma or complicated endoprosthetic knee surgery, primary knee fusion may be the last resort for salvage of the limp. In this case, the patella looses its destination as an anterior knee stabilizer and can become a substantial donor of bone substance, especially if osseous defects are involved. PATIENTS AND METHODS: 12 formalin fixated cadavers were studied in terms of vascular anatomy, pedicle reliability, arc of rotation and their relation to sex, age, and height. Moreover, the operation was performed on a suitable patient. RESULTS: The quadriceps with the vastus medialis and the patella can be raised from the tibial tuberosity up to the entrance of the osteoarticular branch of the superficial femoral artery into the vastus medialis muscle ca 16 cm (15-19 cm) from the inferior patellar pole. This distance correlated well to the overall height of the cadavers (P=0.009). The vascular prerequisites were always present. In the clinical case, there was a favorable outcome with knee fusion after 4 months, despite of the lateral condylar defect. DISCUSSION: The composite vastus medialis-patellar complex osseomuscular flap can be safely used as a source of vascularized femoral condyle substitute in the setting of primary knee fusion.

Arteries↗
PubMed2004

Influence of pores created by laser superfinishing on osseointegration of titanium alloy implants.

The aim of this study was to assess the osseointegration of copper vapor laser-superfinished titanium alloy (Ti6Al4V) implants with pore sizes of 25, 50, and 200 microm in a rabbit intramedullary model. Control implants were prepared by corundum blasting. Each animal received all four different implants in both femora and humeri. Using static and dynamic histomorphometry, the bone-implant interface and the peri-implant bone tissue were examined 3, 6, and 12 weeks postimplantation. Among the laser-superfinished implants, total bone-implant contact was smallest for the 25-microm pores, and was similar for 50- and 200-microm pore sizes at all time points. However, all laser-superfinished surfaces were inferior to corundum-blasted (CB) control implants in terms of bone-implant contact. Within the 12-week study period, remodeling of woven bone initially formed within pores occurred only in the implants with 200-microm pores. Implants with 25-microm pores showed the highest amount of peri-implant bone volume at all time points, indicating that the amount of peri-implant bone was not correlated with the quality of the bone-implant interface. At 3 and 6 weeks postsurgery, we did not find any differences in mineral apposition rates or bone formation rates between the various implant surfaces. However, the peri-implant bone formation rate at the end of the trial was 70 and 62% higher in implants with 50- and 200-microm pores compared with CB implants, respectively. We conclude that, although laser-superfinished implants were not superior to CB control implants in terms of osseointegration, our study has provided further insights into the mechanisms of bone remodeling within pores of various sizes, and may form a basis for future experiments to design optimal implant surfaces with the help of modern laser technology.

Alloys↗
PubMed2004

[The biofeedback sole tested is a suitable device for avoiding overload under partial load].

During healing of fractures and after implantation of artificial joints mobilization with partial load is a widespread and well-accepted therapeutic principle. Translating our recommendations into action, however, overtaxes many of the patients. The use of the biofeedback sole tested should guarantee avoiding overload under partial weight-bearing conditions. The distribution of the strain sensors in the biofeedback sole was primarily checked with the help of an established system controlling the distribution of strain (PAROTEC) in 17 voluntary, healthy people. Afterwards the biofeedback sole was connected to a digital recording system to analyze the number of steps overloaded in different test cycles in 50 volunteers while using crutches and performing partial load with 20 kg. The distribution of the strain sensors in the biofeedback sole is correct to control partial load under weight bearing with 20 kg. The permanent use of the biofeedback sole showed highly significant advantages in avoiding overload. The number of steps overloaded was reduced by 77%. This effect is independent from body weight or age.

Adult↗
PubMed2004

Effect of surface finish on the osseointegration of laser-treated titanium alloy implants.

It was the purpose of this study to examine the osseointegration of laser-textured titanium alloy (Ti6Al4V) implants with pore sizes of 100, 200, and 300 microm, specifically comparing 200-microm implants with polished and corundum-blasted surfaces in a rabbit transcortical model. Using a distal and proximal implantation site in the distal femoral cortex, each animal received all four different implants in both femora. The bone-implant interface and the newly formed bone tissue within the pores and in peri-implant bone tissue were examined 3, 6, and 12 weeks post-implantation by static and dynamic histomorphometry. Here we show that additional surface blasting of laser-textured Ti6Al4V implants with 200-microm pores resulted in a profound improvement in osseointegration, 12 weeks postimplantation. Although lamellar bone formation was found in pores of all sizes, the amount of lamellar bone within pores was linearly related to pore size. In 100-microm pores, bone remodeling occurred with a pronounced time lag relative to larger pores. Implants with 300-microm pores showed a delayed osseointegration compared with 200-microm pores. We conclude that 200 microm may be the optimal pore size for laser-textured Ti6Al4V implants, and that laser treating in combination with surface blasting may be a very interesting technology for the structuring of implant surfaces.

Alloys↗
PubMed2001

The influence of pore geometry in cp Ti-implants--a cell culture investigation.

Biocompatibility testing of differently structured titanium implants was performed using an in vitro test system of a newly established human fetal osteoblastic cell line (hFOB 1.19). Cell adhesion of osteoblastic cells on the different porous geometries and the suitability of a copper vapor laser system for surface structuring was tested with the following parameters: cell-number, cell viability, alkaline phosphatase expression. The analysis of the cell culture results demonstrated that 25 microm and 200 microm porous geometries showed similar or even better results than the negative control of polystyrene; there was no sign of toxic effects. However, the 100 microm porous geometry showed an impressive negative influence on the calculated parameters. The reason for this effect is unclear. The series with 50 microm, 300 microm, 400 microm and 500 microm showed a comparable, intermediate effect on the cell culture with respect to the different parameters. However, the results were worse than with the 25 and 200 microm porous geometry. In conclusion, the 25 microm and 200 microm porous geometry seems to have the most positive effect on the human osteoblastic cell line hFOB 1.19.

Journal Article↗
PubMed2001

[Resection of colorectal liver metastases. What prognostic factors determine patient selection?].

AIM OF THE STUDY: Based on a consecutive series of patients undergoing liver resection for colorectal metastases, indicators of prognosis and selection criteria were evaluated. PATIENTS AND METHODS: From 1960 to 1998, a total of 654 patients underwent resection of colorectal liver metastases. In 516 patients (78.9%) this was an R0 resection for initial metastatic disease. These patients form the basis for the investigation. RESULTS: 30-day mortality in this group was 5.8%, while the total procedure-related mortality was 8.3%. Significant morbidity was observed in 16% of patients. Follow-up information until 1 January, 2000 was achieved in 99.5% of patients. Including operative mortality, the actuarial 5-, 10-, and 20-year survival is 38 +/- 5%, 27 +/- 6% und 24 +/- 24%, rising to 41 +/- 5%, 29 +/- 6% and 26 +/- 26% after excluding operative deaths. Tumor-free survival is 35 +/- 5% at 5 years. In the multivariate analysis the following factors are associated with decreased crude survival: extrahepatic tumor (P < 0.0001), intraoperative hypotension (P = 0.0001), non-anatomical procedures (P = 0.0002), a metastasis diameter > or = 5 cm (P = 0.0002), unfavourable grading of the primary tumor (P = 0.0003), satellite metastases (P = 0.0069), mesenteric lymph node involvement (P = 0.0260), use of FFP (P = 0.0307) and synchronous diagnosis of metastases (P = 0.1240). With respect to disease-free survival metastasis diameter is first, followed by extrahepatic disease (P < 0.0001 each). Satellite metastases are removed, while the primary tumor site becomes important with inferior results for rectal cancer (P = 0.0188). The other factors remain stable and in the same order. The number of independent tumor nodules as well as the width of resection margin fail to be significant in both univariate and multivariate analysis. CONCLUSION: These results underline the paramount importance of an R0 resection, but diminish the relevance of most commonly used "contraindications". For the actual decision on liver resection, beside the possibility of achieving an R0 situation, safety aspects regarding comorbidity and acceptable extent of parenchyma loss represent the prime limitation.

Adult↗
PubMed2001

Direct MR arthrography of the shoulder: 2D vs. 3D gradient-echo imaging.

The aim of this study was to determine the value of a fat suppressed 3D gradient-echo sequence (GRE) data set in comparison to a 2D GRE sequence in direct MR arthrography of the shoulder. For this purpose we examined 50 consecutive patients with subacute or chronic disorders of the shoulder using a 1.5 T scanner: Transverse T1-weighted 2D (slice thickness 4 mm) and 3D GRE (slice thickness 1.5 mm reconstructed from 3 mm), oblique coronal T2- and T1-weighted turbo spin-echo (TSE) and sagittal T1-weighted TSE with fat saturation were applied. Visual image analysis of anatomical and pathological structures was performed by two independent observers. A correlation to surgical results was available in 21 patients. Transverse GRE sequences were well suited for analysis of the anterior/posterior labrum, the middle glenohumeral ligament, and cartilage. 3D GRE with fat suppression was slightly superior to 2D GRE without fat suppression in the evaluation of the anterior/posterior labrum, and the middle glenohumeral ligament, whereas for cartilage no significant differences were found between both sequences. Concerning pathological findings, in most of the cases 2D delivered the same results as 3D. In conclusion, a T1-weighted 3D GRE data set with fat saturation in transverse orientation may be useful for evaluation of the anterior/posterior labrum, and the middle glenohumeral ligament. However, similar measured slice thickness of 3 mm-even if interpolated to 1.5 mm-compared to a 2D sequence with 4 mm does not provide significant diagnostic advantages.

Adolescent↗
PubMed2001

A low-field MR system in acute traumatological imaging in radiology. Technical note.

PURPOSE: In this paper initial clinical observations with the application of a new low-field MR system in acute musculoskeletal imaging in radiology are presented. MATERIALS AND METHODS: This system is designed as a three-sided open permanent magnet with a revolving table. Main magnetic field strength is 0.2 T, maximal gradient field strength 20 mT/m, and minimal gradient rise time is 800 microseconds. First clinical experiences in 25 patients with acute trauma of peripheral joints were obtained. The following sequences were applied: gradient-echo (GRE) STIR, T1-weighted spin-echo, and PD- and T2-weighted turbo spin-echo. Correlation with the findings of high-field MR (1.5 T), plain radiograms (including stress views), CT or ultrasound was available in each patient confirming the low-field diagnoses. Furthermore, phantom measurements were performed to verify the spatial resolution of the system for some sequences with typical measurement parameters. DISCUSSION: This low-field system has several advantages: fast and economic installation, limited required space, easy operation, and high patient comfort. The medical benefit of such a system integrated in the traumatological suite of a radiological department seems to be evident due to the impact on the early initiation of the correct therapy which avoids additional diagnostic procedures and therefore may reduce costs. Implementation of such a system may be useful, if installation of an additional high-field scanner is not possible due to economic considerations.

Adolescent↗
PubMed1999

Prospective randomised trial on adjuvant hepatic-artery infusion chemotherapy after R0 resection of colorectal liver metastases.

BACKGROUND AND AIMS: The liver represents the predominant site of cancer relapse after curative resection of hepatic metastases from colorectal carcinoma. Adjuvant intra-arterial chemotherapy was therefore considered a promising therapeutic approach in high-risk patients. PATIENTS/METHODS: From July 1984 to December 1985, a total of 42 consecutive patients underwent R0 resection of colorectal liver metastases. Thirty patients with mesenteric lymph-node metastases (Dukes C) were randomised into two groups. In 14 group-A patients, a hepatic artery port catheter was placed during liver resection. Four courses of adjuvant chemotherapy were administered at 4-week intervals, consisting of mitomycin C (8 mg/m2, day 1) and 5-fluorouracil (800 mg/m2, days 1-5). Sixteen group-B patients served as controls. The 12 patients with no mesenteric lymph-node metastases (Dukes A/B) were included in the follow-up program. RESULTS: After 5 years, 64% of Dukes A/B patients and 29% of Dukes C patients were alive (P<0.01). The probability of remaining free of recurrent disease after 5 years and 10 years was 55% and 18%, respectively (P<0.01). No significant difference in either 5-year survival (25% vs 31%) or long-term disease-free status (15% vs 23%) was detected between groups A and B. The initial tumour relapse was shifted towards extrahepatic sites in group-A patients, but no difference was obtained regarding the definite distribution of recurrent disease. CONCLUSION: Routine application of adjuvant regional chemotherapy after R0 liver resection is not warranted.

Adult↗
PubMed1998

[Post-traumatic arteriovenous fistula between splenic artery and vein as a rare cause of acute myocardial ischemia].

Arteriovenous fistulas of the portal system are rare. Congenital fistulas have to be differentiated from acquired fistulas; the latter are of posttraumatic or iatrogenic origin. The case presented demonstrates a history of diffuse abdominal pain and the first description of myocardial ischemia caused by a posttraumatic splenic arterioportal fistula. After diagnostic and therapeutic difficulties, the definitive treatment consisted in resection of the fistula system including the pancreatic tail.

Adult↗
PubMed1997

[Selection criteria for conservative therapy of splenic trauma in adults].

The safety and effectiveness of nonoperative management of selected adults have been confirmed in those patients who meet selection criterias of isolated splenic injury and hemodynamic stability. The CT scan is a very precise and the most specific diagnostic procedure in splenic trauma. Nonoperative treatment is successful in 80% of adults in such selected group of patients.

Adolescent↗
PubMed1996

[Surgical resection of colorectal liver metastases: Gold standard for solitary and radically resectable lesions].

From 1960 to 1993, a total of 1.766 patients with liver metastases from colorectal carcinoma was recorded. Five-hundred-and-eight patients (28.8%) underwent hepatic resection which was performed with curative intent in 473 patients (26.8%). 30-day mortality in this group was 4.5%, being 2.6% (4 out of 155) since 1990. Significant morbidity was observed in 16% of patients with a decrease to 7% for the last 4 years. A 99.5 percent follow-up until January 1, 1996, was achieved. Excluding operative mortality there are 376 patients with "potentially curative" initial liver resection, and 65 corresponding patients with minimal macroscopic (n = 19) or microscopic (n = 46) residual disease. The latter group demonstrated a poor prognosis with median and maximum survival times of 14.8 and 56 months, respectively. Among the 376 patients having potentially curative resection the actuarial five, ten, and twenty year survival was 39 +/- 3, 26 +/- 5 and 21 +/- 13 percent, respectively. Tumor-free survival was 34 +/- 3 percent at 5 years. In the univariate analysis, the following factors were associated with decreased crude survival: Presence and extent of mesenteric lymph node involvement (p = 0.0001), poor grading of the primary tumor (p = 0.008), synchronous diagnosis of metastases (p = 0.004), satellite metastases (p < 0.0001), an increasing metastasis diameter (p < 0.0001), preoperative CEA elevation (p = 0.0002), a resection margin of less than 1 cm (p = 0.018), extrahepatic disease (p = 0.02), non-anatomical procedures (p = 0.008), and an operative blood loss exceeding 2.000 ml (p = 0.02). With respect to disease-free survival, extrahepatic disease (p = 0.09) failed to achieve statistical significance, while patients with colon cancer and with delayed resection of synchronous metastases did significantly better than those with rectal cancer (p = 0.02) and with a simultaneous procedure (p = 0.04), respectively. Multiplicity and bilobar involvement did not affect prognosis. Similarly, no significant predictive value of an increasing number of metastases (1-3 vs > or = 4) on either overall (p = 0.35) or disease free survival (p = 0.55) was found after a radical excision of all detectable disease. Using Cox's multivariate regression analysis, presence of satellite metastases, anatomical vs non-anatomical approach, primary tumor grade and diameter of the largest metastasis all independently affected both crude and tumor-free survival (p < 0.05). With respect to survival, this was complemented by the margin of clearance (0.05 < p < 0.1), while for disease-free survival primary tumor site and time of metastasis diagnosis had some additional influence. Twenty-six patients with R0-reresection of the liver, and 32 patients with radical excision of extrahepatic recurrent disease had a subsequent 5-year survival of 57 +/- 15 percent and 32 +/- 12 percent, respectively. This confirms the effectiveness of a close follow-up policy.

Adult↗
PubMed1995

[Recurrent tumor after R0 resection of colorectal liver metastases. Incidence, resectability and prognosis].

In the period 1960 to 1992 a total of 366 patients underwent macroscopic and histologic complete resection (R0) of colorectal liver metastases. Excluding 16 operative deaths and 4 patients with incomplete follow-up information, 346 patients form the basis for this report. Of them, 240 (69.4%) developed recurrent disease involving the liver in 136 (39.3%) instances. 71 patients underwent a tumor related reoperation with a re-resection performed in 60 cases. This involved the liver in 22 patients. 47 of these procedures (19.6% of all recurrences), and 16 re-resections of the liver (11.8% of hepatic recurrences) were ultimately classified R0. Additional 9 patients who had the initial liver resection performed in other hospitals underwent hepatic re-resection which was classified R0 in 8. Out of 8 subsequent reoperations, 3 addressed the liver. Operative mortality in the 34 re-resections at the liver was 2.9% while nonlethal morbidity was 17.7%. After a minimum and median follow-up time of 18 and 49 months, resp., 27 patients are alive without recurrent disease, including 11 patients with hepatic re-resection. Another 4 patients are alive with disease, one of them after repeat liver resection. 5-year survival from re-resection is 39.0% for the entire group of 55 R0-patients, and 45.6% for the 24 who underwent hepatic R0-re-resection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗