Wann wird zementiert?

The aims in implantation of an artificial replacement hip joint should be lasting fixation and pain-free functioning of the elements of the prosthesis in the bone and minimal friction between the articulating parts. Despite improvements in bone cement and in cementing techniques, the question of whether cemented or cement-free hip replacement systems give better results in the long term is still the subject of controversy. The basics of cemented and cement-free implantation of prostheses, of the surgical techniques and of the corresponding results and complications are presented. Despite all the advantages of cement-free implantation over cemented implantation of prostheses, while the former yield good results in the short term, long-term results with a follow-up period of over 10 years are available for only a limited number of cement-free implants. Therefore, until long-term (15-year) results for the cement-free prosthetic systems currently on the market are available, cemented anchorage as practised since the introduction and application of the second-generation cementing techniques with the reduction of the risk of revision surgery by approximately 20% at present should be regarded as standard despite the more demanding implantation process.     

Compartment syndrome. Exclusively the result of increased pressure in the muscular compartment?

Summary The compartment syndrome (cs) is characterized by an increased tissue pressure in a limited space. Pathophysiologically, it is a multifactorial disease that is potentially induced by an initial trauma and develops according to the existence of cofactors. Cofactors are, for instance, the circulation of the patient and the initial treatment of the impending cs. In particular, the microcirculation is altered with endothelial destruction, development of a capillary leak, protein loss from intravasal space and the development of an interstitial and intracellular third space. An impaired drainage of the lymphatic and venous system causes a venous infarction. An arterial infarction results if the tissue pressure exceeds the arteriolar pressure. An accompanying ischemia reperfusion mechanism increases the trauma load. In disadvantageous cases, the patients are in danger of developing a multi-organ deficiency syndrome (MODS) by an uncontrolled inflammatory reaction, by intravasal volume loss and by a myonephropathic systemic reaction. Clinically, the patients suffer a disproportionate amount of pain, followed by neurological signs. Especially in noncompliant patients, tissue pressure measurement is useful. Resuscitation of the circulation as well as splitting of casts is important. In case of a manifest cs, dermatofasciotomy has to be performed as an emergency operation. Even if cs is diagnosed early and fasciotomy is carried out early, the development of sequellae cannot be avoided in every single case.      

Akromioklavikulargelenkverletzungen

There is some controversy over the treatment of acromioclavicular injuries. The use of the Rockwood classification as the basis for decisions on whether operative or nonoperative treatment is indicated is discussed critically, and the authors' preferred operative technique is described and illustrated by examples. We treat injuries classified according to the Rockwood classification as types I and II with conservative methods. In type III injuries the patient's age, job and free time activities determine whether or not surgery is indicated. In the case of type IV or type VI injuries we always perform temporary internal fixation of the acromioclavicular joint, using transarticular K-wire fixation or hookplate osteosynthesis. Satisfactory results of both operative and nonoperative treatment are reported in the literature. The authors' own results are presented.     

Syndecan-4 signals cooperatively with integrins in a Rho-dependent manner in the assembly of focal adhesions and actin stress fibers

The assembly of focal adhesions and actin stress fibers by cells plated on fibronectin depends on adhesion-mediated signals involving both integrins and cell-surface heparan sulfate proteoglycans. These two cell-surface receptors interact with different domains of fibronectin. To attempt to identify the heparan sulfate proteoglycans involved, we used fibronectin-null (FN-/-) mouse fibroblasts to eliminate the contribution of endogenous fibronectin during the analysis. FN-/- fibroblasts plated on the cell-binding domain of fibronectin or on antibodies directed against mouse beta1 integrin chains attach but fail to spread and do not form focal adhesions or actin stress fibers. When such cells are treated with antibodies directed against the ectodomain of mouse syndecan-4, they spread fully and assemble focal adhesions and actin stress fibers indistinguishable from those seen in cells plated on intact fibronectin. These results identify syndecan-4 as a heparan sulfate proteoglycan involved in the assembly process. The antibody-stimulated assembly of focal adhesions and actin stress fibers in cells plated on the cell-binding domain of fibronectin can be blocked with C3 exotransferase, an inhibitor of the small GTP-binding protein Rho. Treatment of cells with lysophosphatidic acid, which activates Rho, results in full spreading and assembly of focal adhesions and actin stress fibers in fibroblasts plated on the cell-binding domain of fibronectin. We conclude that syndecan-4 and integrins can act cooperatively in generating signals for cell spreading and for the assembly of focal adhesions and actin stress fibers. We conclude further that these joint signals are regulated in a Rho-dependent manner.     

Adjuvante Chemotherapie humaner kolorektaler Adeno-Carcinome nach Wachstum auf kongenital thymusdysplastischen Mäusen “Nude”

Zusammenfassung Die kombinierte Chemotherapie mit Vincristin (VCR) und 5-Fluorouracil (5-FU) war nach Festlegung der LD₅₀ im humanmedizinischen Dosierungsbereich bei 150 kongenital thymusdysplastischen nude-Mäusen ohne Komplikationen durchführbar. Unter spf-Bedingungen durchliefen ca. 5 Wochen alte syngene Balb/c-nude-Mäuse einen 9 tägigen Therapiezyklus. Die Teilsynchronisation wurde mit VCR am Tag 1 eingeleitet und 5-FU jeweils vom 1. bis 3. Tag intraperitoneal appliziert. Pathohistologisch entstanden unter VCR bei einer Dosis von 20% der LD₅₀ bei allen Tieren Milzatrophien und schwere Jejunitiden. Die durch Verminderung überwiegend segmentkerniger Zellen entstandenen Leukopenien waren erwartungsgemäß reversibel. Nach 5-FU-Applikation entstanden bei einer 20% igen Dosierung der LD₅₀ hauptsächlich Zystitiden, bei 67% Bronchitiden und Lobärpneumonien.In der Kombination mit humanmedizinisch relevanten Dosierungen entwickelten die Tierkollektive regressive Veränderungen an Harnblasen- und Zottenepithelien des Jejunums. Neben Hepatitiden mit Gruppennekrosen fanden sich Pneumonien bei 50% der Tiere; Milzatrophien waren mäßig ausgeprägt. Die Lymphknoten zeigten eine Tendenz zur Strukturauflösung der Follikel ohne spezifische Veränderungen der paracorticalen Region. Hämatologisch war nach reversibler Leukopenie mit Granulozytopenie die Einleitung eines 2. Zyklus am 9. Tag möglich.Nach Kenntnis dieser Befunde ist die Möglichkeit gegeben, die Wirksamkeit von VCR und 5-FU auf das Wachstum humanen kolorektalen Tumorgewebes nach erfolgter Transplantation auf nude-Mäuse in vivo zu testen.Mit Unterstützung der Deutschen Forschungsgemeinschaft     

Schlusswort

Trauma und Berufskrankheit -     

Diagnostik und operative Therapie der diffusen pigmentierten villonodul?ren Synovitis des Hüftgelenks

Die pigmentierte villonodul?re Synovitis (PVNS) ist eine seltene proliferative Erkrankung der Binnenhaut von Gelenken, Schleimbeuteln und Sehnenscheiden. Sie zeigt ein typisches monolokul?res Auftreten und betrifft bevorzugt Erwachsene im 3. und 4. Lebensjahrzehnt ohne Geschlechtspezifit?t. ?tiologisch und pathogenetisch wird die PVNS kontrovers hinsichtlich einer neoplastischen bzw. einer chronisch-entzündlichen Genese diskutiert. Die pigmentierte villonodul?re Synovitis wird aufgrund der Prognose und Therapieplanung in eine lokale und diffuse Form unterteilt. Als operatives Verfahren kommt die arthroskopische bzw. offene Synovialektomie in Frage.