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DOI: 10.1055/s-0037-1619943
Die Schrauben-Knochen-Verbindung beim Fixateur externe
Eine biomechanische und biologische Analyse im SchafmodellThe pin/bone-interface in external fixatorsA biomechanical and biological analysis in a sheep modelPublication History
eingereicht:
28 July 2010
angenommen:
30 July 2010
Publication Date:
30 December 2017 (online)
Zusammenfassung
Der Schrauben-Knochen-Kontakt ist die Schwachstelle des externen Fixateurs, der die Funktionalität der Osteosynthese und den Behandlungserfolg bedingt. Daher ist eine stabile Integration der Schrauben im Knochen sowohl initial als auch über den Behandlungsverlauf essenziell. Die Hypothese der Studie war, dass das Auftreten von Schraubenlockerungen und -infekten mit der Implantationsdauer ansteigt, während die generelle Stabilität der Schrauben-Knochen-Verbindung mit der Zeit abnimmt. Für die Studie wurde bei 24 Schafen eine Tibia-Osteotomie vorgenommen und mit einem externen Fixateur stabilisiert. Die Schrauben-Knochen-Verbindung wurde nach drei, sechs und neun Wochen Standzeit radiologisch, biomechanisch, mikrobiologisch und histologisch untersucht. Entgegen der Hypothese blieb die Stabilität der Schrauben-Knochen-Verbindung während der Standzeit un-verändert. Dieser unerwartete Effekt könnte auf ein zunehmendes Remodeling im Knochen um die Schrauben zurückzuführen sein, begünstigt durch eine intensive Wundpflege und eine damit einhergehende niedrige Infektrate.
Summary
The pin/bone-interface is the most critical point of the external fixator and determines the success of the whole treatment. To minimize the risk of complications during fracture healing, a stable integration of pins in the bone is required initially, as well as permanently. The hypothesis of this study was that the incidence of pin loosening and pin infection would increase, while the general stability of the pin/bone-interface would decrease with ongoing implantation time. Therefore, 24 sheep received a tibial osteotomy stabilized by an external fixator. The pin/bone-interface was analyzed radiologically, biomechanically, microbiologically and histologically after 3, 6, and 9 weeks. Contrary to our hypothesis, this study showed that the biomechanical pin anchorage during implantation time (weeks 3 to 9) did not alter. This effect may be attributable to an increasing remodelling found in the callus and cortex around the pins and was promoted by a strict pin care routine and consequently a lower infection rate.
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