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Steam Sterilization of joint instruments – Open or closed?

Updated: Sep 11, 2023


Users may get confused by different daily practices: While in the USA open sterilization is recommended by AAMI ST 79 (many times on “stringers”), all over Europe instruments are directly placed in baskets in closed position.


For proper steam access open sterilization is not required. In a large “worst case study” (H. Henn et al. Steam Sterilization of Reusable Surgical Instruments, Zentralsterilisation Nr 4 / 2009 S. 257ff, mhp-Verlag) it was proven, that under pre-vacuum processes (ISO 17665 series) steam access is given even through very complex geometries such as threads and bolts.



Closed position makes handling of the instruments easier and safer, especially for sharp or pointed instruments. The risk of damages, e. g.for fine working ends is reduced. Not directly related to retaining value of the instruments, but an important part, is the raised security in handling by OR personnel. Instruments in closed position prevent injuries or stitches.


Sterilization in closed or assembled position should therefore be preferred, unless there are local regulatory requirements for an open position, the manufacturer is not allowing that in the related processing information according to ISO 17664 or it is imperative by the storage system (such as stringers).



About the author

Gerhard Kirmse is a Senior Expert for Reprocessing and OR Supply at Aesculap and member of the AKI Group. As a Biomedical Engineer with a doctorate about cleaning of instrument he works in research and performed consulting in more than 400 CSSDs worldwide.

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