Affiliations: Barmbek General Hospital, Department of Orthopaedic Surgery, Rübenkamp 148, 22307 Hamburg, Germany | Biomechanics Section, Technical University Hamburg, Denickestraße 15, 21073 Hamburg, Germany | Institute for Material Science, Jet Cutting Section, Appelstraße 11a, 30167 Hanover, Germany
Note: [] Corresponding author: Dr. med. Matthias Honl, Department of Orthopaedic Surgery, Barmbek General Hospital, Rübenkamp 148, 22307 Hamburg, Germany. Tel.: +49 40 6385 2733; Fax: +49 40 6385 2055; E‐mail: honl@ortho‐hamburg.de.
Abstract: In revision surgeries of endoprostheses, the interface between implant and bone cement or bone must be loosened. Conventional tools have many disadvantages because of their size and limited range. Taking advantage of the selective and athermic cutting process, a plain water jet is already used in order to cut soft tissues. This study investigates the possibilities of both a plain and an abrasive water jet as cutting tools for revision surgery. Samples of the mid‐diaphysis of human femora and bone cement (CMW3) were cut with a plain water jet (PWJ) and an abrasive water jet (AWJ) at two different jet‐to‐surface angles (30°,90°) and at five different pressure levels (30, 40, 50, 60, 70 MPa). For a PWJ a selective pressure range was identified, where only bone cement was cut. Injecting a bio‐compatible abrasive (lactose) to the jet stream resulted in significantly higher cut depths in both materials. Material removal in bone was significantly less at the smaller jet‐to‐surface angle for both techniques. No clear selectivity between bone and bone cement was observed for application of the AWJ. However, the material removal rate was significantly higher for bone cement than for bone at all pressure levels. The results indicate that an AWJ might be an alternative tool for cement removal. The possibility for localised cutting at interfaces could be an advantage for revision of a non‐cemented prosthesis.
Keywords: Jet cutting, prosthesis, revision, bone cement, bone
