Abrasive water jet cutting as a new procedure for cutting cancellous bone : in vitro testing in comparison with the oscillating saw

Journal
Journal of biomedical materials research. Part B, Applied biomaterials  
Volume
71
Issue
2
Start Page
223
End Page
228
Citation
Journal of Biomedical Materials Research. Part B Applied Biomaterials 71 (2): 223-228 (2004)
Publisher DOI
10.1002/jbm.b.10078
Scopus ID
2-s2.0-7744225419
Publisher
Wiley
The quality of bone cuts is assessed by the accuracy and biological potency of the cut surfaces. Conventional tools (such as saws and milling machines) can cause thermal damage to bone tissue. Water jet cutting is nonthermal; that is, it does not generate heat. This study investigates whether the abrasive jet cutting quality in cancellous bone with a biocompatible abrasive is sufficient for the implantation of endoprostheses or for osteotomies. Sixty porcine femoral condyles were cut with an abrasive water jet and with an oscillating saw. α-lactose-monohydrate was used as a biocompatible abrasive. Water pressure (pw = 35 and 70 MPa) and abrasive feed rate (ṁ = 0.5, 1, and 2 g/s) were varied. As a measure of the quality of the cut surface the cutting gap angle (δ) and the surface roughness (Ra) were determined. The surface roughness was lowest for an abrasive feed rate of ṁ = 2 g/s (jet direction: 39 ± 16 μm, advance direction: 54 ± 22 μm). However, this was still significantly higher than the surface roughness for the saw group (jet direction: 28 ± 12 μm, advance direction: 36 ± 19 μm) (p < 0.001 for both directions). At both pressure levels the greatest cutting gap angle was observed for a mass flow rate of ṁ = 1 g/s (pw = 35 MPa: δ = 2.40 ± 4.67°; pw = 70 MPa: δ = 4.13 ± 4.65°), which was greater than for ṁ = 0.5 g/s (pw = 35 MPa: δ = 1.63 ± 3.89°; pw = 70 MPa: δ = 0.36 ± 1.70°) and ṁ = 2 g/s (pw = 70 MPa: δ = 0.06 ± 2.40°). Abrasive water jets are suitable for cutting cancellous bone. The large variation of the cutting gap angle is, however, unfavorable, as the jet direction cannot be adjusted by a predefined value. If it is possible to improve the cutting quality by a further parameter optimization, the abrasive water jet may be the cutting technique of the future for robotic usage. © 2004 Wiley Periodicals, Inc.
Subjects
Bone
Cancellous bone
Cutting quality
Implantation of prostheses
Water jet cutting
DDC Class
610: Medicine, Health
620: Engineering