How do jet time, pressure and bone volume fraction influence the drilling depth when waterjet drilling in porcine bone?

Journal article (2016)

Authors

S. den Dunnen Medical Instruments & Bio-Inspired Technology - Mechanical, Maritime and Materials Engineering
J. Dankelman Medical Instruments & Bio-Inspired Technology - Mechanical, Maritime and Materials Engineering
G.J.M. Tuijthof Medical Instruments & Bio-Inspired Technology - Mechanical, Maritime and Materials Engineering
Research Group
Medical Instruments & Bio-Inspired Technology (Mechanical, Maritime and Materials Engineering) (TU Delft)
More Info
expand_more

Published Date

2016

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Mechanical, Maritime and Materials Engineering

Department

Biomechanical Engineering

Research Group

Medical Instruments & Bio-Inspired Technology

Abstract

Using water jets for orthopedic procedures that require bone drilling can be beneficial due to the absence of thermal damage and the always sharp cut. Previously, the influence of the water jet diameter and bone architectural properties on the drilling depth have been determined. To develop water jet instruments that can safely drill in orthopedic surgery, the impact of the two remaining primary factors were determined: the jet time (tjet [s]) and pressure (P [MPa]). To this end, 84 holes were drilled in porcine tali and femora with water jets using Ø 0.4 mm nozzle. tjet was varied between 1, 3 and 5 s and P between 50 and 70 MPa. Drilling depths Lhole (mm), diameters Dhole (mm) and the volume of mineralized bone per unit volume (BV/TV) were determined with microCT scans.

A non-linear regression analysis resulted in the predictive equation: Lhole= 0.22 * tjet0.18 * (1.2–BV/TV) * (P–29) (R2=0.904).

The established relation between the machine settings and drilling depth allows surgeons to adjust jet time and pressure for the patient׳s BV/TV to drill holes at a predetermined depth. For developers, the relation allows design decisions to be made that influence the dimensions, flexibility and accuracy of water jet instruments. For a pressure of 50 MPa, the potential hole depth spread indicated by the 95% confidence interval is <1.6 mm for all tested jet times. This maximum variance is smaller than the accuracy required for bone debridement treatments (2–4 mm deep), which confirms that water jet drilling can be applied in orthopedic surgery to drill holes in bone with controlled depth.