A Configurable Guide for Knee Arthroplasty

A Configurable Guide for Knee Arthroplasty

Herrebrugh, T.O.

Valstar, E.R. (mentor)
Mattheijer, J. (mentor)

Mechanical, Maritime and Materials Engineering

Biomedical Engineering

BME

2015-12-10

In total knee arthroplasty (TKA) the contact surfaces of the knee are replaced with prosthetic components. In order to fit the prosthetic components, the bones are shaped by making bone cuts. Patient specific surgical guides (PSSGs) are guides made from CT or MRI images to fit the patient’s anatomy. They guide the bone cuts. When bone deviations disturb the fit, commercially available PSSGs cannot be adjusted. Our goal is to design a reusable PSSG for TKA which can be configured for a planned alignment and corrected during surgery when unplanned bone deviations occur. Concepts for the functional problems are developed and combined into a final design consisting of three components: the guide, contact points and setting tool. The setting tool configures the contact points. The contact points are magnetically fixated to the guide’s base and can be removed when the fit is disturbed. Pins protrude from the contact points, indicating contact with the bone to evaluate the fit. We assess the ability of inexperienced and experienced subjects to recognize surface disturbances using the protruding pins. Subjects position the guide and are tasked to recognize if and where disturbances occur. With inexperienced users, the disturbed contact point is correctly recognized for 7 out of 26 disturbed experiments. A significant increase is found in the rotational error for placements with a disturbance. No significant increase is found for the translational error. With experienced users, the disturbed contact point is correctly recognized for 18 out of 26 disturbed experiments. No significant increase is found in the rotational and translational error for placements with a disturbance. Inexperienced users cannot recognize disturbances and reconfigure the guide. Experienced users can better recognize disturbances and reconfigure the guide. When disturbances were not correctly recognized by experienced users, the disturbance had only a small effect on the alignment. We recommend to correct the perceived backlash of the contact points and stiffen the guide design. Training of the test subjects is suggested when new experiments are performed.

TKA
knee
arthroplasty
patient specific
guide
configurable

http://resolver.tudelft.nl/uuid:63520a39-fddd-4b2f-bb7e-57069e64b79e

2020-12-10

Student theses

master thesis

(c) 2015 Herrebrugh, T.O.