Patient specific MRI protocol enhancement and Post-operative (imaging-based) evaluation of patient specific Total Knee Arthroplasty

Total knee arthroplasty is the standard treatment for advanced knee arthritis,
resulting in pain relief, restoration of basic function, and it has acceptable
clinical longevity. In the Netherlands about 18.000 knee prostheses are placed
every year [1]. Over the past decade the number of procedures has greatly
increased and because of an aging population it is expected this number will
increase even more [2].
Fehring et al. analyzed the mechanisms of failure in patients who had revision
surgery within 5 years of their TKA. Of the 440 patients with TKA, 279 had
revision surgery (63%). The most important reason for early failure was
infection (105, 38%) and the second leading cause of early failure was
instability (74, 27%) [3]. Instability of the prosthesis is due to suboptimal
placement of the implant.
To optimize implant positioning and therefore reducing the instability, proper
rotational alignment of the femoral and tibial components is needed. Currently,
a mechanically aligned patient-matched system VISIONAIRE (VIS) is used to help
in placing the prosthesis with high accuracy. VISIONAIRE uses MRI scans to
create patient specific 3D cutting blocks which help in placing the prosthesis
with high accuracy.
There only a few articles published which investigated the results of patient
matched instrumentation. These articles all concentrate on the postoperative
outcome/accuracy of this method. The results are divergent and vary from high
and improved accuracy to unsatisfactory accuracy, according to these articles
[4, 5, 6]. Also, no publications can be found about the effects of the
pre-operative MRI scan concerning the number of rescans and the scan
failure-rate.
At the UMC Utrecht, it is known that there is more than 20% scan failure in
patients for VISIONAIRE due to sub-optimal MRI scans. There is a clear need to
improve the current MRI protocol to decrease MRI failure rates and rescan
needs. Our aim is to identify and modify key parameter to improve scan quality
and reduce patient exclusion for the VISIONAIRE procedure due to sub-optimal
MRI scans.
In addition, there is a need to establish the effectiveness of this method and
expand its use in clinic. Post-operative imaging and image processing will
enable us to validate the use of this technology and further asses its
accuracy. This will open the possibility of providing clinical equivalents to
the current FDA lab 30 yr. life time claim.
It should be emphasized that TKA using the VISIONNAIRE protocol is part of the
standard procedure in this hospital. Also, the investigation is non-invasive,
without radiation and no contrast agents are used. We only aim to improve this
method by enhancing the pre-operative imaging and evaluate the accuracy to
improve and insure overall quality and patient comfort/satisfaction, while
retaining manufacturing standards (and 3D print parameters). This will allow
better/further implementation of this procedure in the hospital by reducing MRI
scan failure.

Primary Objective:
- Improvement of MRI image quality and reduction of failure rate/rescan
percentage
- Evaluation of prosthesis placement accuracy and comparison to the planning

Secondary Objective(s):
- Alternative scan protocol
- Reduce scan time --> Increased patient comfort/satisfaction
- Quality assurance

Single centre prospective (and restrospective) study, designed and coordinated
at UMC Utrecht.

no risk, max 15min additional scanning time, and a post operative scan. Max 30
min