Abnormal rate of intraoperative and postoperative implant positioning outliers using “MRI-based patient-specific” compared to “computer assisted” instrumentation in total knee replacement

Abstract

Randomized control trial, Level I.

Handheld Navigation Device and Patient-Specific Cutting Guides Result in Similar Coronal Alignment for Primary Total Knee Arthroplasty: A Retrospective Matched Cohort Study

“…Pfitzner et al reported similar findings, with tibial component alignment of 1.0°, with a 3% outlier (±3°from neutral) rate, and femoral component alignment of 1.0°, with a 3% outlier (±3°from [32,42]. Some of the variability in results may relate to particular surgical methods or to the reference standard used to assess error.…”

“…Nam et al also reported excellent results with KA2, noting 0.04°variation from the tibial mechanical axis with no outliers (beyond ±3°from neutral), and −0.1°variation from femoral mechanical axis with 1.3% outliers (beyond ±3°from neutral) [30]. Prior literature pertaining to VISIONAIRE TKAs is conflicting, with some studies reporting good results [9,10,34] and others reporting unsatisfactory results [21,32,40].…”

“…For example, in the present study, the entire femoral preparation was completed first in order to optimize placement of the tibial cutting guide. Further, some studies used postoperative imaging as the reference standard [34], while others used intra-operative assessments based on computer-assisted navigation instruments [21,32,42]. In the sagittal plane, the KA2 group achieved an average slope closer to 3°of posterior slope (2.7°) compared to the VISIONAIRE group (4.4°).…”

“…Compared to computed tomography (CT)-based PSI, MRI-based PSI accounts for residual articular cartilage, which may allow more accurate fit of the PSI cutting guides on the femur and tibia intra-operatively [20]. Yet, studies specific to VISIONAIRE PSI report conflicting results [9,10,21,32,33,42].…”

Reply to the Letter to the Editor: The John Insall Award: No Functional Benefit After Unicompartmental Knee Arthroplasty Performed With Patient-specific Instrumentation: A Randomized Trial

“…We also have been involved in several trials of patientspecific instrumentation (PSI) on both UKA and TKA in the last several years [1,5,6], highlighting the frequency of outliers, the proportion of PSI procedures that needed to be aborted or modified during surgery, as well as the additional costs incurred by the new technology both directly and in terms of the surgeon's time. We initially hypothesized [4] that PSI could be a useful tool for UKA, particularly to improve the tibial cut.…”