Are MRI-based, patient matched cutting jigs as accurate as the tibial guides?

Abstract

Purpose The aim of this study is to evaluate the accuracy of VISIONAIRE (Smith & Nephew Inc., Memphis, TN, USA) Patient Matched cutting tibial jigs in comparison with extramedullary (EM) tibial instrumentation by analysing data as detected by intra-operative use of VectorVision knee navigation software from BrainLAB (Redwood City, CA, USA). Methods Twelve patients were selected for unilateral total knee replacement (TKR). They underwent a full-length weight-bearing anteroposterior (AP) radiograph and magnetic resonance imaging (MRI). During surgery, once the EM guides were placed and fixed on the tibia, the orientation in the coronal and sagittal planes was checked by the navigator and then compared with the data obtained by measuring the orientation of VISIONAIRE Patient Matched cutting tibial jigs. An unsatisfactory result was considered an error ≥2°in both coronal and sagittal planes for the tibial component as a possible error of 4°could result. Results In the coronal plane the mean deviation of the EM tibial guides from the ideal alignment (0°) was 0.7±0.39°a nd of the VISIONAIRE was 129±1.55°(P00.22). In the sagittal plane the mean deviation of the EM tibial guides from 3°of posterior slope was −1.62±1.78°and of the VISIONAIRE was +1.16±4.29°(P<0.05). Negative values indicate a more posterior slope from the ideal and positive values an anterior slope. Conclusions This preliminary study documented only a fair accuracy of the method with a consistent risk of error of more of 3°especially in the sagittal plane. We could speculate that the problem in the sagittal plane was due to the fact that the pre-operative protocol does not include a lateral X-ray projection of the knee and only includes an AP standing X-ray of the straight leg and MRI.

A comparison of conventional and patient-specific instruments in total knee arthroplasty

“…This is in line with earlier studies with this technology, which also reported no intraoperative complications to date [11,18,31].…”

“…They are in line with other studies of PSI which reported improved alignment [16,30,38]. Although it should be noted that other studies have failed to show a clear advantage for PSI technology [24,32], and that one study with the technology employed in the current analysis observed only a fair rate of accuracy, with higher risk of error >3°in the sagittal plane [11], there does appear to be an overall trend for the superiority of these new technologies over earlier instrumentation methods.…”

“…The process by which the VISIONAIRE instrumentation is produced has been described in detail in other studies [11,18,31]. The surgeon's preferences called for a 9-mm proximal resection, a posterior slope alignment of 3°, a varus/ valgus alignment of 4-7°if there was no rotation in the xrays or, if there was rotation due to malalignment or degenerative joint, 5°for varus knees and 7°for valgus knees.…”

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

“…In two studies of the VISIONAIRE system, Conteduca et al noted tibial component alignment in the coronal plane of 1.2°with satisfactory alignment (±2°from neutral) in 83.3%, and femoral component alignment of 1.2°with satisfactory alignment (±2°from neutral) in 92.6% [9,10]. 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].…”

“…The technique for the VISIONAIRE system has been previously detailed [9,11,14,31]. MRI of the operative knee and ipsilateral AP long-leg standing radiograph were sent to the manufacturer to create tibial and femoral resection guides.…”