Accuracy of Patient-Specific Instrumentation Compared With Conventional Instrumentation in Total Knee Arthroplasty

Abstract

Patient-specific instrumentation (PSI) has recently been introduced to improve the alignment following total knee arthroplasty (TKA). However, controversy remains between PSI and conventional instrumentation. The aim of this study is to compare the accuracy of PSI with conventional instruments for total knee arthroplasty (TKA). A systematic literature search was performed in databases including PubMed, the Cochrane Library, EMBASE, and Web of Science. All of the available randomized, controlled trials (RCTs) or non-randomized, controlled trials (nRCTs) comparing PSI with conventional instruments for TKA were identified. A statistical analysis was performed of this meta-analysis. Eighteen studies with 2417 patients were included in the authors' final analysis. The results of the meta-analysis demonstrated that there were no statistical differences in outliers of the mechanical axis (risk ratio [RR], 0.84; 95% confidence interval [CI], 0.61-1.11), the femoral component in the coronal (RR, 0.56; 95% CI, 0.32-1.05) and sagittal (RR, 0.83; 95% CI, 0.60-1.14) plane, the tibial component in the coronal (RR, 0.84; 95% CI, 0.52-1.35) and sagittal (RR, 1.04; 95% CI, 0.69-1.55) plane, and the femoral component rotation (RR, 1.02; 95% CI, 0.57, 1.83) between the 2 groups. In addition, subgroup analysis showed that the study design and imaging used for preoperative scanning did not affect the outcome of the alignment, but a different PSI system might. The authors' meta-analysis indicated that the accuracy of PSI was not superior to conventional instruments for patients undergoing TKA. Future RCTs should focus on functional outcomes and component survivorship with mid- to long-term follow-up.

A Meta-analysis of Functional Outcomes in Patient-Specific Instrumented Knee Arthroplasty

“…Regarding alignment data, Mannan et al demonstrated comparable restitution of a neutral postoperative mechanical axis, 23 as well as favorable femoral axial alignment in patient-specific instrumented knee arthroplasty. 4 Jiang et al, 5 Shen et al, 6 Cavaignac et al, 7 Thienpont et al, 8 Fu et al, 9 and Russell et al 11 reported similar findings for postoperative mechanical axis. Increased accuracy of reproduction of a target femoral coronal alignment has been reported in several meta-analyses with PSI (Cavaignac et al, 7 Thienpont et al, 8 A picture, therefore, emerges of comparable alignment outcomes in PSI versus conventional instrumentation with a trend toward favorable outcomes in several parameters in PSI (Mannan and Smith, 4 Cavaignac et al, 7 Thienpont et al, 8 and Voleti et al 10 ).…”

“…The results of this meta-analysis demonstrate equivalent functional outcomes between PSI and conventional instrumentation with follow-up of 3 to 24 months. Several published meta-analyses have described component alignment, [4][5][6][7][8][9][10][11] but this is the first in our knowledge to comprehensively synthesize functional data. Regarding alignment data, Mannan et al demonstrated comparable restitution of a neutral postoperative mechanical axis, 23 as well as favorable femoral axial alignment in patient-specific instrumented knee arthroplasty.…”

“…Previous meta-analyses have demonstrated similar restitution of mechanical axis in patient-specific instrumentation (PSI), with favorable outcomes in terms of femoral implant axial alignment in comparison to conventional TKA methods. [4][5][6][7][8][9][10][11] To date, no comprehensive synthesis of data has been conducted specifically for functional outcomes.…”

Significant differences between manufacturer and surgeon in the accuracy of final component size prediction with CT-based patient-specific instrumentation for total knee arthroplasty

“…33 Initial proponents of this technology also suggested that it could help in minimizing blood loss, and 34 improve clinical outcome [10,21,30]. 35 Preliminary studies confirmed that PSI is effective in reducing surgical time [9,10,13,14,16,20,36 21] and may help to achieve better prosthetic component position and sizes in TKA [10,21,30], but 37 recent reviews suggested care when interpreting these initial results [18,29]. 38 Computer software can indeed facilitate pre-operative planning and help predicting intra-operative 39 resections and component sizes.…”

Patient‐specific Instrumentation Affects Rotational Alignment of the Femoral Component in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

“…Therefore, a new technology that could reduce the proportion of incorrectly aligned implants appears appealing. However, there is controversy in the available published literature on the ability of PSI to affect the implant positioning, with some studies showing increased accuracy of femoral rotation with the use of PSI [8][9][10][11] and others revealing no differences from conventional alignment techniques [12][13][14][15][16][17][18][19][20] .…”