Comparison of iASSIST Navigation System with Conventional Techniques in Total Knee Arthroplasty: A Systematic Review and Meta‐Analysis of Radiographic and Clinical Outcomes

Abstract

The iASSIST navigation system is a handheld accelerometer‐based navigation system that has been applied in clinical practice in recent five years. This meta‐analysis aimed to compare the radiographic and clinical outcomes of iASSIST navigation with conventional surgical techniques for patients undergoing total knee arthroplasty (TKA) and to compare the surgery time between an iASSIST group and a conventional treatment group. This systematic review and meta‐analysis included all comparative prospective and retrospective studies published in Pubmed, Embase, the Cochrane Central Register of Controlled Trials, the Web of Science and the CNKI databases over the past 20 years. Inclusion criteria were studies that compared the iASSIST navigation system with conventional TKA. The primary outcomes were mechanical axis (MA) and outliers, which means postoperative MA varus or valgus of more than 3°. Secondary outcomes were coronal femoral angle (CFA) and coronal tibial angle (CTA). Knee Society Score (KSS) was used to evaluate functional outcome. The Newcastle–Ottawa Scale (NOS) was used to assess the methodological quality of included studies. Eight studies involving 558 knees were included in this meta‐analysis. Of these, 275 patients used the iASSIST navigation system and 283 used conventional surgical techniques. A total of 5 studies were considered high quality and the other 3 were considered to be of moderate quality. The occurrence of malalignment of >3° in the iASSIST group was 13.3%, compared with 29.04% in the conventional group. Postoperative MA of the iASSIST group was significantly better than that of the conventional group (I 2 = 19%, OR = −0.92, 95% CI = −1.09 to −0.75, P < 0.00001). The iASSIST navigation system provided significantly increased accuracy in the coronal femoral angle (I 2 = 79%, OR = −0.88, 95% CI = −1.21 to −0.54, P < 0.00001) and the coronal tibial angle (I 2 = 34%, OR = 0.39, 95% CI = −0.48 to −0.30, P < 0.00001) compared with conventional techniques. However, the duration of surgery using the iASSIST procedure was longer and there was no significant difference in the short‐term KSS in the iASSIST group compared with the conventional group. We found that when pooling the data of included studies, the number of outliers was fewer in the iASSIST group, and compared with conventional TKA techniques, the iASSIST system significantly improved the accuracy of lower limb alignment but the duration of surgery was prolonged in addition to there being no apparent advantage in terms of short‐term functional score.

Accelerometer-Based Navigation Versus Conventional Technique in Total Knee Replacement. A Prospective Study in a Tertiary Care Medium Volume Setup in India.

“…(20) This result is congruous with result of Long How Moo et al Bauwens (21) et al who found that there was no signicant difference in mechanical axis alignment between patients who underwent conventional and navigational total knee replacement. By contrast, our study shows contradictory result against many authors who shows that iASSIST gives signicant better alignment of component and (22,23) mechanical axis .…”

New Technologies in Knee Arthroplasty: Current Concepts

“…Only two of six studies that evaluated the proportion of patients with outlier alignments supported accelerometer-based navigation [57,58]; the other four found no differences in this important endpoint [54,55,60,61]. Li et al have reported similar results in a meta-analysis on 275 total knee arthroplasties performed with the iASSIST navigation system [63]. This system provided significantly increased accuracy in the coronal femoral angle (p < 0.00001) and the coronal tibial angle (p < 0.00001) compared with conventional techniques.…”

“…This system provided significantly increased accuracy in the coronal femoral angle ( p < 0.00001) and the coronal tibial angle ( p < 0.00001) compared with conventional techniques. There was no significant difference in functional knee score at short term follow-up in the iASSIST group compared with the conventional group [ 63 ]. No studies have demonstrated better clinical outcomes with accelerometer-based navigation compared with conventional technique TKA [ 53 ].…”

Clinical value of CT-based patient-specific 3D preoperative design combined with conventional instruments in primary total knee arthroplasty: a propensity score-matched analysis

“…Previous literature has shown that malalignment or malposition of the components are often closely associated with complications such as polyethylene wear and aseptic loosening [1][2][3]. However, the incidence of the lower limb malalignment or malposition of the components after conventional TKA is as high as 20-30% [4,5].…”