L’arthroplastie totale de genou sous navigation conduit à un meilleur alignement postopératoire que la technique conventionnelle ou l’instrumentation personnalisée dans un centre chirurgical à volume modéré

Abstract

BackgroundProcedure volume is an important determinant of total knee arthroplasty (TKA) outcomes. We aimed to determine whether computer navigation or patient-specific instrumentation (PSI) would improve postoperative alignment in a low-volume setting. HypothesisPSI for TKA achieves better limb and implant alignment compared to conventional TKA and to computer navigated TKA. Materials and methodsThis is a retrospective cohort study of 385 primary TKAs (Women=59%. Mean age=67 years. Mean BMI=30.1kg/m2) which were performed using conventional instrumentation (n=117; 30%), computer navigation (n=209; 54%), or patient-specific instrumentation (n=59; 15%) in a low-volume center (<50 TKAs/year). The risk of postoperative limb and implant mechanical alignment outliers in the coronal plane (>3° from neutral), average alignment and operation time were assessed. ResultsThe risk of postoperative mechanical alignment outliers (>3°) was reduced by 89% in the navigated group (4% outliers) compared to the conventional group (35%) (RR=0.11; p<0.0001). No significant improvement was observed in the PSI group (27%) (RR=0.91; p=0.772). The risk of postoperative femoral component coronal alignment outliers was reduced by 63% in the navigated group (11%) compared to the conventional group (31%) (RR=0.37; p=0.018). No significant reduction in outliers was observed in the PSI group (32%) (RR=1.08; p=0.816). There was a reduction in the risk of tibial component coronal malalignment of 66% in the navigated group (5%) compared to the conventional group (13%) (RR=0.33; p=0.070). There was a two-fold increase in the risk of tibial component alignment outliers in the PSI group (29%) (RR=1.94; p=0.110). DiscussionNavigated TKA improved postoperative alignment. No evidence of improved alignment was seen with patient-specific instrumentation. The routine use of patient-specific instrumentation in low-volume centers is not supported by the currently available data. Type of studyRetrospective cohort study Level IV.