Pros and cons of navigated versus conventional total knee arthroplasty\u2014a retrospective analysis of over 2400 patients

Abstract

IntroductionBecause of the ongoing discussion of imageless navigation in total knee arthroplasty (TKA), its advantages and disadvantages were evaluated in a large patient cohort.MethodsThis retrospective analysis included 2464 patients who had undergone TKA at a high-volume university arthroplasty center between 2012 and 2017. Navigated and conventional TKA were compared regarding postoperative mechanical axis, surgery duration, complication rates, one-year postoperative patient-reported outcome measures (PROMs) (WOMAC and EQ-5D indices), and responder rates as defined by the criteria of the Outcome Measures in Rheumatology and Osteoarthritis Research Society International consensus (OMERACT-OARSI).ResultsBoth navigated (1.8 ± 1.6°) and conventional TKA (2.1 ± 1.6°, p = 0.002) enabled the exact reconstruction of mechanical axis. Surgery duration was six minutes longer for navigated TKA than for conventional TKA (p < 0.001). Complication rates were low in both groups with comparable frequencies: neurological deficits (p = 0.39), joint infection (p = 0.42 and thromboembolic events (p = 0.03). Periprosthetic fractures occurred more frequently during conventional TKA (p = 0.001). One-year PROMs showed excellent improvement in both groups. The WOMAC index was statistically higher for navigated TKA than for conventional TKA (74.7 ± 19.0 vs. 71.7 ± 20.7, p = 0.014), but the increase was not clinically relevant. Both groups had a similarly high EQ-5D index (0.23 ± 0.24 vs. 0.26 ± 0.25, p = 0.11) and responder rate (86.5% [256/296] vs. 85.9% [981/1142], p = 0.92).ConclusionBoth methods enable accurate postoperative leg alignment with low complication rates and equally successful PROMs and responder rates one year postoperatively.Level of evidenceIII. Retrospective cohort study.