Pros and cons of navigated versus conventional total knee arthroplasty—a retrospective analysis of over 2400 patients

Abstract

Introduction Because of the ongoing discussion of imageless navigation in total knee arthroplasty (TKA), its advantages and disadvantages were evaluated in a large patient cohort. Methods This 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). Results Both 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). Conclusion Both methods enable accurate postoperative leg alignment with low complication rates and equally successful PROMs and responder rates one year postoperatively. Level of evidence III. Retrospective cohort study.

The learning curve associated with imageless navigation in total knee arthroplasty

“…Saiki et al report that the learning curves between a different imageless CAS and an acceleration-based navigation system for TKA converged within five cases after introduction of these systems into surgical workflow, with ultimate average surgical times of 87.8 min and 87.4 min, respectively [ 30 ]. Meyer et al report that mean surgery duration for navigated TKA was 6 min longer than for conventional TKA [ 31 ]. These minimal increases may be enabled by standardization of navigation integration into surgical workflow, as well as ease-of-use characteristics inherent to a specific navigation system [ 31 ].…”

“…Meyer et al report that mean surgery duration for navigated TKA was 6 min longer than for conventional TKA [ 31 ]. These minimal increases may be enabled by standardization of navigation integration into surgical workflow, as well as ease-of-use characteristics inherent to a specific navigation system [ 31 ].…”

Navigation und Robotik in der Knieendoprothetik

“…In den Verlaufskontrollen bis 5 Jahre gab es keinen Unterschied zwischen den beiden Gruppen, zwischen 5 und 8 Jahren konnten sie jedoch eine signifikante Verbesserung des WOMAC und des Function Score des KSS in der nav-TEP-Gruppe identifizieren [51]. Weitere Autoren kamen ebenfalls zum Schluss, dass beide Techniken auch noch nach 10 bis 12 Jahren gleiche Ergebnisse liefern [8,14,33,38,46,55].…”

“…Der Großteil der Studien berichtet über eine signifikant verlängerte Operationszeit, wobei diese mit steigender Erfahrung auf 6-18 min sinkt [4,12,14,21,46,55].…”

“…In einer retrospektiven Studie mit 878 TEP kam es bei 2,3 % der Knie intraoperativ zu Lockerungen des Referenzstabes, Brüchen des Femurs und Ausfällen des Informatiksystems, die intraoperativ einen Wechsel zur konventionellen Technik erforderten [49]. Das Auftreten von postoperativen thrombembolischen Ereignissen und Protheseninfektionen ist bei beiden Verfahren gleich zu bewerten [1,46]. Die Navigation führt anscheinend zu weniger Hämoglobinabfällen [21].…”