Does Computer Navigation Improve Outcomes after TKA?
Research from New Zealand presented the ISAKOS Biennial Congress casts doubt on even short-term gains.
Although computer navigation in total knee arthroplasty continues to have very vocal proponents, it has not been shown to make a difference in long-term clinical outcomes or implant survivorship compared with component positioning and limb alignment done with conventional instruments.
Research presented at the 2015 ISAKOS Biennial Congress in Lyon, France, shows that even short-term gains may not be realized by computer navigation.
Investigators from North Shore Hospital, Auckland, New Zealand, used data from the New Zealand National Joint Registry to test their hypothesis that computer navigation would improve functional outcome following TKA. The registry included data on 9,054 primary TKAs performed from 2006 to 2012. All patients had osteoarthritis, and all received the same implant.
Computer navigation was used in 3,329 cases, compared with conventional instruments in 5,725 cases. The researchers looked at Oxford knee scores 6 month and 5 years after surgery to evaluate functional outcomes between groups.
They also examined whether surgical duration had an effect on functional outcomes and revision rates using a multivariate model that adjusted for surgeon experience, patient demographics (age, sex, comorbidities), whether the patella was resurfaced, the use of cemented versus cementless technique, the surgical approach, the type of bearing surface, and hospital factors (ventilation in the operating room and public versus private hospital).
At 6 months, it appeared there might be an advantage to computer navigation: Oxford knee scores were higher on univariate analysis (39.0 vs. 38.1, P=0.006). But on multivariate analysis, the perceived advantage was not found to be statistically significant (P=0.54).
At 5 years, the difference in mean Oxford scores disappeared (42.2 vs. 42.0, P=0.76), and at most recent follow-up, there was no difference in revision rate between the 2 groups (0.46 vs. 0.43 revisions per 100 component years, P=0.8).
The investigators concluded that, “in this comprehensive analysis … the use of computer navigation did not improve functional outcomes following TKA. At current follow up, any benefit to implant durability from improved component alignment with navigation is yet to be demonstrated.”
Young SW, Roberts T, Frampton C, Clatworthy M. Does Computer Navigation Improve Functional Outcomes After Total Knee Replacement? (ePoster 1430) Presented at the 2015 ISAKOS Biennial Congress, June 7-11, 2015, in Lyon, France.