Midterm functional outcomes of imageless navigation-assisted total knee arthroplasty

Purpose: The study aims to evaluate the functional outcomes of imageless navigation-assisted total knee arthroplasty (TKA) after a minimum follow-up of 7 years. Materials and Methods: Between December 2004 and December 2009, a total of 123 navigation-assisted TKAs in 94 patients were performed by the same surgeon at a single institution. Hospital for Special Surgery (HSS) knee score was recorded pre- and post-operatively, and radiographic assessment for osteolysis, wear, or loosening was performed in all patients. Results: No conversion from navigation-assisted to conventional technique was required in any patient. The mean pre- and post-operative HSS score was 60.3 and 86.8, respectively. None of the patients was lost to follow-up. The survivorship of all knees at an average of 9.5 years after surgery was 99.3%. One patient required revision due to deep infection. There were no pin tracker-related complications. Conclusions: Navigation-assisted TKA produces good clinical outcomes comparable to conventional TKA. Further studies are required to assess long-term functional outcomes.