Navigation-assisted vs Non-navigation-assisted Total Knee Replacement in Obese Patients: A Comparative Randomized Study

Background: Obesity has also been recognized as the most important modifiable risk factor for osteoarthritis.Total knee replacement (TKR) in obese patients presents additional challenges with increased risk of component malpositioning and component loosening.Navigation in TKR results in accurate alignment, titrated soft tissue balancing, reduced blood loss, early rehabilitation, and reduced chances of embolism by not entering the intramedullary space.Whether it actually improves outcomes and reduces complications in obese was the research question of our study.Materials and methods: It was a prospective randomized comparative observational study conducted at our institute between December 2017 and March 2019.Obese patients between ages 50 and 75 years undergoing primary TKR for osteoarthritis were included in the study after an internal review board approval and after prior informed consent.A hundred knees in obese patients [Body mass index (BMI) > 30 kg/m 2 )] with varus deformation undergoing TKR were randomized into a navigated group (NG, n = 50) and a non-navigated group (NNG, n = 50).Results: Patients were followed for a minimum of 2 years.The average follow-up was 4.6 years (2-6.5 years).Two of the patients (four knees) in NG were lost to follow-up and three of the patients (6 knees) had died in the NNG leaving us with a total of 46 knees in NG and 44 knees in NNG at final follow-up.The NG showed better outcomes in terms of alignment, component positioning, range of motion (ROM), deformity correction, blood loss, return to activity, and complications.Conclusion: Computer navigation-assisted TKR significantly improves alignment with marginal functional improvement and reduces perioperative complications in obese patients.