Clinical and Radiologic Outcomes of Contemporary 3 Techniques of TKA

This report compares the radiologic and early clinical results of total knee arthroplasty (TKA) performed by the same surgeon using 3 techniques. In this prospective study, 75 knees were randomized to conventional technique (25 knees), image-free navigation system (25 knees), or minimally invasive surgery (MIS) (25 knees). Age range of the 43 women (65 knees) and 5 men (10 knees) was 58 to 81 years. Posterior stabilized knee prosthesis was used in all patients. Data was collected according to Knee Society System for radiologic evaluation of x-rays. Knee Society clinical (KS-C) and functional knee scores were measured preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2 years. The postoperative KS-C was not statistically better in the MIS group (mean, 88 +/- 11.5; range, 70-100) than the conventional (mean, 85.9 +/- 7.8; range, 74-94) (P=.68) or navigation group (mean, 85 +/- 11; range, 63-100) (P=.59). Mean postoperative delta (mechanical axis) angle was significantly different (P=.014): 2.38 degrees in the conventional group (SD=2.88 degrees, 95% CI, 1.19 degrees-3.57 degrees; range, -1.59 degrees to 6.86 degrees), 0.61 degrees in the navigation group (SD=2.07 degrees; 95% CI, -0.24 degrees to 1.46 degrees; range, -2.07 degrees to 4.25 degrees), and 4.25 degrees in the MIS group (SD=6.52 degrees; 95% CI, 1.56 degrees-6.94 degrees; range, -6.72 degrees to 15.60 degrees). Significant difference could be elicited between navigation-assisted and MIS groups, with navigation-assisted surgery providing more accurate alignment of the mechanical axis (P=.014). Of the three techniques, navigation-assisted surgery gives superior prosthesis alignment and promising longevity of TKA.