Computer navigation did not improve alignment in a lower-volume total knee practice

Abstract

The postoperative alignment of the implanted prosthesis in computer navigation TKA has been reported to be superior to that using the conventional technique. There is an assumption that the adoption of computer navigation technique can make the inexperienced or occasional TKA surgeon perform more like the expert TKA surgeon. To assess the improved accuracy in recreation of the mechanical alignment in TKA performed using computer navigation, a retrospective review of the author's experience before and after adopting computer navigation was performed. Radiographic results of 104 TKAs (52 - computer navigation, 52 - conventional technique) were reviewed. It was found that the accuracy in the postoperative radiographic alignment of the implanted prosthesis was not improved by adopting computer navigation technology as judged by (a) overall limb alignment (Case: varus 1.3°, Con trol: varus 0.3°, p=0.1); (b) femoral component alignment (Case: 90.3°, Control: 90.3°, p=0.999) and (c) tibial component alignment (Case: 89°, Control: 90°, p=0.01). The significant factors which affected the postoperative overall mechanical alignment in the current navigation series included the severity of the preoperative deformity (p=0.028), the amount of error in the execution of bone cuts (p=0.012) and the experience of the surgeon in using the computer navigation system (p=0.023).