An Experimental Study of iAssist Total Knee Arthroplasty Technique
Vanniar Senthur Rajendren, Cheng Yu Huang, Mujtaba Ansari, Umair Masood, Li Ming Wang*
Nanjing First Hospital (Affiliated Hospital of Nanjing Medical University), Han Zhong Road, Nanjing Medical University, 210021, Nanjing, Jiangsu, China
Zimmer® iAssist is an accelerometer and gyroscope-based system, which is as accurate as computer-assisted systems and other optical navigation systems in achieving a neutral mechanical axis. It has better functional outcomes when compared with conventional systems. In this paper, we experimented on a 3D printed model to determine the accuracy of the iAssist system and also checked how the system responded in determining the mechanical axis when the guides were not positioned properly. In our experiment, the iAssist system produced acceptable and consistent results when its guides were positioned properly and when it was improperly positioned, the results were more skewed, which would result in valgus or varus deformity depending on the position of the guide. The iAssist system depends on the surgeon to input accurate data and proper positioning of the guides to acquire the correct mechanical axis of the knee. Even though it's not perfect, it is definitely a step in the correct direction to achieve higher accuracy associated with computer-assisted systems with the familiarity associated with conventional systems.