Acetabular component positioning in total hip arthroplasty with and without a computer-assisted system: a prospective, randomised and controlled study

In a prospective and randomised study of the acetabular component position in total hip arthroplasty, 20 hips were operated using imageless navigation and 20 hips were operated using the conventional method. The same surgeon performed all the operations with the patient in the lateral position. The correct position of the acetabular component was evaluated with computed tomography performed after the surgeries, measuring the operative anteversion angle and the operative inclination angle and determining the cases inside the safe zone. The results were similar in all the analyses: a mean anteversion of 17.4o in the navigated group and 14.5o in the conventional group (p=0.215), a mean inclination of 41.7o in the navigated group and 42.2o in the conventional group (p=0.633), a mean deviation from the desired anteversion (15o) of 5.5o in the navigated group and 6.6o in the conventional group (p=0.429), a mean deviation from the desired inclination (40o) of 3o in the navigated group and 3.2o in the conventional group (p=0.783), and location inside the safe zone of 90% in the navigated group and 80% in the conventional group (p=0.661). The acetabular component positions tomography analyses in total hip arthroplasty, performed with the patient in the lateral position, were similar whether using imageless navigation or performing it conventionally.