Estudio de la concordancia de un sistema de planificación preoperatoria digital en artroplastia total de cadera

Objective: Check the agreement of a preoperative digital templating, compared with the final result in the postoperative radiograph. Material and method: The study was carried out on a 55 total hip prosthesis. A templating-software Neteous® (Socincer®, Gijón, Spain) was used. Agreement was measured using the Kappa Index for the stem offset or Lin Index for others variables: stem size, cup size, femoral neck length, and the distance from the center of rotation of the femoral head to the lesser trochanter. The percentage of accurate hits was also described. Results: Stem size: The exact success or error of only one size was of 61.6%. Quantitatively the Lin Index was 0.64 (substantial). Horizontal offset: satisfactory agreement was obtained (Kappa index of 0.75). In 6 cases (10.90%) was changed to lateralized during surgery, for more joint stability. Size of the cup: the agreement obtained was 0.67 (substantial) with a hit grade of 43.6%. Prosthetic neck length: the exact hit or error of only one size were found in 50.9%, moderate level of agreement. Distance from the center of rotation to the lesser trochanter: was observed for almost perfect agreement with Lin Index of 0.95. The exact percentage of hits or gap error less than 5. mm was 74.5%. Discussion and conclusion: In ours hands, the preoperative templating software analyzed, has provided acceptable agreement rates, when compared with the postoperative result. But it takes more works verified by independent observers.