Comparing inter- and intraobserver reliability between two-dimensional and three-dimensional measurements in the tibial component position of unicompartmental knee arthroplasty.

In unicompartmental knee arthroplasty (UKA), the tibial component has a small coronal plane width, the tibia and tibial component rotations are mismatched, and the large tibial component posterior tilt may make accurate measurements of component positions difficult in radiography. The study aimed to assess the intra- and interobserver reliabilities of radiographic (2D) and 3D computed tomography (3D-CT) measurements and to determine the minimum detectable change (95% confidence level, MDC95) in the tibial component position measurements in UKA. The study included 23 females and 7 males.