Posterior tibial slope of the knee measured on X-rays in a Turkish population

Posterior tibial inclination of the knee joint should be considered during anterior cruciate ligament reconstruction and total knee replacement surgery. This inclination is called the posterior tibial slope (PTS) angle. The PTS differs among populations and the aim of this study was to determine the mean PTS in a Turkish population.

PTS was measured retrospectively on lateral knee X-rays (n = 1024). The angle between the line connecting the anterior and posterior points of the lateral tibial plateau and the tibial longitudinal axis was taken as the PTS angle. Intra- and inter-observer agreement regarding the measurements on 20 X-rays were checked.

The mean PTS angle for the entire cohort was 8.36 ± 3.3° (range: 2.1-18.7°); it was 8.57 ± 3.4° (range: 2.3-17.4°) in men and 8.16 ± 3.2° (range: 2.1-18.7°) in women. Although no significant correlation was detected between PTS and age, PTS was higher in men than in women.

The increasing number of total knee replacement surgeries has increased the need for studies on implant mismatch. In this study, reference PTS values were determined for a Turkish population. It may be beneficial to use patient-specific implants in some cases.