Varus inclination of the tibial plateau in Thai adults: a concise radiographic evaluation.

Abstract

To identify the normal inclination of the tibial plateau in Thai adults. Anteroposterior knee-to-ankle radiographs of 13 healthy Thai male (26 knees) and 11 healthy Thai female (21 knees) subjects aged 20-40 years were obtained with the x-ray beam angled 10 degrees caudally.A special splint was used for rotational control of the examined limbs. Medial proximal tibial angles (MPTA) were measured. The tibial plateau inclination (TPI) was calculated (90 degrees minus MPTA) and analyzed. The mean age of the male subjects was 27.9 +/- 2.5 years and that of the female subjects was 30.5 +/- 5.4 years (p = 0.173). There was no significant difference in TPI between the male (3.2 +/- 1.7 degrees, range 0-6 degrees) and female (2.5 +/- 2.3 degrees, range 0-7 degrees) (p = 0.207) subjects. For each gender, there was no significant difference of TPI between the right and the left knees (p = 0.656 and p = 0.386 for men and women, respectively). No correlations of TPI with age, weight, height or BMI were observed in the present study. Through a concise radiographic evaluation, the commonly reported 3 degrees of TPI can be applied in Thai subjects. In clinical use, this finding can assist the surgeons to restore the tibial plateau geometry for fracture treatments and correct the deformity during reconstructive knee surgery.