Varus Inclination of the Tibial Plateau in Thai Adults: A Concise Radiographic Evaluation
Keerati Chareancholvanich MD*, Tanutum Pikulkaew MD*, Chaturong Pornrattanamaneewong MD*
Affiliation : * Department of Orthopaedic Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To identify the normal inclination of the tibial plateau in Thai adults.
Material and Method: 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° 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° minus MPTA) and analyzed.
Results : 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°, range 0-6°) and female (2.5 + 2.3°, range 0-
7°) (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.
Conclusion : Through a concise radiographic evaluation, the commonly reported 3° 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.
Keywords : Tibial plateau, Medial proximal tibial angle, Thai
