Axial radiography of the normal distal femur for assessment of rotational alignment in Thai.

BACKGROUND It is crucial to recognize and understand anatomical features of the distal femoral condyles especially for orthopedists that take care of the elderly patient with leg deformity. OBJECTIVE Evaluate the rotational alignment of the distal femur by using axial radiographic technique. MATERIAL AND METHOD Thirty-six normal volunteers (72 knees) were enrolled in the present study. Mean age was 39.47 years (range 20 to 57). Axes for rotational alignment of distal femur were outlined including posterior condylar (PC), anteroposterior (AP), anatomical epicondylar line (AEpi), and then angle between each pair of the axes were measured in the medial side including anteroposterior/posterior condylar (AP-PC) angle, anteroposterior/anatomical epicondylar (AP-AEpi) angle, and anatomical epicondylar/posterior condylar (AEpi-PC) angle. Gender and side were compared to each other Pearson correlation was calculated between age and all angles. RESULTS Average AP-PC angle was 95.75 +/- 1.79 degrees. Average AEpi-PC angle was 6.77 +/- 1.97 degrees. Average AP-AEpi angle was 89.81 +/- 1.86 degrees. Results showed no statistically significant difference between side, gender and age. Intraobserver ICC were 0.6 to 0.92 and interobserver ICC were 0.68 to 0.87. CONCLUSION The axial radiographic technique is reliable. The results of the present study are comparable with a previous study using the computerized tomography (CT) technique.