Measurement of the Posterior Condylar Angle in Koreans : Comparison between Three Dimensional Computed Tomography Study and Magnetic Resonance Imaging Study

ABSTRACT

PURPOSE: This study is to measure the posterior condylar angle (the angle between the femoral epicondylar axis and the femoral posterior condylar axis) which is commonly used for determining the degree of femoral component rotation during total knee replacement with magnetic resonance imaging (MRI) and three dimensional computed tomography (3D CT) and to assess the difference of this angle in Koreans. MATERIALS AND METHODS: We examined the 257 knee MRIs and 118 knee 3D CTs. And we measured the clinical posterior condylar angle in MRIs, and the clinical and surgical posterior condylar angle in 3D CTs. RESULTS: The clinical posterior condylar angle on MRI was male, 5.56degrees and female, 5.81degrees (mean, 5.66degrees). The clinical posterior condylar angle was male, 5.48degrees and female, 5.85degrees (mean, 5.55degrees), and the surgical posterior condylar angle was male, 3.68degrees and female, 4.02degrees (mean 3.74degrees) on 3D CT. There was no statistical difference in clinical posterior condylar angle between MRI and 3D CT (p>0.05) and between male and female(p>0.05). CONCLUSION: There was no difference in clinical posterior condylar angle between MRI and 3D CT. We suggest that 3degrees external rotation of femoral component from posterior condylar axis may not be enough in Koreans during total knee replacement.