Assessment of Rotational Anatomy of Distal Femur in Sudanese Population and Its Relevance in Total Knee Arthroplasty

Background: Accurate restoration of normal knee anatomy and alignment is the main goal and objective of knee surgery.In the field of total knee arthroplasty, positioning of the implants in the axial plane is referred to as rotational alignment (Victor et al., 2009).Correct Rotational positioning of femoral and tibial components is critical in total knee arthroplasty (TKA).Failure in implant positioning may result in disproportionate tension on the ligaments, causing complications such as development of pain, stiffness, instability or early loosening of the implant (Aglietti et al., 2008).Objective: This study aims to measure the angular relationships of the distal femoral rotational axis in normal Sudanese population.Material and Methods: Magnetic resonance imaging (MRI) scans of the knees of 148 Sudanese subjects were used to define the axes and angles.114 of these subjects were males and 34 were females.The posterior condylar angle (PCA), the Whiteside-zepicondylar angle (W-EP), the condylar twist angle (CTA), and the Whiteside trochlear anteroposterior line-posterior condyle line angle (WAP/PCL) were measured.Results: The mean posterior condylar angle (PCA) is 1.69˚, the mean condylar twist angle (CTA) is 5.64˚, the mean Whiteside-epicondylar angle is 88.98˚ and the mean Whiteside trochlear anteroposterior line-posterior condyle line angle (WAP/PCL) is 4.64˚.Conclusion: This study concluded that there is a difference in the angular relationships of the distal femoral rotational axes between the Sudanese, western, Chinese, Indian, Iranian, Brazilian and Japanese.So using a fixed value to define the angular relationships between the axes and performing the cuts according to these fixed values could lead to malrotation of the femoral component.