Normal axial angles of the knee joint in adult indigenous Malawians

Abstract

Objective: To determine the normal axial angles of the knee joint in adult indigenous Malawians. Design: A retrospective study. Setting: Radiographs were collected from the archives of the X-ray Department on subjects investigated from Queen Elizabeth Central Hospital in Blantyre City. Subjects: X-ray films of 271 adult black subjects aged 18-67 years were studied. Main outcome measures: Normal axial angles of the knee joint using standard methods were determined and compared with those reported for Caucasians previously studied. Results: The mean femoral and mechanical angles of the femur and the knee joint were greater in Malawian subjects than in Caucasians previously reported, but the tibial angle of Malawians was less than those of Caucasians. The angle between the mechanical and anatomical axes of the femur was 3° in Malawians, but 6° in Caucasians. Malawians, had wider range of the mechanical angle of the Knee joint than Caucasians. These angles did not show significant sex differences in Malawians (P>0.1;0.5, respectively) but significant differences were observed in these angles between Malawians and Caucasians (P>0.001). Conclusion: Our study has demonstrated comparative variations in means and ranges of normal axial angles between Malawians and Caucasians previously reported. Thus as a prerequisite for proper orthopaedic clinical practice in this part of the world, there is need for reference values of these angles.