ACTIVITIES OF DEEP FLEXION IN ARABS: A KINEMATIC COMPARISION BETWEEN NORMAL AND POST TKA VOLUNTEERS

Abstract

Background. Achieving full flexion is critical for total knee arthroplasty patients in the Middle East and Asia, where activities of daily living require a full range of motion. Published kinematic data for these populations is limited. The objective of this study was to compare the normal knee kinematics of Muslim subjects with those of Muslim total knee arthroplasty (TKA) patients with high flexion arthroplasties.

Methods: An electromagnetic tracking system was used to record the motion of the lower limb segments of 14 normal Muslim subjects and 10 Muslim TKA patients. Subjects performed high flexion activities of daily living such as kneeling, Muslim prayer, sitting cross-legged and squatting.

Results. For most activities, the range of motion and maximum angles in three dimensions did not significantly differ between the normal and TKA groups. A statistically significant difference in the mean range of flexion/ extension (but not the mean maximum flexion or mean maximum extension values) was found for the prayer activity only. The majority of normal subjects exhibited an internal rotation pattern with two distinct inflection points and a parabolic abduction pattern over the range of flexion. Fewer TKA patients exhibited these patterns.

Conclusions: Overall, the range of motion and ability to perform activities of daily living did not differ between normal Muslim subjects and Muslim TKA patients with a high flexion mobile bearing total knee arthroplasty. However, patterns of internal rotation and abduction that were exhibited by the majority of normal subjects were evident in fewer TKA patients. Therefore, although the range of motion was not significantly affected by the prosthesis, the patterns of motion for some subjects may have changed.