A
Decreases the abductor lever arm
B
Increases the abductor lever arm and decreases joint reactive forces
C
Increases the risk of bony impingement
D
Decreases the tension on the soft tissues, increasing dislocation risk
Explanation:The correct option is 'b'. Femoral offset is the horizontal distance from the center of rotation of the femoral head to the anatomical axis of the femur. Restoring or slightly increasing offset increases the abductor muscle lever arm, which improves abductor strength and paradoxically decreases the joint reactive forces across the hip, while also improving soft tissue tension.
Reference: McGrath MS, et al. The effect of femoral offset on kinematics and kinetics of total hip arthroplasty. J Arthroplasty. 2001;16(8):107-111.