Impingement is a cause of poor outcomes of prosthetic hip arthroplasty; it
can lead to instability, accelerated wear, and unexplained pain.
Impingement is influenced by prosthetic design, component position,
biomechanical factors, and patient variables.
Evidence linking impingement to dislocation and accelerated wear comes from
implant retrieval studies.
Operative principles that maximize an impingement-free range of motion
include correct combined acetabular and femoral anteversion and an optimal
Operative techniques for preventing impingement include medialization of
the cup to avoid component impingement and restoration of hip offset and
length to avoid osseous impingement.