Dg. Eckhoff et al., MALROTATION ASSOCIATED WITH IMPLANT ALIGNMENT TECHNIQUE IN TOTAL KNEEARTHROPLASTY, Clinical orthopaedics and related research, (321), 1995, pp. 28-31
This study documents the malrotation between the femoral and tibial co
mponents associated with contemporary alignment techniques that positi
on the tibial component relative to the tubercle, posterior tibial con
dyles, transtibial axis, and malleoli, The technique that allows the t
ibial component to float into alignment as the knee is passed through
a range of motion and the technique of coupling the tibial component t
o the femoral component also were assessed, The average external rotat
ion of the tibial component relative to the femoral component associat
ed with each alignment technique is 19 degrees (tibial tubercle), 5 de
grees (transtibial axis), 7 degrees (posttibial axis), 3 degrees (mall
eolar axis), and 14 degrees (range-of-motion technique). The coupled-c
omponent technique produced 2 degrees internal rotation. The observed
tendency to externally rotate the tibial component relative to the fem
oral component with most alignment techniques may account for the high
incidence of posteromedial polyethylene wear reported in retrieval st
udies.