Component stability, evidence of polyethylene wear, and patello-femoral track are carefully examined.
Four to six tissue specimens were collected from different locations: subcutaneous tissues, the hip joint, the femoral canal, screw tracks and were sent for C&S testing.
The second was to investigate the ability of carotid and femoral Doppler measurements to track the changes in cardiac index, during PLR and fluid administration.
An infrared camera was used to track the femoral and tibial reference arrays.
Malrotation of the femoral component affects patellofemoral tracking and may increase the contact pressure and lead to accelerated and excessive wear of the patellar button [ 36, 37].
It has been previously reported that alterations to the design of the P.F.C. system with a more anatomical trochlea in the femoral component improved patellar tracking.
Two methods of analysis of knee kinematics from magnetic resonance images (MRI) in vivo have been developed independently: mapping the tibiofemoral contact, and tracking the femoral condylar centre.
In knee flexion, the patella tendon was then allowed to spontaneously slide medially to track within the femoral groove.
Biomechanical studies have shown that external rotation of the femoral TKA component improves patellar tracking but does not restore it to physiologic values.
Excessive external rotation should also be avoided, as Miller et al. (2001) reported increasing tibiofemoral wear motion and worsening of patellar tracking in excessive femoral external rotation.
Furthermore, some authors suggest that only through a correctly implanted patella inlay it is possible to avoid changing patellar tracking in the femoral groove and with it the associated potential malalignment of the degenerated patella [ 1, 11- 13].
