J Caton, J-L Prudhon (Lyon, France)
Introduction : To resurface or not to resurface that is the question ?
Most of the studies demonstrate a very small difference between resurfaced or not resurfaced patella, so, decision making to resurface or not the patella remains controversial.
Material And Method : When doing a total knee arthroplasty (TKA) there are 3 possibilities: no resurfacing, selective resurfacing (when?), or routinely resurfacing.
Since 1980 after some rare revisions for anterior pain after TKA, we have decided to routinely resurface the patella in order to prevent the risk of a secondary resurfacing.
But whatever is the decision, it is necessary to avoid patello-femoral joint complications.
Results : Most important complications after a TKA are: instability by mal-tracking and or malalignment, fractures, wear. Patellar component loosening are very rare, as well as soft tissue impingement (clunk syndrome) and patellar ligament rupture (increase by patella infera position or previous surgery).
Discussion : The correct choice of patellar component size (diameter and thickness) as well as implant design (dome design is our favourite shape), medial placement of the patellar component and perfect patellar height (determined by modified CATON-DESCHAMPS index) are the main concern when performing patellar resurfacing during TKA.
Some others are also necessary: to reproduce the initial thickness (never less than 15mm),to protect blood supply (no lateral release), to avoid soft tissue impingement and to maintain a normal joint line level in the coronal, frontal and rotational plane.
However correct position of the femoral (external rotation) and tibia (neutral rotation) components are essential to achieve a normal patellar tracking.