Revision total knee arthroplasty - How much constraint is enough?

Revision total knee arthroplasty is a complex situation that requires metic ulous technique to restore a functional outcome. The surgical objective is the same as primary total knee arthroplasty: restore the original anatomy, restore function, and provide a stable joint. To this point of stability, i t is preferable to implant the prosthesis with the least degree of constrai nt. Therefore, in the majority of patients undergoing revision surgery, a p osterior-stabilized articulation is used. However, if there is functional l oss of the medial collateral ligament or lateral collateral ligament, inabi lity to balance the flexion and extension spaces, or a severe valgus deform ity, then a constrained condylar prosthesis is necessary.