Abstract
Total knee arthroplasty (TKA) has shown to portend good long-term survivorship and
excellent patient satisfaction. There are various etiologies of failure of a TKA.
Instability is a major cause of the need for revision. Often, increased constraint
is needed to supplement or perform the function of incompetent ligament and soft tissue
structures. Posterior cruciate retaining (PCR) TKA has the least constraint. Posterior
cruciate substituting (PS) TKA increases sagittal constraint. Varus–valgus constraint
(VVC) adds a marked increase in coronal stability. The ultimate in constraint in TKA
is a linked hinged implant. In revision TKA, it is the surgeon's responsibility to
implant the prosthesis with the necessary constraint to impart adequate stability.
Keywords
knee - arthroplasty - instability - revision