Dislocation of posteriorly stabilized total knee arthroplasties.

Two cases of dislocation of an Insall-Burnstein II knee are reported. They occurred when a rotational force was applied to the loaded knee positioned in extreme flexion. Both dislocations were reduced closed and were found to be stable in the reduced position. The patients did well, and revision surgery was not required. No case of dislocation of this particular posterior stabilized total knee system has been reported previously.