Complete 180-Degree Dislocation of a Rotating Platform after Closed Reduction for Mobile Bearing Spinout.

Rotating-platform total knee arthroplasty was designed to help decrease backside polyethylene wear and allow maximal conformity between the femoral and tibial components, but there have been multiple reports of dislocation and spinout of these implants. There are 4 case reports in the literature of knee dislocations with 180° rotation of the platform, 3 of which occurred during relocation attempts. This is only the second case in a posterior-stabilized mobile-bearing device. We present a case of complete 180° dislocation of a rotating platform after closed reduction in a posterior-stabilized total knee arthroplasty, with subsequent conversion to hinge knee arthroplasty.