Two-stage conversion of fused knee to total knee arthroplasty.

We report 2 cases of conversion of fused knee to total knee arthroplasty (TKA) by way of soft-tissue expansion. Case 1 had had multiple operations on the infected total knee, which was arthrodesed 7 months before conversion. Case 2 had had knee arthrodesis for an intra-articular comminuted fracture 5 years and 10 months before conversion. In both patients, a tissue expander was placed subcutaneously upon the patella and the patellar tendon to gradually expand the anterior knee skin for later coverage and knee flexion. After takedown of the arthrodesis, a fully constrained rotating-hinge prosthesis was implanted as the second-stage procedure. The final range of flexion was 95 degrees in both knees with patients' subjective satisfaction.