Femoral component failure in hybrid total knee arthroplasty

From 1986 to 1991, 74 consecutive hybrid total knee arthroplasties tin 65 p atients) of a single design were performed at the authors' institution. Sev en patients (eight knees) died with well functioning replacements during th e surveillance period. One patient refused to participate in any followup e fforts because of billing disputes. This left 65 total knee arthroplasties (57 patients) for review There were 35 men and 22 women with an average age of 60 Sears (range, 27-83 years) at the time of arthroplasty. The underlyi ng diagnosis was osteoarthritis in 46 knees, rheumatoid arthritis in six kn ees, and other in four knees. The average length of followup was 7.4 years (range, 5-10 Sears), and no patients were lost to followup. The Knee Societ y scores improved from an average of 37 preoperatively to 84 at latest foll owup. The functional score improved from 49 to 69 at latest followup. Ten ( 13.8%) knees required revision surgery. Eight of the nine knees that were r evised had femoral component problems, including a loose component in six a nd a fractured component in two. One knee mas revised for polyethylene wear with secondary osteolysis and one was revised elsewhere in which the opera tive details are unknown. The implant survival to revision at 5 years was 8 9% and 85% at final followup. Femoral component fixation in hybrid total kn ee arthroplasty is unreliable with this component design. In light of the e xcellent 10- to 15- year results of cemented condylar knee designs it is th ought that hybrid fixation should he abandoned.