The mid-term results of a dual offset uncemented stem for total hip arthroplasty.

The Synergy stem is a third-generation proximal in-growth, tapered titanium alloy uncemented stem, with standard and high offset versions. Two hundred ten primary hip arthroplasties were performed using the Synergy stem in 193 patients. There were 124 males and 69 females with an average age of 58 years (range, 22-85 years). The average follow-up was 75 months (range, 60-96 years). Only 1 stem has required revision, for a stem survival rate of 99.5%. The overall incidence of thigh pain was 2.8%. Intraoperative undisplaced fractures of the proximal femur occurred in 3.3% of patients and were managed at the time with wiring, with no effect on outcome. Minor osteolysis was seen proximally in 10% of patients, but no osteolysis was seen distal to the porous coating.