HYBRID PRIMARY TOTAL HIP-ARTHROPLASTY - A 5 TO 9-YEAR FOLLOW-UP-STUDY

One hundred fifty-two hips were reviewed at a minimum of 5 years after hybrid primary total hip arthroplasty using uncemented porous coated acetabular components and cemented femoral stems to determine the inte rmediate term durability of this method of fixation. Five hips (3.6%) have been revised: 1 for dislocation (0.7%), 1 for cup loosening (0.7% ), and 3 for femoral loosening (2.2%). Clinical results proved to be e xtremely reliable in this series with 78% of the patients reporting no pain and 19.7% reporting slight or occasional pain. Radiographic evid ence of polyethylene wear wa evident in more than 1/2 of cups, but sig nificant osteolysis or component loosening was not commonly seen on th e cup side. On the femoral side incomplete radiolucencies were present in 31%, and focal osteolysis in 12.2%, nearly always proximally in Zo nes 1 and 7. These intermediate term results compare favorably on the femoral side and very favorably on the acetabular side to prior report ed series. These results support the continued use of this combination of fixation methods for primary arthroplasty, but polyethylene wear a nd its effects remain a concern regarding the long term performance of these arthroplasties.