Purpose: The purpose of this study is to report clinical and radiographic results over a period of two 2 years after cementless total hip arthroplasty (THA) with fourth generation ceramic-on-ceramic articulation.
Materials and Methods: We studied 22 patients, 23 cases which were followed up for two years among 25 patients, 26 patients who underwent cementless THA with the fourth generation ceramic between April 2009 and December 2009. The average age of the patients was 55.9 years old(22 to 72 years old), and the average follow-up duration was 28 months(24 to 32 months). A clinical evaluation was performed using the Harris hip score (HHS), and radiologic evaluation was based on acetabular cups and osteolysis of the femoral stems, instability, distance, angle, and so on.
Results: HHS showed an increase, from 54 for before-surgical treatment, to 91 at the last follow-up. Inguinal pain was observed in one case, and femoral pain was observed in two cases. Stable fixation was achieved in all cases, and no instability, osteolysis, or movement of acetabular cups and femoral stems was observed.
Conclusion: Clinical and radiological short-term results for use ofthe fourth generation ceramic-on-ceramic cementless THA have favorable so far. Further follow-up study should be performed for evaluation of the long-term results.

Keywords: Hip, Total hip arthroplasty (THA), Ceramic-on-ceramic articulation, The fourth generation