Background The incidence of total hip replacement in the younger and more active patients is ever increasing.The ceramic-on-ceramic (COC) bearing was developed to reduce wear debris-induced osteolysis and loosening and to improve the longevity of hip arthroplasties.Few studies have reported the clinical results and complications of the new zirconia-toughened ceramic total hip arthroplasty (THA).Methods A consecutive series of 132 young patients (177 hips) that underwent primary cementless THAs between January 2010 and December 2012 were included in this study.These arthroplasties all had fourth-generation COC bearings performed through a posterolateral approach.The average age was (41.8±8.3) years (ranging from 22 to 55 years),and the mean follow-up period was (24.5±9.4) months (ranging from 12 to 47 months).The results were evaluated both clinically and radiographically.Harris hip score (HHS) was determined before surgery and at the time of each follow-up.Presence of postoperative groin or thigh pain and squeaking were recorded.Other complications such as dislocations,periprosthetic fractures,and ceramic components fractures were diagnosed and treated in emergency.Results The average HHSs improved from preoperative 60.3±10.7 (ranging from 29 to 76) to 91.0±5.1 (ranging from 74 to 100) at the final follow-up (t=-45.064,P ＜0.05),and 97.7％ of cases were scored as excellent and good results.At the last follow-up,incidental inguinal pain was found in three hips (1.7％) and thigh pain in 11 hips (6.2％).Radiographs showed a high rate of new bone formation around the acetabular and stem components.No obvious osteolysis or prosthesis loosening was detected.Complications occurred in six hips (3.4％):posterior dislocation in two hips (1.1％),periprosthetic femoral fracture in one hip (0.6％),asymptomatic squeaking in two hips (1.1％),and ceramic liner fracture in one hip (0.6％).Conclusions The fourth-generation COC THA showed excellent clinical results in younger active patients with no osteolysis-related prosthesis failure at a short-term follow-up study.Surgeons should still be aware of the potential risks of complications such as dislocation,periprosthetic fracture,squeaking,and ceramic components fracture.