Fig. 4From: Total hip arthroplasty for failed internal fixation of femoral neck fracture: a retrospective study with 2–14 years’ follow-up of 345 patientsKaplan–Meier survival free from revision surgery after THA in Group I and Group II. Group I stands for patients who are 55 years old and younger than 55 years old, and Group II stands for patients who are older than 55 years oldBack to article page