Nowadays, total hip arthroplasty (THA) is frequently performed for serious hip diseases such as osteonecrosis of the femoral head, osteoarthritis of the hip, developed dysplasia of the hip1 and failed internal fixation of femoral neck fractures. In our hospital, more than 1000 patients with hip diseases of average age 71 years (range, 45–82 years) underwent THA last year. During these elderly patients' hospitalizations, we had to face many difficulties because of comorbidities such as cardiovascular and respiratory diseases2. We have found that preoperative preparation and postoperative rehabilitation exercise are as important as the surgery itself in the elderly patients.