Developmental dysplasia of the hip (DDH) is a common cause of secondary hip osteoarthritis. Adult patients with developmental dysplasia of the hip develop secondary osteoarthritis and end up with total hip arthroplasty (THA) at a younger age. Because of the altered anatomy of dysplastic hips, THA in these patients represents a technically demanding procedure. There are different classifications of dysplastic hips in adults. Since in the majority of the cases the diagnosis is formed based on the clinical exam and X-rays, most common classifications are based on X-rays of the pelvis and hips. The most common is classification according to the Crowe with 4 different degrees of dysplasia. Crow classification is based on two-dimensional analysis of the pelvic X-ray and on, basically, just a vertical displacement of the femoral head, it is still predominant classification due to simplicity and availability.With the development of highly accurate CT images, the 3D printing technology has provided high precision implants for surgical solutions, improving the success rate of complex and difficult surgeries. In this study, the time to weight loading in the 3D printing patients was less than that for the conventional hip replacement patients. Additionally, the postoperative Harris scores were higher in the 3D printing group. Indicating that the 3D printed prostheses are closer to patients' anatomical structures, and allow for better coordination of human biomechanics. Also, the 3D printing technology applied in hip arthroplasty speeded up the recovery of patients after surgery and improved their quality of life. Based on these results, we suggest that the 3D printing approach provides a better short-term curative effect that is more consistent with the physiological structure and anatomical characteristics of the patient, and we anticipate that its use will help improve the lives of many patients.