Total hip replacement in developmental dysplasia of the hip grade IV of Crowe's classification presents some difficulties. In this study, we present our results of the treatment for this pathology, also describing the surgical techniques used and the complication we had. In this paper, 18 total hip replacements in developmental dysplasia of the hip Crowe IV were studied clinically and radiologically before and after surgery, with a mean follow-up of 4.2 years (min: 1 year). The average Harris Hip Score improved from 52 to 89. The average leg lengthening was 36 mm. When a subtrochanteric shortening osteotomy was performed, the healing occurred in all cases, in an average time of 5.3 months. At now, the implant survivorship is 100% (no revision required). The techniques and principles described in this paper allow to achieve good results in this surgery. An accurate preoperative evaluation and the availability of specific materials are also important steps. The subtrochanteric shortening is a safe procedure to avoid neurovascular injuries.