Clinical and radiological results after implantation of the femoral neck preserving Delfi M hip prosthesis: a case series

Abstract

Various types of bone preserving total hip prostheses with a proximal force transmission concept have been developed for younger adults, one of these being the implant "Delfi M®", produced by ESKA until 2009. Since the demand could not meet the expectations, the production was stopped due to economic reasons so that only 31 implants of this type were sold and even less actually implanted. This study followed up 15 Delfi M® prostheses in 12 patients for 3.1 years and represents the only existing valid data about this implant.Demographical, preoperative and postoperative data including clinical scores (HOOS and mHHS) were collected retrospectively. Postoperative X-rays were analyzed by an independent radiologist. One implant had to be exchanged due to an infection and another one due to excessive implant migration. The mHHS and the HOOS scores showed a significant improvement after surgery. In the radiological analysis, there were no signs of radiolucent lines or osteolyses.This trial demonstrates good clinical and radiological midterm results for the Delfi M prosthesis. Limitations of this study are a small sample size and a follow-up time of 3 years at only one timepoint.