Preliminary report with the Regenerex™ revision shell: clinical, functional, and radiologic evaluations with a mean follow-up of 25 months

Background Acetabular cup loosening is the primary reason of revision in total hip arthroplasty; this usually occurs as a result of implant fixation failure. There are a variety of surgical hardware and strategies available to address this problem that is one of the most challenging circumstances in hip surgery. The purpose of this prospective nonrandomized study is to present our prelim- inary results in the Ist Orthopaedic and Traumatology Unit of Pisa University with Regenerex™ revision shell. Methods Regenerex™ revision shell is a porous titanium construct optimized for vascularized osteogenesis and designed to accept a cemented all-poly cup. If the bone defects were less than GIR IV or Paprosky type III, the Regenerex™ revision shell was consecutively used, and at the end of December 2011, this shell was placed in 33 patients. In this study, we identified 28 cases with a mini- mum follow-up of 12 months; the mean interval from sur- gery to evaluation was 25 months; we performed clinical, functional, and radiologic evaluations. Results The mean Harris hip score was >83 while the mean Western Ontario and McMaster Universities Osteoarthritis Index score was >75. In five cases, postoperative radiolucent lines were present. No signs of osteolysis were noted around the screws, and none of the 28 cups was thought to be loose. Conclusions This preliminary report is to our knowledge the first one to be published about clinical and radiological results on Regenerex™ revision shell. Our results are prom- ising, but we need further investigations in order to obtain more data about this material in revision surgery.