Phase 3 Randomised, Prospective Study Comparing the PMMA and the Resorbable PEGT/PBT Centralizer by the Uncemented BIHAPRO Total Hip Prosthesis

For a correct placement and early fixation of an uncemented hip prosthesis, a centralizer is used. Normally, the centralizer is made of PMMA, the same material as bone cement. When a revision is needed, PMMA is difficult to remove, which is one of the reason not to use a cemented hip prosthesis. With a PMMA centralizer, still PMMA will remain in the bone and needs to be removed in case of a revision. PEGT/PBT is a reabsorbable material, which gives stability during the first month after the placement of the hip prosthesis. However, PEGT/PBT is reabsorped afterwards and, therefore, will not interfere with a revision procedure.

The goal of this study is to analyse if the PEGT/PBT is as safe as PMMA in terms of alignment, direct postoperative complications and clinical results.

Therefore, 100 patients indicated for a cementless Bihapro hip prosthesis which have signed an informed consent are included and randomised over the used centralizers using a weighted randomisation method. All patients will be treated equally. The patients are examined preoperatively, 1 day, 6 weeks, 3, 6, 12, 24 en 48 months postoperatively using an X-ray, the Harris hip score and a patient questionnaire, the Womac and SF36.