a randomised study to compare metal ion release and long-term performance of the pinnacle™ cup with a ceramic-on-metal or a metal-on-metal bearing

Conditions: Osteoarthritis; Post-traumatic Arthritis; Collagen Disorders; Avascular Necrosis; Congenital Hip Dysplasia; Slipped Capital Femoral Epiphysis

Summary: the purpose of this study is to monitor the performance and compare the metal ion release of two bearing combinations, ceramic-on-metal and metal-on-metal in the treatment of patients with hip joint disease requiring a total hip replacement. patients who enter the study will be randomly allocated to one of the bearing combinations and will be evaluated at regular intervals using, patient, clinical and x-ray assessments. patients will also have blood samples taken at regular intervals to allow the metal ion levels to be determined.


Eligibility criteria:
inclusion criteria: * skeletally mature male or female subjects, aged between 20 and 75 years inclusive at the time of surgery. * subjects who are able to give voluntary, written informed consent to participate in this investigation and from whom consent has been obtained. * subjects who, in the opinion of the investigator, are able to understand this investigation co-operate with the investigational procedures and are willing to return to the hospital for all the required post-operative follow-ups. * subjects undergoing unilateral primary total hip replacement who are suitable for a cementless acetabular component and whose femoral and acetabular bone stock is suitable to receive implants, without the requirement for a bone graft. * subjects with radiographic evidence and primary diagnosis of non-inflammatory degenerative joint disease (nidjd). * subjects with a pre-operative harris hip score of less than or equal to 70 and a pain rating of at least moderate for the operative hip. exclusion criteria: * subjects who, in the opinion of the investigator, have an existing condition, such as active infections, highly communicable diseases, neurological or musculoskeletal disorders that might affect weight-bearing and metastatic or neoplastic disease, that would compromise their participation and follow-up in this study. * subjects who currently have other metallic foreign bodies including trauma products and joint arthroplasties, unless known to be titanium alloy only. * patients who have received a total hip arthroplasty in the contralateral hip within the previous 12 months unless known to be titanium alloy only. * subjects who have undergone previous hip surgery on the operative hip (including previous hip/surface replacements, resection arthroplasty or surgical fusion of the hip). * subjects requiring a simultaneous bilateral hip operation. * subjects who, in the opinion of the investigator, will possibly require a separate joint replacement operation within the next two years, including revision operations. * subjects with an acute femoral neck fracture of the operative hip. * subjects who have undergone above knee amputation of the contralateral and/or ipsilateral leg. * subjects with compromised renal function. * subjects with a known allergy to metal (eg, jewellery). * subjects with an occupational exposure to cobalt, chromium, molybdenum, titanium or nickel. * subjects who have ingested medication or vitamins containing cobalt, chromium, molybdenum, titanium or nickel within the last 12 months, or intend to ingest such substances over the next 2 years. * subjects who have undergone systemic steroid therapy, excluding inhalers, in the three months prior to surgery. * women who are pregnant. * subjects who are prisoners, known drug or alcohol abusers or with psychological disorders that could affect follow-up care or treatment outcomes. * subjects who have participated in a clinical study with an investigational product in the last 12 months. * subjects who are currently involved in any injury litigation claims.

Keywords: hip cementless ceramic-on-metal metal-on-metal