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

Randomised, Controlled, Prospective, Multi-Centre, Post Market Surveillance Study Comparing a Ceramic-on-Metal Bearing and a Metal-on-Metal Bearing in Subjects Requiring Primary Total Hip Arthroplasty for Non-Inflammatory Degenerative Joint Disease

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.

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.