None listed
Conditions
Brief summary
Aseptic loosening, wear and dislocation are complications of primary total hip arthroplasty that have a high cost to society and is unpleasant for the patient to endure. New technology has enabled manufactures to improve the mechanical strength of the bearing surfaces which function well in vitro. Cross-linked polyethylene a second generation polyethylene was introduced into orthopaedic implant designs to address the problems of osteolysis, which is induced by polyethylene wear particles. These implant designs also enable the constructs to accommodate larger femoral heads which create stability and low wear rates which will decrease the amount of osteolysis (Burroughs, Hallstrom et al. 2005) and (Geller, Malchau et al. 2006). X3 'Trademark' represents the third generation of polyethylene, and has been developed in order to address the issues of reduced mechanical properties compared with second generation cross-linked polyethylene, whilst still maintaining the benefits of reduced wear rates. Hip simulator testing shows that the wear rate of X3 polyethylene is significantly less than conventional cross-linked polyethylene (McKellop, Shen et al. 2000). This reduction in wear will result in significantly less wear particles around the joint and therefore less biological reaction, less osteolysis and a lower incidence of osteolysis induced component failure. This Radiostereometry analysis (RSA) study will investigate in vivo wear, migration and performance and the results will be compared to the current standard PE liners study using RSA as the form of analysis (Rohrl, Nivbrant et al. 2005). Hypothesis to be tested Part 1: Annual volumetric wear of the of the highly cross-linked polyethylene (X3 PE) lining used with a 32mm CoCr head is no more than 0.01mm/annum. Part 2: Annual volumetric wear of the of the highly cross-linked polyethylene (X3 PE) lining used with a large (36-40mm) CoCr heads is no more than 0.01mm/annum. Part 3: Annual volumetric wear of the of the highly cross-linked polyethylene (X3 PE) lining used with a Large (36-40mm) CoCr head and thin X3 PE is no more than 0.01mm/annum.
Interventions
Patients with advanced osteoarthritis will be treated with a hip replacement that is the standard practice of the senior author. The migration of femoral head into the polyethylene liner over time will be measured by Radio stereometric analysis (RSA).
The Trident acetabular system comprises a metallic hemispherical acetabular shell, used in association with a highly cross-linked polyethylene liner (X3).. The surgery is performed by a specialist hip arthroplasty surgeon, through a posterior app
Patients with advanced osteoarthritis will be treated with a hip replacement that is the standard practice of the senior author. The migration of femoral head into the polyethylene liner over time will be measured by Radio stereometric analysis (RSA). The Trident acetabular system comprises a metallic hemispherical acetabular shell, used in association with a highly cross-linked polyethylene liner (X3).. The surgery is performed by a specialist hip arthroplasty surgeon, through a posterior approach and according to normal standards at the clinic. During surgery six one-mm tantalum markers are inserted in the plastic liner to facilitate migration measurements. This will add about 5 minutes to the 60 minute surgical procedure. Tantalum is the most biocompatible metal known. In 25 years of use no problems have ever been identified with the use of this technique. Outcomes will be measured by radiological examination and general outcome survey. The general outcome surveys will be compled at the standard follow up visits. These surveys will include the Harris hip a disease specific survey form and SF12 a general outcome survey. The forms will take approximately 20mins to fill out and the patients will be deidentified to protect their privacy The study is an interventional trial of two groups of patients. The first study cohort will include patients implanted with a standard sized 32 mm femoral head articulating with an X3 polyethylene liner. The first group of patients will have a preliminary analysis to ensure safety and efficacy of the X3 polyethylene. Once initial safety requirements have been met a second group of patients will be recruited with the largest femoral head size that permits a minimum 6mm polyethylene thickness, a 36-40 mm Cobalt Chrome (CoCr) femoral head articulating with a highly cross linked (X3) polyethylene liner.
Sponsors
David Campbell
Study design
Allocation
Non-randomised trial
Intervention model
Other
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
50 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
Patients between 50 and 80 years of age, planned for Total Hip Arthroplasty (THA) due to osteoarthritis
Exclusion criteria
Residence outside Adelaide metropolitan area, abnormal gross anatomy of hip, age above 80 years, inflammatory arthritis or severe osteoporosis
Outcome results
None listed