Short summary

Total hip replacement (THR) is a common and well-documented treatment for patient with severe hip osteoarthritis.  Long-term survival of the prosthesis is an important factor in ensuring the best possible outcome for patients. Prosthetic loosening is the primary course (55%) of revision surgery.

Increasing evidence suggests that the combined effects of wear of the prosthetic liner (the plastic insert between femoral head and pelvis joint socket) and continuous migration of the prosthesis play a vital role in the prosthetic loosening and hence the survival of prosthesis.  A new liner material enriched with vitamin E has shown to increase the resistance to wear in laboratory studies. However, no studies have yet investigated the wear of this new type of liner material in a clinical trial with patients.

Rationale

The primary purpose of this project is to investigate the wear properties of the new prosthetic liner enriched with vitamin E compared with the conventional liner, evaluated with RSA (radiostereometric analysis). 

Secondly we want to investigate how:

• The different head sizes affect the migration of the prosthetic component inserted into the pelvis with RSA.
• The use of different femoral size reflects on patient-reported outcome measures(EQ5D, HHS (Harris Hip point), SF-36, UCLA).

The properties of the new vitamin E enriched liner is particularly important to investigate before chancing the standard praxis at the hospitals to ensure a safe and optimal treatment of all patients. Thus, if it is possible to enhance the wear resistance of the liner enriched with vitamin E, then it will improve the longevity of the prostheses and thereby optimize the THR treatment for patient. This will be of great benefit for the patients' quality of life and the general social economics.

Description of the cohort

Patients with severe OA and indication for THR were randomized to either receive a vitamin E enriched liner or a conventional liner. The study has now included over 100 patients and later next year we will finish collecting 5 years data. Comprehensive investigations will be performed at Odense University.

Data and biological material

• Data from the participating patients with THA operations will be collected
• Data from RSA examinations will be collected from post operatively, 12 weeks, 1 year, 2 year and 5 years examinations. 
• Data from patient-reported outcome measures (EQ5D, HHS (Harris Hip point), SF-36, UCLA) at pre-operatively, 12 weeks, - 1 year, - 3 years, and 5 years postoperatively, will be collected and entered into OPEN data base

Collaborating researchers and departments

Odense University Hospital

• Head of Orthopedic Research Unit, Professor Søren Overgaard

Institute of Clinical Research, University of Southern Denmark

Massachusetts General Hospital, Harvard Medical School, USA