1. Oulu University Hospital, PL
21, 90029 OYS, Oulu, Finland.
2. Coxa Hospital for Joint Replacement, PL
652, 33101 Tampere, Finland.
3. Southmead Hospital, Southmead
Road, Westbury-on-Trym, Bristol
BS10 5NB, UK.
4. Turku University Hospital, PL52, 20521
Turku, Finland.