[1] Reinier de Graaf Grp, Dept Orthoped Surg, Reinier de Graafweg 3-11, NL-2625 AD Delft, Netherlands
[2] Ctr Orthoped Surg OCON, Geerdinksweg 141, NL-7555 DL Hengelo, Netherlands
[3] Univ Med Ctr Rotterdam, Erasmus MC, Dept Surg Traumatol, S Gravendijkwal 230, NL-3015 CE Rotterdam, Netherlands
[4] Vrije Univ Amsterdam, Med Ctr, Dept Internal Med, Sect Gerontol & Geriatr, De Boelelaan 1117, NL-1007 MB Amsterdam, Netherlands
[5] Leiden Univ, Med Ctr, Dept Orthoped Surg, Albinusdreef 2, NL-2333 ZA Leiden, Netherlands