[1] Univ Autonoma Barcelona, GREMPAL, Res Grp, CIBERFES,IDIAP Jordi Gol, Av Gran Via Corts Catalanes 587, Barcelona 08007, Spain
[2] Inst Salud Carlos III, Av Gran Via Corts Catalanes 587, Barcelona 08007, Spain
[3] Univ Oxford, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Musculoskeletal Pharmaco & Device Epidemiol, Ctr Stat Med,Botnar Res Ctr, Windmill Rd, Oxford OX3 7LD, England
[4] Univ Autonoma Barcelona, Musculoskeletal Res Unit, IMIM Parc Salut Mar, CIBERFES, Doctor Aiguader 88, Barcelona 08003, Spain
[5] Hosp Univ La Paz, Geriatr Unit, Paseo Castellana 261, Madrid 28046, Spain
[6] Nuffield Orthoped Ctr, Traumatol & Orthopaed Unit, Windmill Rd, Oxford OX3 7HE, England
[7] Hosp Univ Rio Hortega, Calle Dulzaina 2, Valladolid 47012, Spain
[8] Hosp Reg Univ Malaga, Ave Carlos Haya S-N, Malaga 29010, Spain
[9] Hosp Univ Infanta Leonor, Geriatr Unit, Gran Via Este 80, Madrid 28031, Spain
[10] Hosp Infanta Cristina, Internal Med Unit, Ave Elvas S-N, Badajoz 06080, Spain
[11] Complejo Hosp Univ Santiago de Compostela, Traumatol & Orthopaed Unit, Rua Choupana S-N, Santiago De Compostela 15706, A Coruna, Spain
[12] Hosp Puerta Mar, Ave Ana Viya 21, Cadiz 11009, Spain
[13] Hosp Univ & Politecn La Fe, Av Fernando Abril Martorell 106, Valencia 46026, Spain
[14] Hosp Univ Reina Sofia Cordoba, Av Menendez Pidal, Cordoba 14004, Spain
[15] Corp Sanitaria Univ Parc Tauli, Parc Tauli 1, Barcelona 08208, Spain
[16] Alto Deba Hosp, Dept Orthopaed, Arrasate Mondragon, Gipuzkoa, Spain
[17] Hosp Son Llatzer, Carretera Manacor,PQ 4 Son Ferriol, Palma De Mallorca 07198, Spain
[18] Hosp Univ La Paz, Traumatol & Orthopaed Unit, Paseo Castellana 261, Madrid 28046, Spain
[19] Hosp Clin Univ Lozano Blesa, FEA Traumatol & Orthopaed Unit, Ave San Juan Bosco 15, Zaragoza 50009, Spain
[20] Hosp Clin Valencia, Av Blasco Ibanez 17, Valencia 46010, Spain
[21] Hosp Univ Severo Ochoa, Geriatr Unit, Ave Orellana S-N, Madrid 28911, Spain
[22] Univ Autonoma Barcelona, Dept Internal Med, CIBER FES ISCIII, IMIM Hosp Mar Med Res, Barcelona, Spain
[23] Hosp Univ San Agustin, Camino Heros 6, Aviles 33401, Asturias, Spain
[24] Hosp San Pedro, Calle Piqueras 98, Logrono 26006, La Rioja, Spain
[25] Hosp Univ Miguel Servet, IIS Aragon, Paseo Isabel Catolica 1-3, Zaragoza 50009, Spain
[26] Complejo Hosp Torrecardenas, Geriatr Care Unit, Calle Hermandad Donantes Sangre, Almeria 04009, Spain
[27] Hosp Univ Vall de Hebron, Passeig Vall dHebron 119-129, Barcelona 08035, Spain
[28] Hosp Univ Guadalajara, Geriatr Unit, Calle Donante Sangre S-N, Guadalajara 19002, Spain
[29] Hosp Gen Univ Elx, Bone Metab Unit, Internal Med Unit, Carrer Almazara 11, Alicante 03203, Spain
[30] Complejo Hosp Pontevedra, Av Montecelo 0, Casas Novas 36164, Pontevedra, Spain
[31] Hosp Salamanca, Geriatr Unit, Paseo San Vicente 139, Salamanca 37007, Spain
[32] Hosp Univ Getafe, Geriatr Unit, Carr Madrid Toledo,Km 12,500, Madrid 28905, Spain
[33] Univ Zaragoza, Aragon Hlth Res Inst, Dept Surg, Zaragoza, Spain
[34] Univ Autonoma Barcelona, Musculoskeletal Res Unit, IMIM Parc Salut Mar, CIBERFES, Doctor Aiguader 88, Barcelona 08003, Spain