1. Werner CA. U.S. Census Bureau. The older population: 2010. Washington, DC: U.S. Census Bureau;2011.
2. Berend ME, Thong AE, Faris GW, Newbern G, Pierson JL, Ritter MA. Total joint arthroplasty in the extremely elderly: hip and knee arthroplasty after entering the 89th year of life. J Arthroplasty. 2003; 18(7):817–821.
3. Pagnano MW, McLamb LA, Trousdale RT. Primary and revision total hip arthroplasty for patients 90 years of age and older. Mayo Clin Proc. 2003; 78(3):285–288.
Article
4. Pagnano MW, McLamb LA, Trousdale RT. Total knee arthroplasty for patients 90 years of age and older. Clin Orthop Relat Res. 2004; (418):179–183.
Article
5. D'Apuzzo MR, Pao AW, Novicoff WM, Browne JA. Age as an independent risk factor for postoperative morbidity and mortality after total joint arthroplasty in patients 90 years of age or older. J Arthroplasty. 2014; 29(3):477–480.
6. Vochteloo AJ, Borger van der Burg BL, Tuinebreijer WE, et al. Do clinical characteristics and outcome in nonagenarians with a hip fracture differ from younger patients? Geriatr Gerontol Int. 2013; 13(1):190–197.
Article
7. Topinkova E. Aging, disability and frailty. Ann Nutr Metab. 2008; 52:Suppl 1. 6–11.
Article
8. Lunney JR, Lynn J, Foley DJ, Lipson S, Guralnik JM. Patterns of functional decline at the end of life. JAMA. 2003; 289(18):2387–2392.
Article
9. Boyd CM, Xue QL, Simpson CF, Guralnik JM, Fried LP. Frailty, hospitalization, and progression of disability in a cohort of disabled older women. Am J Med. 2005; 118(11):1225–1231.
Article
10. Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol. 1992; 45(6):613–619.
Article
11. Hagino T, Maekawa S, Sato E, Bando K, Hamada Y. Prognosis of proximal femoral fracture in patients aged 90 years and older. J Orthop Surg (Hong Kong). 2006; 14(2):122–126.
Article
12. Kruczynski J, Gorska J, Futyma J, Zurawski R, Banach W. Results of operative treatment of hip fractures in patients over 90. Ortop Traumatol Rehabil. 2008; 10(4):338–349.
13. Intiso D, Di Rienzo F, Grimaldi G, et al. Survival and functional outcome in patients 90 years of age or older after hip fracture. Age Ageing. 2009; 38(5):619–622.
Article
14. Lin WT, Chao CM, Liu HC, Li YJ, Lee WJ, Lai CC. Shortterm outcomes of hip fractures in patients aged 90 years old and over receiving surgical intervention. PLoS One. 2015; 10(5):e0125496.
Article
15. Lee TH, Marcantonio ER, Mangione CM, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation. 1999; 100(10):1043–1049.
Article
16. Mangano DT, Browner WS, Hollenberg M, Li J, Tateo IM. Long-term cardiac prognosis following noncardiac surgery: the Study of Perioperative Ischemia Research Group. JAMA. 1992; 268(2):233–239.
Article
17. Nordstrom P, Gustafson Y, Michaelsson K, Nordstrom A. Length of hospital stay after hip fracture and short term risk of death after discharge: a total cohort study in Sweden. BMJ. 2015; 350:h696.
Article
18. Crum RM, Anthony JC, Bassett SS, Folstein MF. Population-based norms for the Mini-Mental State Examination by age and educational level. JAMA. 1993; 269(18):2386–2391.
Article
19. Ishida Y, Kawai S, Taguchi T. Factors affecting ambulatory status and survival of patients 90 years and older with hip fractures. Clin Orthop Relat Res. 2005; (436):208–215.
Article
20. Lyons AR. Clinical outcomes and treatment of hip fractures. Am J Med. 1997; 103(2A):51S–63S.
Article
21. Kadowaki M, Kono M, Nishiguchi K, Kakimaru H, Uchio Y. Mortality in patients with hip fracture aged over 90 years: a report from a progressively aging island. Arch Gerontol Geriatr. 2012; 54(2):e113–e117.
Article
22. de Luise C, Brimacombe M, Pedersen L, Sorensen HT. Chronic obstructive pulmonary disease and mortality following hip fracture: a population-based cohort study. Eur J Epidemiol. 2008; 23(2):115–122.
Article
23. Gustafson Y, Berggren D, Brannstrom B, et al. Acute confusional states in elderly patients treated for femoral neck fracture. J Am Geriatr Soc. 1988; 36(6):525–530.
Article