Journal of Aging Research health outcomes of total hip or knee replacement in subjects aged 80 years or older [25]. Reported quality of life did not diﬀer between both groups in our cohort. This is in line with the results of several studies presented in a systematic review of the literature showing that subjects who received a THR or TKR performed similar in terms of health-related quality of life, as health-and age-matched controls [26]. Self-reported health status did also not diﬀer between both groups in our cohort. There is evidence that self-reported health status improves after receiving a total joint placement in middle-aged subjects [27]. To our knowledge, this is the ﬁrst study reporting on self-reported health status in oldest old subjects with a total joint replacement compared to age-matched controls after followup of, on average, seven years. The group of participants with a total joint replacement showed a trend towards a healthier phenotype, especially in terms of cardiovascular and pulmonary diseases and attenuated mortality rate, but diﬀerences did not reach signiﬁcance. Elective surgery such as total joint replacement is preferably performed on subjects with a low number of comorbidities [28, 29]. This could explain the diﬀerence in comorbidity and survival between both groups. Oldest olds with a poor physical condition might never have reached the age of 85 years and hence, were not included in our study. If these subjects were operated on despite their lesser health status, they probably died before inclusion in the study (i.e., before they reached the age of 85 years). A limitation of the study is that no detailed informa- tion about the joint replacement surgery, such as surgical technique and prosthesis design, data from the hospital admission, and adverse events (i.e., complications) was available. The presence of a joint replacement was recorded in the study; however, the site of replacement was not consequently recorded. This data was not retrieved for al participants. Another limitation is the lack of information about the status of OA joints (i.e., radiological degree of OA) in lower extremities in both groups and the extent to which the TJR contributes to functional level. OA status can be graded based on the radiological appearance [30, 31]. However, high-grade radiological OA is a modest indication for total joint replacement since there is a poor correlation between radiological and clinical OA [5]. Furthermore, the most important factor in deciding to perform a total joint replacement is enough pain [32]. Furthermore, the average age of participants with a joint replacement was higher compared to the general average age for receiving a THR being 70 to 75 years old, and for TKR being around 70 years old [33, 34]. An explanation could be that, by retrospectively retrieving data on joint replacement, not all implants were identiﬁed. Another reason can be that a group of subjects with a joint replacement deceased before reaching the age of 85 years. To our knowledge, this is the ﬁrst study comparing an 85-year-old population who received a THR or TKR with their contemporaries who did not receive joint replace- ment surgery emphasising on physical functioning, joint complaints, and reported health status. Current literature concerning total joint replacement in the oldest old patient 5 is mostly observational, describing patient satisfaction and complications in cohorts of elderly patients who received a THR or TKR [6, 28]. Some studies compare the outcome after surgery with a cohort of younger patients [29, 35]. Several case-control studies have been published; however, controls were matched based on gender, comorbidity, and surgery type rather than based on age-matched comparison [7, 36]. Another strength of our study is that the participants are part of a large longitudinal population-based cohort study with extensive measures for functioning and health with a followup of twelve years. Future research should focus more on the growing oldest old population. Based on our study, we observed no diﬀerences in most clinical parameters in subjects aged 85 years with and without a joint replacement where those with a joint replacement walked slightly slower. Future studies should focus on gait parameters and physical functioning of the oldest old with and without joint replacement in order to further assess the impact of having a joint replacement at old age. 5. Conclusion Oldest old participants with a joint replacement walked slower and complained more of joint pain compared to those without a joint replacement of the same age. Furthermore, the groups were comparable in terms of physical functioning, activities of daily living, and quality of life. Hence, having received a total hip or knee replacement is not associated with poorer functional level and health status except for a lower walking speed in those with a joint replacement, compared to subjects without a total joint replacement, which might be due to the direct eﬀect of arthritis on gait parameters. Acknowledgments The work was supported by the Program Translational Research of the Netherlands Organization for Health Research and Development, the Leiden University Fund, and by an unrestricted grant from the Netherlands Orga- nization of Scientiﬁc Research (ZonMw), the Ministry of Health, Welfare and Sports, the Netherlands Genomics Initiative/Netherlands Organization for Scientiﬁc Research (NGI/NWO; 05040202 and 050-060-810 Netherlands Con- sortium for Healthy Aging (NCHA)), the seventh framework program MYOAGE (HEALTH-2007-2.4.5-10), and an unre- stricted grant from the Dutch Arthritis Association LRR13. References [1] A. Sona, G. Maggiani, M. Astengo et al., “Determinants of recourse to hospital treatment in the elderly,” European Journal of Public Health. In press. [2] M. Hopman-Rock, E. Odding, A. Hofman, F. W. Kraaimaat, and J. W. J. Bijlsma, “Physical and psychosocial disability in elderly subjects in relation to pain in the hip and/or knee,” Journal of Rheumatology, vol. 23, no. 6, pp. 1037–1044, 1996. [3] v. Wikman, J. Wardle, and A. Steptoe, “Quality of life and aﬀective well-being in middle-aged and older people with