2 In the present study, we compared a group of oldest old subjects with and without a total hip or knee replacement in their history. Since surgery is performed preferably on healthy subjects and based on the aforementioned positive eﬀects of total joint replacement, we hypothesized that the group with total joint replacement would show better results on physical functioning, daily living activities, joint complaints, and quality of life. 2. Methods 2.1. Participants. All data originate from the Leiden 85- plus Study, a community-based prospective follow-up study of inhabitants of the city of Leiden, the Netherlands. All participants were included at the age of 85 years. There were no exclusion criteria. Follow-up visits were performed annually. Enrolment of the study took place between 1997 and 1999 [11]. A total of 599 persons participated in the study, 87% of all eligible inhabitants. The Medical Ethical Committee of the Leiden University Medical Center approved the study. Informed consent was obtained from all participants. 2.2. Total Joint Replacement. In order to determine whether participants had received an elective THR or TKR, medical history concerning total joint replacement was obtained from the hospital charts and from information provided by general practitioners and nursing home physicians. 2.3. Participant Characteristics. Physical functioning was assessed at the participant’s home, by the following items: if a participant was able to stand up and walk, gait speed, a ﬁve times stand-up test, hand grip strength, and a physical activity score. The ability to stand up and to walk was recorded dichotomously. Gait speed was determined by using the six meter walking test [12]. Use of a walking aid was allowed. Gait speed was calculated using distance in meters and time in seconds (m/s). In the ﬁve times stand- up test participants were asked to stand up ﬁve times in a row, from sitting. Time was recorded in seconds. Hand grip strength, as a proxy of muscle strength, was measured with a Jamar hand dynamometer (Sammons Preston Inc. Bolingbrook, IL). Participants were asked to stand up and hold the dynamometer in the dominant hand. After one trial, participants were asked to squeeze three times. The maximum measurement was recorded in kilograms (kg). To calculate the physical activity score (PAS), four items from the Time Spending Pattern questionnaire were selected to constitute physical exercise above routine daily physical activity [13]: (a) walking for fun, (b) cycling for fun, (c) exercise alone or in groups or other physical activity, and (d) working in the garden. Each item was scored from 0 (no activity) to 3 (daily activity), and their sum score made up the Physical Activity Score (PAS). Activities of daily living were measured using the Gronin- gen Activity Restriction Scale (GARS) [14]. The GARS assesses competence in abilities in nine personal basic activ- ities of daily living (ADL) and nine instrumental activities of daily living (IADL). A summed score was calculated for Journal of Aging Research basic IADL ranging from 9, indicating ability to perform all activities without assistance or undue eﬀort, to 36 indicating disability. To assess joint complaints, participants were asked whether they experienced pain and stiﬀness of any hip or knee joint. Quality of life was assessed with the Cantril ladder [15]. This quality of life-score uses a ten-point scale ranging from 0 “worst possible life” to 9 “best possible life.” Furthermore participants were asked to qualify their health status; results were dichotomised between good and poor. 2.4. Other Characteristics of Participants. Participants’ gen- der, demographics, socioeconomic status, marital status, and education were recorded. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared. Chronic diseases identiﬁed from general practitioner and pharmacists’ records included cardiovascu- lar disease (CVD), including myocardial infarction, angina pectoris, and hypertension. Furthermore, diabetes mellitus, obstructive pulmonary disease, Parkinson’s disease and arthritis (including rheumatoid arthritis and osteoarthritis) were recorded. Numbers of prescribed medicines were recorded from pharmacists’ records. Global cognitive perfor- mance was assessed with the Mini-Mental State Examination (MMSE) [16]. Furthermore the 15-item Geriatric Depres- sion Scale (GDS-15) was used to measure depressive symp- toms [17]. This scale is developed to determine depression in the elderly and is ﬁlled in by the participants themselves. A score of six or more indicates the possible presence of depressive symptoms. Because of limited validity of the GDS- 15 in people with moderate and severe cognitive impairment, it was completed only by people with MMSE scores of more than 18. 2.5. Statistics. For continuous data means with standard deviations and for non-Gaussian data medians with inter- quartile ranges were calculated. Diﬀerences between the two groups were calculated using the t-test when data was continuous, Mann-Whitney-U test for nonparametric data, and chi-square test when data was dichotomous. Linear or logistic regression was performed to adjust for gender. Nonparametric data was log transformed in order to obtain a normal distribution. Patient survival was analysed using the Kaplan-Meier method. Cox regression analysis was used to compute a hazard ratio comparing subjects with a THR or TKR with subjects without a joint replacement. P values less than 0.05 were considered to be signiﬁcant. All statistical analyses were performed using SPSS for Win- dows (SPSS Inc, Chicago), version 17. 3. Results From the 599 participants, 38 (6.3%) were identiﬁed with 49 total joint replacements: 29 total hip replacements (THR) and 20 total knee replacement (TKR). The mean age of the subjects during their ﬁrst primary joint replacement was 78.2 (SD 4.7) years. Characteristics of participants at 85 years are shown in Table 1. The prevalence of comorbidities