Association of Physical Activity with Late-life Mobility Limitation among Women with Total Joint Replacement for Knee or Hip Osteoarthritis.

OBJECTIVE

To examine the association between leisure-time physical activity (PA) and survival to age 85 with mobility limitation or death before age 85 after total knee (TKR) or total hip replacement (THR) for osteoarthritis (OA).

METHODS

This was a prospective study among participants from the Women's Health Initiative (WHI), recruited 1993-1998 (baseline age 65-79 yrs) and followed through 2012. Medicare claims data were linked to WHI data to determine TKR (n = 1986) and THR (n = 1034). Self-reported PA was collected before total joint replacement (TJR).

RESULTS

Women who were physically inactive before THR had the highest risk of mobility limitation at age 85 (OR 2.36, 95% CI 1.30-4.26) compared with women who had the highest amount of PA [> 17.42 metabolic equivalent of task (MET)-hrs/week]. Women who reported no moderate to vigorous PA (MVPA) before THR had the strongest risk of mobility limitation (OR 2.00, 95% CI 1.24-3.22) compared with women with the highest level of MPVA (≥ 15 MET-hrs/week). Women who were physically inactive before TKR had the highest risk of mobility limitation (OR 1.68, 95% CI 1.15-2.45) compared with women who had the highest PA level. Women who reported no MVPA before TKR had the strongest risk of mobility limitation (OR 1.60, 95% CI 1.16-2.19) compared with women with the highest level of MPVA. There were significant dose-response associations of lower PA levels with increased risk of late-life mobility limitation and death.

CONCLUSION

Women with lower PA levels before TJR were more likely to experience mobility limitation in late life following TJR for hip or knee OA.