Jasvinder A Singh and David G Lewallen
Objective: To assess the association of post-arthroplasty dependence on walking aids with outcomes after primary TKA. Methods: We used prospectively collected Total Joint Registry data from 1993-2005 to assess the association of dependence on walking aids (some, complete) with moderate-severe pain and activity limitations 2- and 5-years after primary TKA. We used multivariable-adjusted multinomial logistic regression analyses adjusted for age, sex, Deyo-Charlson index, anxiety, depression, body mass index, income, distance to medical center, operative diagnosis, ASA class, preoperative pain and preoperative activity limitation. Results: 7,139 patients provided 2-year and 4,234 provided 5-year data. Some vs. complete dependence on walking aids post-primary TKA was common: 4.9% and 6.2% at 2-years; 6.3% and 8.2% at 5-years. Compared to no dependence on walking aids, patients with dependence on walking aids had significantly higher odds (95% confidence interval; p-value) of: (1) moderate-severe pain at 2-years, 1.96 (1.17, 3.28; p=0.01) and 1.99 at 5-years (1.14, 3.48; p<0.001), associated with some dependence; and with complete dependence, 1.94 (1.16, 3.24; p=0.012) at 2-years and 2.92 (1.73, 4.91; p<0.001) at 5-years; and (2) moderate-severe activity limitation, 9.03 (5.93, 13.80; p<0.001) and 11.25 (7.11, 17.80; p<0.001) at 5-years, with some dependence on walking aids at 2-years; and with complete dependence, 16.09 (9.45, 27.40; p<0.001) at 2-years and 13.31 (7.78, 23.20; p<0.001) at 5-years. Conclusions: Dependence on walking aids was associated with significantly higher risk of moderate-severe pain and activity limitation after primary TKA. Studies of mediators of this association can help us target modifiable factors and improve TKA outcomes.