Gait parameters in women with bilateral osteoarthritis after unilateral versus sequential bilateral total knee arthroplasty

Purpose. To compare gait parameters in women after unilateral total knee arthroplasty (TKA) versus sequential bilateral TKA to determine the need for sequential TKA. Methods. 35 women aged 60 to 74 (mean, 70) years with bilateral varus knee osteoarthritis (OA) underwent unilateral (n= 23) or sequential bilateral (n= 12) TKA by a single surgeon. All patients underwent unilateral TKA; 12 patients then underwent sequential TKA after 3 to 6 months of the first TKA. Gait parameters (step length, step width, gait velocity, single support phase value, and the maximum centre of gravity ratio) were compared before and after TKA, and between patients with unilateral versus bilateral TKA. Results. Patients with sequential bilateral TKA had more severe OA in their contralateral knee than patients with unilateral TKA. In patients with unilateral and sequential bilateral TKA respectively, the mean step width differed at postoperative one month (12.9 vs. 19.1, p< 0.01) and 3 months (11.9 vs. 16, p= 0.03), and the mean maximum centre of gravity ratio differed at postoperative 3 months (2.43 vs. 1.75, p= 0.02), whereas the mean step length, mean gait velocity, and mean single support phase values did not differ significantly between groups. Conclusion. After unilateral TKA, contralateral TKA may not be necessary in some patients whose gait has improved.