Factors characterizing gait performance of patients before and soon after knee arthroplasty.

[Purpose] For monitoring patients with knee osteoarthritis undergoing knee arthroplasty, the Timed Up and Go and maximum walking speed tests are commonly used. To provide appropriate peri-surgical rehabilitation, we evaluated the factors associated with postsurgical changes in Timed Up and Go and maximum walking speed results. [Participants and Methods] We enrolled 545 knee osteoarthritis patients undergoing either of the following knee arthroplasties: conventional total knee arthroplasty, minimally invasive total knee arthroplasty, and unicompartmental knee arthroplasty. Comfortable Timed Up and Go, maximum Timed Up and Go, and maximum walking speed were measured 2 weeks before and soon after surgery. Factors (gender, age, and surgical mode) that might influence changes in test results were evaluated by multiple regression analysis and a two-factor stratification diagram. [Results] Multiple regression analysis revealed that postsurgical changes in comfortable/maximum Timed Up and Go and maximum walking speed results were associated with age and surgical mode after adjustment for preoperative values. Two-factor diagrams showed that the older the patient, the greater was the slowdown in the Timed Up and Go test performed postoperatively. The levels of slowdown in the postoperative Timed Up and Go and maximum walking speed tests were the smallest in those who underwent conventional total knee arthroplasty, followed by those who underwent minimally invasive and unicompartmental knee arthroplasty. Among patients whose preoperative Timed Up and Go and maximum walking speed were slow, slowdown in Timed Up and Go was pronounced with age, and slowdown in maximum walking speed was higher in conventional total knee arthroplasty. [Conclusion] The changes in Timed Up and Go and maximum walking speed results 2 weeks after knee arthroplasty depended on age and surgical modes. These findings are relevant for the implementation of appropriate peri-surgical rehabilitation.