This study was undertaken to identify preoperative physical performance factors predictive of stair climbing ability 1 month following total knee arthroplasty (TKA).

In this prospective cohort study, we assessed a total of 84 patients (8 males and 76 females) who underwent a primary unilateral TKA. Before and 1 month after TKA, patients completed physical performance tests including stair climbing test (SCT), 6-minute walk test (6MWT), timed up and go test (TUG), isometric knee flexor and extensor strength of the surgical and nonsurgical knees.

In the bivariate analyses, the postoperative SCT-ascent had a significant positive correlation with the SCT-ascent (P=0.01), SCT-descent (P=0.01), TUG (P<0.01), preoperative age (P=0.02), and a significant negative correlation with the preoperative 6MWT (P<0.01), peak torque (PT) extensor of surgical knee (P=0.01), PT flexor of surgical knee (P=0.02), PT extensor of the nonsurgical knee (P=0.02), PT flexor of the nonsurgical knee (P=0.02). The postoperative SCT-descent had a significant positive correlation with the SCT-ascent (P=0.01), SCT-descent (P<0.01), TUG (P<0.01), preoperative age (P=0.01), and a significant negative correlation with 6MWT (P<0.01), PT extensor of surgical knee (P=0.04), PT flexor of surgical knee (P=0.03), PT extensor of the nonsurgical knee (P=0.03), PT flexor of the nonsurgical knee (P=0.03). In the linear regression analyses, the postoperative SCT-ascent had a significant positive correlation with the preoperative TUG (P<0.01), PT extensor of surgical knee (P=0.03) and the postoperative SCT-descent had a significant positive correlation with preoperative SCT-descent (P=0.01), and the age (P=0.04).

This study demonstrated that preoperative physical function influenced on postoperative stair climbing ability 1month after TKA. These results could be of importance in determining variable preoperative rehabilitation strategies to improve stair climbing ability, especially focusing on balance, endurance and strengthening exercises.