The amount of femorotibial alignment correction through total knee arthroplasty may affect postoperative hindfoot alignment

Abstract Purpose This study was performed to investigate the relationship between the amount of femorotibial alignment correction and the amount of improvement of hindfoot alignment in total knee arthroplasty (TKA). Methods A total of 159 knees undergoing TKA in 120 patients were assessed preoperatively and at 2 weeks, 1 month, 3 months and 6 months postoperatively. Standing hindfoot alignment was evaluated using the leg‐heel angle (LHA). The amount of change in hindfoot alignment was compared between patients with severe varus knee (Group 1) and those with moderate varus, neutral or valgus knee (Group 2). Results The mean values of pre‐ and postoperative hip‐knee‐ankle (HKA) angle were −14 ± 4° and −1 ± 3° in Group 1 and −7 ± 5° and −1 ± 3° in Group 2, respectively. The differences between pre‐ and postoperative LHA were significantly larger in Group 1 than in Group 2 at 2 weeks, 1 month and 3 months postoperatively (p = 0.006, 0.001 and 0.03, respectively). At 6 months postoperatively, no differences were observed between the two groups (p = 0.31). Conclusion The amount of change in hindfoot alignment was larger in Group 1 than in Group 2 at 2 weeks, 1 month and 3 months after TKA, but there was no significant difference between the two groups at 6 months after TKA. Level of Evidence Prognostic Level II.