The relationship between preoperative foot alignment and postoperative outcomes in patients who underwent initial total knee arthroplasty

We compared the relationship between foot alignments and quality of life in patients who underwent initial total knee arthroplasty (TKA). Among the patients with knee osteoarthritis (KOA) who underwent TKA from May 2015 to May 2017 at our hospital, we focused on those in whom weight-bearing foot radiographs had been evaluated preoperatively. The hallux valgus angle and Meary angle were measured by preoperative radiography, and those with hallux valgus angles of 20 degrees or more were classified into the hallux valgus (HV) group, and those with Meary angles of 4 degrees or more into the high arch (HA) group. Also knee and ankle range of motion, knee pain Visual Analog Scale, and the 36-item short-form health survey (SF-36) were measured preoperatively and at discharge, and the amount of these changes was compared in the presence/absence of HV and HA. Regarding HV, there were no significant differences in any of these items between the HV and non-HV groups. However, the SF-physical function was significantly lower in the HA group than in the normal group. In addition, ankle dorsiflexion was lower in the HA group than that in the normal group, although this difference was not statistically significant. There was little improvement of the ankle dorsiflexion, and it was associated with deterioration of the physical function items of SF-36. In total knee arthroplasty patients with HA, physical therapy of the ankles and feet, as well as of the knees, was considered to enhance the improvement of physical function.