The Influence of Alignment on Midterm Outcome after Total Knee Arthroplasty in Patients With Marked Coronal Femoral Bowing

Whether the mechanical axis should be restored to neutral remains controversial when the patient has marked coronal femoral bowing. Eighty-four total knee arthroplasties were retrospectively reviewed. In the neutral-aligned group A the immediate postoperative mechanical axis of 179 ± 1° held stable (P = 0.841). The postoperative mechanical axis decreased from 176 ± 1° to 173 ± 1° (P = 0.024) in the outlier group. Progressive varus in the outlier group at follow-up was probably due implant instability and ligament imbalance as well as excessive polyethylene wear. At a mean follow-up of 75.8 months, no statistically significant difference was detected between the two groups. Long-term follow up will be needed to determine if the maintenance in radiographic results translates to better clinical outcomes.