Post total knee arthroplasty alignment of 347 consecutive obese patients receiving a fixed distal femoral cut of 6° valgus.

This study examined post-total knee arthroplasty (TKA) mechanical axis (MA), measured on hip-to-ankle radiographs, for patients with a body mass index (BMI) > 30 when a fixed 6° valgus distal femoral cut was made. A retrospective radiographic review included 347 TKAs receiving a distal femoral cut of 6° valgus. A distal femoral cut of 6° valgus successful established a neutral, ±3° MA in 86.7% of the 347 obese patients, with a slight tendency toward varus in patients with a BMI>40. A fixed cut may provide more consistent post-TKA alignment, when visualization of anatomical landmarks is made difficult by increased adipose tissue.