Does sagittal alignment of the femoral component have an impact on radiological loosening and functional results in revision knee arthroplasty?

In this study, we aimed to investigate the effect of sagittal alignment of the femoral component on both radiological loosening and functional results in revision total knee arthroplasty (rTKA), as well as the anterior condylar offset (ACO) and posterior condylar offset (PCO). Between December 2005 and November 2020, a total of 47 patients (12 males, 35 females; mean age: of 67.1±8.4 years; range, 52 to 90 years) who underwent rTKA due to aseptic prosthesis failure were retrospectively analyzed. Demographic data including age, sex, body mass index (BMI), and clinical outcomes of the patients were recorded. Early postoperative sagittal alignment of the femoral component, ACO, and PCO were measured. Radiological loosening of patients was evaluated using the modified Knee Society Score, while the functional outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS). The mean follow-up was 55.4±28.0 (range, 24 to 142) months. While there was a moderate and inverse correlation between the sagittal alignment of the femoral component and ACO (p=0.002), there was no significant correlation between the sagittal alignment of the femoral component and PCO (p=0.980). There was a weak and inverse correlation between BMI and KOOS (p=0.024). There was no significant relationship between the sagittal alignment of the femoral component, ACO, PCO, age, and sex with radiological loosening (p=0.241) or KOOS (p=0.894). In rTKA, sagittal alignment of the femoral component does not affect radiological loosening and functional results. The sagittal alignment of the femoral component exhibits a moderate and inverse correlation with ACO, while it has no significant correlation with PCO.