Rotational Alignment in Total Knee Arthroplasty: A Randomized Clinical Trial of Akagi versus Sahin Tibial Referencing Techniques.

Abstract

Rotational malalignment of the tibial component in total knee arthroplasty (TKA) contributes to patello-femoral complications and functional impairment. While several anatomical landmarks have been proposed for intraoperative referencing, no single method has been universally accepted. This study compared the rotational accuracy and clinical outcomes of Akagi's line and Sahin's combined axis referencing techniques. A total of 78 patients undergoing primary TKA were randomized and prospectively allocated to two groups: Akagi (n = 40) and Sahin (n = 38). Rotational alignment was assessed postoperatively via computed tomography (CT) using the method proposed by the "Société française de la hanche et du genou (SFHG)," by two independent examiners. Clinical outcomes were evaluated preoperatively and at one and two years postoperatively using range of motion (ROM), Knee Injury and Osteoarthritis Outcome Score (KOOS), the 12-Item Short Form Survey (SF-12), and Forgotten Joint Score (FJS). Statistical comparisons were performed using appropriate parametric and non-parametric tests based on the normality of data distribution. There were no statistically significant differences observed between groups in tibial, femoral, or combined rotational alignment (P > 0.05 for all comparisons), with mean combined rotation values remaining within ± 3°, the commonly accepted safe zone. Both groups demonstrated significant improvements in KOOS, SF-12, and FJS from baseline to two years (P < 0.001), with no between-group differences in postoperative ROM or functional outcomes. Interobserver reliability for rotational measurements was high. The Akagi and Sahin techniques provided equivalent rotational alignment and clinical outcomes in TKA, supporting their use as reliable intraoperative referencing methods.