Rotational alignment of femoral component with different methods in total knee arthroplasty: a randomized, controlled trial

• Published in: BMC musculoskeletal disorders 2017-05, Vol.18 (1), p.217-217, Article 217
• Main Authors: Lee, Joon Kyu, Lee, Sahnghoon, Chun, Sae Hyung, Kim, Ki Tae, Lee, Myung Chul
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Arthroplasty, Replacement, Knee - instrumentation; Arthroplasty, Replacement, Knee - methods; Female; Femoral component rotation; Femur - diagnostic imaging; Femur - physiology; Femur - surgery; Gap technique; Humans; Male; Measured resection technique; Middle Aged; Prospective Studies; Range of Motion, Articular - physiology; Rotation; Tensor device; Tomography, X-Ray Computed - methods
• ISSN: 1471-2474; 1471-2474
• DOI: 10.1186/s12891-017-1574-5

Femoral component rotation (FCR) is one of the most important factors in total knee arthroplasty. In this prospective study, we used three different techniques for FCR and analyzed their accuracy with postoperative axial computed tomography (CT) images. We also evaluated effect of FCR to clinical outcome. One hundred sixty-five patients were randomly allocated into three groups. In the measured resection group, FCR was set by externally rotating the axis 3° off the posterior femoral condylar axis. In the tensor group, a gap-tensioning device set at 20 lbf was used. In the block group, spacer blocks of various thicknesses were used. The FCR angle (FCRa) was measured on postoperative axial CT as an angle between the clinical transepicondylar and posterior condylar axes of the femoral component. Outliers were defined as FCRas deviated more than 3° either internally or externally. Postoperative 2 year clinical scores and knee range of motion were checked. The tensor group had significantly better positioning of the femoral component to the neutral position compared with the measured resection group and the block group (mean FCRa: internal rotation 1.79, 0.43 and 2.63°, respectively, p