Intraoperative measurements of femoral anterior tangent (FAT) line for determining the rotational alignment of femoral component of total knee arthroplasty.
Previously, we reported using CT images that the anterior surface of the femur immediately proximal to the trochlea and its tangent line (femoral anterior tangent line; FAT line) could be used as a good index of the femoral rotation. In this study, we developed a jig that allowed us to measure the FAT line during surgery, and we examine the relation between preoperative and intraoperative measurement values. The results indicated that the average intraoperative measurement value of the 'surgical' FAT line was 9.8° ± 3.2° internally rotated using surgical transepicondylar axis reference. This value significantly correlated to preoperative FAT line/clinical transepicondylar axis angle. These findings demonstrated that FAT line is a useful index for appropriate rotational alignment of femoral component, both before and during TKA.
Department of Orthopaedic Surgery, Hachiya Orthopaedic Hospital, Nagoya, Aichi, Japan; Department of Orthopaedic Surgery, Toyama Rosai Hospital, Uozu, Toyama, Japan.
Hiroki
H
Watanabe
Ryuichi
R
Gejo
Ayano
A
Tokunaga
Norikazu
N
Hirano
Tomoatsu
T
Kimura
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D007430:Intraoperative Care; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D012399:Rotation; D014057:Tomography, X-Ray Computed
femoral anterior tangent line; intraoperative measurement; rotational alignment; total knee arthroplasty; transepicondylar axis