Bony landmarks for determining the mechanical axis of the femur in the sagittal plane during total knee arthroplasty.
BACKGROUND
There is no accepted landmark for the mechanical axis of the femoral axis in sagittal plane in conventional total knee arthroplasty.


METHODS
As palpable anatomic landmarks of the femur, lateral epicondyle, and anterior margin of the greater trochanter were identified. The line connecting these two landmarks was defined as the "palpable sagittal axis". The mechanical axis of the femur was compared with the palpable sagittal axis and the distal femoral anterior cortex axis. These axes were also compared with sagittal bowing of the femur.


RESULTS
The distal femoral anterior cortex axis and the palpable sagittal axis were flexed by 4.1 degrees and 2.4 degrees more than the sagittal mechanical axes, respectively (p < 0.05). However, the palpable sagittal axis was not correlated with sagittal bowing of the femur (Spearman's rs, 0.17; p = 0.14).


CONCLUSIONS
The palpable sagittal axis showed a consistent relationship with the sagittal mechanical femoral axes regardless of the severity of the sagittal bowing of the femur.
Seo
Jai-Gon
JG
Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Kim
Byung-Kuk
BK
Moon
Young-Wan
YW
Kim
Jong-Hyun
JH
Yoon
Byeong-Ho
BH
Ahn
Tae-Keun
TK
Lee
Dong-Hoon
DH
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001696:Biomechanical Phenomena; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology / Q000601:surgery; D008297:Male; D008875:Middle Aged