Normal Anatomy
Mechanical Axis
Coronal mechanical axis | Femoral mechanical axis | Tibial mechanical axis | Sagittal mechanical axis |
---|---|---|---|
Center femoral head to center of ankle | Center of femoral head to center knee | Center plateau to center of talus / ankle | Center of femoral head to center of ankle |
10mm medial to the frontal plane center Medial tibial spine |
Just anterior to center of knee joint Aids in passive locking of knee joint in full extension |
Varus malalignment left knee Valgus mechanical axis right knee
Mechanical Axis Deviation
- distance from center of knee to MA in mm
Anatomical Axis
Coronal anatomical femoro-tibial axis | Femoral anatomical axis | Tibial anatomical axis |
---|---|---|
Center of femoral shaft to center of knee to center of tibia |
Piriformis fossa to center knee joint | Center plateau to center of talus / ankle |
5-7o valgus - increased in shorter femurs - decreased in longer femurs |
6o from mechanical axis |
Knee
Knee joint |
aLDFA (anatomical Lateral Distal Femoral Angle) |
mLDFA (mechanical Lateral Distal Femoral Angle) |
MPTA (medial proximal tibial angle) |
Posterior slope |
---|---|---|---|---|
3o valgus relative to MA | 81o | 87o | 87o or 3o varus | 9° |
6o valgus distal femur | ||||
3o varus proximal tibia |