This document discusses methods for measuring alignment in the lower limbs, including the knee and hip joints. It outlines several key anatomical lines used as references, such as the mechanical axis of the femur and tibia. Joint orientation lines and angles are important for assessing malalignment. Measuring these lines and angles helps evaluate deformities and plan corrective procedures like osteotomies, which are performed at the center of rotation angle.

2. • Line between the
center of the femoral
head and the center of
the knee joint (between
both femoral condyles).

3. • A mid diaphyseal line
passing along the
length of the
intramedullary canal.

4. - It extends between center of the femoral
head and the center of the tibial plafond.

6. - Lines represent the
orientation of the joint in
certain plane.
- Knee Joint
- Along the subchondral line of
the tibial plateau.
- Line tangential to the most
distal point of the femoral
condyles.

7. Normally joint lines are parallel within 2
degrees.
Angles greater than 2 degrees are
considered as a source of mechanical axis
deviation (MAD).

8. -Angle between:
-Line along the
mechanical axis of the
femur and line along
the distal point of the
femoral condyles
- Normal range is 85-
90 degrees.

9. -Angle between:
-Line along the
mechanical axis of
the tibia and line
along the tibial
plateau.
- Normal range is
85- 90 degrees.

11. In cases of deformity:-
- Angle between the distal tibial mechanical axis and
line along the tibial plafond.
- If one side is normal then it is used as a template
for the deformed site.
- If both are deformed then consider normal angles.

12. - (Center of rotation angle).
- Point at which proximal and distal axis
lines intersect.
- Osteotomy fracture is done at CORA site.

14. 1- Measure mechanical
axes of both lower limbs.
2- Joint orientation lines.
3- LPFA and MPTA/LDTA.
4- CORA.

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