Valgus vs varus

The terms valgus and varus refer to an angulation (bowing) angulation within the shaft of a bone or at a joint.

It is determined by the distal part being more medial or lateral than it should be. Whenever the distal part is more lateral, it is called valgus. Whenever the distal part is more medial, it is called varus. Therefore, when the apex of a joint points medially, the deformity, if any, would be called valgus, as the distal part points laterally.

It is important to bear in mind that the most proximal part of a bone or joint is the reference point and that varus and valgus angles are relative to the angle in a normal situation, which need not be zero. 

Mnemonic

The L of "lateral" is also in valgus, but not in varus. 

When also remembering that the direction of the distal part is key: distal (more) lateral means valgus and distal (more) medial means varus.

Examples

• coxa valga and coxa vara: relation of the femoral shaft to the femoral neck; in coxa vara the femoral neck is in a relatively flat position whereas in coxa valga the femoral neck is relatively steep
• genu varum and genu valgum: when the distal part of the tibia (which is the distal component of the knee joint) is pointed laterally there is genu valgum and when it is pointed medially there is genu vara
• hindfoot varus and hindfoot valgus: the posterior aspect of the calcaneus is the distal part in relation to the talocalcaneal articulation and the neutral neutral talocalcaneal angle is between 25 and 40 degrees "varus", meaning that normally the posterior part of the calcaneus is positioned medial to the anterior part
• hallux valgus: the distal part of the proximal phalanx of the first digit is pointed laterally, while the first metatarsophalangeal joint itself points medially
• cubitus valgus and cubitus varus: when the distal part of the forearm is pointed laterally there is cubitus valgus; always remember that anatomical terminology concerning the forearm is related to the anatomical position, which has the volar surface of the hand turned anteriorly, putting the radius and the thumb laterally and the ulna medially