Avarus deformity is an excessive inward angulation (medial angulation, that is, towards the body's midline) of thedistal segment of a bone or joint. The opposite of varus is calledvalgus.
The terms varus and valgus always refer to the direction that thedistal segment of the joint points.
For example, in avalgus deformity of the knee, the distal part of the leg below the knee is deviatedoutward, in relation to the femur, resulting in aknock-kneed appearance. Conversely, avarus deformity at the knee results in abowlegged with the distal part of the leg deviatedinward, in relation to the femur. However, in relation to the mid-line of the body, the knee joint is deviated towards the mid-line.
The terminology is made confusing by the etymology of these words.
The termsvarus andvalgus are both Latin, but confusingly, their Latin meanings conflict with their current usage. In current usage, as noted above, a varus deformity of the knee describes bowed legs, but in the original Latin,varus meant "knock-kneed."[1][2] Similarly, while a valgus deformity of the knee would currently describe knocked knees, the original Latin meaning was "bow-legged"[3][4]
Application of these words in adjectival form to other portions of the body by the medical community has resulted in their definitions changing so that they now refer to the angle of the distal segment (i.e. valgus impaction in a Garden I femoral neck fracture).
It is correct for a knock-kneed deformity to be called both avarus deformity at the hip (coxa vara) and avalgus deformity at the knee (genu valgum); although the common terminology is to simply refer to it as avalgus knee.
When the terminology refers to a bone rather than a joint, the distal segment of the bone is being described. Thus, a varus deformity of the tibia (i.e. a mid-shaft tibial fracture with varus deformity) refers to the distal segment in a varus alignment compared to the proximal segment.[citation needed]
^"Talipes equinovarus".Genetic and Rare Diseases Information Center (GARD). 2017. Archived fromthe original on 15 October 2017. Retrieved15 October 2017.
