Lower extremeity alignment is normally neutral with the mechanical axix of the limb falling throught the center of the knee. This neutral alignement allows for evenly distributed physical stress on both the medial and lateral weight bearing compartments of the knee. In cases of lower extremity malalignment the mechanical axis is shifted to either the medial or lateral weight bearing compartment.
This condition causes mechanical overload of the compartment and causes progressive deterioration of the joint cartilage in that area-osteoarthritis. If this condition is left uncorrected the end result will be complete loss of the articular cartilage surface with advanced degenerative arthritis and the need for a knee replacement. Symptoms of lower extremity malalignemt are 'bow legge' (varus) or 'knock knee' (valgus) deformity with associated knee pain.