In children, it is perfectly normal to see bowlegs or knock-knees at certain times during growth. In the vast majority of cases, these mild malalignments resolve by themselves and do not require treatment.
However, sometimes they do not correct spontaneously, and, if not treated during childhood, they can persist and present as genu varum (bowlegs) or genu valgum (knock-knees) in adulthood.
As a result, the knee joints and sometimes the ankle joints are loaded in an unbalanced way, which leads to damage of the cartilage and subsequent arthritis and pain.
The most common causes for bowlegs and knock-knees are genetic predisposition, uncorrected malalignment in childhood, and malunited fractures.
Diagnosis is accomplished by performing clinical examination and obtaining radiographs. The radiographs are measured and analyzed (malalignment test), and the joint angles are evaluated. The exact location of the deformity is found using conventional or digital (software-guided) deformity analysis. Using digital planning software, the correction can be simulated.
Stabilization was performed using a plate, which can be removed approximately 1 year after surgery.
Realignment with correction of the mechanical axis of the limb can be achieved with osteotomy (cutting of the bone) and plate fixation. The aims are to correct the malalignment and to bring the mechanical axis to the middle of the joint for balanced loading. If early changes are already observed, the malalignment can be slightly over-corrected to unload the damaged cartilage. Depending on the location and direction of malalignment, a small wedge of bone can be resected from (closing wedge) or inserted into (opening wedge) the bone. This can be done on the femur (thigh bone) or tibia (shin bone) depending on the location of the deformity.
Realignment of the axis of the limb can protect the joints and can prevent or markedly postpone the need for total joint reconstruction.