Foot and ankle deformities
Considering the functions of transmission of load and propulsion, the mechanical axes of the foot and ankle are of primary importance for proper function. By deformity we mean all alterations of these axes due to disease or trauma. Deformity may thus imply structural bone axes and/or functional joint axes. Deformities may thus be evaluated objectively, especially under weight-bearing conditions. We consider the appearance and shape of the foot to be at least as important as the radiological assessment.
Deformities about the foot and ankle may be present at birth or develop in childhood (developmental), degenerative (with age, arthrosis), associated with neurological diseases due to a dysbalance of muscles and tendons,post-traumatic (following fractures or dislocations), linked with other diseases: inflammatory such as rheumatoid arthritis , or metabolic such as diabetes or caused by tumors.
The foot presents twenty-eight bones: a lot when compared to the four bones which link the pelvis to the foot. Correcting deformities of the foot requires a thorough knowledge of anatomy and the function of bones, joints and the local musculature.
Efficiency of the hand relies on highly mobile joints but the forces involved are low. In contrast, optimal function of the foot relies on less mobile joints subjected to high forces due to gravity and the transmission of kinetic energy. Therefore, correction procedures about the foot and ankle include bone cuts (osteotomies), joint fusions or releases and transfers of muscle tendons.