Bilateral absence of the tibia
Tibial hemimelia; Tibia, absence of
Absence of tibia is a rare birth defect that is characterized by deficiency of the tibia (the shinbone) with other bones of the lower leg relatively intact. The condition may affect one or both legs. Some cases are isolated birth defects, while others are associated with a variety of skeletal and other malformations. It can also be a part of a recognized syndrome such as Werner's syndrome, tibial hemimelia-polysyndactyly-triphalangeal thumb syndrome, and CHARGE syndrome.
- Walking problems
- Deformed leg
- Missing shin bone
- Extra fingers
- The germinal: The germinal theory regards as primary a defect of the mesoblast from which the skeleton of the affected limb is developed. To what this defect is due has not been ascertained; but vascular, microbic, toxic, and endocrinal influences are, without proof, invoked.
- The mechanical (including the postural and the aiminiotic: the mechanical theories state that interference with normal development and growth is brought about by external pressure on the foetus, either, according to the postural theory, by malposition in itero; or, according to the amniotic theory of Dareste(9) by the abnormal tension of the amnnion, itself arrested in development, or by amniotic bands or adhesions formed between the amnion and foetus as the result of inflammation of the amnion, or by constrictions effected by the umbilical cord.
- The traumatic: The traumatic theory regards the cause as violence sustained by the mother during pregnancy and transmitted to the foetus as it lies in utero.
Signs and symptoms of Absence of tibia with polydactyly may vary on an individual basis for each patient.
Treatment varies based on the severity of the condition, but generally involves surgery (i.e. amputation or reconstructive surgery with a prosthesis adapted to growth) and surgical is always an option to treat the patient with the disease.