Tibial hemimelia (TH) is characterized by a shortened or absent tibia bone accompanied by knee and ankle deformities. In some cases the fibula is also affected, often dislocated from the knee. The most complex of all congenital below knee deformities TH may be associated with accessory digits of the toes and even a duplication of the foot. TH comes in many varieties and severity. TH may be a minor as a small part of the tibia near the ankle missing to as severe as the entire tibia, patella (knee cap) and quadricep muscle may be absent.
TH is specifically treated depending on the type and severity. Fixing the foot deformity as well as aligning and lengthening the tibia is often required. Utilizing the fibula as a tibia is often the first line of treatment. At times, the knee needs to be created from the patella (knee cap). Each patient must be individualized in order to create a sensible life plan for function.
Tibial hemimelia is extremely rare and occurs in only one out of one million births. Tibial hemimelia may be present alongside additional congenital deformities, such as congenital femoral deficiency (CFD).
There is no known cause of tibial hemimelia.
TH can be diagnosed in utero by ultrasound as well as at birth with plain x-rays and physical examination
Treatment is based on severity and involves correction of the foot deformity, utilizing the fibula as a tibia, ankle fusion, and reconstruction of the knee.