Fibula Hemimelia is a congenital condition that is characterized by a partial or complete absence of the fibula bone in the leg. The fibula is the smaller outer bone (while the tibia is the larger bone on the inside part of the leg). Not only is the fibula bone missing to some extent, but the leg is also thinner and shorter. Most of the time, it affects only one leg, but it may affect both sides. There are several other physical defects that may be associated with fibula hemimelia, and these include -
- partial or complete absence of the anterior cruciate ligament (ACL) in the knee
- congenital femoral deficiency
- tarsal coalition in which the talus and calcaneus bones are "stuck together" in an abnormal position, this may lead to ankle stiffness and instability
- complete or partial absence of some of the outer toes
- dimpling of skin and crookedness of the tibia bone.
Findings are typically noticeable at birth as the lower portion of the leg is visibly smaller and thinner compared to the other side. The foot may rest in an abnormal position (often pointing down and out), and some of the toes may be missing. An x-ray can confirm the diagnosis.
The ultimate treatment goal, as with other congenital limb deficiencies, is to have a leg that is functioning well and is nearly equal in length to the other side by the time your child is fully grown. Many children with fibula hemimelia are candidates for limb lengthening in the future. Often times, prior to the first lengthening, the foot will be corrected so that it sits in line with the rest of the leg. Lengthening is done with either an external fixator or with an internal lengthening device. Internal lengthening devices cannot be used in the tibia until your child is a teenager. This is due to size limitations of the nail, and the fact that one of the growth areas of the leg is affected by the way the nail is inserted.
Not every child with fibula hemimelia will benefit from a limb lengthening surgery. Ultimately, your COA physician will help guide you on which method is best suited for your child. Please click here to learn more about specifics about limb lengthening.