Fibular Hemimelia explained
Fibular Hemimelia is a partial or total absence of the fibula and is the most common form of lower limb deficiency present at birth. There are two long bones in the lower leg, the thicker one is called the tibia and the thinner one is the fibula. With Fibular Hemimelia the tibia is shorter than normal and the fibula is missing or underdeveloped. A leg affected by Fibular Hemimelia will look shorter than an unaffected leg. The tibia may be bent and the foot may also be smaller than normal, bent outwards at the ankle and may have fewer than five toes. The knee is often also misshapen and may move abnormally.
Usually only one leg is affected, with the right fibula affected more often than the left and males are 50% more likely to be affected than females.
Diagnosis and causes
Severe cases are likely to be seen at scans during pregnancy. In milder cases it may at first be thought to be a foot deformity but when the shortening of the leg becomes more noticeable and the leg is X-rayed the full picture can be seen. Most cases of Fibular hemimelia are thought to occur for no reason.
Steps have produced a downloadable publication, congenital-lower-limb-length-difference for parents who have been told of a possible problem with their baby’s legs.
How can it be treated?
Treatment will depend on the severity of the condition and how normal the foot is.
If the foot is reasonably normal it may be possible to lengthen the leg using the Ilizarov apparatus (pictured right).
If the foot is twisted outwards to the side it may be possible to correct it sufficiently using surgery
If the foot is not sufficiently normally formed and the tibia is too short it may be best to amputate it through the ankle using procedures such as the Syme’s or Boyd amputation and fit an artificial limb (prosthesis). Prosthetic limbs can be used in almost all situations, including in water (pictured below).
Steps have produced a fact sheet about emotionally preparing for an amputation with further publications on preparing for hospital, life with a prosthetic and talking to education providers available in the near future.
In cases where the fibula is present and the shortening is not severe the treatment is usually leg equalisation either by slowing growth of the other leg (epiphyseodesis) or leg lengthening.