What are the other Names for this Condition? (Also known as/Synonyms)

• Congenital Absence of the Fibula
• Fibular Longitudinal Meromelia
• Longitudinal Fibular Deficiency

What is Fibular Hemimelia? (Definition/Background Information)

• Fibular Hemimelia is a congenital (from birth) condition that arises when there is partial or complete absence of the fibula bone
• The fibula is a bone is located in the lower leg; together with the tibia bone, it makes up the bones of the lower leg
• Presently, Fibular Hemimelia has no known cause, and it is not inherited. A family history may be a risk factor in some rare cases
• The signs and symptoms of Fibular Hemimelia is different for each child and ranges in severity. These may include shorter limb length, ankle and foot deformities, and knee weakness
• The treatment for most cases of Fibular Hemimelia may involve surgery. However, rarely in severe cases, amputation may be required
• The prognosis of Fibular Hemimelia is dependent on the severity of the affected limb. In general, getting corrective surgery for the affected limb increases the chances of better outcomes 

Who gets Fibular Hemimelia? (Age and Sex Distribution)

• Fibular Hemimelia is a congenital condition, meaning children are present with the condition at birth
• The incidence is estimated at around 1 in 50,000 among the general population
• Both male and female genders are equally susceptible to the condition
• Individuals of all ethnic and racial groups may be affected worldwide

What are the Risk Factors for Fibular Hemimelia? (Predisposing Factors)

• A family history of Fibular Hemimelia has been seen in a small number of cases. However, most cases are sporadic (random presentation)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Fibular Hemimelia? (Etiology)

Fibular Hemimelia is a congenital defect when all or parts of the fibular bone is missing at birth. 

• Currently, the cause of development of Fibular Hemimelia is not well-understood. A vast majority of cases are sporadic
• Fibular Hemimelia is not known to be inherited. Presently, very few familial cases have been reported
• There has some been some evidence to show a correlation of Fibular Hemimelia with genetic abnormalities 

What are the Signs and Symptoms of Fibular Hemimelia?

The signs and symptoms of Fibular Hemimelia, which can vary from one child to another may be mild or severe. It may include the following: 

• Limb length discrepancy, meaning one leg is shorter than the other 
• Ankle and foot deformities such as:
  • Tarsal coalition, meaning that the bones around the heel of the foot are forced together in an abnormal position
  • Partial or complete absence of the outer toes
• Knee weakness and deformities such as:
  • Ligaments around the knee may be weak or missing
  • The lower leg and knee may bend inward

These signs and symptoms that manifest differently from individual to individual, typically depend on how much of the fibular bone is missing.

How is Fibular Hemimelia Diagnosed?

Fibular Hemimelia may be diagnosed using the following tests and exams: 

• Complete physical and clinical examination; evaluation of family medical history
• X-ray of the affected limb 
• There have been some reports of prenatal diagnosis of Fibular Hemimelia

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Fibular Hemimelia?

Complications due to Fibular Hemimelia may include: 

• Prolonged emotional stress to the child, parents, and caregivers
• Limb amputation
• Walking difficulty affecting the overall quality of one’s life

How is Fibular Hemimelia Treated?

Fibular Hemimelia may not be completely cured. The treatment depends on the severity of the condition of each child. An individualized treatment regimen is planned and provided to improve the quality of life, based on specific conditions/complications that develop in the child.

These may include:

• Use of walking aids and braces: These are important in the treatment of Fibular Hemimelia
• Limb-lengthening procedures to help elongate the leg
• Epiphysiodesis: A surgical procedure that is done when the child has a small difference in the length of their legs. The child must still be in its growth phase for this procedure to be successful
• Reconstruction of the extremity or amputation: This depends on the condition of the foot extremity and the limb-length discrepancy of the patient 
• Systematic utilitarian procedure for extremity reconstruction:
• For hip and knee, to help with restoring hip and knee mobility
• For ankle, to help with restoring ankle mobility
• Prophylactic anterior compartment fasciotomy: It is a surgical procedure designed to decrease the risk of possible pressure build-up in the leg (in the future)

How can Fibular Hemimelia be Prevented?

Currently, there are no specific methods or guidelines available to prevent Fibular Hemimelia.

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of congenital disorders

What is the prognosis of Fibular Hemimelia? (Outcomes/Resolutions)

The prognosis for children with Fibular Hemimelia is normally dependent upon the severity of the condition. Fibular Hemimelia is diagnosed at birth and remains throughout the individual’s life. In many cases, those with mild conditions have better prognosis than children with severe limb deformities.

Often, with adequate treatment, such as surgical correction of the deformity, the outcomes are improved. 

• In many children, Fibular Hemimelia cases are usually benign requiring a single corrective surgery
• In severe cases, multiple surgeries or limb amputations may be necessary during childhood, and these can be debilitating and cause emotional distress to both the parents and the child
• Children with Fibular Hemimelia will need periodic (every year) medical appointments until they stop growing, to make sure they are receiving adequate treatment for their specific case

Additional and Relevant Useful Information for Fibular Hemimelia:

There are voluntary organizations and support groups that provide help and understanding to the families and parents of the Fibular Hemimelia affected.