Fibular hemimelia

Fibular Hemimelia

Fibular hemimelia is a rare, congenital condition characterized by the partial or complete absence of the fibula, which is one of the two bones in the lower leg, the other being the tibia. This condition can affect one leg (unilateral) or both legs (bilateral), with varying degrees of severity. It is the most common congenital absence of a long bone in the limbs, and its incidence is approximately 1 in 40,000 live births.

Causes and Risk Factors

The exact cause of fibular hemimelia remains unknown. However, it is believed to be a result of a disruption in the blood supply to the limb bud or an error in the formation of the fibula during embryonic development. There are no known genetic or environmental risk factors definitively linked to the condition, although some studies suggest a possible genetic component due to its occurrence in families with a history of fibular hemimelia.

Symptoms and Diagnosis

The primary symptom of fibular hemimelia is the shortening of the affected leg, which can vary from mild to severe. Other common features include:

• Absence or underdevelopment of the fibula
• Deformities of the ankle and foot, such as clubfoot
• Knee ligament instability
• Bowing of the tibia
• Absence or underdevelopment of the toes

Diagnosis is typically made through physical examination and imaging studies, such as X-rays, which can reveal the extent of bone absence or malformation. In some cases, prenatal ultrasound may detect fibular hemimelia before birth.

Treatment

Treatment for fibular hemimelia aims to correct or improve the limb length discrepancy and associated deformities to enhance function and mobility. Treatment options vary depending on the severity of the condition and may include:

• Orthotic devices to support the limb and improve function
• Prosthetic fitting for severe cases where limb salvage is not feasible
• Surgical interventions, such as limb lengthening procedures or reconstructive surgery to correct deformities

Limb lengthening and reconstruction are complex processes that may require multiple surgeries over the course of several years. The decision between limb salvage and amputation followed by prosthetic fitting depends on the severity of the condition, potential for functional improvement, and personal preferences.

Prognosis

With early and appropriate treatment, individuals with fibular hemimelia can lead active and functional lives. The prognosis largely depends on the severity of the condition and the success of treatment interventions. Ongoing care from a multidisciplinary team of healthcare providers, including orthopedic surgeons, physical therapists, and prosthetists, is essential for optimal outcomes.

See Also

• Congenital limb defects
• Orthopedic surgery
• Prosthetics