Fibular Hemimelia

Fibular hemimelia is a congenital disorder characterized by the partial or complete absence of the fibula. Most common congenital long bone deficiency.

The precise cause is unknown in most cases and the deformity normally occurs sporadically.

Children with complete fibular hemimelia present with anterolateral bowing of the tibia, equinovalgus deformity of the foot and tarsal coalition, with significant shortening. Milder variants will present at a later age with a lesser degree of shortening and foot deformity.

Fibular hemimelia syndrome has a spectrum of problems

Variable degrees of fibular hypoplasia

Shortening of the tibia and femur

Genu valgum and lateral femoral condyle hypoplasia

Knee ligament laxity

Tibial bowing

Ball and socket ankle joint, tarsal coalitions and missing lateral rays of the foot

Radiographic views of the leg with alignment view are needed to make the diagnosis. Higher imaging modality like magnetic resonance imaging is required to evaluate the cartilage anlage and status of the knee ligament.

Milder variants need observation and non-operative treatment for the limb length discrepancy like heal rise.

Operative treatment includes ablative or salvage procedure, depending on the severity of affection.

Salvage procedure is indicated in children with function foot with more than three rays, leg shortening less than 5 cm at birth or leg shortening less than 10 cm at 9th year of life. Salvage procedures include ankle reconstruction, foot deformity correction, address the hip and knee problems, limb lengthening and epiphysiodesis.

The ablative procedure is indicated in children with the non-functional foot with three or fewer rays, shortening more than 5 cm at birth and predicted shortening above 25cm at maturity.

Long term consequences depend on the severity of the condition and initial treatment, so appropriately treated children with milder variants will lead a normal life. However, inappropriately treated children with severe affection will have a disability, morbidity with early arthritis and degeneration of joints.