Introduction:
Femur fibula ulna syndrome (FFU) is a very rare syndrome characterized by abnormalities of the femur (thigh bone), fibula (calf bone), and ulna (hand bone). In this syndrome, the upper limbs are more frequently affected than the lower limbs, and the right side of the body is more frequently affected than the left. Lenz and Feldman discovered femur fibula ulna syndrome in 1977.
What Is Femur Fibula Ulna Syndrome?
Femur fibula ulna syndrome is a sporadic disorder characterized by defects of the femur, fibula, or ulna. Lenz et al. reported an analysis of 491 FFU syndrome cases in 1993. They discovered that the main characteristics include a striking asymmetry in the presence and severity of limb malformations. These malformations are more common in unilateral than bilateral, and a preference for the upper limbs, the right side, and the male sex. Sometimes this syndrome is associated with PFFD (proximal femoral focal deficiency).
What Causes Femur Fibula Ulna Syndrome?
The femur fibula ulna (FFU) syndrome is a relatively uncommon sporadic syndrome. The cause is unknown. Familial occurrence is extremely uncommon. There is no evidence for parental consanguinity, specific environmental causes, or the effect of maternal or paternal age on the FFU syndrome. Its prevalence is estimated to be one in every 100,000 live births. However, a very low number of cases have been reported, and the exact etiology and the causative factors for this syndrome still need to be identified.
What Are the Symptoms Associated With Femur Fibula Ulna Syndrome?
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Abnormalities of the Ulna - The ulna is the longer of the two forearm bones. It aids in the movement of the arm, wrist, and hand. The ulna also supports many important muscles, ligaments, tendons, and blood vessels. Children born with congenital ulnar defects have their wrists fixed and bent toward the little finger side of the hand. Fingers and thumbs may be affected as well. Other hand muscles and nerves may be out of balance or absent. This is also known as ulnar dysplasia or ulnar club hand.
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Split Hand - A condition in which the middle fingers and metacarpals of the hand (middle portion) are missing, giving a hand a cleft appearance. The severity ranges from slightly hypoplastic middle fingers to missing middle fingers and oligo- or monodactyl hands.
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Micromelia - It is characterized by abnormally small and poorly developed extremities. The affected individuals usually have small extremities and limbs that are smaller or shorter than average.
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Finger Syndactyly - Children with syndactyly are born with fused or webbed fingers. The failure of the fingers to differentiate into separate appendages occurs due to failure of differentiation. Finger webbing or fusion only affects the soft tissues or also affects the bone structure. Bony fusions are called bony syndactyly if the fusion takes place along a radio-ulnar axis. Symphalangism refers to the proximo-distal axis-based fusion of the finger bones.
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Short Stature - An individual is considered short stature if the height is lower than what is expected for one's age and gender. Although there is no universally recognized definition of short stature, many people define it as a height that is more than two standard deviations below the average for age and gender (or below the 3rd percentile for age and gender-dependent norms).
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Elbow Abnormalities - The elbow is the area that surrounds the elbow joint and is located between the arm and the forearm. Those who are affected frequently have an abnormality in the joint that connects the upper and lower arms.
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Short Humerus - The humerus is the longest bone in the upper extremity and is responsible for defining the arm. Patients typically have short upper arms and underdeveloped humerus.
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Humeroradial Synostosis - This is a rare osseous fusion of the radius and humerus.
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Hypoplasia of the Radius - Ulna and radius are two forearm bones. A small or hypoplastic radius is usually seen in femur fibula ulna syndrome.
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Abnormal Femur Morphology - The femur is the strongest and longest bone in the body. Femur fibula ulna syndrome usually presents with femoral structure anomaly.
How to Diagnose Femur Fibula Ulna Syndrome?
The diagnosis of femur fibula ulna syndrome can be made based on clinical symptoms and radiographic features. Prenatal diagnosis can also be made based on ultrasonography. Diagnostic imaging techniques include X- rays, CT (computed tomography), and MRI (magnetic resonance imaging).
What Are the Treatment Options for Femur Fibula Ulna Syndrome?
Treatment options for femur fibula ulna syndrome are determined based on the clinical symptoms. It includes amputation of the foot or a portion of the leg, femur lengthening, extension prosthesis, or custom shoe lifts, depending on the severity of the deformities. However, a standard treatment plan for this syndrome has yet to be developed due to the rare number of reported cases.
Conclusion:
Femoral fibula ulna syndrome (FFU) is an extremely rare congenital disease characterized by an asymmetric combination of several defects. These defects typically affect one side of the body. It usually affects the thigh bone (femur), calf bone (fibula), and ulna. However, because of the relatively low number of reported cases, a standard treatment plan for this syndrome has not been developed.
