Proximal Focal Femoral Deficiency

DESCRIPTION

Proximal focal femoral deficiency (PFFD) is a congenital condition where the end of the femur closest to the hip is either short or underdeveloped and in many cases the hip joint is also underdeveloped. The condition may affect one or both legs.

There are different classes of PFFD based on severity of the condition.

• Class A

  The least severe form of PFFD is indicated by the presence of a femoral head that is connected to the femoral shaft by the femoral neck at skeletal maturity.

• Class B

  In this class the acetabulum is well defined but the femoral head is not well developed at birth.

• Class C

  In this class the femoral head is completely absent and the acetabulum is poorly developed.

• Class D

  The most severe form of PFFD is indicated by the absence of both the acetabulum and femur.

CAUSES

The cause of proximal focal femoral deficiency is unknown.

SYMPTOMS

The thigh may be abnormally short, pulled upwards, and rotated outwards which can cause the foot of the affected leg to be at about the normal level of the other leg’s knee.

DIAGNOSIS

Proximal focal femoral deficiency can be diagnosed during pregnancy by measuring the length of the femur during ultrasound scans. Diagnosis can also be made at birth or later stages when the leg starts growing and there is a considerable difference in the growth of the legs.

TREATMENT

The selection and timing of surgical procedures is very critical to achieving optimum function and quality of life for patients with proximal focal femoral deficiency.

• Milder forms of proximal focal femoral deficiency can be treated with femoral lengthening.
• In cases where a child has a small femur but no hip joint, the femur is fused to the pelvis so that the knee joint functions works as a hip joint.
• The Van Nes rotationplasty process reverses the plane of the ankle joint at the knee level which allows the leg to function. The main disadvantage of this procedure is derotation of the ankle joint. However, modifications have been made to decrease occurrences of such derotations.
• Severe cases require amputation and/or a modified prosthesis to accommodate the foot and the leg.

Sources

1. Proximal Focal Femoral Deficiency. (n.d.) Posna.org. Retrieved on August 15, 2014 from http://www.posna.org/education/StudyGuide/proximalFocalFemoralDeficiency.asp.
2. Skalski, M., & Gaillard, F., et al. (n.d.) Classification of Proximal Focal Femoral Deficiency. Radiopaedia.org. Retrieved on August 15, 2014 from http://radiopaedia.org/articles/classification-of-proximal-focal-femoral-deficiency.