Congenital Femoral Deficiency (CFD) is characterized by a shortened femur bone, associated with hip and knee deformity, deficiency, or instability. Previously known as proximal femoral focal deficiency (PFFD), it has four distinct types in the Paley Classification.
Congenital Femoral Deficiency is a rare hip disorder that we, at the Paley Institute, specialize in treating. The exact management depends on the type of CFD. The approach Is not “just a wait and see one”. We are able to predict the limb length difference at maturity and then create a life plan for the child which includes a preparatory surgery by age three and then limb lengthening planned and performed starting at approximately age 5.
CFD presents in infancy in only one out of forty thousand to fifty thousand births. The affected limb is often very short and with a hip that is quite deformed. At times it involves both hips. Left untreated, the lower extremity can be as much as 15 inches shorter with a hip that does not function well.
At the Paley Institute, we treat a great number of CFD patients. There are essentially four types with the first three in increasing severity and the fourth involving the knee. Treatment often includes an extensive SUPER hip operation that treats the deformity of the hip and then lengthening of the thigh and leg, at a later date. This surgery should only be performed by surgeons who are familiar with CFD and frequently operate on these types of cases. The procedure is quite complicated and if it is not done with appropriate support from physical therapists familiar with the disease, there is a risk of significant failure. With appropriate treatment, the lower extremity can often be made quite functional with no prosthesis or amputation needed. The leg often has involvement as well with another congenital deficiency called fibular hemimelia which is discussed in another section.
Congenital Femoral Deficiency has no known cause and is not passed on genetically.
The diagnosis of CFD can be made by plain x-rays. To determine the exact type, an MRI is required.
The first step in treatment of CFD requires placement of a special orthotic once the child becomes of walking age, at about a year old. Physical therapy for stretching is not necessary as the deformity is a structural one and cannot be stretched or strengthened.
The first surgery in all Type 1, 2 and 3 CFD cases is to prepare the hip and femur for lengthening at a later date. The surgery entails realigning the sometimes severe deformity of the hip and placing a plate on the femur. In some cases, the hip socket is deepened at that time. The knee is straightened and stabilized with ligaments, if needed. The child heals over a six to eight week period and one to three years later we incrementally lengthen the femur. This is the most complicated of all lengthening procedures because the knee and hip need to be protected with physical therapy, bracing and often external fixation. Depending on the limb length discrepancy prediction, we determine the number of lengthening procedures needed to equalize limb length. The first lengthening is usually never more than five centimeters (two inches). With lengthening surgeries spaced approximately three years apart, the procedure can be done with an external fixator or an internal lengthening rod, depending on the size of the child and the size of the femur bone.
The caveat to that is that in some Type 2 and Type 3 cases, the child may be treated with a rotationplasty. This is an uncommon procedure where the lower extremity is rotated one hundred and eighty degrees allowing the ankle to act as a knee. Although it sounds strange, a rotationplasty often makes the patient quite functional with just one procedure as opposed to multiple lengthenings.
Overall, following the right course of treatment, patients with CFD live functional, fulfilling and happy lives.