Congenital femoral deficiency (CFD), also known as proximal focal femoral deficiency (PFFD), is a congenital shortening of the femur. While congenital femoral deficiency more accurately reflects the nature of this condition, both names refer to the same diagnosis. CFD is a rare condition; one or two out of every 100,000 children are affected.

Congenital femoral deficiency can affect one side of the body, or both. Bilateral (both sides) CFD is the rarer of the two, occurring in around 15% of cases.

At Loma Linda University Health, accurate diagnosis and advanced treatment of conditions affecting limb length is provided by the experienced surgeons at our Limb Lengthening Center. CFD is one of the many conditions we specialize in.


For the most common type of CFD, there is no known cause. Because bilateral CFD most often occurs with femoral facies syndrome, it is more likely to have some genetic implications.


The symptoms of CFD vary in severity. Most cases of CFD have some fibular hemimelia (FH), which causes shortening of the leg below the knee in addition to the short femur. Other symptoms may include:

  • A difference in length of limbs
  • Slight asymmetry in gait (walking)
  • Abnormal hip/knee anatomy
  • Deformity that causes one foot to be above the level of the opposite knee


People with symptoms should be checked as early as possible. At our Limb Lengthening Center, congenital femoral deficiency is diagnosed by a physical exam, followed by an EOS low dose X-ray scan for accurate measuring. For small children who are unable to stand on their own, the X-ray may be given lying down.  

These tests measure the length of the femurs and tibias, as well as foot and hip height.  

Using the results, we can determine the difference in limb lengths and the status of the hip and knee joints. After that, we can determine treatment options.


CFD is often treated with lengthening and reconstructive surgery. At Loma Linda University Health Limb Lengthening Center, we are leaders in the use of the Taylor Spatial Frame, PRECICE® magnetic lengthening nail, Ilizarov reconstruction and other fixation systems. Each surgery is done with long term goals in mind, and making sure the timing of these operations does not make a negative impact on the patient’s life.

Using a variety of testing methods, we predict what the patient’s limb length difference will be when he or she reaches maturity. This finding will determine the number and timing of the procedures. When treating congenital femoral deficiency, the goal should be to outline the scope of treatment needed and form a “life plan” for these operations. Human dignity is always the top priority when making clinical decisions.

Using a protocol known as the Paley classification, we determine whether a patient’s case is amenable to reconstructive surgery.

The Paley classification of congenital femoral deficiency is as follows:

Type 1: “intact femur” with mobile hip and knee

  • Normal ossification proximal femur
  • Delayed ossification proximal femur – neck type
  • Delayed ossification proximal femur – subtrochanteric type

Type 2: “mobile pseudarthrosis” with mobile knee

  • Femoral head mobile in acetabulum
  • Femoral head absent or stiff in acetabulum

Type 3: “diaphyseal deficiency” of femur

  • Knee motion 45° or more
  • Knee motion less than 45°
  • Complete absence of femur

Type 4: “distal deficiency” of femur (very rare)

Under the Paley classification, most Type 1 and Type 2 cases may be treated with surgery. If the Paley classification determines that surgery is not the best option, other prescribed treatments for CFD include prosthetic options and shoe lifts.


Failing to treat congenital femoral deficiency can put the patient at risk for a variety of complications. These may include:

  • Acetabular dysplasia
  • Coxa vara
  • Hip flexion, abduction and/or external rotations contractures
  • Knee instability resulting from hypoplasia of the femoral condyles, proximal tibia deformity, and lack of anterior and posterior cruciate ligaments
  • Knee flexion contracture
  • Patella instability
  • Genu valgum (knock knee deformity)
  • Foot and ankle deformity associated with fibular hemimelia

For this reason, it is important for children to be evaluated when symptoms first become present.


If you believe your child may have congenital femoral deficiency, here are the next steps we recommend.

  • Seek medical intervention. Taking proactive action is paramount to avoiding future complications, and a medical exam is the first step. To request an evaluation at Loma Linda University Health, contact the Limb Lengthening Center or schedule the appointment through MyChart.

  • Pay attention to details. If symptoms worsen or expand, make a note of it and bring it up during the appointment. We have the most experienced limb lengthening and reconstruction surgeons in the western United States – but as the patient or parent, you have firsthand knowledge of the condition.

  • Participate in the journey. The Loma Linda University Health Limb Lengthening Center is comprised of a team that works well with patients of all ages. We customize a treatment plan for every patient and design it to accomplish all appropriate goals. Trusting the expertise of our physicians, collaborating with our physical therapists, and strong family participation are all required to make this happen.

Limb lengthening is a journey, and we are here to make that journey great. 

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