What is Congenital Femoral Deficiency?

Congenital femoral deficiency (CFD) is a rare condition where a child is born with underdeveloped or missing thigh bone (femur). This condition can vary, with some cases resulting in a shorter thighbone, and others having more serious deficiencies that affect the hip joint’s stability and mobility. Sometimes, other skeletal abnormalities can accompany this condition, with the most common being fibular hemimelia. In serious cases, the growth of the affected leg could be impacted, and the severity would depend on other existing conditions.

The femur or thigh bone is the largest bone in the human body and plays a key role in the structure and function of the lower limb. The top part of the femur connects with the hip joint, while the bottom part connects with the tibia and patella, forming the knee joint. This bone, vital for leg movement, helps with support, transmits forces, protects important structures, and aids in joint stability and alignment.

Different muscle groups surround the femur, all with specific roles. The quadriceps in front are the muscles that help extend the knee, and the femoral nerve controls them. The muscles on the inside, or medial side, of the thigh mainly pull the thigh inward and help bend the hip. Most of these muscles are controlled by the obturator nerve, with the tibial nerve controlling the hamstring part of one muscle, the adductor magnus. The muscles located at the back, the hamstrings, help flex the knee and extend the hip and are controlled by the sciatic nerve.

The femur’s blood supply comes mainly from the femoral artery and its branches, and the femoral vein is located alongside this artery. The knee joint’s typical alignment is in a straight line for proper weight distribution and smooth knee movement during activities such as walking or jumping. In cases of CFD, knee alignment may be impacted due to the underdevelopment or absence of the femur.

What Causes Congenital Femoral Deficiency?

We are not sure exactly why CFD happens. There are a few different theories, including a disruption in cell nutrition during cell division, damage to certain tissues from blood vessel problems, and pressure on the thigh bone while it’s forming in the womb. It doesn’t seem like it’s passed down in families.

Risk Factors and Frequency for Congenital Femoral Deficiency

Congenital femoral deficiency is a condition that is seen in 1.1 to 2.0 out of 100,000 newborns. It tends to occur more frequently in female children, with twice as many cases compared to males. Most of the time, congenital femoral deficiency affects only one side (85% to 90% of cases), however, it can sometimes occur on both sides. When it does only occur on one side, it is usually the right femur that is affected.

Signs and Symptoms of Congenital Femoral Deficiency

CFD, or a leg-length discrepancy, can sometimes be detected before a child is born during an ultrasound examination. This is done by measuring the length of the bone in the fetus’s thigh. If this is not identified before birth, it can be noticed shortly after or sometimes even later in childhood if the case is mild. The parents may report uneven leg lengths or visible changes like curved or shortened legs. This condition could also affect the child’s mobility, causing issues while walking, limping, or adapting a particular stride. Severe cases may also lead to other problems like stiff joints, back pain, or difficulties in performing everyday tasks.

It’s essential to take the patient’s family history into account. Congenital conditions, and exposure to radiation or harmful drugs or infections during pregnancy could be significant factors to consider. Typically, there’s no family history of CFD.

In a comprehensive physical examination, doctors look for the presence of related deformities. Differences in muscle size or function between the affected and unaffected legs may be noticed. Deformities in the foot and ankle such as clubfoot or flatfoot, can also contribute to movement challenges. Range of motion of the hip, knee, and ankle must also be checked, as patients with CFD usually have either an increased rotation or limited rotation, bending and spreading of the hip along with thigh shortening.

It’s also important to check for systemic abnormalities related to a congenital syndrome. Anomalies in the patient’s genitourinary, cardiovascular, or other visceral systems could be present. Appearance of upper extremities, spine, and face should also be examined. Overall, each patient with CFD could present a mix of musculoskeletal, functional, and visceral issues that need to be holistically understood and addressed.

Testing for Congenital Femoral Deficiency

To evaluate Congenital Femoral Deficiency (CFD), various radiographs or X-rays are taken. These include a full-length standing view, with the knee cap facing forward, and a long side view. There are also special radiographs taken for infants or children who can’t walk yet, which show both the lower limbs and the pelvis. These tests study the bone anatomy of the lower limbs, help assess the type of CFD, check the length of the thighbone and shinbone, and rule out any hip socket abnormalities.

A side view radiograph examines any fixed bending deformity in the knee. Other imaging tests like Magnetic Resonance Imaging (MRI), hip fluid imaging, and Computed Tomography scan (CT) are also used.

MRI is useful for checking the soundness of the top part of the thighbone and distinguishing pseudoarthrosis (an unhealed fracture) from a healthy cartilaginous part of the thighbone neck. This tool can also evaluate the knee joint for any ligament issues.

Hip fluid imaging distinguishes between late bone formation in the head of the thighbone and pseudoarthrosis. After injecting a dye, the lower limb is manipulated to view the top part of the thighbone. If both the head of the thighbone and the top part of the thighbone move together, it suggests a cartilaginous connection, classifying type 1b CFD. This imaging tool also differentiates between Paley types 2a and 2b. The thighbone’s head is present in both types, but bonding between the thighbone head and hip socket indicates a more severe problem, signifying type 2b CFD.

A CT scan is preferred in older children since bone formation in the hip socket and top part of the thighbone is already completed. It is also useful for comparing the abnormal hip socket with the normal side through a three-dimensional reconstruction.

Treatment Options for Congenital Femoral Deficiency

For non-surgical treatment of walking issues caused by congenital femoral deficiency (CFD), options include using prostheses, braces, and shoe lifts to accommodate differing leg lengths. Kids under six are usually reviewed every six months and those older than six should have annual checks done using X-rays to measure their leg length.

When it comes to surgical treatment, professionals should estimate the expected growth of the legs, and the difference in length should be clearly defined before choosing a procedure. Surgery can improve the fit of a prosthesis for a child whose affected leg is projected to be much shorter than the other. On the other hand, techniques to lengthen the limb can be considered if the projected difference is less than around 8 inches. However, the hip and knee must be stabilized before this kind of surgery.

Constructing a longer limb is preferred over creating a prosthetic one in patients with certain types of CFD. Children with proximal focal femoral deficiency (PFFD), a condition where the part of the thigh bone closest to the hip is underdeveloped, typically undergo preliminary operations between ages 2 and 3. This is because in PFFD, the thigh bone’s growth is often delayed, especially in the neck region.

In certain types of PFFD, the hip stability should be assessed using X-rays before making a decision about the lengthening procedure. If certain measurements of the hip structure fall below specific values, a Dega osteotomy (a type of surgical reshaping of the hip bone) should be performed before lengthening.

A procedure called “superhip” should be considered if there are hip deformities present along with a less than average neck-shaft angle, a measure that describes the angle between the thigh and the hip. This procedure involves releasing soft tissue around the hip joint to fix muscle imbalances and stabilizing the joint using a special kind of metal rod or plate.

Lengthening the limb is typically done a year after the preparation surgery and is limited to a maximum increase in one surgery to reduce complications. The rule of thumb is that lengthening should be carried out every four years. Using this rule, three lengthening procedures could be done by the age of 12.

Prepared surgery steps are used in cases with a mobile or immobile femoral head as well. These procedures involve various ways to attach the upper thigh bone to the existing leg or to perform a specialized hip procedure.

For the most severe CFD type, prosthetic surgery could involve amputation or a procedure called rotationplasty, a technique which involves rotating a limb and using a part of it as a joint replacement. The rotationplasty requires certain functionality in the foot and can be used for patients with severe deformity, converting the knee joint into a hip joint and attaching a leg prosthetic to the short limb.

When a child has a condition known as Congenital Femoral Deficiency (CFD), which affects the normal growth of the thigh bone or ‘femur’, doctors need to rule out other similar conditions. These include:

  • Developmental Dysplasia of the Hip (DDH), a condition that can cause the hip joint to develop abnormally and become unstable or even dislocated. In severe cases, the thigh bone also may be affected.
  • Legg-Calvé-Perthes disease, a childhood condition that affects the hip joint by causing blood supply loss to the femoral head, which can cause limping or hip pain.
  • Various bone development disorders, such as multiple hereditary exostoses or diastrophic dysplasia, can affect the growth, shape, or density of the femur and other long bones.
  • Conditions that cause one leg to be longer than the other, such as being born with different leg lengths or due to an injury or infection, may look like CFD but normally don’t affect thigh bone development.
  • Genetic syndromes such as Holt-Oram or TAR syndrome can cause skeletal abnormalities including those affecting the femur, but they typically have other symptoms too.
  • Similarly, Campomelic syndrome and Femoral hypoplasia-unusual facies syndrome, which cause i66ssues with both femurs are also considered in the diagnosis.

To make an accurate diagnosis of Congenital Femoral Deficiency (CFD), doctors conduct a thorough examination, use imaging techniques like X-rays, and consider the patient’s medical and family history. They may also need to work with specialists in orthopedics, genetics, and other relevant medical fields to decide the best treatment approach.

What to expect with Congenital Femoral Deficiency

The future health of a patient with CFD varies, and it largely depends on the severity of their condition and how quickly they receive treatment. Usually, early treatment leads to better results. If CFD isn’t treated, patients may gradually develop an abnormal way of walking, which could impact their appearance over time.

Possible Complications When Diagnosed with Congenital Femoral Deficiency

The conditions that accompany Congenital Femoral Deficiency (CFD) differ according to how severe the condition is and the way it’s treated. These can include:

  • Different leg lengths
  • Restricted joint movement
  • Unstable hips
  • Joint disease due to wear and tear
  • Emotional and psychological issues
  • Complications from surgery, such as infections, nerve damage, blood vessel damage, or failure of support devices used in surgery
  • Limitations in functioning

There could also be related bone deformities, like fibular hemimelia (an abnormality of the fibula), caudal regression syndrome (abnormal development of the lower spine), caudal dysplasia (malformation of the tailbone), cruciate ligament deficiency (issues with the ligaments in the knee), and deformities in the lower spine. These can also affect your mobility and appearance.

Recovery from Congenital Femoral Deficiency

Following surgery, it’s suggested that patients engage in various exercises such as gluteal sets, hip adduction with a towel, abdominal brace placement and lying hamstring stretch within the first six weeks. Beyond six weeks, patients can do shoulder push-ups, hip extensions while lying on the stomach, calf stretches with towels, hip abductions using therabands, and hip extensions on the hands and knees.

After a procedure called rotationplasty, patients and their family members are taught various stretches and strengthening exercises to help improve their movement ability. Initially, they are taught stretches for the hip, ankle, foot, and toes, and then they are gradually introduced to strength training exercises.

Tools like wheelchairs and crutches are particularly useful for helping with movement and transportation. Physiotherapists also guide patients and their families on how to wrap the limb in compression stockings to help reduce swelling. Once the bone has healed properly, it’s often suggested that a prosthetic fitting is done.

Preventing Congenital Femoral Deficiency

People diagnosed with CFD should get medical attention quickly to avoid long-term walking problems and potential changes in appearance, behavior, and emotional wellness. After surgery, it’s crucial to undergo correct rehabilitation and physical therapy. Using suitable supports and braces is also very important for the best recovery and to ensure the body functions as well as possible.

Frequently asked questions

Congenital Femoral Deficiency (CFD) is a rare condition where a child is born with underdeveloped or missing thigh bone (femur).

Congenital Femoral Deficiency is seen in 1.1 to 2.0 out of 100,000 newborns.

Signs and symptoms of Congenital Femoral Deficiency (CFD) include: 1. Uneven leg lengths: Parents may notice that one leg is shorter than the other, leading to an uneven gait or posture. 2. Curved or shortened legs: Visible changes in the shape or length of the legs can be a sign of CFD. 3. Mobility issues: CFD can affect a child's ability to walk properly, leading to difficulties in walking, limping, or adapting a particular stride. 4. Muscle imbalances: Differences in muscle size or function between the affected and unaffected legs may be observed during a physical examination. 5. Foot and ankle deformities: Conditions like clubfoot or flatfoot can contribute to movement challenges in individuals with CFD. 6. Limited range of motion: Patients with CFD may experience limited rotation, bending, and spreading of the hip, knee, and ankle joints. 7. Systemic abnormalities: CFD can be associated with congenital syndromes, so it's important to check for anomalies in the genitourinary, cardiovascular, or other visceral systems. 8. Musculoskeletal, functional, and visceral issues: Each patient with CFD may present a combination of these issues, which need to be understood and addressed holistically. In severe cases, CFD can also lead to additional problems such as stiff joints, back pain, or difficulties in performing everyday tasks. It's crucial to consider the patient's family history and any potential factors during pregnancy, such as exposure to radiation or harmful drugs, to better understand the condition.

We are not sure exactly why CFD happens. There are a few different theories, including a disruption in cell nutrition during cell division, damage to certain tissues from blood vessel problems, and pressure on the thigh bone while it's forming in the womb. It doesn't seem like it's passed down in families.

The doctor needs to rule out the following conditions when diagnosing Congenital Femoral Deficiency (CFD): - Developmental Dysplasia of the Hip (DDH) - Legg-Calvé-Perthes disease - Various bone development disorders, such as multiple hereditary exostoses or diastrophic dysplasia - Conditions that cause one leg to be longer than the other - Genetic syndromes such as Holt-Oram or TAR syndrome - Campomelic syndrome and Femoral hypoplasia-unusual facies syndrome

The types of tests needed for Congenital Femoral Deficiency (CFD) include: - Radiographs or X-rays: full-length standing view, long side view, and special radiographs for infants or children who can't walk yet - Side view radiograph to examine any fixed bending deformity in the knee - Magnetic Resonance Imaging (MRI) to check the soundness of the top part of the thighbone and evaluate the knee joint for any ligament issues - Hip fluid imaging to distinguish between late bone formation and pseudoarthrosis - Computed Tomography scan (CT) to compare the abnormal hip socket with the normal side through a three-dimensional reconstruction.

Congenital Femoral Deficiency (CFD) can be treated through non-surgical methods such as using prostheses, braces, and shoe lifts to accommodate differing leg lengths. Regular check-ups are recommended, with kids under six being reviewed every six months and those older than six having annual checks using X-rays to measure their leg length. Surgical treatment options are also available, with the choice of procedure depending on the expected growth of the legs and the difference in length. Surgery can improve the fit of a prosthesis for a child with a significant leg length difference, while techniques to lengthen the limb can be considered if the projected difference is less than around 8 inches, but the hip and knee must be stabilized before this type of surgery. In certain cases, constructing a longer limb is preferred over creating a prosthetic one. For the most severe cases of CFD, prosthetic surgery may involve amputation or a procedure called rotationplasty.

The side effects when treating Congenital Femoral Deficiency (CFD) can include: - Different leg lengths - Restricted joint movement - Unstable hips - Joint disease due to wear and tear - Emotional and psychological issues - Complications from surgery, such as infections, nerve damage, blood vessel damage, or failure of support devices used in surgery - Limitations in functioning In addition, there could be related bone deformities, such as fibular hemimelia, caudal regression syndrome, caudal dysplasia, cruciate ligament deficiency, and deformities in the lower spine, which can also affect mobility and appearance.

The prognosis for Congenital Femoral Deficiency (CFD) varies depending on the severity of the condition and how quickly treatment is received. Early treatment generally leads to better results. If CFD is not treated, patients may develop an abnormal way of walking over time, which can impact their appearance.

An orthopedic specialist.

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