The femur also called the thighbone, is the long bone present in your legs. It connects the hip and the knee joint. Congenital femoral deficiency is a rare disorder of the lower limbs affecting young children. It is characterized by abnormal or incomplete development of the femur resulting in leg length discrepancy. It may affect one or both the lower limbs.
What are the Causes of Congenital Femoral Deficiency?
The exact cause of congenital femoral deficiency is not clear. However, it may occur due to any of the following reasons:
- Genetic mutation
- Bone infection
- Disturbances during fetal development
Consumption of certain drugs during pregnancy may lead to a birth deformity in the baby.
What are the Signs and Symptoms of Congenital Femoral Deficiency?
The signs and symptoms of congenital femoral deficiency may include:
- Absence of a portion or the entire femur
- One thigh shorter than the normal side and may be crooked
- Leg length discrepancy
- Instability in the hip and/or knee joint
- Abnormal gait (walking style)
- Tripping during walking or running activities
- Pain in the hip or knee joint
- Lack of free movement or limited range of motion
How is Congenital Femoral Deficiency Diagnosed?
You should consult an orthopedic surgeon specializing in knee or hip disorders or a specialist in lower limbs. The doctor will review your child’s medical history, family history, and examine your child’s external symptoms such as bone deformity, leg length discrepancy, and abnormal gait. In addition, strength of the muscles in the lower limbs and range of motion will also be checked. Imaging tests such as X-ray, MRI (magnetic resonance imaging), or a CT (contrast tomography) scan may also be recommended to confirm the diagnosis and develop a treatment plan best suited for your child.
What are the Treatment Options for Congenital Femoral Deficiency?
Congenital femoral deficiency can be treated with the proper diagnosis and a suitable treatment plan. The choice and length of treatment will depend on your child’s age and leg condition. The first choice of treatment is usually the conservative approach. If non-surgical methods do not yield desired results, then your doctor would recommend surgery.
- Orthotic devices such as insoles, knee braces, and crutches to provide walking support
- Physical therapy in the form of exercises and massage
- Pain relief injections into the affected joint to suppress the pain and inflammation
- Immobilization by a cast or splint to allow the affected leg to rest
Each child is unique and will benefit from a customized multidisciplinary approach that combines non-operative and surgical treatment to maximize joint function. The first step is to identify if the child’s age is suitable for surgical treatment. The different surgical options include:
- Partial amputation
- Femoral arthrodesis
Limb lengthening is a reconstructive procedure where the deformed bone is straightened or missing bone is replaced. The process of increasing the bone length depends on tissue and bone regeneration. When the bone is pulled apart, it tends to regenerate at the rate of approximately 1 mm per day.
Partial amputation is a type of limb salvage surgery. It involves debridement- removal of the injured bone and surrounding tissues and reconstructing them into a functional limb. This may be done using an allograft, a bone graft from a donor, a metal implant, or a combination of metal implant and bone graft called allograft-prosthetic composite.
Femoral arthrodesis involves the fusion of the proximal femur with the pelvis. The surgeon makes a small incision in your child’s leg and may remove some portion from the femur and the surrounding muscles. The prepared bone is then connected to the pelvis using rods, screws, plates, or pins. This provides stability to the hip joint and improves mobility.
Rotationplasty is a kind of limb salvage procedure. In this surgery, the lower leg and foot are rotated 180 degrees backwards, so the child’s foot is positioned where the knee used to be, with the heel portion in front and the toes pointing backwards. Placing the ankle joint in the position of the knee creates a functional knee for your child. And the knee joint acts as the hip joint. Then, a prosthesis is placed beneath the functional knee. This significantly improves limb mobility compared to the traditional above-the-knee amputation and prosthesis.