Introduction
Femoral torsion or twisting is a common condition that affects infants. The femur is a thigh bone which is the longest bone in the human body. It helps in stable movement, holds body weight, and connects muscles.
Femoral torsion is divided into two types, internal and external femoral torsion. In internal femoral torsion, the femur bone of the upper leg is twisted or rotated. It occurs in around 9 to 10 % of children. In this condition, a W position (the knees are touching together, and the feet are apart) is seen whenever a child sits down. In most cases, the internal torsion can be around 40 degrees at birth and still be normal.
What Is External Femoral Torsion?
External femoral torsion is a condition in which knees face in opposite directions. As a result, the femoral neck is twisted backward compared to the femoral shaft. Due to this, the hip is rotated posteriorly to the knee. It can occur in both legs or just one. In most cases, external femoral torsion corrects itself without treatment when a child starts standing and walking. It is a congenital condition (present since birth) and does not cause other physical complications.
What Causes External Femoral Torsion?
The exact cause of this condition is unclear, but some of the factors that can cause external femoral torsion include:
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The infant’s position in the womb. If the baby's position is incorrect, it can cause the displacement of the femur.
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One of the other causes considered for this condition is heredity. In many cases, it is seen that one or some of the family members were affected by the same condition.
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In some cases, femur fracture can also lead to external femoral torsion.
What Are the Symptoms of External Femoral Torsion?
The symptoms include:
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Continuous knee pain.
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Difficulty in balancing.
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Poor coordination.
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Out toe (foot placed outward while walking).
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Pain in the lower back.
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Fatigue.
How Is External Femoral Torsion Diagnosed?
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Physical Examination: Firstly, a doctor will do a thorough physical examination and see how the patient walks and sits. The doctor will also note the patient's complete family, medical, and developmental history, which will help diagnose the condition more clearly.
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CT (Computed Tomography) Scan - In many cases, a CT scan helps in diagnosing the deformities related to it. It is an imaging technique that uses computer technology and X-ray to get clear 3D images of the inside of the body. A CT scan has a round or donut-shaped tube that rotates the X-rays around 360 degrees. First, a healthcare professional will ask the patient to remove any jewelry and other metal objects that can affect the scan. Next, the patient is asked to lie on the machine's table, which moves slowly in the scanner. Finally, the images of the affected area are taken and transferred to the computer. It takes around 10 to 30 minutes to complete the scan.
How Is External Femoral Torsion Managed?
In many cases, the children outgrow external femoral torsion without any treatment. Around the age of one or two, when a child starts walking, the effect of this condition fades slowly. If there is a case of excessive external femoral torsion, then a surgical method, a femoral derotational osteotomy, is performed.
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Derotational Osteotomy - This procedure can be done in adults and children above ten. The deformities can be different in each case. A plate can be fixed in the upper femur if the neck shaft is too flat or slanted. Along with this, the femur's abnormal rotation can also be fixed. To perform this procedure, a surgeon will cut the femur and fix the alignment of the bone. Once the bone gets proper alignment, metal plates or rods are fixed to stabilize it. In many cases where the neck shaft is normal, a very small incision can be given as it will not need a plate. A long rod is inserted from where the incision is given, and the muscle is not elevated from the femur.
After the surgery is done, patients are monitored during the rehabilitation program, strengthening the muscles and basic weight-bearing exercises.
Conclusion
Femoral torsion is common in newborns, and the knees point in the opposite direction in external femoral torsion. In most cases, it does not cause severe complications and corrects on its own, but an orthopedic consultation should always be taken. Femoral derotational osteotomy helps re-adjust the femur bone and gives the shaft support by placing a plate. Overall, an early diagnosis will help avoid complications and treat the condition properly.
