Epiphysiodesis

Epiphysiodesis is a surgical procedure performed to correct leg deformities, especially uneven lengths of legs.

The knee joint is made of the femur bone (the thigh bone) and the fibula and tibia (the two bones in the lower leg). The kneecap (a triangle-shaped bone that is a part of the joint) is located over the knee joint. The parts of the femur and tibia around the knee joint contain growth plates that allow the bones to lengthen during the growth and development stage in children. However, certain conditions such as fracture, bone diseases, certain tumours of the bone and neuromuscular problems in children can cause one leg to grow longer than the other one or cause the inward or outward deviation of knees. Epiphysiodesis surgery is performed to correct such problems during adolescence when the child is still at the growing stage. The surgery helps stop the growth of the longer leg to allow the shorter leg to attain the same length by the time the child reaches maturity (completes growth).

Epiphysiodesis is commonly recommended in children with variations in limb length and angular deformities of the legs such as bowed legs or knock knees. The common symptoms of limb length deviations are as follows:

• One leg is longer than the other
• Toe-walking, limping and other walking problems
• Tilted shoulder and other abnormal postures
• Discomfort in the hip, knee, back or ankle

Angular malformations of legs, namely, bowed legs and knock knees are commonly observed conditions in children. In knock knees, the knees are angled inwards (towards each other) when the legs are straight while standing. In bowed legs, the knees angle outwards (away from each other) when the legs are joined at the ankles while standing.

The timing of the surgery is critical as the objective of the surgery is for the shorter leg to reach the same length as the longer leg by the time the child stops growing. Hence, the surgery is performed in children in the mid-to-late adolescent years.

Other indications include children with deformities in the arm and fixed knee flexion deformity (this deformity restricts the individual from stretching or completely straightening the knee). The surgery may also be performed in boys who are predicted to grow to an excessive height (> 205 cm).

Epiphysiodesis is not performed in children with conditions such as:

• Legs with physiological deformity (normal developmental variations in the alignment of the lower extremities that may self-correct)
• When legs show physeal arrest (referred to as interruption or complete stopping of the natural growth of the underdeveloped bone)
• Attained maturity (ideally, the maximum age for children eligible for this surgery is one year prior to maturity or end of growth)

The surgeon and the medical team will conduct a physical examination and specific tests to confirm the variation in the limb length in the child. You will be asked to share your child’s medical history and a list of medicines (current or previous) taken by the child.

The surgeon will check the variation in the child's limb length by placing wooden blocks under the child's shorter leg when he/she is standing without footwear. The surgeon may also order certain imaging tests such as x-ray or computerised tomography to obtain a detailed image of the child's bone and/or to measure the disparity in limb length. A growing child may need imaging tests every few months to check the changes in the discrepancy. Additionally, the child may need to undergo certain blood and urine tests to determine the presence of any coexisting conditions that need to be treated before the surgery.

To prepare the child for the surgery, the surgeon will provide few instructions such as:

• If the child is taking blood-thinning drugs such as warfarin, aspirin, ibuprofen, and so on, the surgeon will ask you to stop those medicines about a week before the surgery.
• The child should take a shower before arriving at the hospital for the surgery. If the child wears nail polish, make-up or has body piercings, they need to be removed prior to the surgery.
• The child may need to skip meals and drinks from midnight, the night before the surgery. Fasting is required to prevent the risk of vomiting while under the effects of anaesthesia during the surgery.
• If the child has flu, fever or cold on the days leading to the surgery, then you should inform the surgeon. In such a case, the surgery may be postponed.

The surgeon will discuss with you the details related to the procedure, including the risks, benefits, postoperative care and follow-up with you. If you agree to the surgery, then you will be asked to sign a consent form, providing your formal approval.

After arriving for surgery at the hospital, the hospital staff will provide a hospital gown to the child and take him/her to the operating room. In the operating room, the surgical team will insert a needle in the arm or hand of the child to supply fluids and medications through an intravenous line during the surgery.

The surgery is conducted under general anaesthesia to keep the child in a deep sleep during the whole process so that he/she does not feel pain. The leg to be operated on will be covered from the foot to the groin region. The surgery is usually performed with the assistance of imaging techniques such as fluoroscopy. There are various methods by which the surgery is performed. Among these methods, the eight-plate method is the most commonly employed procedure.

• Eight-plate method: The surgeon will introduce small incisions (2-3 cm in length) on the side of the child’s knee and insert a metal plate through the incision over the growth plate. He/she will fix the metal plate on the growth plate using screws. To correct angular variations in the knee, the plate is inserted on one side of the growth plate (it will stop the bone development from one region of the knee), whereas the plate is inserted on both the sides to correct the deviations in the limb length (when one leg is longer than the other leg). The eight-plate method is a reversible surgery since the plates can be removed after the correction of the deformity.

Other methods include stapling and percutaneous epiphysiodesis using transphyseal screws.

• Stapling method: Like the eight-plate method, it is a reversible procedure wherein three staples are fixated on any of two sides of the growth plate to stop its growth.
• PETS: A permanent epiphysiodesis technique that involves the insertion of screws in a parallel or crossed fashion into the growth plate to halt its growth. The surgeon creates incisions of 1 cm around the knee and drills holes into the growth plate, up to the desired lengths. Subsequently, the screws are inserted and the incisions are closed.

Absorbable stitches are usually used in this procedure that automatically dissolve after a while. After the surgery, the child may experience dry mouth, restlessness, sore throat and tiredness. These experiences usually fade away within a few hours. Most children are discharged on the same day of the surgery.

The surgeon and a physiotherapist will provide you with instructions to take care of the child at home after the surgery, which include:

• The surgical region will be covered with a dressing before the child is discharged from the hospital. This area should be kept dry for three to five days. However, the child would be allowed to shower after the dressing is removed.
• The surgeon may prescribe some pain medications for the child. You need to ensure that the child takes the medicines as per prescription.
• If the child experiences pain or swelling around the surgical site, you must apply ice wrapped in a cloth or a towel over the area for 10-15 minutes. This can be repeated every three to four hours.
• While sleeping, do not place a pillow below the operated knee as it may prevent straightening of the leg and prolong the recovery period.
• Encourage and help the child to begin their routine as soon as possible after the surgery.
• The child should follow the instructions provided by the physiotherapist for walking, climbing stairs, etc.
• Make sure that the child practises exercises shared by the physiotherapist at least thrice a day. This will help strengthen their operated knee.
• The child may be able to resume going to school once the post-surgical pain is controlled.
• The child should not indulge in physical activities and sports such as running, jumping and contact sports for at least six weeks after surgery.

When to see the doctor?

You should contact the surgeon immediately if your child has any of the following symptoms:

• Body temperature over 38^°C
• Increased swelling, redness and warmth around the operated area
• Bleeding or drainage of the foul-smelling pus from the operated area
• Nausea or vomiting
• Diarrhoea or constipation
• Difficulty in urination
• Fatigue

Some of the potential risks and complications associated with the surgery are as follows:

• Infection (uncommon; can be treated with antibiotics)
• Longer hospitalisation due to excessive pain after surgery
• Loss of or change in sensation around the operated area
• Incomplete correction of the leg deformity
• Overcorrection of the leg deformity
• Scars at and around the incision area
• Risks of general anaesthesia such as confusion, lung infection, allergy, etc.

The surgeon will schedule a follow-up visit about two weeks after the procedure to assess the child's limb. After this, follow-up appointments will be continued at an interval of at least three to six months to allow the surgeon to monitor the growth of the child’s leg.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.