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Dear Doctor

April 2016

Question:

My child has Sticker Syndrome. She has genu valgum. I need information about growth plate surgery or other treatments for this. Is this possible?

Follow up question: Is this surgery that is done in both legs or just the one that is most affected?

- Lane - Michigan (Parent)

Answer:

Great question -- YES - the genu valgum can be treated!  Guided growth is a relatively new technique which is used to correct frontal plane (and to a lesser extent side view) deformities of the legs.  It is an appropriate intervention in any child who is still growing and has open growth plates. At each end of the long bones in children is a segment of cartilage which, under hormonal influence, causes the bone to elongate. That's how our children grow taller.  In general, that growth will stop when girls are about 14 and boys are about 16. While those growth plates are open and actively growing - we can take advantage of that growth by "tethering" one side of the growth plate and allowing only the other side to grow for a while.  In the case of your daughter, she has "knock knees". Seen from the front, the inside of each leg is longer than the outside. Your Pediatric Orthopaedic surgeon can determine by measuring her standing films which bone (the femur or the tibia or both) is contributing to this deformity. With a very small, out-patient surgery and a small incision (less than 2 inches) your surgeon can span the long side of the growth plate with a plate and screws. This surgery most likely will not require an overnight stay and she will not be casted or limited from activities. With subsequent growth - the frontal alignment of her legs will correct. After surgery, your daughter will return at 3 or 4 month intervals to evaluate her correction and determine the appropriate time to take the plates out.

 It is VERY important during treatment to look critically at your daughter's legs.  Kids tend to grow in spurts - and it is crucial to remove the plates once the deformity is corrected or you will see the opposite deformity (bow legs). In Stickler syndrome - there is a bit greater chance of rebound (that is to say that the legs may either over correct or move back to some extent to the knock knee that was corrected). This surgery can be repeated as long as the growth plates remain open. The risks of the surgery are small - but you should talk to your Pediatric Orthopedic surgeon about them.

Follow up answer:
Typically kids who can stand have a x-ray called a standing alignment film.  For that film they are instructed to stand with both knees straight and knee caps pointing forward. IF there is a limb length discrepancy (one leg longer than the other) it is most appropriate to have your child stand for that film on a small block under the shorter leg so that the film is as accurate as possible. The surgeon will draw a mechanical line on the x-ray from the center of the hip on each side to the center of the ankle. That line SHOULD fall directly through the center of the knee. In your daughter’s case – if she has bilateral genu valgum, that line will fall outside the knee.  If both legs are affected – the surgeon will recommend treatment on both sides. The risk – particularly in Stickler is that the plates would be ready to come out at different times (which requires more than one surgery – not ideal or convenient, but very safe).

  

- Lane - Michigan (Parent)