health answers:
If the difference by age 5 is 1cm, your doctor will probably do a period of “watchful waiting” during your son’s prime growing years, because the discrepancy will probably increase, perhaps quite a bit, as he grows. In the meantime, having a discrepancy of 1cm should not harm him for now, especially if you build up the shoe inside and/or outside on the short leg side. The human body can accommodate a short leg of about 1/4 inch long term without problems, and in fact many of us have a short leg and don’t even know it–I found as an adult that I have a short leg, which I only learned about due to increasing back pain. For now, your son may actually find it a bit easier, especially if he has a drop foot on his short leg side, to have a little extra clearance (i.e., due to his short leg) as he swings his leg forward.
You want to address this issue, because over time if he has a uncompensated short leg, he can develop scoliosis, which is a curvature of the spine, as a result of having a short leg.
I find that I’m able to even things out by wearing a heel lift inside my shoe, although you can only add so much height this way, and some shoes work a lot better than others. I’ve also experimented with having my shoe built up on the outside, which feels more stable to me. I just usually wear the inner heel lift, and you will want to be sensitive to your son’s feeling self-conscious about having to wear “ugly” shoes. You can purchase extra-depth shoes, which are designed to accommodate orthotics (or a buildup) inside. Consider his feelings when you are correcting for his short leg.
It’s good to stay attentive to this (without worrying too much), and as you may know, kids with CP often develop a short leg due to taut muscles keeping one leg from growing as fast as the other. One of my best friends from childhood had this problem, which by junior high was probably at least 3cm, something less than 2 inches, I’d estimate. As his leg grew relatively shorter than his other leg, his doctor would prescribe a thicker buildup for his shoe on the short leg side, and it worked very well. The simplest adjustment to make, assuming the discrepancy is not huge, is to stop the longer leg from growing at some point. Your son’s doctor will keep tabs on the discrepancy from year to year, using a table/calculation which tells him when to stop the longer leg from growing more. My friend had this done in a simple procedure, and his legs ended up almost exactly even.
When the time comes, you might consider having the tibia/fibula, not the femur, arrested on the long leg side, so your son does not have knees at different heights, because this can cause some biomechanical problems if he rides a bike, which can be good physical therapy for him, if he is able. This is not a major issue though.
There are other options you can consider, like removing bone from the long leg side, or having the short leg lengthened. There are different procedures for this, the best probably using a procedure named after a Russian doctor, Ilizarov. Your doctor can discuss these options with you.
In the meantime, pay good attention to your son’s feet. Having CP can place unusual stress on one or both of his feet, which will probably lead to problems later in life, if not as a child. Having a short heel cord can lead to developing a flat foot, which may be preventable. As an adult, my friend developed a bunion on his short leg side, and I can’t help but wonder if this could have been prevented. You will want to consider getting a referral to a podiatrist who can critically evaluate your son’s gait and help you to choose the right shoes for him. Ask him what can be done to prevent foot deformity as your son grows and ages.
I know it’s obvious, but be sure your son gets good physical therapy. This is very important.
If you have the right attitude toward his disability, this will go a long long way toward helping him to feel good about himself. I hope you do not have any feelings of guilt for giving birth to a child with CP, because it was not your fault. If you have the right attitude, he will grow into a well-adjusted, happy adult. The most important thing for now is to have an excellent primary care pediatrician you can trust. All the same, don’t hesitate to get second opinions. There’s a lot of information on the web, some of it good and some totally flaky. Inform yourself using reputable sites, and become an active advocate for your son in his health care.
By the way, I’m not a doctor, and you should take all advice you receive here (except mine, of course!) with a grain of salt.
Good luck to you and your son!
