Stuart Mackenzie, MD, is an orthopedic surgeon and Elizabeth W. Snyder endowed chair in skeletal dysplasia at Nemours Children's Hospital in Delaware.
Not everyone with hypochondroplasia has health problems related to the condition. But some people develop bowing of the legs or narrowing of the spinal canal. Orthopedic surgeons watch closely for changes like these, and they can offer treatment if needed.
We talked with Stuart Mackenzie, MD, about choosing an orthopedic surgeon, how they can help "quarterback" a hypochondroplasia health care team, and healthy habits for young people with the condition.
Editor’s Note: This inte
rview has been edited for length and clarity.
Q: What role do orthopedic surgeons play in patient care and the treatment of hypochondria symptoms or complications?
Mackenzie: I meet children who come to our institution for an overall assessment of their short stature and potential skeletal dysplasia. But what
would bring them in most commonly to a surgeon is knee pain, and that usually happens between the ages of 5 and 10 years old. The cause of that knee pain is from bowing of the knees. Children with hypochondroplasia are more at risk for that.
If the bowing progresses and it causes an imbalance, that can result in pain when the child is active. So, often they're doing pretty well, and then with long periods of physical activity, knee pain will start to become an issue. And when I get involved or any orthopedic surgeon gets involved is when it becomes a more-regular form of pain that starts to interrupt them from their regular activities, having fun with their families, participating in organized sports.
Q: How common is it for children with hypochondroplasia to need orthopedic surgery at some point?
Mackenzie: It's relatively uncommon.
Q: Do many children with hypochondroplasia still need some kind of orthopedic care?
Mackenzie: I think that what's helpful about involving the orthopedic surgeon is to educate and set the expectations of the family — just like any patient that we care for — and then also to be about surveilling that child for bowing. There is a way to manage it while the child is still growing that is much less invasive than if they are near maturity, say mid-teenage years or after maturity.
If they're still growing, we can guide the growth of that knee to allow it to straighten, getting better mechanics of the leg and resolution of pain, with what we call a guided-growth plate, or hemiepiphysiodesis. And if we miss that opportunity, then it involves cutting the bone and a more invasive and involved procedure to get them into that same position.
So I think having contact with an orthopedic surgeon for a screening and education is important. And then if there is early bowing or any concern on the family's part, seeing an orthopedic surgeon approximately once a year is a good way to be proactive about caring for these kids.
Q: What types of spinal symptoms or complications do orthopedic surgeons check for?
Mackenzie: There's a risk of a curvature of the spine, or kyphosis, and spinal stenosis in these young people. It's pretty uncommon to have a child with hypochondroplasia have an issue that requires surgical treatment, but there are people who have required care and specifically surgery for this.
I have not had to do a spine surgery on a young person with hypochondroplasia. We think about it. We watch them. We educate them about the signs and symptoms of spinal stenosis. But again, it's pretty uncommon. Surgery certainly has been performed in some young adults with hypochondroplasia, but they're at much lower risk than, say, those with achondroplasia.
Q: What should parents consider when choosing an orthopedic surgeon for a child with hypochondroplasia?
Mackenzie: There are a lot of good orthopedic surgeons out there. Making sure that the provider has some experience with skeletal dysplasia can be very helpful. You also want to make sure that they're thinking about the child within the context of hypochondroplasia and that they have experience with the guided-growth plate technique.
And I would want to make sure that any provider they're going to is familiar enough with hypochondroplasia to be considering the potential for spinal stenosis before they're putting them through general anesthesia for their leg procedure.
You also want someone who isn't hyper-focused just on the bowing, and is getting the child to the subspecialty providers who are going to be helpful outside of orthopedics, like ENT (ear, nose, and throat medicine), pulmonology, sometimes neurology for seizure disorders, which we think are higher prevalence in hypochondroplasia.
Q: How closely do you work along with other health care professionals to manage the symptoms and possible complications of hypochondroplasia?
Mackenzie: For us, it's about collaborating on a regular basis. My pediatrician colleagues and I meet once a week to talk about our shared patients, because there can be crowding of the airway requiring a tonsillectomy or adenoidectomy with an ENT (ear, nose, and throat) surgeon. There can be a speech delay due to the need for eustachian tubes with an ENT as well. You can have pulmonary issues like obstructive sleep apnea requiring a CPAP machine, or some other support overnight requiring a pulmonologist. And again, there's the potential for seizures in hypochondroplasia. There's a higher proportion of learning differences that require a developmental specialist or an education specialist.
I think that every health care system is going to look a little bit differently, but my colleagues and I are trying to make sure that between us, we're getting those patients to the subspecialists that they need. I don't know that every patient needs to see every subspecialist. That's probably not a great use of the family's time. But it helps to have either a surgeon or a pediatrician serving as the quarterback of that patient's care within that health care system so that we don't miss any opportunities for these young people.
Q: Is there anything you wish more people knew about hypochondroplasia or its treatments?
Mackenzie: What I would communicate is how successful, active, and independent these patients can be. And with a diagnosis, I think many families are looking to learn as much as possible to provide the best opportunities for their child, which is incredibly important. And my job is partly to screen them and make sure that they don't have anything that needs surgery or any treatment or even just physical therapy, non-operative treatment. I also encourage them to be active, have as much fun as their average stature peers without hypochondroplasia, play sports, stay strong, stay healthy, maintain a healthy body type. That's a big thing for us. If our patients are not active, if they're not making healthy dietary choices.
We know that for the average person without a diagnosis of hypochondroplasia, excess weight gain and obesity can lead to joint pain, arthritis, back pain. We can't just say that it's the same in hypochondroplasia; we're still learning more and more about the impact of weight. But what I can say is that it increases force across the low back. It increases forces at the hip and knee. So that increases the risk of pain.
Do they respond the same way that someone without hypochondroplasia does? We're still learning about that. But patients have less pain when they maintain a lean, healthy body type. And if they do need surgery, they have fewer complications in the absence of obesity. So I don't want to overstate what we know about hypochondroplasia, but I think that those are really commonsense take-home points that apply to all of our patients.