If your child has cerebral palsy, there's a monitoring schedule for their hips that you may not have heard about yet. It's called hip surveillance, and it's designed to catch displacement early, before it becomes painful or requires major surgery.

Many families don't learn about this pathway until their child is already experiencing discomfort or an orthopedist flags a problem on an X-ray. But the monitoring protocol exists for a reason: children with CP are at higher risk for hip displacement as they grow, and catching it early makes a significant difference in outcomes.

Here's what hip surveillance is, why it matters, and what the recommended schedule looks like based on your child's GMFCS level.

What Hip Surveillance Is

Hip surveillance is a proactive monitoring program using scheduled X-rays to track how well the hip joint is staying in place as your child grows. It's not treatment. It's early detection.

The X-rays measure something called the migration percentage, which shows how much of the femoral head (the ball of the hip joint) is sitting outside the socket. A migration percentage under 30% is generally considered stable. Above that, orthopedists start watching more closely or discussing intervention.

Without monitoring, hip displacement can progress silently. By the time a child is in pain or has visible gait changes, the hip may have migrated significantly, narrowing the window for less invasive options like physical therapy adjustments, bracing, or muscle release surgery.

Why Children with CP Are at Higher Risk

Cerebral palsy affects muscle tone and coordination. In many children, spasticity pulls unevenly on the hip joint over time. The muscles that would normally hold the femoral head centered in the socket are working against imbalanced forces, and the hip can gradually shift out of place.

This risk is highest in children with more significant motor impairment. Research shows that up to 90% of children at GMFCS levels IV and V will experience some degree of hip displacement without proactive monitoring and intervention.

For children at GMFCS levels I and II, the risk is lower but not absent. Hip surveillance guidelines now recommend monitoring for all children with CP, with frequency adjusted based on severity.

The Recommended Surveillance Schedule

The schedule is tied to your child's GMFCS level, which describes their gross motor function. If you're not sure what level your child is, ask your physical therapist or developmental pediatrician. It's a five-level classification that helps guide care planning.

GMFCS Levels IV and V (Non-Ambulatory or Minimal Independent Mobility)

Children at these levels have the highest risk of hip displacement and need the most frequent monitoring.

Recommended schedule:

• X-rays every 6 months from diagnosis until age 8
• Annual X-rays from age 8 onward if hips remain stable

If migration percentage rises above 30%, your orthopedist may recommend more frequent imaging or discuss intervention options like soft tissue release, botulinum toxin injections, or in some cases, reconstructive surgery.

GMFCS Level III (Walks with Assistive Devices)

Children at level III are at moderate risk. The recommendation is less frequent than for levels IV and V but still proactive.

Recommended schedule:

• X-rays annually from diagnosis through age 8
• Every 2 years from age 8 to skeletal maturity if hips remain stable

If migration percentage trends upward or crosses 30%, the schedule may shift to more frequent monitoring.

GMFCS Levels I and II (Walks Independently with or without Limitations)

Children at these levels have lower risk, but hip displacement can still occur. Guidelines recommend baseline imaging and periodic follow-up.

Recommended schedule:

• Baseline hip X-ray at diagnosis or by age 2-3
• Repeat X-rays every 2-3 years through age 8 if initial films are stable
• Clinical monitoring after age 8 unless concerns arise

If your child develops new gait asymmetry, hip pain, or difficulty with positioning, additional imaging may be needed even if they're at a lower GMFCS level.

What Happens at a Hip Surveillance Appointment

Hip surveillance is usually part of your child's regular orthopedic follow-up. If your child doesn't see an orthopedist yet, ask your pediatrician for a referral.

At the appointment, your child will have a pelvic X-ray. The orthopedist or radiologist will measure the migration percentage and assess the shape and alignment of the hip joint. You'll typically get results the same day or within a few days, depending on the practice.

If the hips are stable, you'll schedule the next surveillance X-ray based on the recommended timeline. If there's early displacement, your orthopedist will discuss options. Early intervention often means less invasive treatment.

When to Ask for a Referral

If your child hasn't had a hip X-ray and has been diagnosed with CP, it's worth asking about surveillance. Many pediatricians assume the family will be referred to orthopedics as part of the diagnostic process, but that doesn't always happen automatically.

You can bring it up at your next well-child visit or call your child's care coordinator to request an orthopedic referral. The phrase "hip surveillance per CP guidelines" will signal that you're asking for proactive monitoring, not just responding to a problem.

If your child already sees an orthopedist but hip surveillance hasn't been mentioned, you can ask directly: "Should we be doing scheduled hip X-rays based on her GMFCS level?"

What Migration Percentage Means for Your Child

When the orthopedist reads you a number at the appointment, that number is a measurement, not a verdict. It tells you where your child's hip sits right now and helps shape what monitoring looks like going forward.

A migration percentage under 30% means the hip is well-positioned and stable. You keep following the standard surveillance schedule and continue with your child's existing therapy and positioning supports.

Between 30% and 50%, orthopedists consider the hip "at risk." This is the window where the conversation shifts from watchful waiting to considering early options: adjustments in physical therapy, tone management with botulinum toxin, or soft tissue release surgery. Catching displacement here means the choices are still relatively manageable.

Above 50%, the hip is considered significantly displaced. At that point, options may include reconstructive surgery to reposition the hip, or in some cases, focusing on comfort and function rather than full correction. This is the outcome surveillance is designed to prevent.

Knowing where your child stands in that progression is useful information, even when the number is higher than you'd hoped. It puts you and the care team in a position to act rather than react.

What Happens if Hip Displacement Is Found Early

Early detection doesn't mean surgery is inevitable. Hearing that the migration percentage has moved is unsettling, but it's also the reason surveillance exists: you found out early enough to act.

Many children with early signs of displacement respond to adjustments in therapy, bracing, or spasticity management. Your orthopedist may recommend more frequent PT sessions focused on hip positioning, or changes to your child's seating and stander to optimize alignment. Spasticity treatments like botulinum toxin can reduce the muscle forces pulling the hip out of alignment, which in turn gives the joint a better chance to stay in place.

If the displacement continues to progress despite these measures, soft tissue release surgery (lengthening tight muscles around the hip) is often the next step. This is less invasive than reconstructive surgery and has a shorter recovery time.

Reconstructive surgery, which repositions the femoral head and may involve reshaping the socket, is typically reserved for more significant displacement or cases where other interventions haven't been effective. It exists, and knowing it exists means your care team has options, but the goal of surveillance is to stay well upstream of that point.

Why This Schedule Exists

Hip surveillance protocols were developed after research showed that many children with CP were reaching adolescence with painful, dislocated hips that could have been prevented with earlier monitoring. The pain affects quality of life, limits participation in activities, and complicates caregiving.

Proactive surveillance shifts the timeline. Instead of discovering hip displacement when it's painful and requires major surgery, families and providers can track it from the start and intervene when options are less invasive.

It's not about medicalizing childhood. It's about using X-rays strategically so your child doesn't end up in pain down the line.

Questions to Ask Your Child's Orthopedist

If you're starting hip surveillance or want to understand your child's results better, these questions can help:

• What is my child's current migration percentage, and what does that mean for their monitoring schedule?
• At what migration percentage would we start discussing intervention?
• What early interventions are options if the hips start to displace?
• How does my child's spasticity management plan tie into hip surveillance?
• Should we be adjusting anything in therapy or positioning based on the X-ray findings?

What If Your Child's Provider Hasn't Mentioned This

Hip surveillance is part of the standard of care for children with CP, but not every provider is equally proactive about implementing it. If your child hasn't had a baseline hip X-ray and is past age 2, it's reasonable to bring it up.

You're not overstepping. You're asking about an established monitoring protocol. If your pediatrician or orthopedist isn't familiar with the guidelines, you can reference the American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) care pathways, which outline the recommended schedule.

How This Fits Into the Bigger Picture

Hip surveillance is one piece of the orthopedic care your child may need as they grow. Other common concerns include contractures, spinal curvature, and foot positioning, all of which are monitored alongside hip health.

The goal isn't to create a childhood full of medical appointments. It's to catch issues early enough that the interventions are smaller, the recovery is faster, and your child stays comfortable and functional.

Hip surveillance does that job. It's a scheduled X-ray every six months or once a year, depending on risk level, and it gives you and your child's care team the information to make decisions before pain or limited mobility become the signal that something's wrong.

As a parent, you're already carrying a lot. Staying on top of a monitoring schedule is one of those things that feels like one more item on an impossible list, and some days it will. But it's also one of the clearest examples in CP care where early, consistent attention genuinely changes outcomes. The families who navigate this well aren't the ones with perfect medical systems or unusually cooperative providers. They're the ones who knew to ask, and kept asking.

FAQ

How often should my child with CP have hip X-rays?

The schedule depends on GMFCS level. Children at levels IV-V need X-rays every 6 months until age 8, then annually. Level III children need annual X-rays through age 8, then every 2 years. Levels I-II need baseline imaging and follow-up every 2-3 years through age 8.

What is a normal migration percentage for a child's hip?

A migration percentage under 30% is considered stable. Between 30-50% is at-risk and requires closer monitoring or early intervention. Above 50% is significant displacement and may require surgery.

Can hip displacement in CP be prevented?

Early detection through surveillance allows for interventions like physical therapy adjustments, spasticity management, or soft tissue release surgery before the hip fully dislocates. While not always preventable, the goal is to catch it early when treatment options are less invasive.

What should I do if my child with CP has never had a hip X-ray?

Ask your pediatrician for an orthopedic referral and mention hip surveillance per CP guidelines. If your child already sees an orthopedist, ask directly whether scheduled hip X-rays are part of the care plan.

Does my child need hip surveillance if they walk independently?

Yes. Even children at GMFCS levels I and II can experience hip displacement, though the risk is lower. Guidelines recommend baseline imaging and periodic follow-up through age 8.

What happens if my child's migration percentage is increasing?

Your orthopedist will likely recommend more frequent monitoring and discuss early interventions, which may include adjustments in physical therapy, spasticity management with botulinum toxin, bracing, or soft tissue release surgery to prevent further displacement.