Prader-Willi Syndrome (PWS) is a rare genetic disorder that affects many aspects of a child’s health, including growth, metabolism, muscle tone, and the musculoskeletal system. Children with PWS often have low muscle tone (hypotonia) from birth and face unique challenges such as developmental delays and excessive weight gain. In addition to these well-known features, PWS is commonly associated with orthopedic issues – especially involving the spine. As parents and families navigating a PWS diagnosis, it’s important to understand the potential spine and orthopedic problems, how to monitor for them, and the treatment options available. With specialized pediatric orthopedic care, careful patient selection for interventions, and a compassionate, team-based approach, children with PWS can achieve improved mobility and successful outcomes.

Orthopedic Challenges in PWS: Why Spine Issues Occur

PWS is characterized by severe hypotonia (low muscle tone) in infancy, which gradually improves but never fully normalizes. This muscle weakness means the spine doesn’t have typical muscular support, making children with PWS prone to developing scoliosis, an abnormal curvature of the spine. In fact, scoliosis is present in a large proportion of children with PWS – studies indicate anywhere from about 30% up to 70% or more of patients may develop scoliosis. The curvature often starts early in life (some PWS infants and toddlers show signs of scoliosis by age 2-4) and can progress during rapid growth phases like adolescence. Low muscle tone allows the spine to bend sideways more easily, and if a child with PWS is also overweight (common in PWS due to hyperphagia), the added weight can strain the spine further. Besides scoliosis, kyphosis (forward rounding of the upper back) can appear in later childhood or adulthood. Ligamentous laxity (loose ligaments) in PWS may contribute to abnormal spinal alignment as well. Another factor is the use of growth hormone therapy – many children with PWS receive growth hormone to improve height, muscle mass, and metabolism. There has been some debate about whether growth hormone might trigger or worsen scoliosis. Fortunately, research shows that the incidence of scoliosis in PWS is not significantly increased by growth hormone use. This is reassuring for families using this important therapy, though regular spine monitoring remains critical. Overall, the combination of hypotonia, body composition, and other PWS-related factors creates a “perfect storm” for spinal curvature problems. Families and primary care providers should be aware of this risk so that regular spine check-ups (at least annually) are part of the care plan.

Scoliosis in PWS: Early Detection & Monitoring

Scoliosis (a sideways curvature of the spine) is a major concern for patients with PWS, so proactive monitoring is essential. Because scoliosis can develop very early in PWS, pediatricians and parents should be on the lookout even in infancy and toddler years. Many experts recommend a systematic spine examination at least once a year for children with PWS. In practical terms, this means checking your child’s back for any asymmetry: is one shoulder higher, one shoulder blade more prominent, or does the spine look curved? If any doubt exists, a referral to a pediatric orthopedic specialist for a detailed evaluation is warranted. Early detection is important because mild curves are easier to manage and can often be treated with less invasive methods. According to data from a large study, the median age when scoliosis is first noted in PWS was around 4.5 years. Two peak periods for scoliosis progression in PWS are early childhood (around 5 years old) and adolescence during the pubertal growth spurt. Knowing this, our clinic emphasizes close observation during these high-risk windows. If a curve is detected, the orthopedic team will likely obtain standing spine X-rays (to measure the Cobb angle, which quantifies the curve). For very young children (infants/toddlers) who can’t easily get X-rays, a physical exam or ultrasound might be used to assess the spine until they’re a bit older. Families should also watch for signs like an unusual sitting posture or leaning to one side – since PWS children often have delayed motor milestones, subtle changes in posture during sitting or walking can be clues. It’s important to note that scoliosis in PWS isn’t just a cosmetic or orthopedic issue; it can impact respiratory function. Because children with PWS may already have breathing weaknesses (due to hypotonia and sometimes obesity), a significant spinal curve can restrict lung expansion. Indeed, severe kyphoscoliosis in PWS has been linked to respiratory failure and cor pulmonale (strain on the heart from lung issues). This underlines why timely care of spinal issues is critical – a well-aligned spine contributes to better breathing and overall health for a child with PWS

Treatment Approaches for Spinal Curvature

When it comes to treating scoliosis in PWS, the approach is highly individualized, taking into account the child’s age, the severity of the curve, and their overall health status. Conservative (non-surgical) management is the first line for most children, especially younger ones. For instance, if a toddler or preschooler with PWS has a moderate curve (say 20–30 degrees), our specialists may recommend serial casting. In this technique, performed under anesthesia, we gently manipulate the child’s spine towards straighter alignment and apply a specialized cast from shoulders to hips. The cast holds the spine in a corrected position, and over 2–4 months the child’s growth can help “remold” the spine. Casts are changed periodically (every 2–4 months) as the child grows. This method has shown encouraging results – about one in three young PWS patients in one series had their scoliosis significantly improve with casting, allowing them to transition to a brace thereafter. The goal is to guide the spine’s growth and delay or even avoid surgery while the child is very small. After casting, or for milder curves, bracing is commonly used. A thoracolumbar sacral orthosis (TLSO), which is a custom-molded plastic brace, can be worn typically 16–20 hours a day to hold the spine and prevent further curvature. In PWS, bracing is often started after a period of casting or if a curve is caught early. Families sometimes worry that bracing could be uncomfortable or interfere with daily life, but modern braces are fairly lightweight, and kids can do most activities in them. It’s important to make bracing fun – we often decorate braces with child-friendly designs and stress that wearing the brace is a team effort to “make my back strong.” For older children or more severe scoliosis (curves exceeding ~40–50°), surgery may become necessary. Surgical correction typically involves spinal fusion, where the surgeon straightens the spine and fuses the vertebrae in place with rods and screws. However, children with PWS require extremely careful surgical planning and specialized expertise. Patient selection for surgery is critical – the surgeon, anesthesiologist, and the family must weigh the benefits (a straighter spine, better sitting balance, potentially improved breathing) against the risks. PWS patients have a higher risk of surgical complications than typical scoliosis patients. Some reported complications include difficulties with wound healing, higher chance of spine bone fusion not healing properly (pseudoarthrosis), or even rare neurological issues. Furthermore, PWS children often have increased skin picking behaviors and a high pain threshold, which can affect recovery and wound care. At our pediatric orthopedic center, we mitigate these risks by meticulous pre-operative preparation (including nutrition and respiratory optimization), and engaging a multidisciplinary team for aftercare (such as endocrinologists for hormonal support and pulmonologists for breathing support). In certain cases, newer surgical techniques can be considered: for example, expandable growing rods for younger children (to allow the spine to keep growing after surgery), or vertebral body tethering (VBT) which is a fusionless surgery that preserves motion (though VBT is typically reserved for idiopathic scoliosis and requires careful consideration in PWS due to hypotonia). The bottom line is that if surgery is indicated, having it done at a center familiar with rare diseases like PWS and neuromuscular scoliosis is crucial for safety and success. The encouraging news is that with the right approach, many children with PWS who undergo scoliosis treatment (whether casting, bracing, or surgery) do very well. Families often report that after treatment, their children sit straighter, have improved endurance, and in some cases improved lung function because the spine is better aligned. Successful outcomes are most likely when problems are caught early and managed by an experienced team.

Beyond the Spine: Other Orthopedic Issues in PWS

While spine issues are a major focus, PWS can affect other parts of the musculoskeletal system too. Another common issue is hip dysplasia – an instability or shallow development of the hip joint. Due to low muscle tone, some infants with PWS are born with hip dysplasia or even dislocations. About 30–40% of children with PWS show evidence of hip dysplasia on exams or X-rays. The good news is that serious hip deformities requiring surgery are relatively uncommon, occurring in maybe 5% of patients (around 1 in 20 children with PWS). Often, if a PWS baby has mild hip dysplasia, we may adopt a conservative approach (like soft bracing) and monitor it, because interestingly, adults with PWS do not seem to suffer the typical arthritis from residual hip dysplasia that others would. However, any infant with PWS should have hip screening and, if needed, treatment early – usually with methods like a Pavlik harness or casting if the hip is dislocated. Flat feet (pes planus) are also frequently seen in PWS. Low muscle tone leads to less support of the arches, so many toddlers with PWS develop very flat, flexible feet. Without intervention, they could grow into adults with foot pain due to misalignment. Our clinic’s approach is to use custom orthotic inserts or small braces (UCBL orthoses) in early childhood to shape the foot’s arch and heel alignment. These are usually worn during the day inside shoes. By providing proper foot alignment while a child is growing, we help them develop a more typical arch and improve their walking efficiency. Most kids with PWS tolerate these inserts well, especially if we start them when the child is first learning to walk, as it just becomes a normal part of their routine. Another aspect to be aware of is osteoporosis and fractures. Children and adolescents with PWS have an increased risk of low bone density. Contributing factors include reduced muscle forces on bones, less mobility in some cases, and nutritional differences. Some studies report that up to 20–30% of kids with PWS have had fractures due to osteopenia (brittle bones). Parents should ensure their child has adequate calcium and vitamin D, and endocrinologists sometimes check bone density in PWS patients, especially if there’s a history of fractures. Weight-bearing activities (supervised exercise, walking) can strengthen bones, and newer treatments like bisphosphonates have been used in severe cases to improve bone density. Preventing fractures also circles back to treating scoliosis – a very twisted spine can itself be at risk for vertebral fractures. Whole-child care means we address nutrition, bone health, and physical therapy in conjunction with any orthopedic treatments.

Compassionate, Specialized Care Leads to Success

Caring for a child with PWS requires a team approach, and families should feel that they are not alone on this journey. At our pediatric orthopedic practice, we work closely with geneticists, endocrinologists, nutritionists, pulmonologists, and therapists to support every aspect of the child’s health. We understand that parents of children with PWS often face additional stressors – concerns about their child’s future, questions about surgical risks, and juggling multiple therapies. Our role is not only to provide surgical and medical expertise but also to offer guidance, support, and empathy. For example, if a brace is needed for scoliosis, we take the time to explain to both parent and child why it’s important and how it will help them do the things they love, like playing or sitting comfortably in class. Because PWS is a rare disease, many local providers may have limited experience in its orthopedic management. We frequently provide second opinions for families – perhaps your local doctor has recommended a spine surgery and you feel unsure, or you want to confirm the best course of action for a hip problem. Seeking a second opinion at a specialized center is a wise step; we can often either reassure you that the plan is sound or suggest alternative approaches tailored to PWS. We also welcome families traveling from other regions or even countries (“medical tourism”) when specialized care is not available near home. Our practice is accustomed to coordinating with out-of-town families to make the process as smooth as possible, recognizing the extra effort it takes for you to come to us for expert care. In summary, Prader-Willi Syndrome comes with significant orthopedic challenges, especially involving the spine, but there is hope and help available. Through vigilant monitoring, early interventions like casting and bracing, and judicious use of surgery in the right cases, children with PWS can maintain better alignment and function. We have seen children with PWS go from struggling to sit due to a severe scoliosis, to post-treatment sitting upright with a big smile and engaging more with their world. Every child with PWS is unique, and our commitment is to provide compassionate, individualized care that maximizes their health and abilities. With careful patient selection for any procedure and a focus on safety, we strive for successful outcomes that improve quality of life. Families can take comfort in knowing that with specialized pediatric orthopedic support, many PWS-related orthopedic issues can be managed effectively – allowing your child to focus on being a child, growing, learning, and enjoying life to the fullest extent possible.

For a comprehensive evaluation and to explore your treatment options, don’t hesitate to schedule an appointment or seek a second opinion consultation with Dr. Arun Hariharan at Paley Orthopedic & Spine Institute by calling (561) 602-9155.