Orthopeadic Specialist

Scoliosis | hip dysplasia | musculoskeletal abnormalities | dislocation

There is a high incidence of scoliosis in children with PWS therefore it is recommended that a paediatric orthopaedic surgeon conducts systemic clinical and radiographic evaluations for scoliosis, hip dysplasia, dislocation, and lower limb malalignment annually. 

An orthopaedist should evaluate and treat, if necessary, curvature of the spine (scoliosis) and any other severe musculoskeletal abnormalities that require attention. 

Many Children with Prader Willi Syndrome will develop scoliosis. Approximately 15% of these children will develop severe or significant curves, requiring bracing or surgery. The earlier the curve is detected, the better the possibilities for treating the curve with casting or bracing.

There are two peak ages for scoliosis presentation in children with PWS. Under the age of 4 years, most of the curves are C-shaped, and are most likely related to the hypotonia. The second peak, centered around 10 years of age, typically is the more common idiopathic S-shaped curve.

Importantly spinal deformities in children with PWS have less vertebral rotation than seen in other children with scoliosis curves of a similar size. Vertebral rotation causes the asymmetry of the chest wall seen during forward bending, usually the first sign of scoliosis. Therefore, the child with PWS may have a moderate curve radiographically, but only mild findings clinically. For that reason, there should be a much lower threshold for working up clinical findings in children with PWS, compared to otherwise unaffected children.

Scoliosis in infants with PWS is unlikely to develop prior to the influence of gravity across the spine. Therefore, monitoring of spine should begin when the child first sits independently, usually around the first birthday. Yearly screening radiographs of the seated or standing spine should be used in addition to a clinic examination. If a deviation greater than 10° from straight is noted, radiographs should be obtained more frequently, depending on the age of
the child, size of the curve, and apparent risk towards progression.

Human Growth Hormone (HGH or Growth Hormone GH) has been shown, in multiple studies, to be beneficial for those with Prader-Willi Syndrome (PWS). Previously, it was thought that introducing Growth Hormone potentially could increase the severity of scoliosis, since scoliosis progression is most evident during periods of rapid growth. A long-term study reported at a Paediatric Endocrinology meeting in 2019, looked at the incidence and severity of scoliosis in children with PWS treated with GH. This study showed no difference in the prevalence of scoliosis. However, the severity of scoliosis was modestly better in children who received GH (less curvature), perhaps because of more/stronger muscles in those who received GH.  The research, “Effects of eight years growth hormone treatment on the onset and progression of scoliosis in children with Prader-Willi syndrome,” was presented in September at the European Society for Paediatric Endocrinology in Vienna, Austria, and published in the journal Hormone Research in Paediatrics.

Osteopenia/Osteoporosis, and high pain threshold are aspects of PWS that have the potential to complicate all facets of orthopaedic nonsurgical and surgical management in people with PWS. It is important that the Orthopaedic Specialist is experienced with PWS and understands the complications involved in treating children and adults with PWS.