Clinical Observations and Treatment Approaches for Scoliosis in Prader–Willi Syndrome

Abstract

Prader–Willi syndrome (PWS) is recognized as the first example of genomic imprinting, generally due to a de novo paternal 15q11-q13 deletion. PWS is considered the most common genetic cause of marked obesity in humans. Scoliosis, kyphosis, and kyphoscoliosis are commonly seen in children and adolescents with PWS with a prevalence of spinal deformities cited between 15% to 86%. Childhood risk is 70% or higher, until skeletal maturity, with a bimodal age distribution with one peak before 4 years of age and the other nearing adolescence. As few reports are available on treating scoliosis in PWS, we described clinical observations, risk factors, therapeutic approaches and opinions regarding orthopedic care based on 20 years of clinical experience. Treatments include diligent radiographic screening, starting once a child can sit independently, ongoing physical therapy, and options for spine casting, bracing and surgery, depending on the size of the curve, and the child’s age. Similarly, there are different surgical choices including a spinal fusion at or near skeletal maturity, versus a construct that allows continued growth while controlling the curve for younger patients. A clear understanding of the risks involved in surgically treating children with PWS is important and will be discussed.

Is ghrelin a biomarker of early-onset scoliosis in children with Prader–Willi syndrome?

“…The prevalence of scoliosis is around 40% [ 26 , 27 ], compared with 1–3% in the general population [ 28 ]. The scoliosis prevalence in PWS increases with age, from 23% in children under 4 to 75% in adults [ 29 , 30 ], with both sexes equally affected [ 27 ]. The age of diagnosis has a bimodal distribution: the first peak in early childhood and the second in the pre-pubertal period.…”

Prader-Willi Syndrome: Kyphoscoliosis is an underdiagnosed problem in young patients

“…The incidence and prevalence of scoliosis is approximately 40% and the prevalence increases with age (infants and juveniles: 30%, adolescents: 80%) [5][6][7]. Vertebral rotation is responsible for the asymmetry of the chest wall seen during forward bending, usually the fi rst sign of scoliosis.…”

“…There are two types of expandable implants: "growth rods" or "Non-Fusion Spinal Instrumentation" (NFSI) and the "Vertical Expandable Prosthetic Titanium Rib" (VEPTR)device. Because of osteopenia in PWS, the NFSI which has greater hardware stability has been shown to be superior to VEPTR in this population[10]. Defi nitive spinal fusion should be performed for curves exceeding 50 degrees out-of-brace in older children since a curve of this size has a 95% chance of progressing, even after skeletal maturity.…”

“…Defi nitive spinal fusion should be performed for curves exceeding 50 degrees out-of-brace in older children since a curve of this size has a 95% chance of progressing, even after skeletal maturity. Since children with PWS may have delayed skeletal maturation, and it is advantageous to wait until 12 years of age for girls and 14 years for boys before performing defi nitive spinal fusion[8].Overall, 15% of curves diagnosed before 4 years of age will eventually require surgical treatment and 41% of curves diagnosed after 4 years of age require surgical correction[8].Conservative treatment should be the preferred treatment option for non-progressive scoliosis curves within certain limits (usually < 50 degrees), considering the lack of evidence for the long term outcome of surgery and the high risks of surgical intervention such as hardware failure due to osteopenia, skin picking and poor quality of the soft tissues resulting in high rates of wound dehiscence and related deep infections (19% and 38% of cases)[10,11] . Postoperatively PWS patients can experience life-threatening complications such as protracted ileus and stomach rupture due to overeating and chronic constipation.…”

“…Postoperatively PWS patients can experience life-threatening complications such as protracted ileus and stomach rupture due to overeating and chronic constipation. Because PWS individuals often suffer from sleep apnea (80%) and narcolepsy (30%) a pre-operative pulmonary evaluation including a sleep study is necessary to assess the need for BPAP or CPAP in the post-operative recovery period[10,12] .…”