A non-obese boy with Prader-Willi syndrome shows cardiopulmonary impairment due to severe kyphoscoliosis

High Prevalence of Scoliosis in a Large Cohort of Patients with Prader-Willi Syndrome

The characteristics of scoliosis were investigated in a large cohort of children and adults with Prader–Willi syndrome (PWS), analysing the role of age, gender, puberty, body mass index (BMI), genotype and growth hormone therapy (GHT) on its onset and severity. A retrospective cross-sectional study was performed in 180 patients with genetically confirmed PWS (96 females), aged 17.6 ± 12 years. Eighty-five subjects (47%) were obese. One hundred and fifty subjects (83.3%) were on GHT, while 30 patients had never been treated. Overall, 150 subjects (83.3%) were affected by scoliosis, 80.2% of children and adolescents and 87.8% of adults. A mild degree of scoliosis was observed in 58 patients (38.7%), moderate in 43 (28.7%) and severe in 49 (32.6%). Median age at diagnosis of scoliosis was 6.3 years, while the severe forms were diagnosed earlier (median age: 3.8 years). The cumulative probability at 5 years of age was equal to 0.403 and almost doubled at 15 years. No significant associations were found between scoliosis and genotype, gender, pubertal stage, GHT and BMI. A corset was prescribed to 75 subjects (50%) at a median age of 7.5 years, while 26 subjects (17.3%) underwent surgery at a median age of 13.1 years. Our data indicate that scoliosis is one of the major concerns for PWS patients that increases with age, and therefore suggest the need for regular systematic monitoring of spinal deformity from paediatric age.

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

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.

Intraoperative adrenal insufficiency in a patient with prader-willi syndrome

Prader-Willi syndrome (PW) is a rare genetic disorder with multi-organ system involvement. These patients present many perioperative challenges including sleep-related breathing disorders, morbid obesity, thick salivary secretions, mental retardation, and difficult intravenous access. PW has been suggested to be associated with central adrenal insufficiency. We report a novel case of persistent severe hypotension from previously undiagnosed and asymptomatic adrenal insufficiency in a pediatric patient with Prader-Willi syndrome during spine surgery that resolved upon treatment with hydrocortisone.

Growth hormone supplement treatment reduces the surgical risk for Prader-Willi Syndrome patients

INTRODUCTION

Many complications have been reported to occur with surgery for scoliosis in Prader-Willi Syndrome (PWS). However, growth hormone (GH) treatment has contributed to improvements in height, body composition, bone density and breathing functions in PWS patients. The purpose of this study was to investigate patients who underwent surgery for scoliosis in PWS.

MATERIALS

There were 136 PWS patients being followed-up by the Pediatrics Department of our hospital. Among these, we investigated nine patients who had undergone surgery. Their mean age was 11 years. The mean follow-up period was 6 years 10 months.

RESULTS

The mean body mass index was 22.5 kg/m(2). GH therapy was administered to eight patients. Brace treatment was performed in two patients. Spinal correction and fusion were performed in six patients, and the growing rod method was performed in three patients. Necessary reoperations were performed in two patients. For the total 11 surgeries in the nine patients, the mean blood loss was 397 ml and the mean operation time was 4 h and 20 min. The mean Cobb angles were 76.0 degrees preoperatively and 35.8 degrees at follow-up. Regarding complications, one patient experienced early dislodgment of the hook and one patient experienced a superior wound infection.

CONCLUSION

There were no severe complications such as deep infections or neurovascular damage. A few obese patients underwent surgery, but there were no dangerous complications. Overall, we consider that GH treatment before surgery may reduce postoperative complications. The growing rod method was effective for PWS patients who resisted brace treatment owing to mental retardation.

Treatment of scoliosis in patients affected with Prader-Willi syndrome using various techniques

BACKGROUND

The incidence of spinal deformity in children with Prader-Willi syndrome (PWS) is high, with 86% of these patients found to have a significant structural scoliosis; however, there are very few case reports describing surgical treatment for this deformity.

METHODS

The authors reviewed a case series consisting of 6 patients who underwent spine surgery for scoliosis. Children's mean age at index surgery was 12 years and 10 months (range, 10 to 15 yrs). Clinical evaluation revealed the typical phenotypic features of the PWS in all of the patients; 4 subjects had a karyotype confirmation of PWS. Major structural curves showed preoperative mean Cobb angles of 80.8 degrees (range, 65 degrees to 96 degrees ). Hybrid instrumentation with sublaminar wires, hooks and screws was used in the first 2 patients, while the remaining 4 were treated with titanium pedicle screw constructs.

RESULTS

The mean clinical and radiological follow-up was 3 years and 10 months (range, 2 years to 9 years). Major complication rate was 50%. One patient who developed a major intraoperative complication (paraparesis) prevented spinal fusion to be obtained: the neurologic deficit resolved completely after instrumentation removal. Solid arthrodesis and deformity correction in both coronal and sagittal plane was, however, achieved in the other 5 cases and no significant curve progression was observed at follow-up. Another major short-term complication was encountered 3 months after surgery in a patient who experienced the detachment of a distally located rod and required correction through revision surgery and caudal extension by one level. Cervico-thoracic kyphosis was seen in 1 patient who did not require revision surgery.

CONCLUSIONS

Spine reconstructive surgery in patients with PWS is rare and highly demanding.The best method of reconstruction is posterior multilevel pedicle screw fixation. Moreover, even with modern techniques, the risk of complications is still high. These new techniques, however, have shown to improve the postoperative course by allowing for immediate mobilization without any brace or cast. The use of the growing rod techniques, requiring repeated surgeries, should be carefully evaluated in each single case.

Scoliosis in patients with Prader-Willi Syndrome

OBJECTIVE

Our goals were to determine the prevalence and estimate the evolution of spinal deformities in patients suffering from Prader-Willi syndrome; find out which kind of spine deformity predominates regarding genotype and clinical patterns; and evaluate the affect of growth-hormone treatment on the onset and progression of spinal deformities.

PATIENTS AND METHODS

This was a retrospective longitudinal, clinical, and radiologic study. One hundred forty-five children followed between 1980 and 2006 were studied in 2 referral centers for Prader-Willi syndrome. Genetic testing confirmed the diagnosis in 133 patients. Ninety-three patients (64%) received growth-hormone therapy. For statistical analysis, age-adjusted comparison between groups was performed by using multivariate logistic regression.

RESULTS

Mean age of the patients was 10.2 +/- 6.2 years. Sixty-three (43.4%) patients were afflicted with scoliosis. Scoliosis frequency steadily rose with age, and a large majority of patients were affected at skeletal maturity (66.7%). Scoliosis prevalence was not affected by the genotype or by growth-hormone treatment. Patients with higher BMI values had an increased risk of developing a kyphotic deformity in association with scoliosis. We found a statistical association between kyphotic deformity and the need for surgical treatment.

CONCLUSIONS

Scoliosis is a major concern for patients with Prader-Willi syndrome, and a regular (annual) systematic back examination is mandated. The role of growth-hormone treatment on the natural history of scoliosis could not be determined, and careful monitoring during treatment is recommended.

Complications of scoliosis surgery in Prader-Willi syndrome

STUDY DESIGN

Retrospective case series of 16 consecutive patients.

OBJECTIVE

To evaluate the results of scoliosis surgery in Prader-Willi syndrome (PWS) with special emphasis on the complications and their risk factors.

SUMMARY OF BACKGROUND DATA

PWS is a rare genetic disorder characterized by obesity, hypotonia, and frequent scoliosis. The literature dealing with scoliosis surgery in PWS consists of only few case reports. Surgical treatment was reported to be difficult with frequent and severe complications.

METHODS

Sixteen patients (3 males, 13 females) in 63 presenting scoliosis and PWS were operated on between 1974 and 2004. Preoperative, postoperative and last follow-up clinical and radiologic data were analyzed. Complications, treatment, and outcome were investigated.

RESULTS

Mean age at scoliosis diagnosis was 6.2 years (range 0.5-13.5). Mean age at surgery was 12.3 years (range 5-15). Mean follow-up was 5.4 years (range 2-18). There were 9 major complications (4 severe kyphosis above fusion, 2 deep infections, 1 transient paraplegia, 1 pseudarthrosis, 1 delayed wound healing). The 4 kyphosis required reoperation, 3 of which were complicated with permanent spinal cord injury. Minor complications affected 6 patients.

CONCLUSION

Scoliosis surgery is frequently necessary in PWS and is associated with high rate of complications. These are often related to specific features of this syndrome the surgeon should recognize and consider.