Three Mount Sinai orthopedic surgeons have published a guide for managing children and adults with Down syndrome, covering the range of musculoskeletal conditions these individuals experience along with other medical issues that orthopedists should keep in mind when evaluating them.
Down syndrome is the most frequent chromosomal abnormality in Americans, affecting about 1 in 700 babies born in the United States. Their distinct physical features include flattened facial profiles, short stature, and epicanthal folds. Common associated medical conditions include congenital heart disease, thyroid disease, vision problems, and leukemia, along with a range of musculoskeletal complications resulting from generalized ligamentous laxity.
Nonetheless, due to medical advances the lifespans of people with Down syndrome have increased from 25 years of age in 1983 to 60 years in 2020. Guidelines have been published for managing both children and adults with the condition, but some of the recommendations conflict. Additionally, none covers the broad array of orthopedic issues these individuals may experience while also calling attention to medical problems that may have escaped detection in other health settings.
“There’s no medical home for these people once they hit adulthood, since historically they didn’t often hit adulthood. Orthopedic surgeons tend to be among the ones to frequently see them,” notes Abigail K. Allen, MD, Chief of Pediatric Orthopedic Surgery and Director of the Pediatric Orthopedic Clinic at the Mount Sinai Health System.
“Orthopaedic management in Down syndrome” was published in the May 2021 issue of the Journal of the Pediatric Orthopaedic Society of North America. Dr. Allen is a co-author, along with Sheena C. Ranade, MD, Assistant Professor of Orthopedic Surgery at the Icahn School of Medicine at Mount Sinai, and Kyle Rako, MD, a third-year Orthopedic Surgery resident at Icahn Mount Sinai. The guidance is intended for both pediatric and adult orthopedic specialists as well as other clinicians who treat individuals with Down syndrome. The authors address four key concepts:
Musculoskeletal manifestations in Down syndrome are related to generalized ligamentous laxity, joint hypermobility, and hypotonia. These can vary in presentation at almost every anatomic level, including atlantoaxial instability, atlanto-occipital instability, scoliosis, spondylolisthesis, hip dysplasia/instability, patellar instability, pes planus, and hallux valgus.
Management of most of these conditions is symptom-driven. However, a high index of suspicion should be maintained for associated conditions such as cervical instability, scoliosis, hip instability, or slipped capital femoral epiphysis, since those can present subtly.
The pathologic laxity in these patients can complicate surgical management. The document includes a table outlining perioperative cervical spine, cardiac, pulmonary, and hematologic considerations. A multidisciplinary approach, such as the one in place at Mount Sinai, is strongly advised.
Although current pediatric and adult guidelines for Down syndrome do address systemic disorders such as hypothyroidism, leukemia, and inflammatory arthritis, these conditions can slip through the cracks. The orthopedist should always keep those possibilities in mind when evaluating patients and refer if any are suspected.
Another table in the paper provides specific evaluation and management guidance for atlantoaxial instability, one of the most common and challenging of the orthopedic manifestations of Down syndrome. According to the American Academy of Pediatrics guidelines, screening X-rays are no longer recommended routinely, but they should be considered in an individual with neck or radicular pain, weakness, spasticity, gait difficulties, change in bowel or bladder function, or signs/symptoms of cervical myelopathy. And if atlantoaxial instability is seen on the X-ray, follow-up magnetic resonance imaging is advised.
Surgical intervention for atlantoaxial instability is recommended when atlanto-dens interval (ADI) is greater than 10mm. Whether to restrict sports is a controversial topic—guidelines for the Special Olympics conflict with some others – but generally should be considered for ADI >4.5mm.
Overall, says Dr. Allen, “As orthopedists we want to help people have better motion and live their lives to the fullest, but for a child or adult with Down syndrome, there are a lot of other issues to consider. Physicians should be aware of these issues in order to treat the whole patient. This paper is a go-to source that allows health care providers to quickly see what to do for their patients.”
Abigail K. Allen, MD
Assistant Professor Orthopedic Surgery and Pediatrics