Deformity of the adult spine includes patients with curvature of the spine (scoliosis) of varying degrees caused or impacted by degenerative disc and joint disease. Adult scoliosis may be the result of persistent or progressive deformity since adolescence or a new, de novo, onset of deformity resulting from degeneration or aging of the spine. Degenerative scoliosis accounts for most scoliosis cases in older populations aged 65 years and older, as reflected in the low proportion of older patients with a diagnosis of primary idiopathic scoliosis.

Degenerative scoliosis is one of the most challenging spine conditions to treat because of the variability of the condition. Generally, it is thought to originate with the degeneration of the intervertebral discs, which leads to misalignment of the vertebral column. Degenerative scoliosis, particularly in the very elderly, is often associated with other conditions, such as osteoporosis. Treatment outcomes for both nonsurgical and surgical procedures are not well documented; hence, recognition and earlier intervention are important to ward off the more complex problems of adult scoliosis. The role played by undiagnosed, mild idiopathic adolescent scoliosis on the development of degenerative scoliosis in later life is unknown.

The clinical presentation and management of adults with scoliosis is characterized by a great deal of variability. There is a poor correlation between the magnitude of deformity and the impact of scoliosis on health status, as patients with large spinal curvatures may have limited pain and disability and patients with relatively mild deformity may be severely impaired. Deformity in the sagittal plane is associated with disability more than scoliosis.1 Patients with adult scoliosis seek medical care for symptoms, including back pain, neural symptoms, and progression of deformity. It is often neural symptoms secondary to spinal stenosis that leads patients to seek treatment.

Prevalence of Adult Scoliosis

The prevalence of adult spinal deformity and scoliosis is not well established, with estimates ranging from 2.5% to 25% of the population.2^,3^,4^,5^,6^,7 A 2005 study reported mild to severe adult scoliosis prevalence as high as 68% in a healthy (no known scoliosis or spine surgery) population aged 60 years and older.8 Many cases of degenerative scoliosis are undiagnosed, but elderly patients often seek care because of back and leg pain that may be caused by scoliosis and associated spinal stenosis.

According to 2010 US Census Population Estimate, there were 235,205,658 people in the United States over the age of 18 years. Prevalence of adult scoliosis cited in the literature ranges from 2.5% to 60%, depending on severity. A conservative estimate (2.5%) of the prevalence of adult scoliosis yields an incidence of a minimum of 5.88 million adults in the United States with adult scoliosis. In 2013, an estimated 1.28 million of these adults received treatment either as an inpatient or on an outpatient basis. (Reference Table 2B.2.2 PDF CSV)

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Management of Adult Scoliosis

The management of adult scoliosis includes nonsurgical and surgical resources. Nonsurgical treatments of adult scoliosis utilize significant resources, and include interventions such as exercises, physical therapy, injections, pain medications, and manual manipulation.9 Data on nonsurgical treatments is not available; however, a 2010 nonrandomized study reported that two years of nonsurgical treatment in adult scoliosis patients resulted in substantial expenditures and yielded no improvement in health status.10

Operative management of scoliosis in the adult encompasses a spectrum of procedures, including decompression alone, decompression with limited fusion, and fusion of the deformity. The type of procedure performed is typically determined by the predominant symptoms. Neural symptoms in patients with smaller curves (<30 degrees) are treated with decompression alone, while patients with larger curves and neural symptoms are treated with decompression and fusion.11 Adult scoliosis associated with sagittal deformity is more commonly treated with decompression, osteotomies, and larger fusions of greater than four level (five or more vertebrae).12

In 2013, a query of the Healthcare Costs and Utilization Project (HCUP) Nationwide Inpatient Survey (NIS) resulted in approximately 142,600 hospitalizations of people age 18 and over associated with a discharge diagnosis of scoliosis (ICD-9-CM of 373). The majority of these, or 140,200 patients, were diagnosed as idiopathic scoliosis or scoliosis of unknown cause. Hospitalization with a scoliosis diagnosis was higher among the elderly, with those 65 and older accounting for nearly half (43%) among all ages. Females accounted for nearly three-quarters (73%) of all scoliosis hospitalizations. Race/ethnicity and region in the US did not show significant differences. (Reference Table 2B.2.1 PDF CSV, Table 2B.2.2 PDF CSV, Table 2B.2.3 PDF CSV, Table 2B.2.4 PDF CSV)

In 2013, more than one-half (53.6%) of patients with a diagnosis of acquired/secondary scoliosis had a surgical procedure, but only one in five (20.7%) of those with a diagnosis of idiopathic scoliosis had surgery. The most common procedure performed on scoliosis patients was spinal fusion, with 26,600, or 16%, having this procedure. A majority of scoliosis patients with a fusion procedure (83%) had fusion of 4 or more levels. Sex of the patient was not a factor in having a procedure, but persons age 45 to 64 were most likely to have a procedure. (Reference Table 2B.5.0.1 PDF CSV, Table 2B.5.0.2 PDF CSV, Table 2B.5.1 PDF CSV, Table 2B.5.2 PDF CSV)

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Burden of Adult Scoliosis  

The cost of care for adults with scoliosis includes direct costs and indirect costs of lost wages, time away from work, cost of care providers, and opportunity costs. Estimates of the direct costs of nonsurgical care in adult scoliosis are estimated to be as high as $14,000 per year.10 The national mean cost of a hospitalization, including surgical treatment, for patients with a primary diagnosis of idiopathic scoliosis was $69,400 in 2013 for an average hospital stay of 5.3 days. The mean cost for those with an acquired or secondary scoliosis diagnosis were significantly higher at $120,400 per discharge, with an average stay of 5.9 days. The HCUP NIS database does not provide hospitalization costs associated with secondary discharge diagnoses, and does not include fees to doctors, tests, and other typical charges associated with hospitalization. Therefore, the most conservative estimate of only the hospitalization cost for adult scoliosis, both idiopathic and acquired/secondary in 2013 was an estimated $11.5 billion (166,600 hospitalizations). Charges are not necessarily actual costs paid. Mean charges for scoliosis diagnosed patients are significantly higher than for all hospital discharge patients. (Reference Table 2B.3.2 PDF CSV)

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In 2013, slightly more than one-half (58%) of patients with a scoliosis diagnosis were discharged to home, while 70% of patients with any diagnosis had a routine discharge. Patients with a scoliosis diagnosis are more likely to be transferred to a skilled nursing or intermediate care facility (long-term care) than are patients with all diagnoses. This is particularly true for the elderly population, with 39% of persons age 65 and older with a scoliosis diagnosis moving to a long-term care facility. (Reference Table 2B.4.2 PDF CSV)

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The real cost of the management of adult scoliosis to our healthcare system is significant, and the value of care measured by change in health status remains incompletely defined for both nonsurgical and surgical care.

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