Deformity of the spine encompasses a broad spectrum of conditions and affects individuals in every age and demographic group. Spinal deformity has a significant and measurable impact on health-related quality of life, including pain, function, self-image, mental health, work status, and disability. Prevalence of disease, utilization of healthcare resources, impact of disease on health-related quality of life, and cost of care are useful tools for measuring the burden of deformity on our population and on our healthcare economy. The purpose of this chapter is to provide information on the burden of spinal deformity on patients and on our healthcare system.
Conditions related to the spine and spinal deformity often sound similar, but affect the spine in different ways. Key conditions discussed in this section include the following.
Curvature of the spine: Spine curvature can refer to two distinct conditions. The human spine normally curves, but more commonly the term "spinal curvature" refers to abnormalities from the standard spinal.
Spondylolisthesis: Forward movement of one vertebra in relationship to a vertebra next to it.
Spinal fractures:
Spinal infection:
Spondylopathies: Any disease of the vertebrae or of the spinal column.
Surgical procedures: Often performed to reduce pain from spinal curvature include fusion and kyphoplasty/vertebroplasty.
Injuries involving the spine represent a relatively small percentage of the overall number of acute musculoskeletal injuries, but have a disproportionate impact on patient impairment, economic cost, and societal burden. These injuries encompass a wide spectrum of spinal trauma, from devastating high-energy spinal cord injuries (SCI) in younger patients that often require complex spinal reconstruction procedures to more benign low-energy osteoporotic vertebral compression fractures (VCF) in the elderly. Yet as many as 40% of patients with low energy VCF will go on to develop chronic disabling pain and deformity.1 Because spinal trauma has such a large and disproportionate impact on disability and utilization of health care resources, frequently resulting in significant structural abnormalities, we have chosen to include a focused evaluation of spinal fractures in the Deformity Chapter. High- and low-energy fractures are also discussed in the Musculoskeletal Injuries and Osteoporosis chapters, respectively. Data is derived from the various public-use databases using traumatic spine fracture injury and vertebral compression fracture codes listed at the end of this chapter.
Vertebral compression fractures are most commonly low-energy injuries that occur in patients with underlying osteopenia or osteoporosis. They affect between 700,000 and 1,000,000 persons in the US annually, and 25% of woman in their lifetime.1,2 Many low-energy fractures are treated nonsurgically with a short period of bed rest, pain medications, bracing, and therapy. Approximately 30% to 40% of patients, however, develop disabling pain and/or deformity (kyphosis), resulting in 150,000 hospitalizations annually. Frequently, patients with VCF also have reduced pulmonary function (FVC), increased risk of mortality (compared to age-matched controls), and a lower 5-year survival when compared to hip fracture patients.3 Treatment of symptomatic VCF with vertebral augmentation (vertebroplasty or kyphoplasty) has been shown in various studies to be a cost-effective intervention that both decreases pain and improves survival.4,5,6 Various strategies have been employed to prevent and treat the osteoporosis that predisposes to these “fragility fractures” and is further discussed in the Osteoporosis chapter.
Traumatic spine fractures are usually high-energy injuries that typically involve young, male patients. Most injuries are the result of high-energy falls (35% to 40%), followed by traffic accidents (20% to 30%), and low-energy falls (20% to 25%).1,2,3,4 Approximately one-half involve the thoracolumbar spine (T12–L2), while 20% involve the cervical spine. Neurologic injury occurs in 16% to 25% overall, but in as many as 40% of cervical fractures. There are approximately 12,000 spinal cord injuries each year,2,3 which are associated with a significant mortality rate. Fractures without neurologic injury generally occur three times more frequently, with an estimated 36,000 traumatic spine fractures each year. Most traumatic spine fractures are treated nonsurgically with a one- to three-month period of immobilization and bracing. Unstable fractures and those with neurologic impairment may require surgical treatment, extensive rehabilitative services, and often develop long-term disability.
Based on the HCUP Nationwide Inpatient Sample (NIS) and Nationwide Emergency Department Sample (NEDS) databases queried, there were an estimated 795,300 hospital discharges and emergency department visits for spinal fractures in 2010–/2011. Nearly three out of five spinal fractures occurred in women.
The great majority of hospital/ED combine spinal fracture patients (773,000, or 97%) were treated for vertebral compression fractures (VCF), and more than one-half (58%) involved women. Nearly half of discharges and visits for VCFs were for persons age 75 years and older.
Traumatic fractures were far less common, with 27,100 (3%) hospital discharges or outpatient visits reported in the 2010–2011 Heathcare Cost and Utilization (HCUP) databases. Numbers were too small for reliable reporting in the National Center for Health Statistics (NCHS) databases, which include outpatient and physician office visits. Traumatic fractures predominantly involve men (about 60%), and are most likely to involve patients between the ages of 18 and 44 years. These are coarse estimates, as some ED patients are admitted (samples may overlap and overestimate), while outpatient visits are not included. (Reference Table 3.1.1 PDF [2] CSV [3] and Table 3.1.2 PDF [4] CSV [5])
Discharge status from the hospital had a direct and linear correlation with age. For patients under 18 years of age, 72% were discharged home while only 15% were discharged to a long-term facility. The discharge status progressively changed with increasing age so that, for patients age 75 years and older, 19% were discharged home while 58% were discharged to a long-term facility. Although the overall rate of patients discharged to long-term care is slightly higher than for traumatic fractures than for VCF (54% vs. 42%), the age correlation appears to be independent of fracture severity because younger patients likely had more severe fractures. (Reference Table 3.3.1 PDF [6] CSV [7] and Table 3.3.3 PDF [8] CSV [9]) (G3A.2.1)
The average length of stay for those patients discharged from hospitals with a spine fracture diagnosis was 6.8 days, with an average charge of $69,500. The charges for both males and younger patients were 30% to 60% higher than the average. Similarly, the length of stay was higher in younger patients (8 days or more), and gradually decreased with age (6 days for those older than 75 years of age). This correlation most likely reflects the higher association of more complicated traumatic fractures in these younger patient populations. (Reference Table 3.4.1 PDF [10] CSV [11])
Nearly two in three patients seen in the ED with spinal fractures were transferred to a hospital. Patients admitted to the hospital from an emergency department had slightly longer average length of stay (LOS) (7.2 days) and higher charges ($70,700) than those directly admitted to the hospital. Most patients with a primary diagnosis of spine fracture admitted to the hospital from the ED were discharged to a long-term care facility (42%) and another 37% were discharged to home. The likelihood of discharge to a long-term facility was also directly related to age as noted previously. (Reference Table 3.1.2 PDF [4] CSV [5]; Table 3.4.2 PDF [12] CSV [13]; and Table 3.3.2 PDF [14] CSV [15])
The greater severity of traumatic spinal fractures is dramatically illustrated by average hospital stays more than twice as long as for VCFs (14 days vs. 6.6 days), and average charges three times as high ($197,700 vs. $65,700). Differences in LOS and charges are particularly dramatic for persons under the age of 45 years. (Reference Table 3.4.3 PDF [16] CSV [17])
Only a small proportion of patients hospitalized with a spinal fracture undergo surgery. Of the 334,300 hospital admissions in the NIS database, fusion (8.8%) and kyphoplasty/vertebroplasty (10.6%) were the most common procedures performed. Similar rates of procedures were found in the NEDS hospitalized patients and National Hospital Discharge Survey (NHDS) databases. (Reference Table 3.5.1 PDF [18] CSV [19])
The majority of spinal fusion procedures on spine fractures were performed on patients under the age of 44 years, with patients age 65 years and older rarely undergoing surgery for spinal fractures. This is due to a much higher rate of fusion procedures performed on patients with traumatic fractures than on patients with VCFs. (Reference Table 3.5.2 PDF [20] CSV [21])
Fusions were performed most frequently in the cervical spine (41%), followed by thoracic spine (38%) and lumbar spine (26%). On average across the three databases included in the analysis, three out of four fusions performed were on four or fewer levels, with the remaining quarter of procedures involving five or more levels. (Table 3.5.3 PDF [22] CSV [23])
On the average, of 305,600 patients discharged with diagnosis of a vertebral compression fracture, 12% were treated with a kyphoplasty/vertebroplasty procedure. These patients were twice as likely to be female, and were most likely to be 65 or older. (Reference Table 3.5.4 PDF [24] CSV [25])
Spondylolisthesis is a forward slippage of one vertebral body over the one below. There are a variety of causes and classification schemes, but most can be described as either degenerative, caused by chronic inter-segmental instability involving degenerative disc and facet joints or isthmic, caused by developmental defects involving the posterior arch of the vertebra. Degenerative spondylolisthesis usually affects older patients, more frequently involves women at the L4/L5 vertebra level, and has relatively small slips (<30%) with associated stenosis. In contrast, isthmic spondylolisthesis usually affects patients younger than 50 years, primarily involves the L5 vertebra level, and may have quite severe progression (>50-100% slip) and associated structural abnormalities, including kyphosis.
The prevalence of spondylolisthesis ranges from 6% to 9% of the population, depending on the etiology studied and screening tools employed.1,2 Spondylolisthesis has not been reported in utero, in non-ambulatory patients, or mammals other than humans, implicating weight bearing forces unique to the upright bipedal spine. Spondylolisthesis and spondylolysis (a defect in the posterior arch without slip or translation) are seen in 4% of children at 6 years of age, 6% at maturity, and as many as 47% of athletes in high-risk sports such as gymnastics.1,2,3 Back pain is the most common complaint, but neurologic involvement may be seen with associated stenosis or progression and deformity. Children diagnosed prior to skeletal maturity or with slips greater than 50% are most likely to progress.4
Many patients with spondylolisthesis have no symptoms, and most likely do not require any significant treatment or intervention. Symptomatic patients are most frequently treated nonsurgically with NSAIDs, activity modification, physical therapy, and possibly epidural steroid injections. Bracing may be appropriate in some patients, particularly children with acute lesions.1,2 Surgical treatment is indicated when patients have significant disabling pain despite 6 months of adequate nonsurgical care or, less commonly, a progressive lesion. Treatment typically involves a posterior lumbar fusion. Instrumentation is thought to improve the fusion rate and clinical outcome,3 and decompression is included for patients with stenosis and associated radicular leg symptoms. Reduction of slips of greater than 50% remains controversial, but is thought to correct kyphosis and global sagittal balance, decrease the length of fusion, and protect against adjacent segment degeneration.4,5
Analysis of various inpatient and outpatient databases from 2008–2011 showed 778,700 visits with a diagnosis for spondylolisthesis. The majority of these visits (81%) were outpatient visits, primarily to a physician office. More than two in three (69%) visits for spondylolisthesis were by females with an average age between the late 50s or early 60s. More recent data from 2010–2011 demonstrate 185,400 hospital or emergency department discharges for spondylolisthesis with similar age and sex distribution (Reference Table 3.1.1 PDF [2] CSV [3] and Table 3.1.2 PDF [4] CSV [5]).
In 2011, there were 146,100 hospital discharges for spondylolisthesis reported in the HCUP NIS database. The average length of stay for these patients was 4 days, and tended to trend slightly upwards with age. The mean charges for hospital discharges with a diagnosis of spondylolisthesis was $93,900, which was unexpectedly higher than all other deformity codes evaluated and statistically similar to costs associated with hospital discharges for patients with complications of spine surgery diagnosis.
Among the much smaller sample of patients with a diagnosis of spondylolisthesis who were first seen in the emergency department (ED) and transferred to inpatient status, the average length of stay was slightly longer (5.2 days), but with lower average charges of $46,800. The proportion of patients with a spondylolisthesis diagnosis hospitalized after being seen in the ED who had a surgical procedure was much lower than those reported in the inpatient database. (Reference Table 3.4.1 PDF [26] CSV [27]; Table 3.4.2 PDF [28] CSV [29]; and Table 3.5.1 PDF [30] CSV [31])
Nearly two-thirds (61%) of inpatients with a spondylolisthesis diagnosis were discharged from the hospital to home, although the proportion was lower when hospitalized after visiting the ED. Another 15% to 18% went home with home health care. One in five (21%) were transferred to a skilled nursing facility. Age is a major factor in discharge status, with 44% of patients age 75 years and older discharged to skill nursing/intermediate care. (Reference Table 3.3.1 PDF [6] CSV [7] and Table 3.3.2 PDF [14] CSV [15])
Three out of four patients (75%) hospitalized with a diagnosis of spondylolisthesis were treated with a spinal fusion. About one-half were treated with instrumentation and decompression. Patients with spondylolisthesis often received more than one procedure in their stay. The overall costs for treatment of spondylolisthesis would be much higher than simply the hospitalization cost. The direct cost of nonsurgical treatments, such as medications, therapy, injections, braces, etc., and the indirect costs associated with treatment of this condition such as lost wages, non-productive time away from work, costs of medical care providers, are not included in these databases although they may be quite substantial. (Reference Table 3.5.1 PDF [30] CSV [31])
Spinal infections are usually the result of bacterial or fungal infections from other places in the body that spread to the spine though the bloodstream (hematogenously). Less commonly, they occur from local extension of a neighboring infection (eg, psoas abscess). Spinal infections are usually categorized by their location as discitis (infection of the vertebral disc space), vertebral osteomyelitis (infection of the vertebral body), and epidural abscess (infection of the spinal canal space). Vertebral osteomyelitis is the most common, with an estimated prevalence of 2.4 cases per 100,000 persons. The risk increases with age, and accounts for 4% to 6% of all cases of osteomyelitis. Epidural infections are relatively rare (0.2 to 1.2/10,000 hospital admissions), but are more likely to require emergent surgical treatment and are associated with significant morbidity and mortality rates.1,2,3
Postoperative wound infections and adverse events are relatively rare but are predictable risks and consequences of surgery. Although the absolute number is small in comparison to the volume of cases overall, they tend to have a disproportionate impact on both patient outcome and societal cost. There are many potential adverse events reported with any procedure, and the frequency and severity of these events varies based upon both patient and disease-specific variables. The codes included for query of the various databases for wound infections and adverse events are 996.2 (mechanical complication of nervous system device/implant), 996.59 (mechanical complication due to other implant/device), 996.63 (infection due to nervous system device/implant), 996.75 (other complications due to nervous system device/implant). Postoperative infections were queried for codes 998.51, 995.59, and 998.60. No differentiation was found in rates of infection between the spine and other areas within the body.
The most common adverse events associated with spine surgery include neurologic injury, infection, re-operation, medical complications, and dural tear.1 Of these, infection is the most frequently studied and reported both in the literature and within healthcare delivery organizations. Infection rates for lumbar spine surgery are frequently reported between 3% to 5% in many studies, but have a wide range depending on the type of procedure performed. Studies have reported an infection rate of 1% or less in single-level micro-discectomy cases (a small decompression procedure for disc herniation with sciatic pain); 3% to 7% in instrumented fusion cases (a stabilization procedure usually involving one to two levels for back pain or instability); 7% to 10% in adult deformity reconstruction (procedures to realign the spine in patients with scoliosis/kyphosis); and greater than 20% in neuromuscular deformity cases.1,2,3,4
In 2011, a total 370,000 discectomy and 498,700 fusion/refusion procedures were performed. Based on conservative estimated infection rates of 1% and 5%, for discectomy and fusion/refusion, respectively, we can estimate there were 28,600 postoperative spine infections. It is unknown what proportion of spinal infection diagnosis-related health care visits this represents. (Reference Table 2.14 PDF [32] CSV [33] and Table 2.19 PDF [34] CSV [35])
Risk factors associated with postsurgical complications and infection following spine surgery include obesity, diabetes, steroid and alcohol use, revision surgery, age, and operative time and blood loss. Postsurgical wound infections can arise from direct inoculation of the wound intra-operatively or indirectly by hematogenous seeding from other sources (ie, spread through the bloodstream). The most frequent organism cultured is Staphylococcus aureus (Staph infection), while gram-negative organisms are more commonly seen in polymicrobial infections (infections involving multiple types of bacteria).1
The most frequently reported symptoms are back pain, fever, and wound drainage, usually within the first 10-20 days of surgery, although latent infections may occur more than one year from surgery.
Superficial infections are frequently managed with oral antibiotics, while deep infections typically require surgical debridement (removal of dead, damaged, or infected tissue) and IV antibiotics. A small percentage of infections may be complicated by large soft tissue defects and compromised host immune systems, requiring extensive and prolonged treatments and surgical procedures.
Although major complications are rare, they are more likely to be seen in patients with complicated cases and have been reported to occur in as many as 28% to 32% of adult deformity cases.1 These include complications that are device-related (2% to 5%), neurologic (1% to 2%), vascular (3% to 4%), medical (>10%), stroke (2%), and include death (0.8%).1,2 Sentinel events (relatively infrequent, clear-cut events that occur independently of a patient's condition), including bowel or peritoneal injury, neurovascular injury, wrong site surgery, and retention of a foreign body, occur in 0.8/1,000 cases.3
Both major complications and sentinel events frequently require further medical interventions, resulting in longer hospitalizations, greater costs, and increased mortality.
In the summary years of 2008 to 2011, there were 261,900 hospital discharges or outpatient visits for complications related to spine surgery. These were evenly distributed between men and woman, with an average age in the mid- to late 40s. Health care visits occurred most frequently in the population under age 18 years, and least frequently among persons age 65 years and older.
In addition, there were 1.87 million patient visits related to spinal infections. The majority of the spinal infection diagnoses were for discitis, an infection in the small spaces between the vertebrae of the spine. Only 1% of diagnoses treated in 2010 were to those under the age of 18 years. (Reference Table 3.1.1 PDF [2] CSV [3] and Table 3.1.2 PDF [4] CSV [5])
Postsurgical infections, which are not isolated to spinal surgeries, accounted for 290,400 hospital discharges in 2011, and 217,600 emergency department visits in 2010, of which 63% were admitted to the hospital. Postsurgical infections were most commonly found in persons age 45 to 64 years. (Reference Table 3.2.1 PDF [36] CSV [37])
The majority of health care visits for both spinal infection and complications of spinal surgery were to a physician's office, but 22% of cases for complications from spinal surgery resulted in re-hospitalization. (Reference Table 3.1.1 PDF [2] CSV [3] and Table 3.3.2 PDF [14] CSV [15])
The average length of hospital stay (LOS) for infections and complications were 9.9 days and 8.8 days, respectively. Mean hospital charges for infections and complications were $76,100 and $92,000, respectively. Mean charges for complications of spinal surgery were second highest of all spinal deformity conditions evaluated. Charges related to males were higher than for females for both conditions, and were highest for the youngest patients, those age 17 years and younger. (Reference Table 3.4.1 PDF [10] CSV [11])
In 2011, total costs for patients discharged from a hospital with a diagnosis of either spinal infection or complications of spinal surgery were $12.4 billion. Hospital charges related to postsurgical infections were more than $25.5 billion. These estimates encompass hospital charges only; they do not include other direct costs such as physician charges, outpatient ancillary services, physical therapy, injections, or indirect costs including lost workdays and income. (Reference Table 3.4.4 PDF [38] CSV [39])
About one-half of patients treated for infection and complications were discharged to home (44% and 62%, respectively), but a substantial proportion were transferred to a long-term facility (29% and 16%, respectively), adding to the cost of treatment for spinal infection and complications from spinal surgery. Discharge status for postsurgical infection hospitalizations were similar. The likelihood of being transferred home declined with age for all groups, with a third to half of patients discharged to long-term care. One in four received additional home health care, increasing the cost of treating these conditions. (Reference Table 3.3.4 PDF [40] CSV [41])
The normal spine viewed from the side forms a gentle "S" shape. When viewed from the back, the normal spine appears straight. The naturally occurring soft curves of the spine are designed to distribute mechanical stress in the body when at rest and during movement. When the curvature is even slightly abnormal, a person may experience occasional mild or annoying discomfort. If the curve is severely abnormal, the pain is usually severe and accompanied by disability. Abnormal curves are referred to as spinal deformities, and include scoliosis, kyphosis, excess lordosis, and flatback.
Spinal deformity and scoliosis can be found at birth due to genetic causes, develop during childhood, or develop late in life because of degenerative disc and joint disease. Common signs of scoliosis are a prominent shoulder or shoulder blade, or chest wall asymmetry. Another sign is uneven hips, with one hip seemingly higher than the other hip. It is important not to confuse scoliosis with poor posture and to realize that scoliosis will usually not disappear with age. In spite of the severity of these conditions and the impact they have on the lives of children, the prevalence of spinal deformities in children under the age of 18 years is difficult to determine because of relatively low numbers and the degree to which the condition manifests initially in pain or disability. Estimated prevalence of spinal deformity conditions has been cited in numerous studies, and ranges from 1 in 1,000 for congenital scoliosis to 68 in 100 for adult spinal deformity or scoliosis for persons age 60 years and older. (Reference Table 3.1.3 PDF [42] CSV [43])
There are several different types of scoliosis. The most common type of scoliosis is idiopathic, meaning the cause of is unknown. Approximately 80% to 85% of scoliosis cases are idiopathic.1 Idiopathic scoliosis can initially occur as early as the first three years of life, which is known as infantile idiopathic scoliosis. If diagnosed between the ages of 4 to 10 years, it is known as juvenile idiopathic scoliosis, and from 10 years of age to skeletal maturity, as adolescent idiopathic scoliosis. Adolescent idiopathic scoliosis is the most common type.
Scoliosis, if severe enough (>25°), is usually treated with bracing if the child is growing, or with surgery if the curvature is more severe (>45° to 50°). The standard radiograph measurement method for all forms of scoliosis is the Cobb angle measurement technique, measured from the end plates of the maximally tilted end vertebral bodies in a standing radiograph.2 Whether the curve is >25° or >40° to 45°, the treatment is preventative in nature, helping to avoid progression of the curve and more significant future problems that might occur if it was left untreated. While this preventative aspect is hugely valuable and intuitively important, its benefit is difficult to measure from a public health standpoint, especially for rare conditions of childhood such as juvenile and adolescent pediatric scoliosis.
According to the Scoliosis Research Society (SRS), idiopathic scoliosis is diagnosed when a patient has asymmetry on forward bending combined with a curve of at least 10°.1 By this definition, the prevalence of adolescent idiopathic scoliosis in children from 10 to 16 years of age is 2% to3%. Though the male-to-female ratio for smaller curves is about equal, larger curves seem to be more common in females. Similar results were found in a study conducted in 1985, where 29,195 children were screened for idiopathic scoliosis.2
Several studies have investigated the natural history and natural course of curve progression in adolescent idiopathic scoliosis. All report the strongest predictive factors in the development of idiopathic scoliosis are age, magnitude of curve, and gender.3,4,5,6,7 Girls are more likely to have adolescent idiopathic scoliosis than boys, and some studies report the onset is earlier in girls than boys. A factor highly correlated with curve progression is age at diagnosis; patients diagnosed at a younger age have a greater risk of curve progression. However, those diagnosed at a younger age seem to have a more favorable response to milder forms of treatment, which supports the practice of school screening to detect and lead to earlier diagnosis for those children with a smaller degree of curvature.
Treatment decisions for individuals with adolescent idiopathic scoliosis are made based on location, shape, pattern, and cause of the curve. The treatment choice is also a function of the patient’s future growth potential. Treatment choices include observation, bracing, and surgery. Observation is usually reserved for patients who have curves ≤25°. Bracing, which is used to stop curve progression (rather than for lasting correction of the curve), is usually used for patients who have curves ≥25° and who are still growing. Surgery is generally used for patients with curves ≥45°.
In 12% to 21% of idiopathic scoliosis cases, the diagnosis is made between 4 and 10 years of age. Between the ages of 4 and 6 years, the female-to-male ratio of juvenile idiopathic scoliosis is 1:1. However, the ratio of female to male cases rises to between 2:1 and 4:1 in children between the ages of 4 and 10 years, and to 8:1 in children who are 10 years of age or older.1 Both right and left curves are found with equal frequency for patients younger than 6 years, but rise to a 3:1 ratio of right versus left thoracic curves after the age of 6.2
Observation is the main treatment for patients with a small curve of less than 20° to 25°. Follow-up visits are recommended every 4, 6, 9, or 12 months, depending on the patient’s age, the degree of the curve, and the characteristics of the clinical deformity.1
Curves between 25° and 50° are usually treated with bracing in this age group. Bracing can be done either on a part-time or full-time basis, depending on the size of the curve as well as the age of the child. A study completed in 1982 evaluating the success of bracing reported an excellent prognosis when part-time bracing was utilized for patients with a curve of ≤35° and rib-vertebra angle difference (RVAD)3 of ≤20°; however, curves ≥45° and RVAD of ≥20° had a less favorable prognosis for successful treatment with bracing.1
Overall, the curve patterns in patients with juvenile idiopathic scoliosis are similar to those with adolescent idiopathic scoliosis. Approximately 70% of patients with juvenile idiopathic scoliosis exhibit curve progression and require some form of treatment. In a study conducted in 1981, 55 of 98 patients (56%) with juvenile idiopathic scoliosis required spinal surgery. The most common and traditional surgery is posterior instrumentation and fusion.1
Infantile scoliosis currently accounts for less than 1% of all cases of idiopathic scoliosis in the United States. Boys are affected by infantile idiopathic scoliosis at a higher rate than girls (3:2 ratio).1 Infantile scoliosis curves tend to be left-sided (75% to 90%). Past studies have indicated this rare type of scoliosis occurs more frequently in Europe than in North America.2
Treatment for patients with infantile idiopathic scoliosis is determined by anticipated or actual curve progression. Several common measurement techniques are used, with angles ≤20° generally considered at low risk for progression. Re-evaluation is recommended every 4 to 6 months.1
In addition to measuring the Cobb angle, the RVAD is used as a common predictor of curve progression.3 Patients with a Cobb angle of ≤25° and a RVAD of ≤20° are at a low risk for progression and should be re-evaluated every 4 to 6 months.1
Nonsurgical treatment, such as bracing or casting is initiated if a curve progression of ≥10° occurs. Surgical treatment should be considered when nonsurgical measures, including both bracing and casting, are not successful. Surgical treatment is utilized when a curve is ≥45° and progressive in an immature child.1 Overall, surgical methods are continually evolving, with the goal of obtaining and maintaining curve correction while simultaneously preserving or encouraging spinal and trunk growth.
Surgical options currently utilized include various types of spinal fusion or hemiepiphysiodesis, a minimally invasive implant procedure to slow progression of curve growth. Additional techniques include growing-rod instrumentation (rods that expand and support the deformed spine) and vertical expandable (telescoping) prosthetic titanium rib (VEPTR) instrumentation.4The goal of using surgical methods is to halt the progression of the curve and gain correction of the deformity, allowing maximum growth of the spine, lungs, and thoracic cage.1
Congenital scoliosis is believed to affect approximately one child for every 1,000 live births.1 The cause is unknown in most cases, but in some cases, it is associated with various syndromes, as shown in the illustration below. Diagnosis occasionally is made during prenatal ultrasound. In cases of congenital scoliosis, additional congenital conditions, such as chest wall malformation or kidney or heart abnormalities, are often present. Treatment options for congenital scoliosis are bracing and/or surgery, and are similar to those discussed for idiopathic scoliosis. Bracing is not as effective for congenital scoliosis as it is for idiopathic scoliosis.
Major abnormal spinal deformity presenting during infancy or early childhood poses a clinical problem because of the anticipated long growth period (at least 10 years), variable presentation and treatment methods, and the length of time that must pass before meaningful outcome results can be assessed in the small number of patients for definitive studies. Curves that result from congenital scoliosis are often not treated as easily as idiopathic curves because the deformity is in the bones rather than the soft tissue, causing the curve to be rigid.2
Scoliosis also occurs in conjunction with several congenital conditions that occur in infancy or childhood. These include muscular dystrophy, cerebral palsy, spina bifida, and spinal muscular atrophy. Scoliosis associated with these conditions is referred to as neuromuscular scoliosis. Both the likelihood and the severity of the scoliosis generally increases with the severity of the underlying condition. For example, a child with severe cerebral palsy who is unable to walk is more likely to have severe scoliosis than a child with mild cerebral palsy who can walk.
Because of the low prevalence of scoliosis in children and adolescents, analysis of the health care impact this condition causes is difficult. However, the impact of scoliosis over a lifetime in terms of pain, inability to work, and cost to the health care system are substantial.
In 2010–2011, 92% of the 663,700 health care visits with a diagnosis of scoliosis for those under the age of 18 years were classified as idiopathic scoliosis. The majority (94%) were outpatient visits to either an outpatient clinic or physician office. Only 3% represented hospital discharges; however, this still accounted for 20,100 discharges for this often painful condition in children and adolescents. (Reference Table 3.1.2 PDF [4] CSV [5])
In 2011, 42% of children and adolescents under the age of 18 years discharged from the hospital with a diagnosis of scoliosis had surgery. Spinal fusion was the most common surgery performed, followed by instrumentation and decompression. Of those having surgery, three-fourths (78%) had only one type of surgery. However, one in five had two or all three types of surgery. Reference Table 3.5.1 PDF [18] CSV [19])
Average hospital charges for patients with scoliosis under 18 years of age who had surgery in 2011 were four or more times the average for all scoliosis patients in this age group, even though the length of stay was only about 50% longer. Patients who had an instrumentation procedure had the highest average charges of $165,600, although this may have been in conjunction with another procedure.
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 the majority of 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.
While scoliosis is the primary form of spinal curvature, two other spine curvature disorders are included in the data cited here. These are lordosis, also known as swayback, where the spine curves significantly inward at the lower back, and kyphosis, characterized by an abnormally rounded upper back with a curvature of more than 50º.
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 with and patients with relatively mild deformity may be severely impaired. Deformity in the sagittal plane (lateral) is most closely associated with disability.1 Patients with adult scoliosis seek medical care for symptoms including back pain, neural symptoms, and progression of deformity.
The prevalence of adult spinal deformity and scoliosis is not well established, with estimates ranging from 2.5% to 25% of the population.1,2,3,4,5,6 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.7 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 2010–2011, an estimated 1.61 million of these adults received treatment either as an inpatient or on an outpatient basis. (Reference Table 3.1.2 PDF [4] CSV [5])
Estimates for prevalence of lordosis or kyphosis as the primary diagnoses is approximately 17% of spine curvature diagnoses in hospital and emergency departments, with patient hospital discharges higher (23%). (Reference Table 3.2.2 PDF [47] CSV [48])
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.1 Data on nonsurgical treatments is not available; however, a 2010 non-randomized study reported that two years of nonsurgical treatment in adult scoliosis patients resulted in substantial expenditures and yielded no improvement in health status.2
Operative management of scoliosis in the adult encompasses a spectrum of procedures including decompression alone, decompression with limited fusion, and fusion of the deformity. In 2011, a query of the Healthcare Costs and Utilization Project (HCUP) Nationwide Inpatient Survey (NIS) resulted in approximately 229,100 hospitalizations associated with a discharge diagnosis of scoliosis or spinal curvature (ICD-9-CM of 373). The majority of these, or 155,900 patients, were diagnosed as idiopathic scoliosis, or scoliosis of unknown cause. Most of the remaining discharges, 66,000 people, were associated with a primary diagnosis of acquired adult scoliosis, while the remaining 10,500 discharges were associated with adult scoliosis as the secondary diagnosis to another condition. (Reference Table 3.1.1 PDF [2] CSV [3])
In 2011, nearly 27.6 thousand patients admitted to the hospital with a diagnosis of scoliosis underwent a decompression procedure. Among patients having decompression, 82% also had spinal fusion, with 42% undergoing fusion of one to three levels, while 34% had fusion of four or more levels. Overall, 22% of all scoliosis patients underwent a fusion procedure (N=50,009), with 10% having fusion of one to three levels and 12% fusion of four or more levels.
In 2011, only about one-half (53%) of patients with a scoliosis diagnosis were discharged to home, while 70% of patients discharged for 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 than are patients with all diagnoses. This is particularly true for the elderly population, with 46% of persons age 75 and older with a scoliosis diagnosis moving to a long-term care facility. (Reference Table 3.3.1 PDF [6] CSV [7])
The cost of care for adults with scoliosis includes direct costs and indirect costs including lost wages, time 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.1
The national mean cost of a hospitalization (presumably for surgical treatment) for patients with a primary diagnosis of idiopathic scoliosis was $67,400 in 2011 for an average hospital stay of 5.6 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 in 2011 was an estimated $15.44 million (229,000 hospitalizations). 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. (Reference Table 3.4.1 PDF [10] CSV [11])
Mean charges for scoliosis diagnosed patients are similar to those for other spinal deformity diagnoses, but significantly higher than for all hospital discharge patients.
While technical outcomes of surgery are well known and show obvious benefits for those with significant deformity, long-term health related outcomes have yet to be precisely documented. The lack of quality, long-term studies of sufficient size hampers our understanding of the mortality and morbidity rates for patients with congenital and idiopathic scoliosis, with and without treatment. Fifty years of follow-up studies of children and adolescents with untreated scoliosis have shown conflicting results, with some studies indicating a higher risk of mortality and respiratory compromise.1,2
Another study shows compromise only in patients with early reduced lung function and a large curvature.3 Yet another study has shown no differences in untreated childhood scoliosis and a control group.4 Several articles from the 1960s and one recent article report that low back pain does not occur more frequently in untreated scoliosis patients than in the general population4,5,6 unless the curvature is greater than 40°.7,8 It has also been shown that persons treated with surgery rather than bracing for adolescent idiopathic scoliosis have less pain at 10- to 20-year follow-up, although function remains similar.9,10 The cosmetic/self-image aspect of scoliosis is obvious and important, and often a major factor affecting the lives of individuals with this condition.
Scoliosis in the adult has an impact that is similar to other common medical conditions including osteoarthritis, coronary artery disease, and chronic obstructive pulmonary disease. Overall, the burden of scoliosis on health-related quality of life is severe relative to other common medical conditions. With the aging demographic profile of the US, the burden of adult scoliosis is increasing and has a significant impact on the health of our population, and on the cost of care for spinal disorders.
Likewise, vertebral compression fractures, which may contribute to adult degenerative scoliosis, are also a growing concern for the aging population, particularly when associated with kyphosis and/or disabling pain.
The burden of spinal deformity includes health care costs, pain management, therapy, alternative care, and lost work days due to pain. The total cost of spinal deformity is difficult to determine because hospital charges are the only expenditures available in the databases. In addition, not all persons suffering from spinal deformity seek medical care.
In 2011, charges for 1.14 million hospital discharges for spinal deformity were $75.8 billion. Charges due to spinal fractures and trauma were the largest share (31%), followed by spondylopathies (24%) and curvature of the spine (20%). Spinal deformity charges accounted for 6% of all hospital charges in 2011, but only 3% of hospital discharges. (Reference Table 3.4.1 PDF [10] CSV [11])
In addition to direct and indirect costs, persons afflicted with spinal deformity experience a reduced quality of life, which may include major constraints on mobility and activity for those with the most serious conditions.
Curvature of Spine:
Idiopathic Scoliosis: 737.30-737.32
Acquired Kyphosis and Lordosis: 737.0, 737.10, 737.12, 737.19, 737.20-737.29, 737.34, 737.39
Secondary Scoliosis, Kyphosis, and Lordosis: 737.11, 737.33, 737.40-737.43, 737.8, 737.9
Spondylolisthesis: 737.40, 756.12
Adolescent Postural Kyphosis: 737.00
Kyphosis: 737.10-737.19, 737.41
Lordosis: 737.20-737.29, 737.42
Scoliosis: 737.30-737.39, 737.40, 737.43, 737.8, 737.9
Trauma: Spinal Fractures Contributing to Deformity:
Vertebral Compression Fractures: 805.00-805.08, 805.2, 805.4, 805.6, 805.8
Traumatic Fractures: 805.10-805.18, 805.3, 805.5, 805.7, 805.9, 806.00-806.09, 806.10-806.19, 806.20-806.29, 806.30-806.39, 806.4, 806.5, 806.60-806.02, 806.69, 806.70-806.72, 806.79, 806.8, 806.9
Infection/Complications Codes:
Tuberculosis of Vertical Column: 015.00 to 015.06
Tuberculosis Unspecified: 015.90 to 015.96
Intracranial and Intraspinal Abscess (Epidural abscess): 324.1, 324.9
Acute Osteomyelitis: 730.00, 730.08, 730.09
Chronic Osteomyelitis: 730.10, 730.18, 730.19
Discitis: 722.90 to 722.93
Complications of Surgery: 996.2, 996.59, 996.63, 996.72
Spondylopathies:
Ankylosing Spondylitis: 720.00
Spinal Enthesopathy: 720.1
Sacroiliitis, not elsewhere classified: 720.2
Other Inflammatory Spondylopathies: 720.81, 820.89
Unspecified Inflammatory Spondylopathy: 720.9
Cervical Spondylosis with Myelopathy: 721.1
Thoracic or Lumbar Spondylosis with Myelopathy: 721.4
Spondylosis with Myelopathy, Thoracic Region: 721.41
Spondylosis with Myelopathy, Lumbar Region: 721.42
Intervertebral Disc Disorder with Myelopathy: 722.70 to 722.73
Spinal Stenosis in Cervical Region: 723.00
Cervicalgia: 723.1
Cervicocranial Syndrome: 723.2
Cervicobrachial Syndrome (diffuse): 723.3
Brachial Neuritis or Radiculitis NOS: 723.4
Torticollis, Unspecified: 723.5
Panniculitis Specified as Affecting Neck: 723.6
Ossification of Posterior Longitudinal Ligament in Cervical Region: 723.7
Spinal Deformity Procedures:
Decompression: 0309, 8050, 8051
Cervical Fusion: 8102, 8103
Thoracic/Dorsal or Dorsolumbar Fusion: 8104, 8105
Lumbar and Lumbosacral Fusion: 8106, 8107, 8108
Other Fusion: 8100, 8101
Cervical Refusion: 8132, 8133
Thoracic, Dorsal or Dorsolumbar Refusion: 8134, 8135
Lumbar and Lumbosacral Refusion: 8136, 8137, 8138
Other Refusion: 8130, 8131, 8139
Fusion/Refusion of Multiple Vertebrae: 8162, 8163, 8164
Instrumentation/Insertion of Spinal Device: 8451, 8452, 8459
Vertebraplasty: 8165
Kyphoplasty [Percutaneous Vertebral Augmentation]: 8166
Decompression: 0309
Diskectomy: 8050, 8051
Epidural injection: 8192, 8396, 8397
Links:
[1] http://www.spinalcord.uab.edu
[2] https://www.boneandjointburden.org/docs/T3.1.1.pdf
[3] https://www.boneandjointburden.org/docs/T3.1.1.csv
[4] https://www.boneandjointburden.org/docs/T3.1.2.pdf
[5] https://www.boneandjointburden.org/docs/T3.1.2.csv
[6] https://www.boneandjointburden.org/docs/T3.3.1.pdf
[7] https://www.boneandjointburden.org/docs/T3.3.1.csv
[8] https://www.boneandjointburden.org/docs/T3.3.3.pdf
[9] https://www.boneandjointburden.org/docs/T3.3.3.csv
[10] https://www.boneandjointburden.org/docs/T3.4.1.pdf
[11] https://www.boneandjointburden.org/docs/T3.4.1.csv
[12] https://www.boneandjointburden.org/docs/T3.4.2.pdf
[13] https://www.boneandjointburden.org/docs/T3.4.2.csv
[14] https://www.boneandjointburden.org/docs/T3.3.2.pdf
[15] https://www.boneandjointburden.org/docs/T3.3.2.csv
[16] https://www.boneandjointburden.org/docs/T3.4.3.pdf
[17] https://www.boneandjointburden.org/docs/T3.4.3.csv
[18] https://www.boneandjointburden.org/docs/T3.5.1.pdf
[19] https://www.boneandjointburden.org/docs/T3.5.1.csv
[20] https://www.boneandjointburden.org/docs/T3.5.2.pdf
[21] https://www.boneandjointburden.org/docs/T3.5.2.csv
[22] https://www.boneandjointburden.org/docs/T3.5.3.pdf
[23] https://www.boneandjointburden.org/docs/T3.5.3.csv
[24] https://www.boneandjointburden.org/docs/T3.5.4.pdf
[25] https://www.boneandjointburden.org/docs/T3.5.4.csv
[26] http://bmus.latticegroup/docs/T3.4.1.pdf
[27] http://bmus.latticegroup/docs/T3.4.1.csv
[28] http://bmus.latticegroup/docs/T3.4.2.pdf
[29] http://bmus.latticegroup/docs/T3.4.2.csv
[30] http://bmus.latticegroup/docs/T3.5.1.pdf
[31] http://bmus.latticegroup/docs/T3.5.1.csv
[32] https://www.boneandjointburden.org/docs/T2.14.pdf
[33] https://www.boneandjointburden.org/docs/T2.14.csv
[34] https://www.boneandjointburden.org/docs/T2.19.pdf
[35] https://www.boneandjointburden.org/docs/T2.19.csv
[36] https://www.boneandjointburden.org/docs/T3.2.1.pdf
[37] https://www.boneandjointburden.org/docs/T3.2.1.csv
[38] https://www.boneandjointburden.org/docs/T3.4.4.pdf
[39] https://www.boneandjointburden.org/docs/T3.4.4.csv
[40] https://www.boneandjointburden.org/docs/T3.3.4.pdf
[41] https://www.boneandjointburden.org/docs/T3.3.4.csv
[42] https://www.boneandjointburden.org/docs/T3.1.3.pdf
[43] https://www.boneandjointburden.org/docs/T3.1.3.csv
[44] http://www.niams.nih.gov/Health_Info/Scoliosis/default.asp
[45] http://www.wheelessonline.com/ortho/congenital_scoliosis_and_vertebral_defects
[46] http://www.ncbi.nlm.nih.gov/pubmed/15931035
[47] https://www.boneandjointburden.org/docs/T3.2.2.pdf
[48] https://www.boneandjointburden.org/docs/T3.2.2.csv