Congenital scoliosis due to a hemivertebra requires surgical stabilization prior to skeletal maturity if rapidly progressive curve growth occurs. Here the authors present the unique case of a man who, at the age of 12 years, had undergone Harrington rod placement for stabilization of progressive congenital scoliosis due to a T-11 hemivertebra and then, at the age of 53 years, presented with acutely progressive myelopathy due to spinal cord compression from an arachnoid web at T-11 despite a solid fusion mass at the prior surgical site. The patient underwent a posterior midline approach for resection of the T-11 pedicle at the level of the hemivertebra, intradural spinal cord detethering with resection of the arachnoid web at T-11, and T2–L2 instrumented fusion with deformity correction, leading to subsequent resolution of his acute myelopathic symptoms. In conclusion, arachnoid web formation superimposed on preexisting tension on the thoracic spinal cord from congenital scoliosis due to a T-11 hemivertebra caused acute myelopathy in an adult with a previously solid fusion mass from childhood. The resolution of acute myelopathy and halting of further progression occurred with pedicle resection, arachnoid web fenestration, and spinal deformity correction.
Molly E. Hubbard, Matthew A. Hunt, Kristen E. Jones and David W. Polly
A. Noelle Larson, David W. Polly Jr., Stacey J. Ackerman, Charles G. T. Ledonio, Baron S. Lonner, Suken A. Shah, John B. Emans, B. Stephens Richards III and Minimize Implants Maximize Outcomes Study Group
There is substantial heterogeneity in the number of screws used per level fused in adolescent idiopathic scoliosis (AIS) surgery. Assuming equivalent clinical outcomes, the potential cost savings of using fewer pedicle screws were estimated using a medical decision model with sensitivity analysis.
Descriptive analyses explored the annual costs for 5710 AIS inpatient stays using discharge data from the 2009 Kids’ Inpatient Database (Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality), which is a national all-payer inpatient database. Patients between 10 and 17 years of age were identified using the ICD-9-CM code for idiopathic scoliosis (737.30). All inpatient stays were assumed to represent 10-level fusions with pedicle screws for AIS. High screw density was defined at 1.8 screws per level fused, and the standard screw density was defined as 1.48 screws per level fused. The surgical return for screw malposition was set at $23,762. A sensitivity analysis was performed by varying the cost per screw ($600–$1000) and the rate of surgical revisions for screw malposition (0.117%–0.483% of screws; 0.8%–4.3% of patients). The reported outcomes include estimated prevented malpositioned screws (set at 5.1%), averted revision surgeries, and annual cost savings in 2009 US dollars, assuming similar clinical outcomes (rates of complications, revision) using a standard- versus high-density pattern.
The total annual costs for 5710 AIS hospital stays was $278 million ($48,900 per patient). Substituting a high for a standard screw density yields 3.2 fewer screws implanted per patient, with 932 malpositioned screws prevented and 21 to 88 revision surgeries for implant malposition averted, and a potential annual cost savings of $11 million to $20 million (4%–7% reduction in the total cost of AIS hospitalizations).
Reducing the number of screws used in scoliosis surgery could potentially decrease national AIS hospitalization costs by up to 7%, which may improve the safety and efficiency of care. However, such a screw construct must first be proven safe and effective.
Osa Emohare, Alison Dittmer, Robert A. Morgan, Julie A. Switzer and David W. Polly Jr.
Recently published data make it possible to generate estimates of bone mineral density (BMD) by using CT attenuation; this innovation can save time and reduce costs. Although advanced age is associated with reduced BMD, especially in patients with a fracture of C-2, relatively few patients ever undergo formal dual x-ray absorptiometry studies. To the authors' knowledge, this is the first study to assess the utility of this technique in elucidating BMD in patients with an acute fracture of the cervical spine.
Patients who presented to a Level I trauma center with an acute fracture of the cervical spine and underwent abdominal (or L-1) CT scanning either at admission or in the 6 months before or after the injury were evaluated. Using a picture-archiving and communication system, the authors generated regions of interest of similar size in the body of L-1 (excluding the cortex) and computed mean values for CT attenuation. The values derived were compared with threshold values, which differentiate between osteoporotic and nonosteoporotic states; age-stratified groups were also compared.
Of the 91 patients whose data were reviewed, 51 were < 65 years old (mean 43.2 years) and 40 were ≥ 65 years old (mean 80.9 years). The overall mean CT attenuation values (in Hounsfield units [HU]), stratified according to age, were 193.85 HU for the younger cohort and 117.39 HU for the older cohort; the result of a comparison between these two values was significant (p < 0.001).
Using opportunistic CT scanning, this study demonstrates the relative frequency of osteoporosis in acute fractures of the cervical spine. It also objectively correlates overall BMD with the known higher frequency of C-2 fractures in older patients. This technique harnesses the presence of opportunistic CT scans of the abdomen, which potentially reduces the need for the extra time and cost that may be associated with dual x-ray absorptiometry scanning.
Ian McCarthy, Michael O'Brien, Christopher Ames, Chessie Robinson, Thomas Errico, David W. Polly Jr. and Richard Hostin
Incremental cost-effectiveness analysis is critical to the efficient allocation of health care resources; however, the incremental cost-effectiveness ratio (ICER) of surgical versus nonsurgical treatment for adult spinal deformity (ASD) has eluded the literature, due in part to inherent empirical difficulties when comparing surgical and nonsurgical patients. Using observed preoperative health-related quality of life (HRQOL) for patients who later underwent surgery, this study builds a statistical model to predict hypothetical quality-adjusted life years (QALYs) without surgical treatment. The analysis compares predicted QALYs to observed postoperative QALYs and forms the resulting ICER.
This was a single-center (Baylor Scoliosis Center) retrospective analysis of consecutive patients undergoing primary surgery for ASD. Total costs (expressed in 2010 dollars) incurred by the hospital for each episode of surgical care were collected from administrative data and QALYs were calculated from the 6-dimensional Short-Form Health Survey, each discounted at 3.5% per year. Regression analysis was used to predict hypothetical QALYs without surgery based on preoperative longitudinal data for 124 crossover surgical patients with similar diagnoses, baseline HRQOL, age, and sex compared with the surgical cohort. Results were projected through 10-year follow-up, and the cost-effectiveness acceptability curve (CEAC) was estimated using nonparametric bootstrap methods.
Three-year follow-up was available for 120 (66%) of 181 eligible patients, who were predominantly female (89%) with average age of 50. With discounting, total costs averaged $125,407, including readmissions, with average QALYs of 1.93 at 3-year follow-up. Average QALYs without surgery were predicted to be 1.6 after 3 years. At 3- and 5-year follow-up, the ICER was $375,000 and $198,000, respectively. Projecting through 10-year follow-up, the ICER was $80,000. The 10-year CEAC revealed a 40% probability that the ICER was $80,000 or less, a 90% probability that the ICER was $90,000 or less, and a 100% probability that the ICER was less than $100,000.
Based on the WHO's suggested upper threshold for cost-effectiveness (3 times per capita GDP, or $140,000 in 2010 dollars), the analysis reveals that surgical treatment for ASD is cost-effective after a 10-year period based on predicted deterioration in HRQOL without surgery. The ICER well exceeds the WHO threshold at earlier follow-up intervals, highlighting the importance of the durability of surgical treatment in assessing the value of surgical intervention. Due to the study's methodology, the results are dependent on the predicted deterioration in HRQOL without surgery. As such, the results may not extend to patients whose HRQOL would remain steady without surgery. Future research should therefore pursue a direct comparison of QALYs for surgical and nonsurgical patients to better understand the cost-effectiveness of surgery for the average ASD patient.
Christopher I. Shaffrey and Justin S. Smith
Stacey J. Ackerman, David W. Polly Jr., Tyler Knight, Tim Holt and John Cummings Jr.
Low-back pain (LBP) is highly prevalent among older adults, and the cost to treat the US Medicare population is substantial. Recent US health care reform legislation focuses on improving quality of care and reducing costs. The sacroiliac (SI) joint is a recognized generator of LBP, but treatments traditionally have included either nonoperative medical management or open SI joint fusion, which has a high rate of complications. New minimally invasive technologies have been developed to treat SI joint disruption and degenerative sacroiliitis, so it is important to understand the current cost impact of nonoperative care to the Medicare program. The objective of this study was to evaluate the medical resource use and associated Medicare reimbursement for patients managed with nonoperative care for degenerative sacroiliitis/SI joint disruption.
A retrospective study was conducted using claim-level data from the Medicare 5% Standard Analytical Files (SAFs) for the years 2005–2010. Included were patients with a primary ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) diagnosis code for degenerative sacroiliitis/SI joint disruption (ICD-9-CM diagnosis codes 720.2, 724.6, 739.4, 846.9, or 847.3) with continuous enrollment for at least 1 year before and 5 years after diagnosis. Claims attributable to degenerative sacroiliitis/SI joint disruption were identified using ICD-9-CM diagnosis codes (claims with a primary or secondary ICD-9-CM diagnosis code of 71x.xx, 72x.xx, 73x.xx, or 84x.xx), and the 5-year medical resource use and Medicare reimbursement (in 2012 US dollars) were tabulated across practice settings. A subgroup analysis was performed among patients who underwent lumbar spinal fusion.
Among all Medicare patients with degenerative sacroiliitis or SI joint disruption (n = 14,552), the mean cumulative 5-year direct medical costs attributable to degenerative sacroiliitis/SI joint disruption was $18,527 ± $28,285 (± SD) per patient. The cumulative 5-year cost was $63,913 ± $46,870 per patient among the subgroup of patients who underwent lumbar spinal fusion (n = 538 [3.7%]) and $16,769 ± $25,753 per patient among the subgroup of patients who had not undergone lumbar spinal fusion (n = 14,014 [96.3%]). For the total population, the largest proportion of cumulative 5-year costs was due to inpatient hospitalization (42.1%), outpatient physician office (20.6%), and hospital outpatient costs (14.9%). The estimated cumulative 5-year Medicare reimbursement across practice settings attributable to SI joint disruption or degenerative sacroiliitis is approximately $270 million among these 14,552 Medicare beneficiaries ($18,527 per patient).
In patients who suffer from LBP due to SI joint disruption or degenerative sacroiliitis, this retrospective Medicare claims data analysis demonstrates that nonoperative care is associated with substantial costs and medical resource utilization. The economic burden of SI joint disruption and degenerative sacroiliitis among Medicare beneficiaries in the US is substantial and highlights the need for more cost-effective therapies to treat this condition and reduce health care expenditures.
Doniel Drazin, Terrence T. Kim, David W. Polly Jr and J. Patrick Johnson
Image-guided surgery (IGS) has been evolving since the early 1990s and is now used on a daily basis in the operating theater for spine surgery at many institutions. In the last 5 years, spinal IGS has greatly benefitted from important enhancements including portable intraoperative CT (iCT) coupled with high-speed computerized stereotactic navigation systems and optical-based camera tracking technology.