13SProceedings of the NASS 27th Annual Meeting / The Spine Journal 12 (2012) 1S–21S

27. Cost-Effectiveness Analysis of Treatments for Vertebral

Compression Fractures

Kevin L. Ong1, Av Edidin, PhD2, Edmund Lau1, Jordana Schmier3, Jason

E. Kemner, MS4, Steven M. Kurtz, PhD1; 1Exponent Inc., Philadelphia, PA,

US; 2Portola Valley, CA, US; 3Exponent Inc., Alexandria, VA, US;4Medtronic, Philadelphia, PA, US

BACKGROUND CONTEXT: In recent years, surgicalmanagement of ver-

tebral compression fractures (VCFs) has become controversial, due largely to

inconsistent outcomes reported from vertebroplasty randomized trials.

PURPOSE: To characterize the cost to Medicare for treating VCF diag-

nosed patients by nonsurgical management, vertebroplasty (VP), or bal-

loon kyphoplasty (BKP). We hypothesized that surgical treatments for

VCFs using VP or BKP would be a cost-effective alternative to nonsurgical

management for the Medicare patient population.

STUDY DESIGN/SETTING: The study utilized the 100% and 5% U.S.

Medicare national claims data from 2005-2008.

PATIENT SAMPLE: BKP and VP patients were identified using ICD-9-

CM and CPT-4 codes. Life expectancy was based on a cohort of 858,978

VCF patients in the 100% Medicare data, while payer costs were based on

67,018 VCF patients in the 5% Medicare data.

OUTCOME MEASURES: Cost per life year gained (LYG).

METHODS: Cost per LYG for VCF patients was compared between op-

erated (BKP and VP) and non-operated patients and between BKP and VP

patients, all as a function of age and gender. Life expectancy was estimated

using a parametric Weibull survival model (adjusted for comorbidities).

Median payer costs were identified for each treatment group for up to 3

years following VCF diagnosis. A discount rate of 3% was used for the

base case in the cost-effectiveness analysis, with 0% and 5% discount rates

used in sensitivity analyses.

RESULTS: After accounting for the differences in median costs and using

a discount rate of 3%, the cost per LYG for BKP and VP patients ranged

from $1,863 to $6,687 and from $2,452 to $13,543, respectively, compared

with non-operated patients. The cost per LYG for BKP compared with VP

ranged from -$4,878 to $2,763.

CONCLUSIONS: Among patients for whom surgical treatment was indi-

cated, BKP was found to be cost-effective, and perhaps even cost saving,

compared to VP. Both interventions would be considered cost-effective in

terms of cost per LYG.

FDA DEVICE/DRUG STATUS: Vertebroplasty (Approved for this indi-

cation), Kyphoplasty (Approved for this indication).

http://dx.doi.org/10.1016/j.spinee.2012.08.055

28. Cost-Effectiveness of Interlaminar Stabilization Compared with

Instrumented Posterior Spinal Fusion for Spinal Stenosis and

Spondylolisthesis

Joshua D. Auerbach, MD1, Jordana Schmier2, Kevin L. Ong3,

Edmund Lau3; 1Brooklyn, NY, US; 2Exponent Inc., Alexandria, VA, US;3Exponent Inc., Philadelphia, PA, US

BACKGROUND CONTEXT: While decompression and lumbar spinal

fusion are standard treatments for spinal stenosis and degenerative spondy-

lolisthesis, the rising costs and frequency of such procedures have led to

the need for more comprehensive cost-effectiveness analyses to support

continued resource allocation. More recently, less-invasive procedures

have been introduced which have the potential for cost savings over the

duration of the course of treatment of disease, while providing the same

or improved clinical outcomes. No study to date has compared the cost-ef-

fectiveness of less-invasive interlaminar stabilization with lumbar fusion in

these patient populations.

PURPOSE: The purpose of the current study is to report and compare the

relative cost-effectiveness of decompression and interlaminar stabilization

compared with decompression and instrumented posterolateral fusion by

using data on collected costs, resource utilization, and patient-reported out-

comes from an ongoing randomized clinical IDE trial.

All referenced figures and tables will be available at the Annual Mee

STUDY DESIGN/SETTING: Randomized, prospective, multicenter IDE

trial.

PATIENT SAMPLE: The Coflex� IDE study is a prospective, 2:1 ran-

domized, multicenter trial comparing Coflex� interlaminar stabilization

to laminectomy and posterolateral fusion for the treatment of spinal steno-

sis with spondylolisthesis.

OUTCOME MEASURES: Oswestry Disability Index scores collected dur-

ing the trialwere converted to utilities.A third-party payer perspectivewas used,

and costs (US 2011$) and outcomes were discounted at 3% annually. Both

Medicare and private-payer costs were modeled. Sensitivity analyses examined

the influence of costs, utilities, and discount rates. Quality-adjusted life years

(QALY), and cost perQALY,were also comparedbetween the treatment groups.

METHODS: A model was developed to compare interventions. The pri-

mary source for the model’s clinical input parameters was the recent

IDE trial of Coflex�, supporting premarket approval application to

FDA. Treatment patterns over five years were estimated based on claims

data analyses and expert opinion.

RESULTS: Patients receiving Coflex� had higher success rates and lower

costs in both the Medicare and private payer models, resulting in cost sav-

ings. Payments over five years were estimated at $14,534 for Coflex� im-

plant patients compared to $25,620 for controls (Medicare costs; $17,714

vs. $31,747 for private coverage). Utilities were higher for Coflex�-treated

patients at all assessments, and totaled 3.03 quality-adjusted life years

(QALY) compared to 2.98 for controls. Incremental cost-effectiveness

could not be calculated, as the novel implant dominated, demonstrating

both lower costs and better outcomes. Sensitivity analyses identified no

scenario in which fusion was preferred over the Coflex�.

CONCLUSIONS: The use of interlaminar stabilization to treat stenosis

and spondylolisthesis is cost saving, and associated with equivalent or im-

proved patient outcomes. Subgroup analyses comparing indications and pa-

tient characteristics should be conducted to confirm robustness of findings.

FDA DEVICE/DRUG STATUS: Coflex (Investigational/Not approved).

http://dx.doi.org/10.1016/j.spinee.2012.08.056

Wednesday, October 24, 20125:40 – 6:40 PM

Concurrent Session: Tumor/Infection

29. Preoperative Embolization of Thoracolumbar Spinal Tumors:

Technique and Outcomes from a Single Center

Sreejit Nair, MD1, Yves P. Gobin, MD2, Lewis Z. Leng, MD1, Mark

H. Bilsky, MD3, Ilya Laufer, MD3, Athos Patsalides, MD2; 1Weill Cornell

Medical College, NY Presbyterian Hospital, New York, NY, US; 2Weill

Cornell Medical College, New York, NY, US; 3Memorial Sloan-Kettering

Cancer Center, New York, NY, US

BACKGROUND CONTEXT: Preoperative angiography is indicated for

hypervascular primary and metastatic tumors. The goal of embolization

is to reduce tumor opacification in an effort to reduce intraoperative blood

loss and surgical morbidity.

PURPOSE: To describe our experience with preoperative angiography and

embolization of primary and metastatic thoracic, lumbar, and sacral spinal

tumors causing spinal instability and/or high-grade spinal cord compression.

STUDY DESIGN/SETTING: Retrospective review of angiograms and

periprocedural chats was conducted for 228 procedures performed between

December 2001 and December 2010.

PATIENT SAMPLE: Two hundred twenty-eight angiograms and/or em-

bolizations were performed in 198 patients. Tumor embolization was un-

dertaken in 188 cases. Fifteen patients underwent repeat embolization of

the same lesion because of tumor recurrence and repeat surgery. Twelve

patients underwent embolization of new, different lesions.

OUTCOME MEASURES: Vascularity was graded as normal (0, similar

to the normal vertebral body blush), mild hypervascularity (1, slightly

ting and will be included with the post-meeting online content.

14S Proceedings of the NASS 27th Annual Meeting / The Spine Journal 12 (2012) 1S–21S

more prominent than normal vertebral body blush), moderate hypervascu-

larity (2, significant tumor blush without arteriovenous shunting), and se-

vere hypervascularity (3, severe tumor blush with arteriovenous shunting).

Visualized and embolized tumor feeders were recorded. Angiograms were

reviewed for degree of embolization. Final tumor pathology and periproce-

dural complications were recorded.

METHODS: The criteria for embolization included tumor hypervascular-

ity, absence of a radiculomedullary artery arising from the tumor feeder,

and ability to achieve stable catheter position thereby avoiding reflux into

the aorta and resulting embolic complications. Thoracic procedures were

typically performed under general anesthesia to improve image acquisi-

tion. Lumbar and sacral procedures were typically performed with sedation

alone. Embolization materials included polyvinyl alcohol (PVA) particles,

detachable platinum coils, and liquid embolics. The embolization endpoint

was absence of residual tumor hypervascularity.

RESULTS: Angiography revealed hypervascularity in 201/228 cases in 174/

198 patients. The most common pathology was metastatic renal cell carci-

noma (44.2%), followed by metastatic thyroid carcinoma (9.2%) and leio-

myosarcoma (6.6%) with mean vascularity of 2.0, 2.0, and 1.0

respectively. Embolization of tumor-feeding branches was undertaken in

188/201 hypervascular tumors. Mean vascularity of embolized tumors was

2.0 with a mean number of embolized tumor-feeding branches of 2.4 (range

1-8). Thirteen patients with hypervascular tumors did not undergo emboliza-

tionof any tumor-feedingbranches owing to thepresence of a radiculomedul-

lary artery and/or minimal hypervascularity. All embolizations were

performed with PVA particles. In 51.6% of embolizations, detachable coils

were also utilized, most commonly to occlude the ventral branch of the lum-

bar or intercostal artery to divert the particles into the tumor. Liquid embolic

material was used in 2.7% of embolizations. 86.0% of hypervascular tumors

were completely embolized, 12.7% were nearly completely embolized, and

1.3% were only partially embolized. Complete embolization with PVA par-

ticles only versus PVAparticles and coilswas 80%vs 92.0%.Onepatient suf-

fered a cardiac event secondary to anesthesia and another had a large groin

hematoma; neither resulted in long-term morbidity. There were no new

post-procedure neurologic deficits.

CONCLUSIONS:We conclude that preoperative angiography of thoracic,

lumbar, and sacral spinal tumors and embolization of hypervascular tumors

is safe when performed at a high volume center with a rigorous protocol

and criteria for embolization.

FDA DEVICE/DRUG STATUS: This abstract does not discuss or include

any applicable devices or drugs.

http://dx.doi.org/10.1016/j.spinee.2012.08.058

30. En-Bloc Resection of Primary Spinal and Paraspinal Tumors

with Critical Vascular Involvement

Raja Y. Rampersaud, MD, FRCSC1, Arun Ranganathan, FRCS, MD,

MBBS1, Rajesh Reddy, MBBS, MS, FRACS2; 1Toronto Western Hospital,

Toronto, ON, Canada; 2Sydney, Australia

BACKGROUND CONTEXT: Curative resection of primary spinal and

paraspinal tumours invading the spine are challenging. Critical vascular in-

volvement is thought to be a relative contraindication.

PURPOSE: To report our experience of curative resection of spinal and

paraspinal tumours with critical vascular involvement.

STUDY DESIGN/SETTING: Between 2002 and 2011, a single surgeon

series of 44 consecutive en-bloc resections and reconstructions for primary

spinal and paraspinal tumours was reviewed.

PATIENT SAMPLE: Of these, 11 cases had critical vascular involvement

requiring reconstruction for curative intent.

OUTCOME MEASURES: Survivorship, tumour recurrence and micro-

scopic margin clearance.

METHODS: There were 6 males and 6 female patients, with a mean age of

54 years (range 38-66). There were 4 primary spinal tumours – 2 cervical

chordomas, one malignant fibrous histiocytoma (MFH) and one chondrosar-

coma. The remaining 9 were paraspinal tumours invading the vertebral

All referenced figures and tables will be available at the Annual Mee

bodies – 3 lung, one neural ectodermal, one retrocrural liposarcoma, one ret-

roperitoneal haemangiopericytoma, one leiomyosarcoma and one mediasti-

nal angiosarcoma. One patient had subclavian artery reconstruction

(segmental Goretex graft-SGG), 2 had vertebral artery bypass (saphenous

vein), one had venacaval and left renal vein reconstruction (SGG), one pa-

tient had common iliac vein reconstruction (bovine pericardium), one pri-

mary aortic shortening, one subclavian resection-reanastamosis, 3 had

aortic surgical skeletonization (adventitial/intimal separation) – of these, 2

had endovascular stenting and 3 had aortic segmental replacement (SGG).

Patients had spinal column resections ranging from 1-5 levels with circum-

ferential reconstruction. Anterior reconstructionwere performed usingmesh

cages (n51), structural allograft (n54) and vascularised fibula (Clivus-C4 x

2). Posterior reconstruction utilized spinal segmental instrumentation (mean

number of levels 5 6.25) in all patients as well as autologous rib struts for

posterior column defect reconstruction in 3 patients.

RESULTS: Ten cases were staged with posterior spinal release and instru-

mentation followed a week to a month later by anterior resection and re-

construction. The mean total operative time for stage one was

13.12 hours and stage 2 was 14.83 hours. The mean EBL for stage 1

was 2446.12 mL and for stage 2 was 6360 mL. Ten cases had clear resec-

tion margins microscopically (range 0.5 to 4.5 cm). The 2 positive margins

occurred at the superior surface of T1 in a case of adenosquamous carci-

noma of lung and in periuretreric tissue and tissue over the external iliac

vein in a case of high grade retroperitoneal sarcoma. Perioperative compli-

cations occurred in all cases. No major complication or mortality occurred

due to the vascular component of these cases. 1 patient (lung CA) died at 3

months postoperatively from ICU complications and one patient (MFH)

died at 8 months postoperatively from widespread metastasis. 10 patients

have had no recurrence at a mean follow-up of 4.3 years (range 1-7 years).

CONCLUSIONS: Critical vascular involvement of localised primary spi-

nal and paraspinal tumours is not a contraindication for en-bloc resection.

The development of advanced techniques in spinal and vascular recon-

struction combined with highly specialized, multidisciplinary, oncologic

surgical teams now makes curative resection of these tumours possible.

FDA DEVICE/DRUG STATUS: This abstract does not discuss or include

any applicable devices or drugs.

http://dx.doi.org/10.1016/j.spinee.2012.08.059

31. The Effect of Surgery on Health-Related Quality of Life and

Functional Outcome in Patients with Metastatic Epidural Spinal

Cord Compression: The AOSpine North America Prospective

Multicenter Study

Michael G. Fehlings, MD, PhD, FRCSC1, Charles G. Fisher, MHSc(Epi),

MD, FRCSC2, Branko Kopjar, MD, PhD3, Alexander R. Vaccaro, MD,

PhD4, Paul M. Arnold, MD5, James M. Schuster, MD, PhD6, Joel

A. Finkelstein, MD7, Laurence D. Rhines, MD8, Mark B. Dekutoski, MD9,

Ziya L. Gokaslan, MD, FACS10, John C. France, MD11; 1Toronto Western

Hospital, Toronto, ON, Canada; 2Vancouver General Hospital, Vancouver,

BC, Canada; 3Mercer Island, WA, US; 4Rothman Institute, Philadelphia,

PA, US; 5University of Kansas Medical Center Department of

Neurosurgery, Kansas City, KS, US; 6University of Pennsylvania

Department of Neurosurgery, Philadelphia, PA, US; 7Sunnybrook Health

Sciences Centre, Toronto, ON, Canada; 8Houston, TX, US; 9Mayo Clinic,

Rochester, MN, US; 10Johns Hopkins University Department of

Neurosurgery, Baltimore, MD, US; 11Robert C. Byrd Health Sciences

Center, Morgantown, WV, US

BACKGROUND CONTEXT: Metastatic epidural spinal cord compres-

sion (MESCC) is a common and devastating complication of cancer. Re-

cent studies have provided evidence that in selected patients combined

surgery and radiotherapy provides optimal neurological recovery, in partic-

ular as assessed by walking function. However, many patients with

MESCC have a relatively short life-expectancy and face numerous health

challenges. Hence, the impact of surgery on improving quality of life out-

comes in the setting of MESCC is less clear. This is a critical issue given

ting and will be included with the post-meeting online content.