80S Proceedings of the NASS 23rd Annual Meeting / The Spine Journal 8 (2008) 1S–191S

PURPOSE: To compare the effectiveness of PDD to fluoroscopy-guided

transforaminal epidural injections (TFEI) for treating symptomatic con-

tained lumbar disc herniation.

STUDY DESIGN/ SETTING: Multi-center, prospective randomized con-

trolled clinical trial.

PATIENT SAMPLE: Ninety patients (18-75 years old) who had radicular

pain (visual analogue scale (VAS) score $50) associated with a single-

level lumbar contained disc herniation on MR or CT imaging and had

failed $1 epidural corticosteroid injection 3–24 weeks prior to enrollment.

OUTCOME MEASURES: VAS scores for leg and back pain, Oswestry

Disability Index (ODI), SF-36 questionnaire, satisfaction with treatment

questionnaire, and procedure-related adverse events.

METHODS: A priori sample size estimation, using a common standard

deviation of 25 points on a 100-point VAS for pain and setting type I error

rate at 5%, suggested that a sample size of 44 subjects in each group would

have 80% power to detect a difference in means of 15 VAS points at 6

months after PDD. Patients were randomly assigned to receive PDD

(n546) or up to two TFEI (n544). The PDD was performed using

a plasma-mediated device (DLR or DLG; ArthroCare, Sunnyvale, CA).

Comparisons for non-ordered categorical data, ordered categorical data,

and continuous data were evaluated using the chi-square test, Wilcoxon’s

two-sample rank test, and t-test, respectively; longitudinal change was

evaluated using the generalized estimating equations (GEE) technique.

RESULTS: Five patients withdrew before treatment and 3 were excluded

by the DSMB as inappropriate, leaving 82 patients. Age (46612 vs 42611

years, p50.13), gender (male: 49% vs 54%, p50.65) and baseline scores

for leg pain (72613 vs 75615, p50.40), back pain (42624 vs 53623,

p50.06), ODI (42615 vs 44617, p50.52), and SF-36 components (all,

pO0.05) did not differ significantly between PDD and TFEI patients, re-

spectively. The PDD group had significantly lower leg pain scores at 6

weeks (32626 vs 55628), 3 months (27624 vs 51628), and 6 months

(21626 vs 53628) than the TFEI group (GEE; p!0.01). The PDD group

also had significantly lower back pain scores (6 weeks: 26623 vs 51626;

3 months: 32626 vs 56629; 6 months: 20624 vs 47628; GEE; p!0.01).

At 6 months, O25 points improvement in leg pain scores was shown by

55% of PDD and 18% of TFEI patients (p!0.01); for back pain, the pro-

portions were 54% and 12% (p!0.01). Oswestry scores were significantly

better in PDD than TFEI patients (6 weeks: 29621 vs 39617; 3 months:

27618 vs 39614; 6 months: 21617 vs 39617; GEE; p!0.01). At 6

months, improvement in SF-36 physical component summary (PCS)

scores was significantly greater with PDD than TFEI (968 vs 365 points;

p50.004) and significantly more PDD patients were satisfied with treat-

ment (69% vs 46%; p50.04). Procedure-related adverse events, including

injection site pain, increased leg or back pain, weakness and lightheaded-

ness, were observed in 5 PDD (7 events) and 7 TFEI (14 events) patients.

CONCLUSIONS: In patients who had leg and back pain due to contained

lumbar disc herniation, PDD was associated with significantly greater pain

reduction and improved quality of life scores than a continued series of

epidural injections.

FDA DEVICE/DRUG STATUS: DLR SpineWand: Approved for this in-

dication; DLG SpineWand: Approved for this indication.

doi:10.1016/j.spinee.2008.06.188

156. The Necessity of Needle Biopsy During Kyphoplasty Procedures

Spiros Pneumaticos, MD1, Anastasia Pilichou2, Christiana Savidou2,

Sofia Chatziioannou2; 1University of Athens Medical School, Athens,

Greece; 2Athens, Greece

BACKGROUND CONTEXT: Vertebral augmentation procedures are

currently widely performed to treat vertebral compression fractures.

PURPOSE: The purpose of this study was to determine the frequency

of underlying previously unrecognized etiology in a consecutive series

of patients undergoing kyphoplasty to treat vertebral compression

fractures.

STUDY DESIGN/ SETTING: A prospective clinical series with histolog-

ical evaluation in a university hospital setting.

PATIENT SAMPLE: Seventy five consecutive patients with 154 vertebral

compression fractures who underwent kyphoplasty over a 2 year period

OUTCOME MEASURES: Histological evaluation.

METHODS: A prospective histological evaluation of vertebral body biopsy

specimens from presumed osteoporotic vertebral compression fractures

were performed in order to identify aforementioned causes. Over a two-year

period, vertebral body biopsies from 154 vertebral levels were performed in

75 patients undergoing kyphoplasty for vertebral compression fractures. All

patients received a preoperative work-up that included plain radiographs,

MRI, whole body bone scan, and laboratory examinations. Bone specimens

were obtained from affected vertebral bodies and submitted for histologic

evaluation to identify the prevalence of an underlying cause.

RESULTS: All specimens demonstrated fragmented bone with variable

amounts of unmineralised bone, signs of bone-remodeling and/or frac-

ture-healing. In 11 patients underlying pathology other than osteoporosis

was identified (prostate cancer 1; pancreatic cancer 1; colon cancer 1;

breast cancer 2; multiple myeloma 3; leukemia 1 and lung cancer 2). In

all but one patient the results of the biopsy confirmed the diagnosis sus-

pected from the preoperative work-up. For the last patient, namely the

one with pancreatic cancer, the work-up did not identify the origin of

the primary tumor, although the patient was considered to have a compres-

sion fracture secondary to metastatic disease of unknown origin, the verte-

bral biopsy suggested the presence of adenocarcinoma which eventually

was proven to be pancreatic cancer.

CONCLUSIONS: Vertebral compression fractures are quite common,

largely resulting from insufficiency secondary to osteoporosis. A small

number of these fractures are the results of underlying causes such as pri-

mary or metastatic disease and metabolic syndromes. The treating physi-

cian performing augmentation procedures needs to identify such patients

in order to avoid a missed diagnosis. In our series, all patients with a pos-

itive biopsy had preoperative work-up that had already suggested the pres-

ence of an underlying condition. The results of the biopsy confirmed the

suspected diagnosis. Based on these findings obtaining a biopsy in all pa-

tients may not add to the diagnosis, provided a preoperative work-up is

performed.

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

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.189

Friday, October 17, 20084:20–5:20 PM

Special Interest Paper Presentation 2: Fusion

157. RhBMP-2 vs. Iliac Crest Bone Graft for Lumbar Spine Fusion:

A Randomized Controlled Study in Patients Over 60 Years of Age

Steven Glassman, MD1, Leah Carreon, MD, MSc2, Mladen Djurasovic,

MD2, Mitchell Campbell, MD1, Rolando Puno, MD1, John Johnson, MD1,

John Dimar, II, MD2; 1Leatherman Spine Center, Louisville, KY, USA;2Louisville, KY, USA

BACKGROUND CONTEXT: RhBMP-2/ACS (Infuse Bone Graft) has

been widely used ‘‘off-label’’ for posterolateral spinal fusion (PSF). De-

spite encouraging initial reports, outstanding issues include the need for

high quality evidence regarding safety and efficacy in an older patient pop-

ulation. Determination of the appropriate role for rhBMP-2/ACS in PSF

also requires an assessment of cost effectiveness.

PURPOSE: The purpose of this study is to report on clinical, radiographic

and economic outcomes, at two year follow-up, in patients treated by PSF

with ICBG vs. rhBMP-2/ACS.

81SProceedings of the NASS 23rd Annual Meeting / The Spine Journal 8 (2008) 1S–191S

STUDY DESIGN/ SETTING: Prospective randomized controlled trial

(RCT) of rhBMP-2/ACS vs. ICBG for lumbar spine fusion in patients over

60 years old.

PATIENT SAMPLE: 102 patients with complete 2 year clinical, radio-

graphic and economic data.

OUTCOME MEASURES: ODI, SF-36, Numeric Rating Scales (NRS)

for Back and Leg Pain, radiographic fusion, and directly measured costs.

METHODS: Patients over 60 years old requiring single and multiple level

PSF were randomized to rhBMP-2/ACS (n550) or ICBG (n552) groups.

Other than the requirement for rhBMP-2/ACS (prepared according to the

package labeling instructions) or ICBG harvest, fusion was performed ac-

cording to the surgeons’ standard clinical practice. Fusion was evaluated

by fine cut CT scan two years after surgery by 3 blinded reviewers. All

economic measures were directly recorded by a dedicated hospital coder.

Recorded costs included all in-patient and subsequent out-patient events.

Economic analysis included an assessment of total costs, in-patient hospi-

tal costs, in-patient physician services, out-patient facility costs and out-

patient physician services.

RESULTS: Statistically significant improvement was observed for all

measures in the rhBMP-2/ACS and ICBG groups at both 1 and 2 yrs

post-op. Mean change in ODI at 2 yrs post-op was 15.8 in the rhBMP-2/

ACS group and 13.0 in the ICBG group. Change in SF-36 PCS was 6.6

in the rhBMP-2/ACS group and 7.5 in the ICBG group. Mean improve-

ment in NRS back pain was 3.5 in the rhBMP-2/ACS group and 3.4 in

the ICBG group. Mean improvement in NRS leg pain was 4.0 in the

rhBMP-2/ACS group and 3.3 in the ICBG group. There were 20 compli-

cations in the ICBG group versus 8 complications in the rhBMP-2/ACS

group (p50.014). Sixteen patients in the ICBG group and 10 in the

rhBMP-2/ACS group required additional treatment for persistent symp-

toms. Two patients had revision procedures in the rhBMP-2/ACS group,

one for nonunion. Eight patients in the ICBG group had revision proce-

dures, 5 for nonunion. Mean CT grade was significantly (p50.030) better

in the rhBMP-2/ACS (4.3) compared to the ICBG group (3.8). The mean

cost of the initial admission was $36,530 in the rhBMP-2/ACS group and

$34,235 in the ICBG group with a total cost of care over two years of

$42,574 for the ICBG group and $40,131 for the rhBMP-2/ACS group.

Mean costs related to costs of complication, additional treatments and re-

vision surgeries are summarized in the table below.

Table

Mean Costs for Entire Cohort over Two Years

COST ICBG rhBMP-2/ACS

Initial Admission

$34,235 $36,530

Treatment of Complications

$1,815 $1,185

Additional Nonsurgical Treatment

$769 $486

Revision Surgery

$5,754 $1,929

Total Cost of Care over Two Years

$42,574 $40,131

CONCLUSIONS: The findings of this RCT indicate that rhBMP-2/ACS is

a viable ICBG replacement in older patients in terms of safety, clinical ef-

ficacy and cost effectiveness.

FDA DEVICE/DRUG STATUS: rhBMP-2/ACS (Infuse): Not approved

for this indication.

doi:10.1016/j.spinee.2008.06.191

158. Epsilon Amino Caproic Acid (EACA) Reduces Red Cell

Transfusion Requirements in Patients Undergoing Major Spinal

Surgery: A Prospective Randomized Placebo-controlled Trial in 182

Patients

Sean Berenholtz1, Khaled Kebaish, MD1, Julius Pham1, Elizabeth Garrett-

Mayer2, David Cohen, MD, MPH1, Todd Dorman1, John Kostuik, MD1;

1Johns Hopkins University, Baltimore, MD, USA; 2Medical University of

South Carolina, Charleston, SC, USA

BACKGROUND CONTEXT: Spinal surgery, can be associated with sig-

nificant blood loss and as a result, patients often receive multiple red-cell

transfusions which may be associated with significant morbidity, including

infectious transmission, immunosuppression and transfusion reactions.

Prior studies evaluating the efficacy of EACA in patients undergoing spinal

surgery have produced conflicting results. In addition, several of these

studies have significant limitations.

PURPOSE: Evaluate the effectiveness of EACA in reducing allogeneic

red cell transfusion in patients undergoing major spinal surgery.

STUDY DESIGN/ SETTING: This is a prospective, randomized, double-

masked, placebo-controlled trial conducted at an academic medical center

between Feb 2001 & Feb 2006.

PATIENT SAMPLE: All patients undergoing major spinal reconstructive

surgery at a tertiary care hospital. 310 patients were evaluated, 128 were

excluded. The remaining 182 patients were randomly assigned, 91 to re-

ceive aminocaproic acid and 91 to receive placebo.

OUTCOME MEASURES: On the basis of the results from this study we

believe that EACA could benefit patients undergoing major spinal surgery

METHODS: We evaluated 310 patients, 128 were excluded. The remain-

ing 182 patients were randomly assigned, 91 to receive aminocaproic acid

and 91 to receive placebo. Average age in the EACA group was 55.5614.0

and in the control group (55.4615.5). Randomization was performed 24–

72 hs prior to surgery, all study personnel, patients and care-providers were

blinded to treatment allocation. The study drug (EACA, 100 mg/kg) or an

identical-appearing placebo was administered in the operating room imme-

diately after anesthesia induction followed by an infusion (EACA 10 mg/

kg/hr) or placebo. that was continued for 8 hs postoperatively. Potential

thrombotic and infectious complications were compared between the

two groups using Fisher’s exact test. Statistical analyses were based on

the intention-to-treat principle and involved all randomized patients.

RESULTS: The characteristics of the patients, medical co-morbidities,

preoperative medications, diagnosis, surgeon and surgical procedure in

the two groups were similar. Median estimated blood loss tended to be less

in the EACA group (2440 vs 3020 cc, p50.08). The mean number of al-

logeneic plus autologous red-cell transfusions during the postoperative pe-

riod (post-surgery through POD 8) in the EACA group was significantly

less than in the placebo group (median 2 & 3 units, respectively, p50.04)

CONCLUSIONS: This is the largest study to date to evaluate the effect of

EACA on red-cell transfusion requirements in patients undergoing major

spinal surgery. There was a 30% reduction in the mean number of alloge-

neic plus autologous red-cell transfusions during the postoperative period

among patients in the EACA group compared to the placebo group.

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

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.192

159. Fusion Enhancement of Single Level ACDF in Smokers: A

Randomized Prospective Study

Glenn Buttermann, MD; Midwest Spine Institute, Stillwater, MN, USA

BACKGROUND CONTEXT: An ongoing long-term follow-up study of

anterior cervical discectomy and fusion (ACDF) patients by the authors

found that smokers had twice the rate of nonunion. Other studies have also

found greater nonunion rates in smokers.

PURPOSE: To determine whether single-level ACDF patients who

smoked had improved fusion rates and outcomes if they had adjuvant treat-

ment with an anterior plate or electrical bone growth stimulation.

STUDY DESIGN/ SETTING: Three arm non-blinded prospective random-

ized study of single level ACDF patients treated with iliac crest bone graft

(IBG), IBG with instrumentation (plate), or IBG and capacitive coupling

bone growth stimulation (BS). All patients completed 2–4 year follow-up.