2S Proceedings of the NASS 23rd Annual Meeting / The Spine Journal 8 (2008) 1S–191S

pain groups. Similar non-operative outcomes were observed for the three

pain location groups at 2 years in both the DS and SpS cohorts.

CONCLUSIONS: Overall, surgery resulted in better outcomes compared

to non-operative treatment for all patients regardless of pain location.

However, predominant leg pain patients improved more with surgery than

predominant back pain patients.

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

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.003

3. Radiographic Predictors of Clinical Outcomes Following

Operative or Non-Operative Treatment of Degenerative

Spondylolisthesis

Adam Pearson, MD1, Jon Lurie, MD1, Emily Blood, MS1, John Frymoyer,

MD1, Heike Braeutigam, MD1, Howard An, MD2, Federico Girardi, MD3,

James Weinstein, DO1; 1Dartmouth College, Lebanon, NH, USA;2Chicago, IL, USA; 3New York, NY, USA

BACKGROUND CONTEXT: It has been suggested that certain radio-

graphic features (i.e. magnitude of slip, disk space narrowing, and interver-

tebral hypermobility) are related to outcomes in degenerative

spondylolisthesis (DS).

PURPOSE: This study evaluated whether baseline radiographic findings

predicted outcomes in patients with degenerative spondylolisthesis (DS).

STUDY DESIGN/ SETTING: The Spine Patient Outcomes Research

Trial (SPORT) included randomized and observational cohorts, with 13

participating institutions in 11 states.

PATIENT SAMPLE: 222 DS patients with radiographs available for re-

view, representing a subset of the total cohort of 591 DS patients

OUTCOME MEASURES: SF-36 bodily pain (BP) and physical function

(PF) scales, Oswestry disability index (ODI), stenosis bothersomeness in-

dex (SBI), and low back pain bothersomeness scale

METHODS: Using the SPORT DS cohorts, we analyzed the data accord-

ing to treatment received. The Meyerding listhesis grade was determined

on the neutral radiograph (n5222). A patient was classified as having

low disk height if the disk height was less than 5 mm. Flexion-extension

radiographs (n5185) were evaluated for mobility. Those with greater than

10� rotation or 4 mm translation were considered Hypermobile. Changes in

outcome measures were compared between listhesis (Grade 1 vs. Grade 2),

disk height (Low vs. Normal) and mobility (Stable vs. Hypermobile)

groups using longitudinal regression models adjusted for potential

confounders.

RESULTS: Overall, 86% had a Grade 1 listhesis, 78% had Normal disk

height, and 73% were Stable. Baseline symptom severity was similar be-

tween the groups. Overall, surgery patients improved more than patients

treated non-operatively. At one year, outcomes were similar in surgery pa-

tients across listhesis, disk height, and mobility groups (ODI: Grade 1

�23.7 vs. Grade 2 �23.3, p50.90; Normal disk height �23.5 vs. Low disk

height �21.9, p50.66; Stable �21.6 vs. Hypermobile �25.2, p50.30).

Among those treated non-operatively, Grade 1 patients improved more

than Grade 2 patients (BP +13.1 vs. �4.9, p50.019; ODI �8.0 vs. +4.8,

p50.010 at 1 year), and Hypermobile patients improved more than Stable

patients (ODI �15.2 vs �6.6, p50.041; SBI �7.8 vs �2.7, p50.002 at 1

year).

CONCLUSIONS: Regardless of listhesis grade, disk height or mobility,

patients who had surgery improved more than those treated non-opera-

tively. Surgical treatment effects were greater for Grade 2 patients and

for Stable patients. These differences were due, in part, to differences in

non-operative outcomes, which were better in patients classified as Grade

1 or Hypermobile.

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

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.004

4. This paper will be presented during the TSJ Outstanding Paper

Awards presentations Thursday morning, October 16, 2008.

5. Outcome of Lumbar Fusion in Patients Over 65 Years Old

Steven Glassman, MD1, David Polly, Jr., MD2, Christopher Bono, MD3,

Kenneth Burkus, MD4, John Dimar, II, MD5; 1Leatherman Spine Center,

Louisville, KY, USA; 2University of Minnesota, Minneapolis, MN, USA;3Boston, MA, USA; 4Hughston Clinic, PC, Columbus, GA, USA;5Louisville, KY, USA

BACKGROUND CONTEXT: Most of the literature regarding lumbar fu-

sion in older patients has focused on the rate of complications. In 2006,

a CMS advisory panel meeting assessing evidence for spinal fusion surgery

in the Medicare population indicated a need for ‘‘better evidence to con-

clusively demonstrate improvement in health outcomes’’. Additionally,

the panel noted that the majority of evidence was in younger patients

and that it was unclear whether this data could be applied to the Medicare

population.

PURPOSE: The purpose of this study is to compare clinical outcomes for

lumbar fusion in older versus younger patients, within a clearly defined

study population.

STUDY DESIGN/ SETTING: Patients were treated as part of an IRB ap-

proved, FDA regulated, randomized, nonblinded IDE trial of rhBMP-2 ma-

trix for posterolateral lumbar spine fusion. The patients were those

randomized to the control arm (ICBG) of the IDE trial. Inclusion criteria

for this study were single level lumbar DDD in patients over 18 yrs of

age with no greater than Grade I spondylolisthesis.

PATIENT SAMPLE: 224 patients who underwent single-level posterolat-

eral lumbar fusion with ICBG.

OUTCOME MEASURES: ODI, SF-36, Numeric Rating Scales for Back

Pain and Leg Pain, and radiographic fusion.

METHODS: Outcomes were compared for 50 patients over 65 yrs of

age (mean 70.5 yrs) and 174 patients under 65 yrs of age (mean 47.0

yrs). Change in outcome measures were evaluated based upon both net

mean change and the percentage of patients reaching an MCID threshold.

Published MCID thresholds of 5.42 pts for SF-36 PCS and 10 pts for

ODI were utilized. Fusion was assessed by plain radiographs and CT

scans.

RESULTS: Statistically significant improvements from baseline were

noted in all of the HRQOL measures at the six month, one year and

two yearr post-op intervals. Mean improvements in ODI at two years

post-op were 28.5 in older patients and 24.5 in younger patients. Older

patients performed better at all time intervals, though only the six month

difference between groups was significant (p50.041), after adjusting for

preoperative ODI score. For the SF-36 PCS, mean improvement from

pre-op baseline was 14.2 in the over 65 group and 11.7 in the under

65 group at two years. Older patients also demonstrated a greater im-

provement in back pain NRS scores at all time intervals with the differ-

ence at six months being statistically significant and the difference at two

years post-op trending towards significance (8.8 vs. 7.7, p50.077). Leg

pain NRS scores were also better in older patients at all time intervals,

with the difference at two years post-op being statistically significant

(10.4 pts vs. 6.4 pts, p50.002). Percentage of patients reaching MCID

was also higher in the older group than the younger group at all time in-

tervals. At two years after surgery, a decrease in ODI score of 10 pts or

greater was achieved in 85.0% of older patients and 72.7% of younger

patients. Improvement of 5.42 pts or more in SF-36 PCS was observed

in 75.0% of older patients and 63.6% of younger patients. Successful

fusion was seen in 94.7% of patients over 65 years old and 87.7% of

patients under 65 years old.

CONCLUSIONS: This study demonstrates substantial benefit for

a Medicare age population treated by single-level lumbar decompression

and instrumented fusion. This improvement is evident both in compar-

ison to literature standards and to a control population of younger

patients.