13SProceedings of the NASS 23rd Annual Meeting / The Spine Journal 8 (2008) 1S–191S

monitoring identified all spinal cord versus 1/3 cauda equina deficits. Im-

aging aided in diagnosis in 10/17 cases. Likelihood of recovery from a spi-

nal cord deficit was 50% and a cauda equina deficit 86%. Recovery

occurred in 59% of adults and 80% of kids.

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

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.029

26. Risk Factors and Outcomes for Catastrophic Failures at the Top

of Long Pedicle Screw Constructs (FPSC): A Matched Cohort

Analysis Performed at a Single Center

Patrick O’Leary, MD, Keith Bridwell, MD, Christopher Good, MD,

Lawrence Lenke, MD, Jacob Buchowski, MD, Yongjung Kim, MD,

Jennifer Flynn; Washington University in St. Louis, St. Louis, MO, USA

BACKGROUND CONTEXT: Acute fractures at the proximal aspect of

all-pedicle screw constructs in adult deformity patients present particular

challenges. Risk factors and outcomes in relation to a matched cohort were

investigated.

PURPOSE: Acute fractures at the top of long segmental pedicle screw

constructs (FPSC) are often catastrophic. Substantial surgical increase in

lordosis predisposes to this problem. In relation to a matched cohort, we

postulated that age, body mass index (BMI) and significant correction of

lumbar lordosis would increase risk of FPSC and patients with FPSC

would have lesser improvements in outcomes.

STUDY DESIGN/ SETTING: Retrospective matched cohort analysis at

a single center.

PATIENT SAMPLE: 13 fracture patients and 31 matched patients from

a total of 264 patients with fusion from thoracic spine to sacrum (2000-

2007) at a single center.

OUTCOME MEASURES: Radiographic/clinical follow-up and Oswes-

try Disability Index scores.

METHODS: 13 patients who sustained FPSC at one institution between

2000 and 2007 were evaluated. During this time, 264 patients aged 40 or old-

er had a spinal fusion from the thoracic spine to the sacrum utilizing an all-

pedicle screw construct. A cohort of 31 of these patients without FPSC but

with all pedicle screw constructs was matched for diagnosis of ‘+’ sagittal

imbalance, gender, preop C7 sagittal plumb, and number of levels fused.

All patients in both groups were fused from the thoracic spine to the sacrum.

RESULTS: FPSC occurred within 69 (24-117) days of surgery. A history

of minor trauma was elicited in 4 cases. There was a statistically significant

difference in age (p5.02) and BMI (p5.006) between the matched groups.

There was no significant difference in preop/postop C7 plumb or change in

lumbar lordosis between groups (Table 1). Acute paraplegia developed in 3

patients; only 1 patient returned to neurologic baseline. The second patient

has persistent deficits and the third remains paraplegic. 9 patients had fur-

ther surgery - proximal extension of the fusion. For 7 of the 13 FPSC pa-

tients with bone mineral density data (BMD) available, average T-score

was �1.73; �0.58 for the matched group (p5.02). There was less clinical

improvement, thought not statistically significant, in the FPSC group based

on Oswestry (ODI) scores.

CONCLUSIONS: Factors that increased the risk of FPSC included obe-

sity and older age. Osteopenia increased the risk as evidenced by BMD

(based on 17 patients) and the older age of these patients. Neuro deficits

were severe. There was no statistical difference in clinical improvement

between groups based on ODI. In female patients with BMIO30 and

ageO60, surgeons should consider alternatives to segmental pedicle screws

at the proximal end of the construct.

Table

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

any applicable devices or drugs.

doi:10.1016/j.spinee.2008.06.030

27. Complications in 910 Growing Rod Surgeries: Use of Dual Rods

and Submuscular Placement of Rods Decreases Complications

Shay Bess, MD1, Behrooz Akbarnia, MD1, George Thompson, MD2,

Paul Sponseller, MD3, David Skaggs, MD4, Suken Shah, MD5,

Sarah Canale, BS1, Connie Poe-Kochert, CNP6; 1San Diego Center for