77SProceedings of the NASS 24th Annual Meeting / The Spine Journal 9 (2009) 1S–205S

Because DNA-PK is a key protein involved in the repair of DNA double

stranded breaks, these results suggest that siRNA-mediated silencing of

this molecule may permit the increased sensitization of metastatic breast

cancer to the spine with ionizing radiation.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2009.08.178

Friday, November 13, 200911:00 AM–12:00 PM

General Session: Deformity

Approach GroupPSO

GroupSVA³

Correction (cm)Post-Op SVA

(cm)Post-Op SRS

22Complications Pseudo

Mean = 8.00 Mean = 1.05 Mean = 3.68Median = 5.55 Median = 2.50 Median = 3.88 2PSO¹

n=9 (0.02 - 17.90) (-6.9 - 6.0) (2.60 - 4.60) (in 2 patients)

2

Mean = 3.34 Mean = 2.83 Mean = 3.70Median = 2.70 Median = 1.70 Median = 3.94 12

Anterior/Posterior (n=30) No

PSO² n=21 (-3.68 - 15.00) (-3.5 - 10.0) (2.00 - 4.64) (in 8 patients)

2

Mean = 5.92 Mean = 1.51 Mean = 3.80Median = 4.34 Median = 1.55 Median = 3.80 0PSO¹

n=4 (1.55 - 13.45) (-0.5 - 3.4) (3.80 - 3.80)

0

Mean = 0.34 Mean = 4.14 Mean = 3.77Median = 0.25 Median = 4.30 Median = 3.70 1

Posterior Only (n=14) No

PSO² n=10 (-7.91 - 8.40) (0.0 - 9.0) (2.70 - 4.80) (in 1 patient)

0

1PSO: Patients who had a pedicle subtraction osteotomy2No PSO: patients who had Smith-Peterson osteotomy or no osteotomy3Sagittal Vertical Axis (C7-S1 offset)

Table.

145. Complications of Pedicle Screw Fixation in Scoliosis Surgery:

A Systematic Review

John Hicks, MD1, Amit Singla, MD2, Vincent Arlet, MD1; 1University of

Virginia, Charlottesville, VA, USA; 2SUNY- Upstate Medical University,

Syracuse, NY, USA

BACKGROUND CONTEXT: The use of pedicle screws in adolescent

scoliosis surgery is common. Although many reports have been published

regarding the use of pedicle screws in pediatric patients, there has been no

systematic review on the risks of complications.

PURPOSE: A systematic review of the published literature on the use of

pedicle screws in the correction of pediatric scoliosis and spinal deformity

was undertaken. Complications were compiled to quantify the risks associ-

ated with pedicle screw instrumentation, particularly in the thoracic spine.

STUDY DESIGN/SETTING: A systematic review of the use of pedicle

screws in pediatric deformity surgery.

PATIENT SAMPLE: Patients under the age of 21 with spinal deformity.

Exclusion criteria include neuromuscular disease, trauma, tumor, osteo-

dyslplasia and osteodystrophy.

OUTCOME MEASURES: N/A.

METHODS: Pubmed, Ovid Medline and Cochrane databases were

searched for literature describing the complications of thoracic pedicle

screws. Data were compiled for the complications reported. Case reports

were also reviewed.

RESULTS: Twenty one papers were included with 14,890 pedicle screws

in 1686 patients. The mean age of the patients was 17.6 years. 812 patients

were female, 252 were male, 5 studies did not identify gender. 518 (3.47%)

screws were reported as malpositioned. The reported rate of patients with

malpositioned screws ranged from 1.2 to 30%. In studies where postoper-

ative CT scans were used, the rate of malpositioning was 15.7% per screw.

11 patients underwent revision surgery for instrumentation malposition.

Loss of curve correction was reported at one to five percent. Twenty seven

intraoperative pedicle fractures were reported. Four cases of dural lacera-

tion were reported. Ten cases of deep infection were reported. Twenty

cases of decompensation or ‘‘adding on’’ were reported. Pseudarthrosis

was reported in only one patient. 38 incidences of intraoperative loosening

were reported. Only one transient neurologic compromise was reported.

There was no permanent neurologic injury reported, except in case reports.

There were no major vascular complications reported.

CONCLUSIONS: Malposition is the most commonly reported complica-

tion of thoracic pedicle screw placement, at a rate of 3.47% per screw in-

serted. This corresponds to a much higher rate of patients with at least one

malpositioned screw. The rate of revision for misplaced pedicle screws is

0.86%. The use of pedicle screws in the thoracic spine for the treatment of

pediatric deformity seems to be safe despite the high rate of patients with

malpositioned screws. Major complications, such as neurologic or vascular

injury, are exceptionally reported in the literature.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2009.08.180

146. Outcomes and Complications of Extension of Previous Long

Fusion to the Sacro-Pelvis: Does Surgical Approach Make

a Difference?

Douglas Burton, MD1, Oheneba Boachie-Adjei, MD2,

Christopher Shaffrey, MD3, Frank Schwab, MD4, Richard Hostin, MD5,

Alexis Shelokov, MD5, Shay Bess, MD6, Behrooz Akbarnia, MD7;1University of Kansas Medical Center, Kansas City, KS, USA; 2Hospital

for Special Surgery, New York, NY, USA; 3University of Virginia,

Charlottesville, VA, USA; 4NYU Hospital for Joint Diseases, New York, NY,

USA; 5Baylor Scoliosis Center, Plano, TX, USA; 6Rocky Mountain

Hospital for Children, Denver, CO, USA; 7La Jolla, CA, USA

BACKGROUND CONTEXT: An increasing number of adult spine de-

formity patients are presenting with new complaints related to functional

problems (pain, degeneration, deformity, stenosis, imbalance) thus requir-

ing extensions of their fusion to the sacrum. Scoliosis patients treated with

Harrington rod instrumentations as adolescents are now adults with varied

scenarios of flatback, junctional degenerative disc, instability and pain.

Current surgical techniques and modern instruments being employed in-

clude PSF/PLIF/TLIF; ASF/PSF; osteotomy; and PSO all with variable

results.

PURPOSE: Few studies have reported the results and complication rates

for extension of previous long scoliosis fusions terminating at L3, L4, or

L5 to the sacro-pelvis. The purpose of this study was to evaluate the effi-

cacy and complications of different surgical approaches to optimize spinal

alignment correction in patients requiring revision spinal surgery with ex-

tension of fusion to the sacro-pelvis. Specifically, potential study benefits

include an increased understanding of: 1) the natural history and character-

istics of transition zone syndrome in fusions to L3, L4, L5, 2) the present-

ing complaints and surgical indications for proper patient selection, and 3)

the best practice for revision surgical intervention.

STUDY DESIGN/SETTING: Retrospective, consecutive (1995-2006),

multicenter, chart, HRQL, and radiographic review of adult deformity

pts previously fused distally to L3, L4, or L5 receiving revision surgery

to extend the fusion to the sacro-pelvis.

PATIENT SAMPLE: Inclusion criteria: age O18 years, degenerative sco-

liosis O20 degrees, diagnosis of spinal deformity (scoliosis, kyphosis, flat-

back, etc), prior fusion to L3, L4, L5 distally and L1, or higher, proximally.

44 pts of 54 eligible pts, mean age 49.0 yrs (21-73 yrs), had 2 yr radio-

graphic data. Mean follow-up was 41.9 months (23-135 months). 41 of

54 pts had 2 yr SRS 22 scores.

OUTCOME MEASURES: Radiographic evaluation included coronal and

sagittal spino-pelvic measures, preoperative and 2 yr postoperative. HRQL

outcomes included the SRS-22 at 2 yrs postop.

METHODS: Pts were divided into APSF (n530) and PSF (n514; 10 of

14 had either a PLIF or TLIF) approach groups. Pts were evaluated for

pedicle subtraction osteotomy (PSO; n513) or no PSO (n531). Perioper-

ative complications were noted.

RESULTS: No statistically significant preoperative differences existed be-

tween the APSF and PSF groups, except the APSF group had a larger TL

curve (p50.011). Only pts receiving PSO had significant sagittal vertical

axis (SVA) correction postoperatively (p50.002). Although not statisti-

cally significant, more complications occurred in APSF compared to

PSF (14 vs 1; p50.092; Table 1). Table 1 indicates that there was no