63SProceedings of the NASS 22nd Annual Meeting / The Spine Journal 7 (2007) 1S–163S

disease. It has been hypothesized that biomechanical stresses are increased

at levels adjacent to fusions and lead to hypermobility and accelerated

degeneration.

PURPOSE: To determine the incidence of adjacent segment degeneration

in patients who have undergone ALIF.

STUDY DESIGN/SETTING: Retrospective study using FDA-regulated

post-approval data.

PATIENT SAMPLE: 72 patients with symptomatic, single-level degener-

ative lumbar disc disease who were treated with ALIF.

OUTCOME MEASURES: Dynamic motion radiographs were evaluated

at a minimum of 6 years after surgery.

METHODS: 72 patients underwent an open, single-level ALIF with

paired threaded interbody cages. 25 had surgery at the L4-5 level, and

46 had surgery at the L5-S1 level. We reviewed dynamic flexion-extension

lateral radiographs preoperatively, at 6 months and at 6 years after surgery

in these patients. Changes in segmental angulation and motion were as-

sessed through validated computerized digital analysis (validated to 0.5 de-

grees and 0.5 mm) at the index surgical level, at adjacent levels and global

spine motion from L1 through S1.

RESULTS: At 6 years after surgery, adjacent level range of motion varied

widely among study patients. L4-L5 surgical level: At 6 years, 69%

showed a decrease in motion at the superior L3-L4 level when compared

with preoperative and six month values. Similarly, 56% at the level below

the fusion (L5-S1) showed a decrease in motion at 6 years. At the L4-L5

surgical level, motion decreased by an average of 10.5 degrees from pre-

operative values while global lumbar motion decreased by 21.5 degrees.

L5-S1 surgical level: Again, at 6 years at the level above the fusion,

69% showed decreased motion at the superior L4-L5 level. Global spinal

motion was decreased by 13.7 degrees; the index surgical level accounted

for a loss of only 8.6 degrees.

CONCLUSIONS: At 6 years after surgery, changes in the global range of

lumbar motion cannot be entirely accounted for by the isolated reduction

in motion seen at the surgically fused level. The loss of motion at the fused

segment contributes only approximately 50% of the reduction seen at

6 years following surgery. Hypermobility at adjacent levels to the fusion

was not seen. Biomechanical stresses may be transferred to levels adjacent

to an ALIF; however, these increased stresses are not manifested by an

increase in motion at the adjacent segments.

FDA DEVICE/DRUG STATUS: LT-CAGE Device: Approved for this

indication.

doi: 10.1016/j.spinee.2007.07.154

Friday, October 26, 20074:16–5:16 PM

Special Interest Poster Presentation 1:Medical Management

131. Preliminary Experience with (Functional Anesthetic

Discography) FAD

Jonathan Luchs, MD1, Mona Cho, MD1, Alexandre Demoura, MD1, A.

Orlando Ortiz, MD1; 1Winthrop-University Hospital, Mineola, NY, USA

BACKGROUND CONTEXT: Functional anesthetic discography has

been developed to add realtime analysis of patients with suspected disc

pain. This technology has been FDA approved but has not yet become

a mainstream examination of patients with lower back pain and suspected

disc pain.

PURPOSE: We have been adding the FAD technique to our practice as an

adjunct to conventional discography and will discuss our results and con-

clusion regarding this relatively new technique.

STUDY DESIGN/SETTING: This is a prospective study of patients who

have already been determined to have lower back pain and suspected disc

pain. All of these patients have been referred for conventional discography

and present with an MRI of the lumbar spine in hand at the time of the

study.

PATIENT SAMPLE: FAD was performed in 19 consecutive patients (13

male, 6 female; mean age 47.2 years, range 34 to 69 years) who underwent

lumbar discography for suspected discogenic low back pain.

OUTCOME MEASURES: Patients were subsequently examined before

and after (0, 5, 10, and 15 minutes post disc anesthetic injection) the injec-

tion of the disc via the FAD catheter using 1–2 mL of 0.5 to 2% local an-

esthetic agent. Patients were asked to perform maneuvers that would

typically elicit their pain symptoms and their pain response was recorded.

The patient used a standard 1–10 pain scale to rate their patient.

METHODS: A total of 53 potentially pain-producing discs were studied.

A 21 gauge FAD catheter was placed into one or more potentially pain pro-

ducing discs as determined by a provocative discograms (32 discs) or ab-

normal discograms (26 discs) study using an over-the-wire exchange

technique. Patients were kept blind to the level of disc injection and to

the level of FAD placement. At the completion of the discogram, a multi-

detector CT scan was obtained in order to analyze the injected discs for the

presence of radial tears and other pathology using the modified Dallas dis-

cogram scale. Patients were subsequently examined before and after (0, 5,

10, and 15 minutes post disc anesthetic injection) the injection of the disc

via the FAD catheter using 1–2 mL of 0.5 to 2% local anesthetic agent.

Patients were asked to perform maneuvers that would typically elicit their

pain symptoms and their pain response was recorded.

RESULTS: 19 out of 29(65.5%) of the injected discs showed a favorable re-

sponse (pain relief greater than 3 visual analog pain scale units) to anesthetic

injection. 10 out of 29 (34.5 %) did not show a favorable response. In those pa-

tients with a favorable FAD response, 19 discs showed a provocative response

during discography and 18 discs showed the presence of disc pathology on CT

examination. In patients with no pain relief after anesthetic injection (an unfa-

vorable FAD response), 8 discs showed a provocative discographic response,

and 6 discs showed the presence of disc pathology on CT examination.

CONCLUSIONS: FAD is a useful procedure and can be used to confirm

the presence of pathologic discs as the source of a patient’s low back pain

symptoms.

FDA DEVICE/DRUG STATUS: Kyphon- FAD: Approved for this

indication.

doi: 10.1016/j.spinee.2007.07.156

132. Are Acute, Chronic, Back Pain-Only, and Sciatica-with-Neural-

Deficit Valid Low Back Pain Subgroups? Not for Most Patients

Audrey Long, PT1, Ronald Donelson, MD, MS2, Tak Fung, PhD1,

Kevin Spratt, PhD3; 1Calgary, Alberta, Canada; 2Hanover, NH, USA;3Lebanon, NH, USA

BACKGROUND CONTEXT: Acute and chronic low back pain (LBP), as

well as LBP-only and sciatica with neural deficit, are commonly considered

very different disorders needing different treatments with greatly different re-

covery and cost expectations. During patient intake for a randomized clinical

trial (RCT), patients were categorized as having acute, sub-acute or chronic

LBP and also by Quebec Task Force (QTF) 1-4 categories ranging from

LBP-only to sciatica with neural deficit. Prior to randomization, the pain of

74% of 312 consecutive patients reduced, centralized or abolished with a sin-

gle direction of repeated end-range testing. That single direction is called

the patient’s ‘‘directional preference’’ (DP). Those DP patients were then

randomized to directional exercises matching their DP (N580) and reported

significantly better results in all seven outcome measures compared with

those DP patients treated with one of two non-matching exercise treatments.

PURPOSE: To evaluate the value of subgrouping patients based on pain

duration and QTF pain location/neural status categories.

STUDY DESIGN/SETTING: A secondary analysis of data related to

LBP patients presenting for care to multiple physical therapy clinics.

PATIENT SAMPLE: 80 LBP patients found at baseline to have a DP who

were then treated with matching directional exercises.

64S Proceedings of the NASS 22nd Annual Meeting / The Spine Journal 7 (2007) 1S–163S

OUTCOME MEASURES: Back and leg pain intensity, activity interfer-

ence, self-rated improvement, Roland-Morris Disability Questionnaire,

medication use and Beck Depression Inventory.

METHODS: A secondary analysis was conducted of the 80 DP patients

treated with ‘‘matching’’ directional exercises. General linear modeling anal-

yses were used to evaluate the effects of pain duration and QTF pain location/

neural category for seven outcome measures after two weeks of treatment.

RESULTS: No significant differences were reported for any of the seven out-

come variables across QTF 1-4 location/neural subgroups or in five of the seven

across the three duration subgroups. Chronic patients reported substantial reduc-

tion in back pain intensity but significantly less than acute patients (p!.005).

Acutes reported 100% improvement or full recovery in just two weeks, chronics

91% (p!.011), and patients with sciatica and neural deficit 83%.

CONCLUSIONS: When the large subgroup of DP patients (74% of pre-

senting LBP patients) were treated with directionally-matching exercise

treatment, their QTF 1-4 pain location/neural status or their pain duration

did not predict 12 of 14 outcome measures. Despite anticipated differences

in outcomes by symptom duration with just two weeks of treatment, rates

of improvement and recovery in acutes, chronics and sciatica-with-neural-

deficit were far higher than expected. The clinical finding of DP appears to

be a useful and reliable baseline indicator of a reversible pain-generator

common to a large percentage of patients with acute, subacute, chronic

LBP and sciatica, even with neural deficit.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2007.07.157

133. Do Preoperative Steroid Injections Increase the Risk

of Postoperative Infection?

Timothy R. Kuklo, MD, JD1, Michael K. Rosner, MD2, Ross Moquin, MD3;1Washington University in St. Louis, St Louis, MO, USA; 2Walter Reed

Army Medical Center, Silver Spring, MD, USA; 3Washington, DC, USA

BACKGROUND CONTEXT: No previous study has determined the

postoperative risk of infection in patients previously managed with steroid

injections.

PURPOSE: To determine the postoperative risk of infection in patients

previously managed with steroid injections.

STUDY DESIGN/SETTING: A retrospective consecutive case series of

thoracolumbar surgical cases with 2 yrs. minimum follow-up.

PATIENT SAMPLE: 3266 adult (O21 yrs. old) thoracolumbar surgical

cases from 2000-2005 (min. 2 yr. follow-up)

OUTCOME MEASURES: Cases were reviewed for incidents of postop-

erative infection and any preoperative steroid injections.

METHODS: This is a consecutive case series of 3,266 adult (age O21;

ave. age 42.6, range 21–78; M:F ratio 1.6:1) thoracolumbar surgical cases

from 2000-2005 which were reviewed to identify a history of postoperative

infection (eliminating patients with a history of tumor or previous infec-

tion) and to determine any association with preoperative steroid injections

in terms of type of injection (epidural steroid injection - ESI or transfora-

minal steroid injection - TFI), number of injections, steroid and dose, and

timing before surgery. Analysis also included patient age and gender, obe-

sity, diabetes, tobacco and revision surgery, as well as surgical approach

and number of levels, the use of instrumentation, laminectomy, osteotomy,

length of procedure (!orO3 hrs.), EBL, and the presence of a dural tear to

determine any other potential contributing factors.

RESULTS: Overall, there were 54 postoperative infections (1.7%). This

included 38 of 1,168 (3.9%) receiving preoperative steroid injections

(ESI 31/606 (5.1%), p!0.05: TFI 7/562 (1.2%), pO0.05), versus 16 of

2,098 (0.8%) not receiving an injection. Of those receiving ESI, there

was also an increased infection rate with those patients receiving 3 or more

injections (p!0.05), or with diabetes and ESI (p!0.05). Further, there was

a trend toward an increased infection rate when receiving an ESI within 3

months of surgery (p5.10), or when instrumentation is used (p50.08). Ad-

ditional analysis found no association with age, gender, obesity, tobacco

use, or with surgical approach and number of levels, laminectomy, osteot-

omy, length of procedure, EBL, dural tear, or type of steroid. There was

a trend toward increased infection with revision surgery (p!0.05).

CONCLUSIONS: In this series, there is an increased postoperative infec-

tion rate in patients preoperatively treated with ESI (but not TFI); espe-

cially when receiving 3 or more injections. There is also a trend toward

increased infection when receiving an injection within 3 months of surgery

or when instrumentation is used. This has not changed our practice; how-

ever, patients should be counseled on this association when undergoing

surgical intervention.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2007.07.158

134. False-positive Zygapophyseal Joint Blocks in the Cervical Spine

Eugene Carragee, MD1; 1Stanford University, Stanford, CA, USA

BACKGROUND CONTEXT: Some authors have purported that a positive

response to medial branch blocks (MBB) of the zygapophyseal joint by either

comparative anaesthetic blocks or placebo-controlled blocks establish the

‘‘definitive diagnosis’’ of zygapophyseal pain. There have been no gold stan-

dard comparisons of the results of zygapophyseal blocks in the cervical spine.

PURPOSE: To compare the results of cervical zygapophyseal blocks

against a gold standard (clear pathologic diagnoses) in a consecutive series

of patients.

STUDY DESIGN/SETTING: Consecutive case-series.

PATIENT SAMPLE: Consecutive patients having zygapophyseal blocks

in a university spine clinic.

OUTCOME MEASURES: Results of controlled cervical zygapophyseal

joint blocks by standard protocol against a Gold Standard diagnostic

finding.

METHODS: A prospective clinic database from 2000–2004 was searched

for all patients receiving controlled (placebo-controlled or comparative

anaesthetic blocks). Subjects with positive injections were identified and

compared to a Gold Standard diagnosis where available.

RESULTS: During the observation period 42 patients had controlled diag-

nostic blocks at levels between C3 and T1. Of these 19 (45%) were found to

have single level positive results. Three of 19 (16%, 95% CI 0–32%) had de-

finitive diagnoses established for the neck pain at other sites: herniated C3/4

disc; odontoid fracture; a pseudarthrosis at an adjacent level; and a plasmacy-

toma of C6. In each case, treatment of the pathologic diagnosis resulted in

relief of symptoms. That is, although the controlled facet injections indicated

the cause of pain to be primary zygapophyseal joint pain, the true cause of the

pain was found to be unrelated to the joint identified by injection. In only one

case was clear pathology identified at the same level and side as the injection-

diagnosed facet (a unilateral facet impaction fracture of C5/6).

CONCLUSIONS: Pain relief with controlled-diagnostic MBB to the

zygapophyseal facet may be positive when the pain source is definitively

found at a different location. Contrary to the literature suggesting con-

trolled zygapophyseal joint injections ‘‘definitively diagnose’’ primary fac-

et joint pain when positive, this study demonstrates the false-positive-rate

of controlled cervical facet injections may be significant and may divert

attention from the true source of neck pain. The specificity of MBB has

not been well established.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2007.07.159

135. Validity of Self-Reported History in Patients with Back

and Neck Pain after Motor-Vehicle Accidents (MVA)

Eugene Carragee, MD1; 1Stanford University, Stanford, CA, USA

BACKGROUND CONTEXT: A validity analysis is crucial to determin-

ing the usefulness of diagnostic data. Patients reporting pain in the back or