The Spine Journal 11 (2011) 1S–173S

NASS 26th Annual Meeting – Proceedings

Wednesday, November 2, 20111:10–2:10 PM

General Session: Best Papers

1. Functional and Quality of Life Outcomes in Geriatric Patients

with Type II Odontoid Fracture: One-Year Results from the

AOSpine North America Multicenter GOF Prospective Study

Branko Kopjar, MD, PhD1, Alexander Vaccaro, MD, PhD2,

Michael Fehlings, MD, PhD, FRCSC3, Jens Chapman, MD4,

Christopher Shaffrey, MD5, Paul Arnold, MD6,

Ziya Gokaslan, MD, FACS7, Roger Hartl, MD8, Darrel Brodke, MD9,

John France, MD10, S. Tim Yoon, MD, PhD11, Mark Dekutoski, MD12,

Rick Sasso, MD13, Christopher Bono, MD14; 1University of Washington,

Seattle, WA, USA; 2Rothman Institute, Philadelphia, PA, USA; 3Toronto

Western Hospital, Toronto, ON, Canada; 4UW Harborview Medical

Center, Seattle, WA, USA; 5University of Virginia Department of

Neurosurgery, Charlottesville, VA, USA; 6University of Kansas Medical

Center, Department of Neurosurgery, Kansas City, KS, USA;7Johns Hopkins University, Department of Neurosurgery, Baltimore, MD,

USA; 8NY Presbyterian Hospital - Weill Cornell, New York, NY, USA;9University Orthopaedic Center, Salt Lake City, UT, USA; 10Robert C.

Byrd Health Sciences Center, Morgantown, WV, USA; 11The Emory Spine

Center, Atlanta, GA, USA; 12Mayo Clinic, Rochester, MN, USA; 13Indiana

Spine Group, Indianapolis, IN, USA; 14Brigham & Women’s Hospital,

Department of Orthopedic Surgery, Boston, MA, USA

BACKGROUND CONTEXT: Type II odontoid fractures are common in

the elderly and represent a major management challenge, with diverging

opinions of risks/benefits of surgical vs. nonoperative management. This

lack of consensus among clinicians as to the optimal management strategy

for geriatric odontoid fractures is exacerbated bythe paucity of objective,

prospective information regarding treatment outcomes in this condition.

Hence, better evidence related to treatment efficacy and safety is warranted

to inform management decisions regarding elderly patients who present

with an odontoid fracture.

PURPOSE: To evaluate treatment efficacy and safety of surgical vs.

nonoperative management within elderly patients who present with an

odontoid fracture.

STUDY DESIGN/SETTING: We conducted a prospective multi-center

cohort study of subjects O65 yrs old with a type II odontoid fracture at

13 sites in North America.

PATIENT SAMPLE: A total of 166 subjects presenting with an odontoid

fracture were recruited between January 2006 and May 2009.

OUTCOME MEASURES: Outcomes assessments included the SF36v2,

Neck Disability Index (NDI) and rates of mortality and complications.

METHODS: Patients received nonoperative or surgical treatment at the

discretion of the surgical team and were followed for 12 months.

RESULTS: The average age was 80.7 (SD 7.6) with a range from 65

to 101 years. 59.6% were females. 65.6% patients were treated oper-

atively (15.2% anterior odontoid screw; 76.2% posterior C1- C2 screw

fixation; 6.7% posterior transarticular screw fixation and 1.9% other)

and 34.4% with conservative approaches. A total of 26 (15.7%) sub-

jects expired and 5 subjects withdrew from the study. Baseline NDI

and SF-36v2 values were based on estimate of pre-injury status. The

baseline NDI was 20.5 (SD 16.7) and the 12-month NDI was 28.3

(SD 20.1) (p!.01). SF36v2 PCS at baseline was 41.8 (SD 10.05)

All referenced figures and tables will be available at the Annual Mee

and at 12-month 39.4 (SD 10.1) (p5.03). SF36v2 MCS at baseline

was 52.48 (SD 10.3) and at 12-month 48.1 (SD 11.9) (p!.01). There

were no differences in age and gender between the surgically and con-

servatively treated subjects. Mortality was similar in the surgical and

nonoperative groups. SF36v2 PCS outcomes were similar between the

two treatment groups but the SF36v2 MCS outcomes were better in

the surgical group as compared to the cohort of patients managed non-

operatively (49.8 and 45.2 in surgical and conservative groups, respec-

tively, p5.05). Moreover, functional outcomes as measured by NDI

were significantly better in the operative than the nonoperative group.

After adjustment for baseline characteristics, the 12-month NDI was

34.1 in the nonoperatively-managed group as compared to 25.1 in

the operative group (p!.01).

CONCLUSIONS: Elderly patients with type II odontoid fracture experi-

ence significant mortality which is probably due to advanced age and gen-

erally compromised health status. However, the vast majority of patients

(85% in our study) survive 12 months following the initial injury. Our re-

sults do suggest that functional and quality of life outcomes may be better

in the surgical group, though the possibility of selection bias needs to be

carefully considered.. Judgment is required by the treating team when

selecting the optimal management strategy for the elderly with Type II

odontoid fractures. In good risk, highly functioning patients, we recom-

mend an operative approach. In poor risk, medically compromised individ-

uals, a nonoperative approach to type II odontoid fractures is safe and

clinically reasonable.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2011.08.016

2. No Orthosis is Equivalent to TLSO for the Treatment of

Thoracolumbar Burst Fractures without Neurologic Injury: Results

from a Multicenter RCT

Christopher Bailey, MD, FRCSC1, Marcel Dvorak, MD, FRCSC2,

Melissa Nadeau, MD3, Allan Aludino4, M. Patricia Rosas-Arellano, MD3,

Michael Boyd, MD2, Scott Paquette, MD5,

Brian K. Kwon, MD, PhD, FRCSC2, John France, MD6,

Kevin R. Gurr, MD7, Stewart Bailey, MD3, Charles Fisher, MD6;1University of West Ontario London Health Sciences Centre, London, ON,

Canada; 2Blusson Spinal Cord Centre, Vancouver, BC, Canada; 3London,

ON, Canada; 4University of British Columbia, Vancouver, BC, Canada;5Vancouver, BC, Canada; 6Robert C. Byrd Health Sciences Center,

Morgantown, WV, USA; 7London Health Sciences Centre, London, ON,

Canada

BACKGROUND CONTEXT: Thoracolumbar burst fractures are com-

mon injuries. Good outcomes can be expected for those patients presenting

without neurologic injury who are treated with a thoracolumbosacral or-

thosis (TLSO) and early ambulation. However, anecdotal experience and

low grade evidence suggest these fractures may be satisfactorily treated

without a brace.

PURPOSE: To compare the functional outcome of patients with AO type

A3 burst fractures randomly treated with a TLSO versus no orthosis (NO).

STUDY DESIGN/SETTING: A multi-centred prospective randomized

controlled equivalence trial.

PATIENT SAMPLE: Patients were recruited from three Canadian tertiary

spine centres.

ting and will be included with the post-meeting online content.

2S Proceedings of the NASS 26th Annual Meeting / The Spine Journal 11 (2011) 1S–173S

OUTCOME MEASURES: The primary outcome measure was the Ro-

land Morris Disability Questionnaire (RMDQ) assessed at 3 months post

injury. Secondary outcomes were assessed at 2 and 6 weeks, 3, 6, 12

and 24 months and included: pain (Visual Analogue Scale), functional out-

come (RMDQ), generic health related quality of life (SF-36), patient sat-

isfaction, sagittal alignment, length of hospital stay and complications.

METHODS: Consecutive patients who satisfied the following inclusion

criteria were considered eligible for this study: 1) AO-A3 burst fractures

between T11 and L3, 2) skeletally mature and less than sixty years of

age, 3) admitted to the participating hospital within seventy-two hours

of their injury, 4) initial kyphotic deformity of less then thirty-five degrees,

5) no neurologic deficit. Randomization was stratified according to

worker’s compensation status and severity of kyphosis at admission

(!20� versus $20�). Enrollment continued until the sample size satisfied

a power of 90%. The NO group was encouraged to ambulate immediately

following randomization with bending restrictions for eight weeks. The

TLSO group was weaned from the brace between the eight to ten week pe-

riod. Both groups were encouraged to perform a standardized physiother-

apy routine.

RESULTS: 47 patients were enrolled into the TLSO group and 49 patients

into the NO group. The mean subject age was 40 years and 70% were

male. The majority of fractures occurred at L1 (49) then T12 (18) and

L2 (15). At the three month primary endpoint 46 patients were evaluated

in each group. This declined to 36 patients followed in each group at 2

years. There was no difference in average length of hospital stay

(TLSO54.7 days, NO55.0 days). No difference was found between

groups for any of the primary or secondary outcomes at any of the fol-

low-up periods (student t-test). One way analysis of variance identified

a significant improvement of the RMDQ within both groups at 6 weeks

(p!.05) (figure). The average kyphotic deformity was 14� (range: �1 to

35) at admission that increased to 21� at 6 weeks and did not progress fur-

ther. No difference in average kyphotic deformity existed between treat-

ment groups. Six patients required surgical stabilization, five of these

prior to initial hospital discharge.

CONCLUSIONS: Neurologically intact thoracolumbar burst fractures can

be successfully treated using early ambulation without a brace.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2011.08.017

3. Incidence and Impact of Acute Adverse Events in Patients with

Traumatic Spinal Cord Injury

Antoinette Cheung1, John Street, PhD2, Vanessa Noonan, PT2,

Lydia Cartar1, Marcel Dvorak, MD, FRCSC3; 1Rick Hansen Institute,

Vancouver, BC, Canada; 2Vancouver, BC, Canada; 3Blusson Spinal Cord

Centre, Vancouver, BC, Canada

BACKGROUND CONTEXT: Adverse events with significant resultant

morbidity are common during the acute hospital care of patients with trau-

matic spinal cord injury (TSCI). The Rick Hansen SCI Registry (RHSCIR)

collects Canada wide data on patients with TSCI; data such as sociodemo-

graphic, injury, diagnosis, intervention, and health outcome details. This

data contributes to an evidence base for informing best practice and im-

proving SCI care. As the RHSCIR captures data on patients from pre-hos-

pital to community phases of care, it is an invaluable resource for

providing information on health outcomes resulting from TSCI, including

outcomes related to adverse events.

PURPOSE: To determine the incidence and types of adverse events occur-

ring in patients with TSCI during acute care and the impact on length of

stay (LOS) and health status.

STUDY DESIGN/SETTING: Prospective cohort study at an academic

quaternary referral centre.

PATIENT SAMPLE: Patients with TSCI discharged from Vancouver

General Hospital between 2008-2009 were identified using the RHSCIR.

All referenced figures and tables will be available at the Annual Mee

The RHSCIR includes patients of any age admitted to one of the partici-

pating centres across Canada, who have been clinically diagnosed with

an acute TSCI or classified as AIS A, B, C, D, or cauda equina.

OUTCOME MEASURES: Acute phase LOS and health status were as-

sessed for impact resulting from the number and type of adverse events ex-

perienced. Health status was determined using the Short-Form 36 (SF-36)

Physical and Mental Component Scores (PCS and MCS, respectively).

METHODS: Data related to patients’ injury, diagnoses, hospital admis-

sion, and SF-36 scores was obtained from the Vancouver RHSCIR. Data

on intra-, pre-, and post-operative adverse events was collected prospec-

tively using the Spine Adverse Events Severity (SAVES) data collection

system, documenting all adverse events experienced by each patient. Mul-

tivariate analyses were performed to determine whether patient and injury

characteristics were associated with number and type of adverse events ex-

perienced, and whether these were associated with LOS and SF-36 scores

determined upon follow-up.

RESULTS: 110 patients with TSCI were included, 78.2% were male and

mean age at injury was 45.8619.6 years. Follow-up ranged from 11-27

months post-injury. Adverse events occurred in 83.6% of patients;

20.0% experienced an intra-operative and 79.1% experienced a pre-/

post-operative event. The most frequent pre-/post-operative adverse events

were urinary tract infections (UTIs) (36.5%), pneumonias (34.6%), neuro-

pathic pain (22.1%), pressure sores (19.2%) and delirium (18.3%). LOS

was significantly impacted by pressure sores, delirium, pneumonias and

UTIs (p!.01), increasing 1.8 (UTIs) to 2.2 (pressure sores) times com-

pared to patients without the specific adverse events. SF-36 MCS was sig-

nificantly reduced in patients with UTIs (p!.05), indicating lower health

status.

CONCLUSIONS: This prospective study found that more than 83% of

patients with TSCI sustain an adverse event during acute hospital care, sig-

nificantly higher than previously reported. We demonstrate the utility of

a dedicated adverse event collection system and the effect of these events

on health status.

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

any applicable devices or drugs.

doi: 10.1016/j.spinee.2011.08.018

4. Preclinical Study of Human Allograft Amniotic Membrane as

a Barrier to Epidural Fibrosis in the Early Wound of

a Postlaminectomy Rat Model

Andrew Mahar1, R. Todd Allen2, Jennifer Massie3, Frank Phillips, MD4;1Alphatec Spine, Inc., Carlsbad, CA, USA; 2University of California San

Diego, San Diego, CA, USA; 3VA Medical Center, San Diego, CA, USA;4Midwest Orthopaedics at Rush, Chicago, IL, USA

BACKGROUND CONTEXT: After lumbar spine surgery, epidural scar-

ring is thought to compromise clinical results and makes revision surgery

more challenging. Barriers that limit the adherence of scar to the dura, and

reduce post-operative neuropathic pain, are desirable. Amniotic membrane

is known to prevent scar formation, and has been used for ulcerative and

burn wound healing making it a potential candidate material for reducing

post-laminectomy scarring.

PURPOSE: The purpose of the current study is to evaluate the use of hu-

man amniotic membrane for prevention of dural adhesions in a well-estab-

lished post-laminectomy animal model.

STUDY DESIGN/SETTING: In vivo animal survival study.

PATIENT SAMPLE: 32 mature male rats.

OUTCOME MEASURES: histology, biomehcanics, pain thresholds

METHODS: Thirty two mature male Harlan Sprague–Dawley rats had bi-

lateral laminectomies (L5 and L6) and a right unilateral ‘‘joystick’’ disc

injury (L5–6). Rats were then randomly assigned to receive human amni-

otic roofing barrier (Amnioshield�, Alphatec Spine, Carlsbad, CA) over

the laminectomy site or no barrier treatment (control). Animals survived

for 8 weeks. For each group, 8 animals were dedicated to histological

ting and will be included with the post-meeting online content.