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

any applicable devices or drugs.

CONFLICT OF INTEREST: No conflicts.

doi: 10.1016/j.spinee.2006.06.352

P144. Analysis of the Recurrence Rate of the Lumbar Disc

Herniation

Min-Seok Kim, MD1, Young-Kyun Lee1, Changju Hwang, MD1,

Dong-Ho Lee, MD2, Choon-Ki Lee1, Bong-Soon Chang, MD, PhD1;1Seoul National University, Seoul, South Korea; 2Asan Medical Center,

Ulsan University, Seoul, South Korea

BACKGROUND CONTEXT: In active young men, the prevalence of

lumbar disc herniation is higher than that of old men. Difference of recur-

rece rate after open discectomy in both groups is questionable.

PURPOSE: This study aims to estimate the true recurrence rate of lumbar

disc herniations, that exhibit high prevalence in active young men, after

open discectomy.

STUDY DESIGN/SETTING: retrospective study.

PATIENT SAMPLE: From January 1992 to September 2005, this study

examined 241 cases, patients who had been operated by an open discec-

tomy on a single level and had no other spinal lesions such as spondylolis-

thesis, spondylosis, or spinal stenosis.

OUTCOME MEASURES: In 195 on the 241 cases (80.9%), follow-up

study was possible. The average duration of the follow-up was

8.5560.12 years (1 to 14 years). The average age of the patients was

23.4864.83 years (20 to 39 years); the most common lesion of lumbar disc

herniation was L4-5 (158 cases, 65.6%) at the initial diagnosis. The simple

recurrence rate was 7.1% (17 cases) using the conventional method, in

which the cases lost to follow-up were excluded.

METHODS: Physical examination and MRI were used to confirm the di-

agnosis of a lumbar disc herniation in all cases. The recurrence of lumbar

disc herniation was diagnosed only in those patients who had the same pat-

tern of symptoms as confirmed by MRI. The patients who had undergone

additional surgery at another hospital at the same spinal level were also

counted as recurrence. The medical records and radiological findings,

including a telephone survey, were studied.

RESULTS: Statistical analysis showed that the annual recurrence rate was

highest at the first year postoperatively as 2.9% (7 cases). At the last fol-

low-up of 14 years, the cumulative survival rate was 91.5% and recurrence

rate was estimated to be 8.5% at final stage.

CONCLUSIONS: Though a high prevalence rate of lumbar disc hernia-

tion in young active men has been reported, there is no difference between

the true recurrence rate of lumbar disc herniation after an open discectomy

calculated in young men and that in the general population.

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

any applicable devices or drugs.

CONFLICT OF INTEREST: No conflicts.

doi: 10.1016/j.spinee.2006.06.353

P145. Comparison of Traditional Midline Approach versus Muscle

Splitting Paraspinal Approach for Posterior Non-Fusion

Stabilization of the Lumbar Spine – An Analysis of Functional

Outcome

Neel Anand, MD, Robert Bray, Jr, MD; Cedars Sinai Medical Center, Los

Angeles, CA, USA

BACKGROUND CONTEXT: Minimally invasive muscle sparing ap-

proaches have become popular though few outcome studies show signifi-

cant advantage over the traditional midline approach.

PURPOSE: To analyze the influence of approach on functional outcome

with nonfusion stabilization.

STUDY DESIGN/SETTING: Prospective consecutive series, outcome

analysis.

PATIENT SAMPLE: 67 patients had posterior nonfusion stabilization of

the lumbar spine at 118 levels using the Dynesys system. The indications

were predominantly spondylolisthesis in 22 patients, 8 retrolisthesis, 29

central/lateral recess stenosis, 6 dynamic foraminal stenosis, 26 degenera-

tive disc disease, and 4 patients were instrumented adjacent to a previous

fusion.

OUTCOME MEASURES: Data were collected prospectively using VAS,

ODI, SF36, and the Treatment Intensity Score (TIS). The TIS objectively

measures the amount of medication and other treatments the patient was

seeking. The minimum score is 0 with a maximum of 100. Patients were

followed regularly up to 2 years. Patient satisfaction and recommendation

was also documented.

METHODS: Patients needing decompression (n531) were operated

through a midline approach with microscopic laminotomy/foraminotomy

with/without a discectomy followed by posterior nonfusion stabilization

with the Dynesys system. None had a complete laminectomy. Patients

not needing a decompression (n536) were operated on through bilateral

paraspinal muscle splitting approaches and stabilized. Age, sex distribu-

tion, and levels operated were comparable. There were no smokers and

no compensation cases. The average follow-up was 12 months (6 months

to 26 months).

RESULTS: The surgical time and blood loss were 150 minutes and 350 cc

respectively for the midline approach and 120 minutes and 300 cc for the

paraspinal approach. All outcome measures in both groups showed signif-

icant improvement at last follow-up. Between the groups there was signif-

icant difference in the reduction of the Treatment Intensity Score (TIS)

when measured at 1 week and 4 weeks. The preoperative, 1-week, and

4-week values for the midline group were 66, 48, and 40 respectively

and 80, 32 (p!.05), and 28 (p!.05) for the paraspinal group. This trend

continued through 3 months to 6 months though not significant. At 12

months there was no difference between the two groups. Pain scores sim-

ilarly showed a nonsignificant trend to lower values in the first month in

the paraspinal group when compared with the midline group. The ODI

and SF36 scores reflected no significant difference between the groups.

Three patients in the midline group rated the procedure as fair, as did 2

in the paraspinal group. The rest rated it excellent or good, none poor.

29/31 patients in the midline group were satisfied and would recommend

it compared with 34/36 in the paraspinal group. Two patients were reoper-

ated, both in the paraspinal group, one for a misplaced screw and the other

for extension to the next level. Three patients in the midline group have

needed postoperative selective nerve root blocks whereas two in the para-

spinal group have needed facet blocks. None have needed conversion to

a fusion or shown screw loosening.

CONCLUSIONS: The significant improvement in outcomes, especially

pain medication requirement, with the muscle sparing paraspinal approach

indicates that minimal disruption of the anatomy may be the key for

soft-tissue balance and unloading of the disc in posterior nonfusion

stabilization procedures.

FDA DEVICE/DRUG STATUS: Dynesys: Not approved for this

indication.

CONFLICT OF INTEREST: No conflicts.

doi: 10.1016/j.spinee.2006.06.354

P146. Favorable Outcome in the Treatment Of High Grade L5-S1

Spondylolytic Spondylolisthesis with Autogenous Fibular Strut

Grafting

Michael Goytan, BSc, MD, FRCSC1, Jean Ouellet, MD, FRCSC2,

Vincent Arlet, MD, FRCSC3; 1University of Manitoba, Winnipeg,

Manitoba, Canada; 2McGill University, Montreal, Quebec, Canada;3University of Virginia, Charlottesville, VA, USA

BACKGROUND CONTEXT: The complete reduction and stabilization

of a high grade (Meyerding Grade 3 or greater) spondylolytic

153SProceedings of the NASS 21st Annual Meeting / The Spine Journal 6 (2006) 1S–161S