Proceedings of the NASS 19th Annual Meeting / The Spine Journal 4 (2004) 3S–119S 85S

STUDY DESIGN/SETTING: The study is based on a retrospective reviewof 185 lumbosacral fusions with pedicle screw fixation (100%) and use ofinterbody cages (91%).PATIENT SAMPLE: Spinal nerve roots were monitored with spEMGand trEMG in all cases, and additionally with tceMEPs in 40/185 procedures.OUTCOME MEASURES: Pedicle breaches were detected with trEMGin 28/185 (15%) procedures. Neurotonic EMG also was noted in 28/185procedures, most episodes occurring during decompression or cage place-ment.METHODS: Significant tceMEP attenuation (�50%) occurred in 4/40(10%) procedures, all associated with insertion of cages which were subse-quently removed; 2 patients showed new-onset lower extremity weaknesspost-operatively. New- onset weakness also followed 6 other procedureswithout tceMEP monitoring; in 4 cases there was no neurotonic EMG whilein 2 others neurotonic discharges coincided with decompression but notcage insertion.RESULTS: All patients showed substantial improvement in 4–12 months.CONCLUSIONS: The results of this study suggest that tceMEPs aresensitive indicators of spinal nerve root injury secondary to insertion ofinterbody cages. The relatively poor predictive value of spEMG in thisregard may indicate a significant ischemic component in the mechanismof injury.DISCLOSURES: No disclosures.CONFLICT OF INTEREST: No Conflicts.

doi: 10.1016/j.spinee.2004.05.170

P77. Comparative analysis of pedicle screw versus hybridinstrumentation in posterior spinal fusion of adolescent idiopathicscoliosis: a match cohort analysisYong-Jung Kim1, Lawrence Lenke, MD1*, Keith Bridwell2, BrendaSides, MA1; 1Washington University in St. Louis, St. Louis, MO, USA;2Washington University Medical Center, St. Louis, MO, USA

BACKGROUND CONTEXT: The comparative results of the posteriorcorrection and fusion with segmental hybrid (proximal hook and distalpedicle screw) instrumentation versus those with pedicle screw constructsalone in adolescent idiopathic scoliosis (AIS) is unknown.PURPOSE: The purpose of this study is to compare the results of posteriorcorrection and fusion with segmental hybrid (proximal hook and distalpedicle screw) instrumentation versus those with pedicle screw constructsalone in adolescent idiopathic scoliosis (AIS) using a matched cohort studywith medical records and x-rays.STUDY DESIGN/SETTING: A retrospective match cohort study.PATIENT SAMPLE: 58 patients.OUTCOME MEASURES: Radiographs, SRS 24 outcome scores, PFTs.METHODS: 58 AIS patients at a single institution underwent posteriorfusion with hybrid instrumentation (29) or pedicle screw (29) instrumenta-tion were sorted and matched according to four criteria; similar patientage, fusion levels, identical Lenke curve type (14 for Type 1-main thoracic,3 for Type 2-double thoracic, 8 for Type 3-double major, 1 for Type 4-triple major, and 3 for Type 6-major thoracolumbar/lumbar and minorthoracic structural), and identical operative methods. Patients were com-pared at a minimum 2-year follow-up according to radiographic changes,operative time, intraoperative blood loss, pulmonary function tests, andSRS 24 outcome scores.RESULTS: The two cohorts were well matched. The preoperative majorCobb angle averaged 60� in the hybrid group and 62� in the screw group.Average major curve correction was 56% in the hybrid group and 70% inthe screw group (p�0.001). At 2-year follow-up, major curve correction was46 % and 65% respectively (p�0.001). At 2-year follow-up, thoracic sagittalCobb angle changes between T5 and T12 were 2.4� decrease in the hybridgroup and 9.0� decrease in the screw group (p�0.019). With hybrid instru-mentation, the lowest instrumented vertebra was 0.4 vertebrae below thelower end vertebra, whereas in the screw group it was 0.6 vertebrae belowthe lower end vertebra (p�0.557). Both group demonstrated similar sagittalproximal (p�0.817) and distal junctional changes (p�0.223). Operative

time was similar in both groups (p�0.149). Average estimated blood losswas 1074ml in the hybrid group and 961ml in the screw group (p�0.543).Two years following surgery, the hybrid group demonstrated decreasedpulmonary function values (FVC 85% to 79%, FEV1 78% to 75%), whilethe screw group had unchanged or improved percent predicted pulmonaryfunction values (FVC; 81% to 81%, FEV1; 73% to 79%) (Changes in FVCp�0.084 and FEV1 p�0.001). Postoperative total SRS 24 scores weresimilar in both groups (Hybrid group; 99 vs screw group; 95) (p�0.186).There were no neurologic complications related to hook or pedicle screwinstrumentation.CONCLUSIONS: Pedicle screw instrumentation offers a significantlybetter major curve correction and postoperative pulmonary function valueswithout neurologic problems as compared to hybrid constructs. Both instru-mentation methods offer similar junctional change, lowest instrumentedvertebra, operative time and postoperative SRS 24 outcome scores in theoperative treatment of adolescent idiopathic scoliosis.DISCLOSURES: No disclosures.CONFLICT OF INTEREST: No Conflicts.

doi: 10.1016/j.spinee.2004.05.171

P22. The results of cervical epidural injections for cervicalradiculopathyEric Lin, MD, Vi Lieu, Lee Halevi, Jeffrey Wang, MD; University ofCalifornia, Los Angeles, Los Angeles, CA, USA

BACKGROUND CONTEXT: Cervical disc herniations are a commoncause of radicular pain from nerve root impingement and may necessitatesurgical decompression and fusion in order to alleviate symptoms. The use ofepidural steroid injections for the treatment of lumbar disc herniations iswell accepted with several published reports. However, the use of cervicalepidural injections has not been studied in detail.PURPOSE: The purpose of this study was to examine the efficacy ofcervical epidural injections for the treatment of symptomatic herniated discs.STUDY DESIGN/SETTING: In a clinical setting, patients who failedconservative treatment for their cervical disc herniations were treated withcervical epidural injections. Following the procedure, patient data, symptomrelief and surgical outcome were examined for an average of 13 months.PATIENT SAMPLE: Seventy patients with symptomatic cervical discherniations with failed conservative treatment (physical therapy, oral ste-roids, NSAIDs) were included in the study.OUTCOME MEASURES: The patient’s symptom relief and future sur-gery determined the effectiveness of the cervical epidural injections. Thosepatients that underwent surgical treatment, the success of their surgery wasalso examined and compared to that previous treatment.METHODS: Patients failing conservative treatment were treated with cer-vical epidural injections and the results were examined and documentedspecifically in regard to symptom relief, need for surgical intervention,and the overall clinical results and complications.RESULTS: Of the 70 total patients (average age�52, range 25–77, 31males and 39 females), 44 (63%) had significant relief of their symptomsand did not wish to proceed with surgical treatment, while 26 (37%) didnot have lasting relief and underwent surgical discectomy and fusion. Theaverage follow up was 13 months (range 6 months – 4 years). Of the 26patients who underwent surgical decompression, 24 (92%) had successfulresolution of their symptoms. The average number of injections was 1.46.In the surgical group, relief lasted an average of 34.65 days with theaverage time to surgery being 216.7 days. In contrast, the non-surgicalgroup continued to enjoy symptom relief for an average of 414.5 days.CONCLUSIONS: Cervical epidural injections appear to be a reasonablepart of the non-operative treatment of patients with cervical disc herniations.The success rates appear to be very similar to prior studies on lumbarepidural injections for symptomatic lumbar disc herniations. It appears thata large percentage of the patients may obtain relief from radicular symptomsand avoid surgery for the follow-up period up to one year. Long-termfollow-up is needed to understand the length of relief and the percentagethat may recur and require surgical intervention.

Proceedings of the NASS 19th Annual Meeting / The Spine Journal 4 (2004) 3S–119S86S

toward early discharge of patients and in an effort to improve surgicaloutcomes, minimally invasive methods have come into vogue. Ketorolactromethamine (ketorlac) is a nonsteroidal anti-inflammatory drug withproven efficacy in decreasing post-operative pain in various surgical set-

DISCLOSURES: No disclosures.CONFLICT OF INTEREST: No Conflicts.

doi: 10.1016/j.spinee.2004.05.172

P72. Posterior C1–C2 pedicle screw rod fixation: surgical outcomeof 24 patients and biomechanical in vitro studyJon Park1, Harsimran Brara2, Michael Wang2, Sungmin Kim1, DanielKim1; 1Stanford University, Stanford, CA, USA; 2CA, USA

BACKGROUND CONTEXT: There are various techniques of posteriorC1–C2 fusion which have evolved over past several decades. Among them,transarticular screw fixation with posterior wiring is considered as “goldstandard” with a high fusion rate. However, the transarticular fixation istechnically demanding and must meet certain anatomical requirements inorder to avoid neurovascular complications. Most recent introduction ofposterior C1–C2 pedicle screw rod fixation technique with or withoutposterior wiring has gained significant popularity. However, the source ofliterature report of the biomechanical study and surgical outcome studyof this new technique have been limited to only one institution.PURPOSE: To determine and compare stability and feasibilty of C1–C2pedicle screw rod fixation vs transarticular fixation via biomechanical andclinical outcome study.STUDY DESIGN/SETTING: The two C1–C2 fixation techniques arebiomechanically compared in vitro. The clinical study is conducted inpatients with C1–C2 instability.PATIENT SAMPLE: NAOUTCOME MEASURES: NAMETHODS: Biomechanical study: 8 cadeveric human cervical spines withthe occiput attached were tested in 3-dimentional flexion-extension, axialrotation, and lateral bending motions after destabilization using C1–C2instability model. In each loading mode, moments were applied to a maxi-mum of 1.5 N, and the range of motion, neutral zone and elastic zone weredetermined and compared using intact spine, the destabilized spine andthe spine after C1–C2 pedicle screw fixation and transarticular fixation.Clinical Study: 24 patients with C1–C2 instability received C1–C2 pediclescrew rod fixation. Among them, 7 received additional posterior interspi-nous wiring. The indications were trauma (16), rheumatoid arthritis (5),and os odontoideum(3). Average age was 67. Average post op follow upwas 6.2 months. The clinical outcome is determined by rate and type ofintraoperative complication, rate of fusion and over all clinical outcome.RESULTS: Biomechanical study: Both C1–C2 pedicle screw rod fixationand transarticular fixation restored the biomechanical stability to betterthan that of the intact specimen. Though, statistically insignificant, C1–C2pedicle screw rod fixation method showed greater decreases in values ofrange of motion, neurtal zone and elastic zone in axial rotation than thetransarticular fixation. Clinical study: There was no neurovascular complica-tion. With exception of 2 patients (follow-up time less than 3 months),rest of the patients showed both clinical and radiographical arthrodesis atminimum 6 month follow up. No failure of fusion is observed in patientswithout additional posterior interspinous wiring.CONCLUSIONS: Both in vitro and in vovo study indicate that C1–C2pedicle screw rod fixation techinque is safe and viable alternative to transar-ticular screw fixation.DISCLOSURES: No disclosures.CONFLICT OF INTEREST: No Conflicts.

doi: 10.1016/j.spinee.2004.05.173

P17. Postoperative bleeding risk with toradol aftermicrodiscectomy: a prospective pilot studyKingsley R. Chin, MD, Hari Sundram, MD; University of Pennsylvania,Philadelphia, PA, USA

BACKGROUND CONTEXT: Limitations to early ambulation subsequentto spine surgery can be attributed both to the invasive nature of the surgeryand to inadequate peri and post operative pain control. Given the trend

tings. However, some studies have raised questions regarding the potentialside effects of this agent, particularly bleeding within the surgical wound.PURPOSE: We studied the effective pain control and post-operative bleed-ing risk of single dose ketorolac iv (30mg) in lumbar microdiscectomies.STUDY DESIGN/SETTING: This is a prospective study of a group ofpatients undergoing lumbar microdiscectomy (L4–L5 & L5-S1) with onesurgeon at a major academic center. All patients were ASA PS 1 & 2 withpreoperative labs including PT/PTT and platelet counts which were normal.66% of patients were female with the overall mean patient age of 49 yrwith normal liver and kidney functions. There were no patients in the groupwho expressed an allergic reaction to NSAIDS prior to surgery.PATIENT SAMPLE: 21 consecutive patients.OUTCOME MEASURES: Postoperative bleeding complications weremonitored along with pain levels and time to discharge.METHODS: 21 patients receiving microendoscopic discectomy (MED)for herniated lumbar discs were given 30 mg IV toradol subsequent towound closure. Patients received analgesia required for intubation (150 ugof fentanyl) and local anesthetic to the surgical site prior to incision (10cc of 1% lidocaine with 1:200,000 epinephrine). Postoperative pain require-ments were based on patient request.RESULTS: Our analyses detected no significant changes in PT/PTT orplatelet counts postoperatively (up to 24 hrs). Patients had no incidence ofbleeding from the surgical site and no systemic bleeding diatheses werenoted. In addition, postoperative pain management consisted solely of oralpain meds with no postoperative requirements for IV analgesia. 8 of21 patients (38%) were also discharged the same day as surgery with oralpain meds. 2 out of 21 patients had complications, neither of which wererelated to bleeding or pain.CONCLUSIONS: Single dose IV toradol provides significant analgesiawithout incurring any increased risk of bleeding in minimally invasivespine surgery. In addition, patients are able to recover function more quickly,potential enabling minimally invasive spine surgery to more readily becomean ambulatory procedure.DISCLOSURES: No disclosures.CONFLICT OF INTEREST: No Conflicts.

doi: 10.1016/j.spinee.2004.05.174

P67. Ten-year follow up laparoscopic lumbar reconstruction anddecompressionDavid Mccord1, Douglas Olsen2, David Dyer2, Ruben Garcia3;1Nashville, TN, USA; 2CMC, TN, USA; 3TN Spine Center, TN, USA

BACKGROUND CONTEXT: Although numerous articles detail mini-mally invasive fusion techniques, there are few reports long term relectinga single surgeon experience on 100 consecutive patients treated with laparo-scopic spinal reconstruction. Unlike previously described procedures, thisoperation routinely involves anterior spinal decompression and foramino-tomy along with substantial alteration of lordosis.PURPOSE: To determine if anterior laparoscopic spinal decompressionand substantial alteration of saggital (lordosis) balance is safe andefficacious.STUDY DESIGN/SETTING: 100 consecutive patients beginning August20, 1993 were prospectively followed measuring multiple clinical parame-ters for efficacy and complications. Patient self assessment was obtainedand compared to the primary author’s personal evaluation. Further surgicalprocedures (including adjacent levels) were tabulated. All patients had atleast 5 year follow-up.PATIENT SAMPLE: 100 consecutive adult patients with a primary diag-nosis of degenerative spinal disease and who had failed at least 1 year ofconservative therapy were prospectively followed clinically and radiograph-ically. There was a 50/50 mix of male/female patients. 52% were smokers.22% had worker’s compensation. Avg. ht.-5’7" and Avg. wt-178lbs.