Showing papers in "Journal of Spinal Disorders & Techniques in 2012"

The influence of thoracic inlet alignment on the craniocervical sagittal balance in asymptomatic adults.

Abstract: Study Design:A prospective radiographic study.Objectives:To analyze the relationship between craniocervical sagittal balance and thoracic inlet (TI) alignment and to present the parameters that would help predict physiological lordosis of the cervical spine.Summary of Background Data:The physiologic

Incidence and epidemiology of cervical radiculopathy in the United States military: 2000 to 2009

Abstract: Study DesignEpidemiological review of a prospectively collected military database.ObjectiveThis investigation sought to determine the incidence of cervical radiculopathy and risk factors for its development within the population of the United States military from 2000 to 2009.Summary of Background D

Assessment of pedicle screw placement accuracy, procedure time, and radiation exposure using a miniature robotic guidance system.

Abstract: Conclusions: The advantages associated with a robotic guidance system may make the surgeon more at ease about offering minimally invasive or percutaneous surgical options to patients and more comfortable about implementing pedicle-based fixation in general. This advanced technology may also allow inclusion of patients with complicated anatomic deformities, who are often excluded from pedicle screw-based surgery options.

Polymethylmethacrylate augmentation of pedicle screws increases the initial fixation in osteoporotic spine patients.

Abstract: Study design A retrospective comparative study. Objectives To investigate the clinical efficacy of polymethylmethacrylate (PMMA) augmentation in vertebral pseudarthrosis after osteoporotic vertebral fractures. Summary of background data Despite being the most rigid form of posterior instrumentation, pedicle screws sometimes achieve poor initial fixation primarily in patients with osteoporosis. One method for improving pedicle screw fixation in osteoporotic spines is pedicle augmentation using bone cement such as PMMA. Although various biomechanical studies of osteoporotic spines have shown improved pullout strength of pedicle screws augmented with bone cement, there have been few studies that have examined the clinical significance of PMMA augmentation. Methods Thirty-eight patients with posterior fusion using pedicle screws for vertebral pseudarthrosis after osteoporotic vertebral fracture were included in the study. The level of fracture ranged from T7 to L5. The mean follow-up period was 31 months. Patients were divided into 2 groups: those with posterior instrumentation using pedicle screws augmented with PMMA (group C, N=17) and those without PMMA augmentation (group NC, N=21). Clinical and radiographic results for the 2 groups were compared. Results With the exception of osteoporotic status, there were no significant differences in the baseline data of the 2 groups. The incidence of clear zones around the pedicle screws was significantly suppressed in group C compared with group NC (29.4% vs. 71.4%). Correction loss was significantly decreased (3 degrees vs. 7.2 degrees) and fusion rate was significantly higher in group C (94.1% vs. 76.1%). Back pain improved in 64.7% of the group C patients. There were no perioperative complications related to the PMMA cement in group C. Conclusions Reinforcement of pedicle screws using PMMA augmentation may be a feasible surgical technique for osteoporotic spines.

Fluoroscopic caudal epidural injections with or without steroids in managing pain of lumbar spinal stenosis: one-year results of randomized, double-blind, active-controlled trial.

Abstract: Study design A randomized, double-blind, active-controlled trial. Objective To evaluate the effectiveness of caudal epidural injections with or without steroids in providing effective and long-lasting pain relief in the management of chronic low back pain related to lumbar spinal stenosis. Summary of background data Multiple interventions including surgery and interventional techniques such as epidural injections and adhesiolysis are commonly performed in managing pain related to spinal stenosis. There is continuing debate on the effectiveness of all interventions, and a paucity of literature regarding effectiveness. Methods One-hundred participants were randomly assigned to 1 of the 2 groups, with Group I participants receiving caudal epidural injections of local anesthetic (lidocaine 0.5%), whereas Group II participants received caudal epidural injections with 0.5% lidocaine 9 mL mixed with 1 mL of steroid (nonparticulate Celestone). Outcomes assessment Multiple outcome measures were used, including the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake with assessment at 3, 6, and 12 months posttreatment. Significant pain relief and improvement in disability were defined as 50% or more. Results Overall, significant pain relief and functional status improvement (≥50%) were demonstrated in 48% in Group I and 46% in Group II. However, significant pain relief and functional status improvement were seen in 60% of the participants in both groups in the successful category when the participants were separated into successful and failed categories. The overall number of procedures was 3.1±1.3 or 3.6±1.1 in the successful category in Group I, with overall 2.9±1.4 or 3.5±1.2 in the successful category in Group II. Conclusion Caudal epidural injections of local anesthetic with or without steroids may be an effective treatment for a select group of patients with chronic function-limiting low back and lower extremity pain secondary to spinal stenosis.

Stand-alone anterior versus anteroposterior lumbar interbody single-level fusion after a mean follow-up of 41 months.

Abstract: STUDY DESIGN Prospective cohort study comparing evaluations of single-level anterior lumbar interbody fusion (ALIF) versus anteroposterior lumbar fusion (APLF) OBJECTIVE To clinically and radiologically compare the outcome after angle-stable, locked, stand-alone ALIF with that obtained after APLF, in cases with degenerative disc disease (DDD) SUMMARY OF BACKGROUND DATA Fusion rates have been reported to be highest after interbody fusion with transpedicular fixation However, transpedicular fixation is linked to significant damage of the paravertebral muscles, to screw displacement-related neurological and vascular complications, and to an increased rate of adjacent segment degeneration When performed as a stand-alone procedure, the disadvantages of transpedicular fixation can be completely avoided by ALIF METHODS Eighty patients with chronic low-back pain due to a single-level DDD (Modic ≥2) and facet joint arthritis (Fujiwara ≥3) were enrolled in this study Forty patients received an anteroposterior fusion (ALIF with transpedicular fixation: APLF group) and 40 patients (ALIF group) were treated with a stand-alone ALIF using the Synfix-LR device At 7 days, 3, 6, 12, and 24 months, and at a mean follow-up of 41 months, patients were clinically (visual analog scale, Oswestry Low Back Pain Disability Index, satisfaction) and radiologically (x-ray, and at 12 months, thin-slice computed tomography) compared RESULTS Blood loss and duration of surgery were significantly lower in the ALIF group (P<0001) Visual analog scale and Oswestry Low Back Pain Disability Index improved significantly over time (analysis of variance, P<0001) in both groups, but both scores were significantly better in ALIF group (analysis of variance, P<0001) Patients' satisfaction consistently ranked higher in the ALIF group (P=0042 at 12 mo) No significant difference was found in the fusion rate throughout the study CONCLUSIONS Stand-alone ALIF leads to better clinical results than APLF, without differences in fusion rates after 41 months Therefore, when a posterior approach is not needed for decompression or reposition, we suggest performing a stand-alone ALIF in cases with single-level DDD

Acute hospital costs after minimally invasive versus open lumbar interbody fusion: data from a US national database with 6106 patients.

Abstract: Study design Retrospective multi-institutional database review. Objective To determine if minimally invasive interbody fusion is associated with cost savings when compared with open surgery. Summary of background data Minimally invasive spine (MIS) surgeries are increasingly recognized as equivalent to open procedures. Although these techniques have been advocated for reducing pain, disability, and length of hospitalization, to date there has been little data demonstrating these benefits. Methods This study analyzed inpatient hospital records from the Premier Perspective database (2002 to 2009), including patients who underwent a posterior lumbar fusion with interbody cage placement by ICD-9 code, and had implant charge codes that allowed determination if MIS pedicle screws were utilized. Exclusion criteria included a refusion surgery, deformity, >2 levels, and anterior fusion. Total costs were adjusted for covariates (age, sex, race, hospital geography and setting, payor, and comorbidities) using an analysis of covariance model. Results A total of 6106 patients were identified (1667 MIS and 4439 open). Length of stay (LOS) for 1-level MIS surgery averaged of 3.35 days versus 3.6 days for open surgery (P≤0.006). For 2-level MIS surgery LOS averaged of 3.4 days versus 4.03 days for open surgery (P≤0.001). Total inflation-adjusted acute hospitalization cost averaged $29,187 for 1-level MIS procedures versus $29,947 for open surgery, a nonsignificant difference (P=0.55). Total inflation-adjusted acute hospitalization cost averaged $2106 lower for 2-level MIS surgery (total costs of $33,879 for MIS vs. $35,984 for open surgery, P=0.0023). Cost savings were attributable primarily to lower room and board ($857), operating room ($359), pharmacy ($304), and laboratory ($166) costs in the MIS group. High variances in the 2-level open surgery with prolonged hospital stay also accounted for overall cost differences. Conclusions This data from a large nationwide sample of hospitalizations demonstrates that MIS lumbar interbody fusion results in a statistically significant reduction in hospital LOS and a reduction in total hospital costs with 2-level surgery after adjusting for significant covariates. The majority of cost savings from MIS surgery were due to more rapid mobilization and discharge, as well as a reduction in outliers with extended hospitalizations.

Impact of multimodal intraoperative monitoring during surgery for spine deformity and potential risk factors for neurological monitoring changes.

Abstract: Study design Retrospective review. Objective To evaluate the efficacy of multimodal intraoperative neuromonitoring for predicting iatrogenic neurological injury during surgical correction of a spine deformity and evaluate the potential risk factors for neurological monitoring changes. Summary of background data Single modal intraoperative neuromonitoring is insufficient to predict neurological injury during surgical correction of spine deformity. Multimodal monitoring can provide more accuracy. Some risk factors were reported to be correlated with high rates of neurological deficits during scoliosis correction. But few studies have reported on the risk factors for neurological monitoring changes (NMCs). Methods The records of 176 consecutive patients who underwent surgery for the treatment of spinal deformities were reviewed. The patients were monitored using transcranial electric motor-evoked potential (MEP) and/or somatosensory-evoked potential (SEP). Alterations with the MEP wave amplitude decreasing more than 75% and SEP amplitude decreasing more than 50%, as compared with the baseline, were diagnosed as positive changes. Risk factors related to NMCs were evaluated, in light of preoperative neurological deficits, comorbidity of spinal cord deformity, procedure of osteotomy, main curve Cobb angle, and a diagnosis of kyphosis. Results Combined MEP/SEP monitoring was successfully achieved in 175 of 176 cases. Eleven cases were presented with true NMCs according to MEPs. One patient had an irreversible neurological deficit and 4 patients had transient neurological deficits after waking up from the operation. SEP lagged MEP for an average of 15 minutes when both were presented with positive changes. The sensitivity and specificity of MEP were 91.7% and 98.8%, respectively. Solo SEP were 50% and 95.2%. Combined MEP and SEP were 92.9% and 99.4%. The procedure of osteotomy, curve Cobb angle more than 90 degrees, and preoperative kyphosis were correlated with a higher incidence of NMCs. Conclusions Multimodal intraoperative monitoring provides higher sensitivity for monitoring during spine deformity surgery and can predict events of neurological injury. The detection of NMCs and adjustment of surgical strategy may prevent irreversible neurological deficits. The possible risk factors for NMCs during spine deformity surgery include an osteotomy procedure, kyphosis correction, and preoperative Cobb angle more than 90 degrees.

Reliability analysis of a smartphone-aided measurement method for the Cobb angle of scoliosis.

Abstract: Study design A comparison between the smartphone-aided measurement method and the manual measurement method for the Cobb angle in adolescent idiopathic scoliosis. Objective To evaluate the reliability and measurement error for the smartphone-aided Cobb angle measurement method and compare its reliability and measurement error with those of the manual method. Summary of background data The development of smartphones has provided new opportunities that integrate mobile technology into daily clinical practice. Smartphone applications can provide quick assistance in the diagnosis and treatment of disease. Cobbmeter is a smartphone application designed for the measurement of Cobb angle on Apple iPhone smartphones. There is no study on the reliability and measurement error of this smartphone-aided measurement method. Methods : Fifty-three posteroanterior radiographs of adolescent idiopathic scoliosis patients with thoracic scoliosis were used for the standard Cobb method of measurement (manual set) and the smartphone-aided Cobb method of measurement (smartphone set). Five spinal surgeons measured the Cobb angle with the use of both the manual method and the smartphone-aided method. The measurement time was recorded for every measurement. The frequency and the cumulative percent distribution for intraobserver differences were tabulated, both for the individual examiners and for the overall results for the 5 examiners. The intraclass correlation coefficient (ICC) 2-way mixed model on absolute agreement was used to analyze measurement reliability. Summary statistics from analyses of variance calculations were used to provide 95% prediction limits for the error in measurements. A paired t test was used to compare the time consumed for the measurement between both sets. Results The intraobserver and interobserver ICCs were excellent in the smartphone set and in the manual set. Both the intraobserver ICC and the interobserver ICC were better in the smartphone set than in the manual set. The mean Cobb angle of all measured x-rays was 29.3 degrees (range, 17-58 degrees) in the manual set and 29.1 degrees (range, 18-56 degrees) in the smartphone set. The mean time consumed was 13.7 seconds (range, 8.6-18.5 s) for the smartphone set, whereas it was 37.9 seconds (range, 30.1-46.9 s) for the manual set, and the mean time consumed for the smartphone set was significantly shorter than that of the manual set (P Conclusions Smartphone-aided measurement for Cobb angle showed excellent reliability and efficiency. It is suggested to popularize the use of this method in clinical practice.

Comparison of kyphoplasty and vertebroplasty for treatment of painful osteoporotic vertebral compression fractures: twelve-month follow-up in a prospective nonrandomized comparative study.

Abstract: Study DesignA prospective nonrandomized comparative study.ObjectiveTo compare the efficacy and safety of kyphoplasty and vertebroplasty for treatment of painful osteoporotic vertebral compression fractures (VCFs) with respect to pain, functional outcome, radiomorphology, cement leakage, and incidenc

Bacteriology of degenerated lumbar intervertebral disks.

Abstract: Study Design:A prospective microbiological analysis of intervertebral disk material in surgically treated patients presenting lumbar disk degeneration.Objective:To determine the prevalence and species of bacteria in degenerated lumbar disks, their eventual role in the pathophysiology, and the possib

Designers' guide to Eurocode : basis of structural design EN 1990

Abstract: Preface Introduction General Requirements Principals of limit states design Basic variables Structural analysis and design assisted by testing Verification by the partial factor method Annex A1 (normative) - Application for buildings Management of structural reliability for construction works Basis for partial factor design and reliability analysis Design assisted by testing Appendix A. The Construction Products Directive (89/106/EEC) Appendix B. The Eurocode suite Appendix C. Basic statistical terms and techniques Appendix D. National standard organisations

Posterior Spinal Fusion From T2 to the Sacrum for the Management of Major Deformities in Patients With Parkinson Disease: A Retrospective Review With Analysis of Complications

Abstract: Study Design:Description of the surgical management of major spinal deformities in patients with Parkinson disease (PD).Objective:To evaluate the effectiveness of the construct, the incidence and types of complications, and patient satisfaction.Summary of Background Data:The association of degenerat

Posterior-only approach surgery for fixation and decompression of thoracolumbar spinal tuberculosis: a retrospective study.

Abstract: STUDY DESIGN: A retrospective case study series. OBJECTIVE: To evaluate the results of posterior decompression and transpedicular screw fixation in 18 cases of thoracolumbar spinal tuberculosis with neurological deficit. SUMMARY OF BACKGROUND DATA: Spinal tuberculosis has been managed with various modalities of treatment ranging from only antitubercular drugs to radical procedures such as anterior or combined approach surgeries. However, although the former method of treatment sometimes is met with unacceptable kyphosis, the later is considered to be too drastic. In the present study, authors have shown the results of posterior decompression and pedicle screw fixation in selected cases of Pott paraplegia. METHODS: The cases (12 males and 6 females) were operated with a posterior decompression and transpedicular screw fixation in a single stage along with antitubercular drug treatment. All of these patients had varying degrees of neurological deficit (4 with Frankel grade A, 8 Frankel B, 4 Frankel C, and 2 Frankel D) and single level involvement with <50% vertebral body destruction and mild kyphosis of 8-27 degrees. Short-segment pedicle screw fixation, posterior decompression, and correction of kyphosis were performed in single stage. RESULTS: Kyphosis improved from preoperative value of 17.7±5.8 degrees to 9.4±4.6 degrees postoperatively. At a follow-up period of 24-46 months, final kyphosis correction was maintained at 11.6±5.4 degrees. Bony fusion was achieved in 55.5% cases. Neurological recovery occurred in 17 patients (94.4%). All patients became pain free, with final visual analogue score 0-2. CONCLUSIONS: The procedure in safe and has satisfactory results in early active cases of Pott paraplegia with less destruction of vertebral bodies.

Analysis of sagittal spinal alignment in 181 asymptomatic children.

Abstract: Study Design:A cross-sectional study.Objectives:To determine the “normal” radiographic parameters of the sagittal profile of the spine in asymptomatic children.Summary of Background Data:There was consensus that cervical kyphosis is pathologic, but we suspected that the cervical kyphosis or loss of

Optimization of Radiation Exposure and Image Quality of the Cone-beam O-arm Intraoperative Imaging System in Spinal Surgery.

Abstract: STUDY DESIGN: Retrospective study. OBJECTIVES: To optimize the radiation doses and image quality for the cone-beam O-arm surgical imaging system in spinal surgery. SUMMARY OF BACKGROUND: Neurovascular compromise has been reported after screw misplacement during thoracic pedicle screw insertion. The use of O-arm with or without navigation system during spinal surgery has been shown to lower the rate of screw misplacement. The main drawback of such imaging surgical systems is the high radiation exposure. METHODS: Chest phantom and cadaveric pig spine were examined on the O-arm with different scan settings: 2 were recommended by the O-arm manufacturer (120 kV/320 mAs, and 120 kV/128 mAs), and 3 low-dose settings (80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs). The radiation doses were estimated by Monte Carlo calculations. Objective evaluation of image quality included interobserver agreement in the measurement of pedicular width in chest phantom and assessment of screw placement in cadaveric pig spine. RESULTS: The effective dose/cm for 120 kV/320 mAs scan was 13, 26, and 69 times higher than those delivered with 80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs scans, respectively. Images with 60 kV/40 mAs were unreliable. Images with 80 kV/80 mAs were considered reliable with good interobserver agreement when measuring the pedicular width (random error 0.38 mm and intraclass correlation coefficient 0.979) and almost perfect agreement when evaluating the screw placement (κ value 0.86). CONCLUSIONS: The radiation doses of the O-arm system can be reduced 5 to 13 times without negative impact on image quality with regard to information required for spinal surgery. (Less)

Preservation of spinal instrumentation after development of postoperative bacterial infections in patients undergoing spinal arthrodesis.

Abstract: Study DesignThis is a retrospective review.ObjectiveThe purpose of this study is to evaluate the efficacy of medical and surgical management of postoperative infections after the placement of spinal instrumentation in the context of retaining the instrumentation.Summary of Background DataThe impleme

Surgical correction of spinal deformity in patients with cerebral palsy using pedicle screw instrumentation.

Abstract: STUDY DESIGN Retrospective review of a prospectively collected single surgeon's series. OBJECTIVE To investigate the efficacy of pedicle screw instrumentation in correcting spinal deformity in patients with quadriplegic cerebral palsy. In addition to assess quality-of-life and functional improvement after deformity correction as perceived by the parents of our patients. SUMMARY OF BACKGROUND DATA All pedicle screw constructs have been commonly used to correct adolescent idiopathic scoliosis. There is limited information on their effectiveness in treating patients with cerebral palsy and neuromuscular scoliosis. METHODS We reviewed the medical records and serial radiographs of 45 consecutive patients with quadriplegia who underwent spinal arthrodesis using pedicle screw/rod instrumentation and a standardized surgical technique. All patients were wheelchair bound with collapsing thoracolumbar scoliosis and pelvic obliquity. Twenty-eight patients had associated sagittal deformities. A telephone survey was performed by an independent investigator to assess parents' perception on surgical outcome. RESULTS Thirty-eight patients underwent posterior-only and 7 staged anteroposterior spinal arthrodesis. Mean age at surgery was 13.4 years (range: 9 to 18.3 y) and mean postoperative follow-up was 3.5 years (range: 2.8 to 5 y). Pedicle screw instrumentation extended from T2/T3 to L5 with bilateral pelvic fixation using iliac bolts. Scoliosis was corrected from mean 82.5 to 21.4 degree (74.1%). Pelvic obliquity was corrected from mean 24 to 4 degree (83.3%). In posterior-only procedures, average blood loss was 0.8 blood volumes, intensive care unit stay 3.5 days, and hospital stay 17.6 days. In anteroposterior procedures, average blood loss was 0.9 blood volumes, intensive care unit stay 8.9 days, and hospital stay 27.4 days. Major complications included 1 deep infection and 1 reoperation to remove prominent implants but no deaths, no neurological deficit, and no detected pseudarthrosis. Parents' survey showed 100% satisfaction rate. CONCLUSIONS Pedicle screw instrumentation can achieve excellent correction of spinal deformity in quadriplegic cerebral palsy with low complication and re-operation rates and high parent satisfaction.

Sagittal alignment after single cervical disc arthroplasty.

Abstract: Study DesignProspective study.ObjectivesTo analyze the sagittal balance after single-level cervical disc replacement (CDR) and range of motion (ROM). To define clinical and radiologic parameters those have a significant correlation with segmental and overall cervical curvature after CDR.Summary of B

Surgical outcome of lumbar fusion surgery in patients with Parkinson disease.

Abstract: Study design Retrospective study. Objectives To investigate the overall surgical outcome of lumbar fusion surgery in patients with Parkinson disease (PD). SUMMARY OF BACK GROUND DATA: Poor bone quality and muscular dysfunction are important clinical manifestations connected with musculoskeletal diseases in PD patients. These secondary changes caused by PD often result in spinal pathology, indicating spine operations for some patients with scoliosis, kyphosis, osteoporotic fracture, or degenerative spondylosis. However, little is known about the surgical outcome or prognosis of spine surgery in PD patients. Methods Lumbar fusion surgery was performed on 20 patients who had PD and degenerative spinal diseases. At the time of lumbar fusion surgery, the mean duration of PD, age, sex, the preoperative visual analog pain scale (VAS, 0 to 100 mm) for low back pain, Hoehn and Yahr staging, and other comorbidities were evaluated. Patients' postoperative clinical outcome was measured using the criteria of Kim and Kim and VAS for back pain. Radiographic assessment was made using plain films and a dynamogram. Results At the time of the spine surgery, Hoehn and Yahr staging of PD was from 1 to 2 in all patients. Only 1 patient had a satisfactory outcome; a good result according to Kim and Kim's criteria. The average postoperative VAS (mm) was 55.2, whereas the mean preoperative VAS (mm) was 53.9. Radiological assessment showed fusion status in 15 patients and probably no solid fusion mass in 5 patients. Conclusions A poor surgical outcome would be inevitable because of the worsening of symptoms owing to the natural history of PD. Therefore, our current study suggested surgical indication should be exercised cautiously in the patients with PD and spinal stenosis.

Lumbarized sacrum as a relative contraindication for lateral transpsoas interbody fusion at L5-6.

Abstract: STUDY DESIGN Retrospective review. OBJECTIVE To determine if lumbarized sacra at the L5-6 level (functional L4-5) are a contraindication to a lateral transpsoas approach. SUMMARY OF BACKGROUND DATA Transitional vertebrae at the lumbosacral junction present mechanical and morphologic changes, though these changes have not been characterized with respect to the feasibility of a lateral transpsoas approach. METHODS Three hundred fifty-one patients were scheduled for lumbar interbody fusion using a mini-open lateral transpsoas approach (XLIF) at L4-5 from 2004 to 2008 at a single institution. In patients with 6 lumbar vertebrae, accessibility, based on neuromonitoring, of the L5-6 level (functional L4-5) was reviewed. Qualitative assessments using axial magnetic resonance imaging (MRI) were performed and compared with a sample of patients with normal anatomy treated at L4-5. RESULTS Of the 351 patients scheduled for treatment at L4-5, 10 (2.8%) were determined to have 6 lumbar vertebrae with the symptomatic level at L5-6. Of those 10, 2 (20%) could be treated using a lateral transpsoas approach, and 8 (80%) were converted to another approach after a corridor through the psoas muscle was not found, based on neuromonitoring feedback. Review of axial MRI showed a teardrop-shaped psoas detached from the lateral border of the disc space in patients with transitional anatomy unapproachable at L5-6, resemblant of L5-S1 in normal anatomy. In the 2 patients who could be safely approached, the psoas anatomy at L5-6 was similar to a normal L4-5 level, with a domed/helmet shape, attached laterally to the disc space. CONCLUSIONS Treating the L5-6 level using a lateral transpsoas approach in individuals with lumbarized sacra can be challenging due to anatomy more similar to the L5-S1 level in normal patients. Preoperative planning using axial MRI and intraoperative adherence to advanced neuromonitoring can aid in identifying and avoiding injury in these rare patients.

Quantitative Magnetic Resonance Imaging Characteristics: Evaluation of Prognostic Value in the Dog as a Translational Model for Spinal Cord Injury

Abstract: Summary of Background Data:The mechanisms of injury in spinal cord injury in dogs are similar to those in human patients and the dog is considered to be a valuable translational model for new treatment modalities. Studies regarding the quantitative characteristics of magnetic resonance imaging (MRI)

Surgical outcome of percutaneous endoscopic interlaminar lumbar diskectomy for recurrent disk herniation after open diskectomy.

Abstract: Study Design:Technical report.Objective:To present a detailed surgical technique of percutaneous endoscopic interlaminar diskectomy (PEID) for recurrent lumbar disk herniation and present features of postoperative magnetic resonance images that were unavailable in previous studies.Summary of Backgro

Lower incidence of adjacent segment degeneration after anterior cervical fusion found with those fusing C5-6 and C6-7 than those leaving C5-6 or C6-7 as an adjacent level.

Abstract: Study design Retrospective analysis of adjacent disc degeneration (ADD) after anterior cervical decompression and fusion (ADF). Objectives To elucidate the influence of the number of levels fused in ADF on the incidence of ADD. Summary of background data ADD is known as a complication associated with ADF. However, how the number of levels fused affects the incidence of ADD is not well understood. Methods One hundred and two patients with cervical degenerative disease, who underwent ADF and were followed for more than 24 months, were retrospectively analyzed. They were classified into 2 groups, a long group (L group) consisting of 50 cases with ADF of 4 or more disc levels, and a short group (S group) consisting of 52 cases with ADF of 3 or fewer disc levels. Furthermore, the patients were also divided into 2 groups according to inclusion or exclusion of C5-6 and C6-7 (C group: including both, NC group: not including both). The incidence of ADD, and that of symptomatic ADD (sADD), was compared between the 2 classifications. Results In the L group, there were 13 cases of ADD (26.0%), including 1 case of sADD (2.0%), whereas in the S group, there were 22 cases of ADD (42.3%), including 11 cases of sADD (21.2%). The incidence of sADD was significantly lesser in the L group (P=0.024). Three cases with sADD in the S group required revision surgery, whereas no additional surgery related to ADD was performed on patients in the L group. In addition, in the C group, ADD occurred in 20 of 71 cases (28.2%) and sADD occurred in 4 of 71 cases (5.6%), whereas in the NC group, ADD occurred in 15 of 31 cases (48.4%) and sADD occurred in 8 of 31 cases (25.8%). The incidence of ADD and sADD were significantly lesser in the C group (P=0.048). Conclusions ADD occurs less frequently among patients in whom C5-6 and C6-7 are fused than among those in whom C5-6 or C6-7 is left at an adjacent level, irrespective of the length of the fusion.

Hemostasis with a bipolar sealer during surgical correction of adolescent idiopathic scoliosis.

Abstract: STUDY DESIGN Retrospective before-after comparison study. OBJECTIVE The primary aim of this study was to evaluate the effectiveness of a radiofrequency-based bipolar hemostatic sealer during surgical correction of adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA Spinal reconstructive surgery is commonly associated with excessive blood loss. Perioperative bleeding is of particular concern during correction of AIS, which often requires allogeneic or autologous transfusion. However, there are specific risks and limitations that often preclude the utilization of transfusions. Alternatives include the use of antifibrinolytic drugs and topical fibrin-based and thrombin-based agents, although safety and effectiveness are yet to be fully established. There is a clear need for assessing alternative methods of hemostasis. METHODS One hundred seventy-six AIS patients undergoing corrective spinal surgery were included in this study. Seventy-six consecutive patients were treated intraoperatively with a standard method of hemostasis consisting of hypotensive anesthesia, thrombin-soaked sponges, and intraoperative blood salvage (Control). Subsequently, an additional 100 consecutive patients were treated after the introduction of a bipolar sealer (Aquamantys 2.3 Bipolar Sealer, Salient Surgical Technologies, Portsmouth, NH). The outcomes of this study were estimated blood loss (total and per level) and transfusion rate. RESULTS Blood loss was reduced by 57% after the introduction of the bipolar sealer compared with the Control (bipolar sealer: 435±192 mL, Control: 1009±392 mL; P<0.001). There was a statistically significant difference between groups for blood loss per fusion level (bipolar sealer: 39±17 mL, Control: 95±33 mL; P<0.001). Five (6.6%) Control patients required blood transfusions versus none treated with the bipolar sealer (P=0.014). Complication rates were similar between the groups. CONCLUSIONS These findings suggest that the Aquamantys 2.3 bipolar sealer effectively supports hemostasis and reduces the need for transfusions during surgical correction of AIS.

Kyphoplasty versus vertebroplasty: restoration of vertebral body height and correction of kyphotic deformity with special attention to the shape of the fractured vertebrae.

Abstract: Study design Retrospective comparative analysis. Objective We analyzed kyphosis correction, vertebral height restoration, and bone cement leakage in patients treated by vertebroplasty (VP) and kyphoplasty (KP) to compare the effectiveness of VP and KP for the treatment of osteoporotic vertebral compression fractures. Summary of background data Superior results have been reported for the use of KP for kyphotic deformity correction and collapsed vertebral height restoration. However, there are no previous comparative reports comparing the efficacy of KP versus VP according to the shapes of fractured vertebrae. Methods A total of 103 patients underwent either VP (n=58) or KP (n=45) for treatment of osteoporotic vertebral compression fracture between October 2006 and September 2009. We organized the patients into 6 groups according to treatment method and fracture type: VP (wedge-shaped), VP (V-shaped), VP (flat-shaped), KP (wedge-shaped), KP (V-shaped), and KP (flat-shaped). Comparisons were performed for kyphosis correction, vertebral height restoration, and cement leakage between VP and KP groups. Results KP was more effective than VP, especially for middle column height restoration and bone cement leakage prevention, for all fracture types (P value 0.05). Conclusions KP has a significant advantage over VP in terms of kyphosis correction, vertebral height restoration, and cement leakage prevention. KP has an obvious advantage in terms of middle vertebral height restoration and cement leakage prevention, especially for V-shape compression fractures.

Endoscopic interlaminar lumbar discectomy with splitting of the ligament flavum under visual control.

Abstract: Study design Technical report and cases series. Objective To present the technique of interlaminar endoscopic lumbar discectomy (ED) with ligamentum flavum (LF) splitting under direct visualization. Summary of background data The most distinguishing advantage of ED is a decrease in tissue trauma, which has been associated postoperatively with less back pain and less adhesion or scar tissue formation. In transforaminal ED the LF is completely spared, whereas in interlaminar ED the LF must be removed under direct visualization, no matter how small the opening may be (3 to 5 mm). It is also possible to keep the LF intact using serial dilators, but this procedure cannot be performed under direct visualization. Methods We performed operations on 16 male and 14 female patients with herniated lumbar disc disease using interlaminar ED with LF splitting under direct visual control. The average age of the patients in the study was 48±15 years. The chief complaint before surgery was radiculopathy confined to 1 leg. The anatomic operative level was L3-4 in 1, L4-5 in 13, and L5-S1 in 16 patients. The ruptured disc had migrated superiorly in 4 cases and inferiorly in 7 cases, and intraoperative electromyographic monitoring was performed in all surgeries. The LF was split with a working channel under direct visualization, and after withdrawing the working channel the split LF closed on its own. The total operation time was 20 to 40 minutes, and the follow-up period was 149±108 days. Results There were no abnormal signals on the intraoperative electromyography in any of the cases, and the reported symptoms immediately improved in all patients after the operation. Follow-up magnetic resonance imaging showed a disappearance of the ruptured disc with almost no defect in the LF. There were no operation-associated complications. Conclusions The LF could be safely split under direct visualization using a working channel with a minimal resulting defect. This technique of LF splitting endoscopic discectomy is a feasible approach, even for migrated disc herniation.

Characterization of the incidence and risk factors for the development of lumbar radiculopathy.

Abstract: Study DesignEpidemiological study of a prospectively collected database.ObjectivesThis investigation sought to evaluate the incidence of symptomatic lumbar radiculopathy, and identify risk factors for its development, among individuals serving in the United States military over a 10-year period.Summ

Does the lower instrumented vertebra have an effect on lumbar mobility, subjective perception of trunk flexibility, and quality of life in patients with idiopathic scoliosis treated by spinal fusion?

Abstract: Study design Cross-sectional study in patients with idiopathic scoliosis treated with spinal fusion. Objectives To measure lumbar spine mobility in the study population; determine low back pain intensity (LBPi), subjective perception of trunk flexibility (TF), and quality of life using validated outcome instruments; and investigate correlations of the lower instrumented vertebra (LIV) with TF, LBPi, and quality of life. Summary of background data The loss of range of motion resulting from spinal fusion might lead to low back pain, trunk rigidity, and a negative impact on quality of life. Nonetheless, these outcomes have not been conclusively demonstrated because lumbar mobility and LIV have not been correlated with validated outcome instruments. Methods Forty-one patients (mean age, 27 y) with idiopathic scoliosis treated by spinal fusion (mean time since surgery, 135 mo) were included. Patients were assigned to 3 groups according to LIV level: group 1 (fusion to T12, L1, or L2) 14 patients; group 2 (fusion to L3) 13 patients, and group 3 (fusion to L4, L5, or S1) 14 patients. At midterm follow-up, patients completed the Scoliosis Research Society (SRS)-22 Questionnaire and Quality of Life Profile for Spine Deformities to evaluate perceived TF, and rated LBPi with a numerical scale. Lumbar mobility was assessed using a dual digital inclinometer. Results Group 3 (fusion to L4, L5, or S1) showed statistically significant differences relative to the other groups, with less lumbar mobility and poorer scores for the SRS subtotal (P = 0.003) and SRS pain scale (P = 0.01). Nevertheless, LBPi and TF were similar in the 3 groups. TF correlated with SRS-22 subtotal (r = -0.38, P = 0.01) and pain scale (r = -0.42, P = 0.007) scores, and with LBPi (r = 0.43, P = 0.005). Conclusions LIV correlated moderately with lumbar mobility, health-related quality of life (SRS-22), and spinal pain (SRS-22 pain subscale), but not with intensity of pain in the lumbar area or perceived TF.

Lumbar Juxtafacet Cyst Resection: The Facet Sparing Contralateral Minimally Invasive Surgical Approach

Abstract: Study Design:A retrospective review.Objective:To report our approach and results using a contralateral minimally invasive spinal surgical muscle splitting approach that allows visualization of the cyst without extensive removal of the adjacent facet joint.Summary of Background Data:The use of tubula