A Retrospective Analysis of the L3-L4 Disc and Spinopelvic Parameters on Outcomes in Thoracolumbar Fusion: Was Art Steffee Right?

OBJECTIVE: To determine whether the L3-L4 disc angle may be a surrogate marker for global lumbar alignment in thoracolumbar fusion surgery and to explore the relationship between radiographic and patient-reported outcomes after thoracolumbar fusion surgery. METHODS: Retrospective chart review was conducted on patients who had undergone a lumbar fusion involving levels from T9 to pelvis. EuroQol-Five Dimension (EQ-5D-3L) scores and adverse events including adjacent-segment disease and degeneration, pseudoarthrosis, proximal junctional kyphosis, stenosis, and reoperation were collected. Pre- and postoperative spinopelvic parameters were measured on weight-bearing radiographs, with the L3-L4 disc angle of novel interest. Univariate logistic and linear regression were performed to assess the associations of radiographic parameters with adverse event incidence and improvement in EQ-5D-3L, respectively. RESULTS: In total, 182 patients met inclusion criteria. Univariable analysis revealed that increased magnitude of L3-L4 disc angle, anterior pelvic tilt, and pelvic incidence measures are associated with increased likelihood of developing postoperative adverse events. Conversely, increased lumbar lordosis demonstrated a decreased incidence of developing a postoperative adverse event. Linear regression showed that radiographic parameters did not significantly correlate with postoperative EQ-5D-3L scores, although scores were significantly improved postfusion in all dimensions except Self-Care (P = 0.51). CONCLUSIONS: L3-L4 disc angle magnitude may serve as a surrogate marker of global lumbar alignment. The degree of spinopelvic alignment did not correlate to improvement in EQ-5D-3L score in the present study, suggesting that quality of life metric change may not be a sensitive or specific marker of postfusion alignment.

Two cases of supratentorial lobar intracranial hemorrhage following lumbar decompression and stabilization.

BACKGROUND: Lumbar spine surgery with or without intraoperative dural tear (DT) may contribute to postoperative subdural hematomas and/or cerebellar intracranial hemorrhages (ICHs). Here, we present two patients, one with and one without an intraoperative DT occurring during lumbar surgery, both of whom developed acute postoperative supratentorial ICHs. CASE DESCRIPTION: Two patients developed supratentorial lobar ICH following lumbar decompressions and fusion. The first patient, without an intraoperative DT, developed multiple ICHs involving the left cerebellum and left temporal lobe. The second patient, following an L4-5 decompression/instrumented fusion involving a DT, postoperatively developed a large right frontal ICH. CONCLUSION: Here, two patients undergoing lumbar spine surgery with/without DT subsequently developed significant ICH.

Machine Vision Navigation in Spine Surgery.

The advancements in computing and digital localizer technologies has led to the evolving clinical application of image-guided technology for the surgical management of spinal disorders. Image-guided spinal navigation addresses the limitations of fluoroscopy and improves the accurate placement of fixation screws. Several navigation platforms are currently available, each having its own unique advantages and disadvantages. The most recent spinal navigation system developed utilizes machine vision structured light imaging which creates a precise and detailed three-dimensional image of the exposed surface anatomy and co-registers it to a pre-operatively or intra-operatively acquired image. This system improves upon the intraoperative workflow and efficiency of the navigation process. With the continued advancements in machine vision, there is a potential for clinical applications that extend beyond surgical navigation. These applications include reducing the potential for wrong level spine surgery and providing for real-time tracking of spinal deformity correction. As the adoption and clinical experience with navigation continues to expand and evolve, the technology that enables navigation also continues to evolve.

Epidemiology, Treatment, and Performance-Based Outcomes in American Professional Baseball Players With Symptomatic Spondylolysis and Isthmic Spondylolisthesis.

BACKGROUND: Repetitive lumbar hyperextension and rotation during athletic activity affect the structural integrity of the lumbar spine. While many sports have been associated with an increased risk of developing a pars defect, few previous studies have systematically investigated spondylolysis and spondylolisthesis in professional baseball players. PURPOSE: To characterize the epidemiology and treatment of symptomatic lumbar spondylolysis and isthmic spondylolisthesis in American professional baseball players. We also sought to report the return-to-play (RTP) and performance-based outcomes associated with the diagnosis of a pars defect in this elite athlete population. STUDY DESIGN: Descriptive epidemiology study. METHODS: A retrospective cohort study was conducted among all Major and Minor League Baseball (MLB and MiLB, respectively) players who had low back pain and underwent lumbar spine imaging between 2011 and 2016. Players with radiological evidence of a pars defect (with or without listhesis) were included. Analyses were conducted to assess the association between player-specific characteristics and RTP time. Baseball performance metrics were also compared before and after the injury episode to determine whether there was an association between the diagnosis of a pars defect and diminished player performance. RESULTS: During the study period of 6 MLB seasons, 272 professional baseball players had low back pain and underwent lumbar spine imaging. Overall, 75 of these athletes (27.6%) received a diagnosis of pars defect. All affected athletes except one (98.7%) successfully returned to professional baseball, with a median RTP time of 51 days. Players with spondylolisthesis returned to play faster than those with spondylolysis, MLB athletes returned faster than MiLB athletes, and position players returned faster than pitchers. Athletes with a diagnosed pars defect did not show a significant decline in performance after returning to competition after their injury episode. CONCLUSION: Lumbar pars defects were a common cause of low back pain in American professional baseball players. The vast majority of affected athletes were able to return to competition without demonstrating a significant decline in baseball performance.

Analyzing the role of adjuvant or salvage radiotherapy for spinal myxopapillary ependymomas.

OBJECTIVE: The authors sought to describe the long-term recurrence patterns, prognostic factors, and effect of adjuvant or salvage radiotherapy (RT) on treatment outcomes for patients with spinal myxopapillary ependymoma (MPE). METHODS: The authors reviewed a tertiary institution IRB-approved database and collected data regarding patient, tumor, and treatment characteristics for all patients treated consecutively from 1974 to 2015 for histologically confirmed spinal MPE. Key outcomes included relapse-free survival (RFS), postrecurrence RFS, failure patterns, and influence of timing of RT on recurrence patterns. Cox proportional hazards regression and Kaplan-Meier analyses were utilized. RESULTS: Of the 59 patients included in the study, the median age at initial surgery was 34 years (range 12-74 years), 30 patients (51%) were female, and the most common presenting symptom was pain (n = 52, 88%). Extent of resection at diagnosis was gross-total resection (GTR) in 39 patients (66%), subtotal resection (STR) in 15 (25%), and unknown in 5 patients (9%). After surgery, 10 patients (17%) underwent adjuvant RT (5/39 GTR [13%] and 5/15 STR [33%] patients). Median follow-up was 6.2 years (range 0.1-35.3 years). Overall, 20 patients (34%) experienced recurrence (local, n = 15; distant, n = 5). The median RFS was 11.2 years (95% CI 77 to not reached), and the 5- and 10-year RFS rates were 72.3% (95% CI 59.4-86.3) and 54.0% (95% CI, 36.4-71.6), respectively.STR was associated with a higher risk of recurrence (HR 6.45, 95% CI 2.15-19.23, p < 0.001) than GTR, and the median RFS after GTR was 17.2 years versus 5.5 years after STR. Adjuvant RT was not associated with improved RFS, regardless of whether it was delivered after GTR or STR. Of the 20 patients with recurrence, 12 (60%) underwent salvage treatment with surgery alone (GTR, n = 6), 4 (20%) with RT alone, and 4 (20%) with surgery and RT. Compared to salvage surgery alone, salvage RT, with or without surgery, was associated with a significantly longer postrecurrence RFS (median 9.5 years vs 1.6 years; log-rank, p = 0.006). CONCLUSIONS: At initial diagnosis of spinal MPE, GTR is key to long-term RFS, with no benefit to immediate adjuvant RT observed in this series. RT at the time of recurrence, however, is associated with a significantly longer time to second disease recurrence. Surveillance imaging of the entire neuraxis remains crucial, as distant failure is not uncommon in this patient population.

Vasopressor Infusion During Prone Spine Surgery and Acute Renal Injury: A Retrospective Cohort Analysis.

BACKGROUND: Hypotension is associated with acute kidney injury, but vasopressors used to treat hypotension may also compromise renal function. We therefore tested the hypothesis that vasopressor infusion during complex spine surgery is not associated with impaired renal function. METHODS: In this retrospective cohort analysis, we considered adults who had complex spine surgery between January 2005 and September 2014 at the Cleveland Clinic Main Campus. Our primary outcome was postoperative estimated glomerular filtration rate. Secondarily, we evaluated renal function using Acute Kidney Injury Network criteria. We obtained data for 1814 surgeries, including 689 patients (38%) who were given intraoperative vasopressors infusion for ≥30 minutes and 1125 patients (62%) who were not. Five hundred forty patients with and 540 patients without vasopressor infusions were well matched across 32 potential confounding variables. RESULTS: In matched patients, vasopressor infusions lasted an average of 173 ± 100 minutes (SD) and were given a median dose (1st quintile, 3rd quintile) of 3.4-mg (1.5, 6.7 mg) phenylephrine equivalents. Mean arterial pressure and the amounts of hypotension were similar in each matched group. The postoperative difference in mean estimated glomerular filtration rate in patients with and without vasopressor infusions was only 0.8 mL/min/1.73 m (95% CI, -0.6 to 2.2 mL/min/1.73 m) (P = .28). Intraoperative vasopressor infusion was also not associated with increased odds of augmented acute kidney injury stage. CONCLUSIONS: Clinicians should not avoid typical perioperative doses of vasopressors for fear of promoting kidney injury. Tolerating hypotension to avoid vasopressor use would probably be a poor strategy.

The effect of C2-3 disc angle on postoperative adverse events in cervical spondylotic myelopathy.

OBJECTIVEComplete radiographic and clinical evaluations are essential in the surgical treatment of cervical spondylotic myelopathy (CSM). Prior studies have correlated cervical sagittal imbalance and kyphosis with disability and worse health-related quality of life. However, little is known about C2-3 disc angle and its correlation with postoperative outcomes. The present study is the first to consider C2-3 disc angle as an additional radiographic predictor of postoperative adverse events.METHODSA retrospective chart review was performed to identify patients with CSM who underwent surgeries from 2010 to 2014. Data collected included demographics, baseline presenting factors, and postoperative outcomes. Cervical sagittal alignment variables were measured using the preoperative and postoperative radiographs. Univariable logistic regression analyses were used to explore the association between dependent and independent variables, and a multivariable logistic regression model was created using stepwise variable selection.RESULTSThe authors identified 171 patients who had complete preoperative and postoperative radiographic and outcomes data. The overall rate of postoperative adverse events was 33% (57/171), and postoperative C2-3 disc angle, C2-7 sagittal vertical axis, and C2-7 Cobb angle were found to be significantly associated with adverse events. Inclusion of postoperative C2-3 disc angle in the analysis led to the best prediction of adverse events. The mean postoperative C2-3 disc angle for patients with any postoperative adverse event was 32.3° ± 17.2°, and the mean for those without any adverse event was 22.4° ± 11.1° (p < 0.0001).CONCLUSIONSIn the present retrospective analysis of postoperative adverse events in patients with CSM, the authors found a significant association between C2-3 disc angle and postoperative adverse events. They propose that C2-3 disc angle be used as an additional parameter of cervical spinal sagittal alignment and predictor for operative outcomes.

Short-term outcomes following posterior cervical fusion among octogenarians with cervical spondylotic myelopathy: a NSQIP database analysis.

BACKGROUND CONTEXT: Degenerative changes in the cervical spine occur in an age-dependent manner. As the US population continues to age, the incidence of age-dependent, multilevel, degenerative cervical pathologies is expected to increase. Similarly, the average age of patients with cervical spondylotic myelopathy (CSM) will likely trend upward. Posterior cervical fusion (PCF) is often the treatment modality of choice in the management of multilevel cervical spine disease. Although outcomes following anterior cervical fusion for degenerative disease have been studied among older patients (aged 80 years and older), it is unknown if these results extend to octogenarian patients undergoing PCF for the surgical management of CSM. PURPOSE: The present study aimed to quantify surgical outcomes following PCF for the treatment of CSM among the octogenarian patient population compared with patients younger than 80 years old. STUDY DESIGN/SETTING: This was a retrospective study that used the National Surgical Quality Improvement Program (NSQIP). PATIENT SAMPLE: The sample included patients aged 60-89 who had CSM and who underwent PCF from 2012 to 2014. OUTCOME MEASURES: The outcome measures were multimorbidity, prolonged length of stay (LOS), discharge disposition (to home or skilled nursing/rehabilitation facility), 30-day all-cause readmission, and 30-day reoperation. METHODS: The NSQIP database was queried for patients with CSM (International Classification of Disease, Ninth Revision, Clinical Modification code 721.1) aged 60-89 who underwent PCF (Current Procedural Terminology code 22600) from 2012 to 2014. Cohorts were defined by age group (60-69, 70-79, 80-89). Data were collected on gender, race, elective or emergent status, inpatientor outpatient status, where patients were admitted from (home vs. skilled nursing facility), American Society of Anesthesiologists class, comorbidities, and single- or multilevel fusion. After controllingfor these variables, logistic regression analysis was used to compare outcome measures in the different age groups. RESULTS: A total of 819 patients with CSM who underwent PCF (416 aged 60-69, 320 aged 70-79, and 83 aged 80-89) were identified from 2012 to 2014. Of the PCF procedures, 79.7% were multilevel. There were no significant differences in the odds of multimorbidity, prolonged LOS, readmission, or reoperation when comparing octogenarian patients with CSM with patients aged 60-69 or 70-79. Patients aged 60-69 and 70-79 were significantly more likely to be discharged to home than patients over 80 (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.8-10.4, p<.0001, and OR 2.7, 95% CI 1.1-6.4, p=.0005, respectively). CONCLUSIONS: Compared with patients aged 60-69 and 70-79, octogenarian patients with CSM were significantly more likely to be discharged to a location other than home following PCF. After controlling for patient comorbidities and demographics, 80- to 89-year-old patients with CSM who underwent PCF did not differ in other outcomes when compared with the other age cohorts. These results can improve preoperative risk counseling and surgical decision-making.

The Utility of Preoperative Magnetic Resonance Imaging for Determining the Flexibility of Sagittal Imbalance.

BACKGROUND: Scoliosis X-rays are the gold standard for assessing preoperative lumbar lordosis; however, particularly for flexible lumbar deformities, it is difficult to predict from these images the extent of correction required, as standing radiographs cannot predict the thoracolumbar alignment after intraoperative positioning. OBJECTIVE: To determine the utility of preoperative MRI in surgical planning for patients with flexible sagittal imbalance. METHODS: We identified 138 patients with sagittal imbalance. Radiographic parameters including pelvic incidence and lumbar lordosis were obtained from images preoperatively. RESULTS: The mean difference was 2.9° between the lumbar lordosis measured on supine MRI as compared to the intraoperative X-rays, as opposed to 5.53° between standing X-rays and intraoperative X-ray. In patients with flexible deformities (n = 24), the lumbar lordosis on MRI measured a discrepancy of 3.08°, as compared to a discrepancy of 11.46° when measured with standing X-ray. CONCLUSION: MRI adequately determined which sagittal deformities were flexible. Furthermore, with flexible sagittal deformities, lumbar lordosis measured on MRI more accurately predicted the intraoperative lumbar lordosis than that measured on standing X-ray. The ability to preoperatively predict intraoperative lumbar lordosis with positioning helps with surgical planning and patient counseling regarding expectations and risks of surgery.

Pelvic retroversion: a compensatory mechanism for lumbar stenosis.

OBJECTIVE The flexed posture of the proximal (L1-3) or distal (L4-S1) lumbar spine increases the diameter of the spinal canal and neuroforamina and can relieve symptoms of neurogenic claudication. Distal lumbar flexion can result in pelvic retroversion; therefore, in cases of flexible sagittal imbalance, pelvic retroversion may be compensatory for lumbar stenosis and not solely compensatory for the sagittal imbalance as previously thought. The authors investigate underlying causes for pelvic retroversion in patients with flexible sagittal imbalance. METHODS One hundred thirty-eight patients with sagittal imbalance who underwent a total of 148 fusion procedures of the thoracolumbar spine were identified from a prospective clinical database. Radiographic parameters were obtained from images preoperatively, intraoperatively, and at 6-month and 2-year follow-up. A cohort of 24 patients with flexible sagittal imbalance was identified and individually matched with a control cohort of 23 patients with fixed deformities. Flexible deformities were defined as a 10° change in lumbar lordosis between weight-bearing and non-weight-bearing images. Pelvic retroversion was quantified as the ratio of pelvic tilt (PT) to pelvic incidence (PI). RESULTS The average difference between lumbar lordosis on supine MR images and standing radiographs was 15° in the flexible cohort. Sixty-eight percent of the patients in the flexible cohort were diagnosed preoperatively with lumbar stenosis compared with only 22% in the fixed sagittal imbalance cohort (p = 0.0032). There was no difference between the flexible and fixed cohorts with regard to C-2 sagittal vertical axis (SVA) (p = 0.95) or C-7 SVA (p = 0.43). When assessing for postural compensation by pelvic retroversion in the stenotic patients and nonstenotic patients, the PT/PI ratio was found to be significantly greater in the patients with stenosis (p = 0.019). CONCLUSIONS For flexible sagittal imbalance, preoperative attention should be given to the root cause of the sagittal misalignment, which could be compensation for lumbar stenosis. Pelvic retroversion can be compensatory for both the lumbar stenosis as well as for sagittal imbalance.

Septic Arthritis of an Atlantoaxial Facet Joint with Normal Inflammatory Markers: Case Report and Literature Review.

BACKGROUND: Septic arthritis of the atlantoaxial facet joint is extremely rare. Contiguous spread to the median atlantoaxial joints with subsequent dens erosion can lead to atlantoaxial instability. Misleading normal inflammatory markers can result in delayed diagnosis and catastrophic consequences. CASE DESCRIPTION: A 56-year-old man presented with right-sided neck pain that had lasted for 2 days. He did not have fever or chills, and his serum C-reactive protein and erythrocyte sedimentation rate were normal. The patient was diagnosed with acute neck strain and treated conservatively. The pain continued for the next 3 weeks; cervical spine radiographs demonstrated normal findings with the exception of degenerative changes. The patient was treated with physical rehabilitation for the presumed neck strain and degenerative changes of the cervical vertebrae. Worsening neck pain and stiffness prompted a magnetic resonance imaging study obtained 5 weeks after the initial presentation, which showed an epidural collection with septic arthritis of the right facet and median atlantoaxial joints. Computed tomography demonstrated severe dens erosion. Surgical evacuation of the abscess and occipitocervical fusion were performed. Pathologic evaluation of tissue obtained during surgery demonstrated the presence of an infection, and Streptococcus anginosus grew from cultures. CONCLUSIONS: Infection must be considered in the differential diagnosis for neck pain when imaging findings are suggestive of an infectious process, even in an afebrile patient with normal C-reactive protein and erythrocyte sedimentation rate levels. Magnetic resonance imaging and computed tomography can play a critical role in such cases, potentially leading to a more timely diagnosis.

Efficacy of i-Factor Bone Graft versus Autograft in Anterior Cervical Discectomy and Fusion: Results of the Prospective, Randomized, Single-blinded Food and Drug Administration Investigational Device Exemption Study.

STUDY DESIGN: A prospective, randomized, controlled, parallel, single-blinded noninferiority multicenter pivotal FDA IDE trial. OBJECTIVE: The objective of this study was to investigate efficacy and safety of i-Factor Bone Graft (i-Factor) compared with local autograft in single-level anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy. SUMMARY OF BACKGROUND DATA: i-Factor is a composite bone substitute material consisting of the P-15 synthetic collagen fragment adsorbed onto anorganic bone mineral and suspended in an inert biocompatible hydrogel carrier. P-15 has demonstrated bone healing efficacy in dental, orthopedic, and nonhuman applications. METHODS: Patients randomly received either autograft (N = 154) or i-Factor (N = 165) in a cortical ring allograft. Study success was defined as noninferiority in fusion, Neck Disability Index (NDI), and Neurological Success endpoints, and similar adverse events profile at 12 months. RESULTS: At 12 months (follow-up rate 87%), both i-Factor and autograft subjects demonstrated a high fusion rate (88.97% and 85.82%, respectively, noninferiority P = 0.0004), significant improvements in NDI (28.75 and 27.40, respectively, noninferiority P < 0.0001), and high Neurological Success rate (93.71% and 93.01%, respectively, noninferiority P < 0.0001). There was no difference in the rate of adverse events (83.64% and 82.47% in the i-Factor and autograft groups, respectively, P = 0.8814). Overall success rate consisting of fusion, NDI, Neurological Success and Safety Success was higher in i-Factor subjects than in autograft subjects (68.75% and 56.94%, respectively, P = 0.0382). Improvements in VAS pain and SF-36v2 scores were clinically relevant and similar between the groups. A high proportion of patients reported good or excellent Odom outcomes (81.4% in both groups). CONCLUSION: i-Factor has met all four FDA mandated noninferiority success criteria and has demonstrated safety and efficacy in single-level ACDF for cervical radiculopathy. i-Factor and autograft groups demonstrated significant postsurgical improvement and high fusion rates. LEVEL OF EVIDENCE: 1.

Polyetheretherketone (PEEK) intervertebral cage as a cause of chronic systemic allergy: a case report.

BACKGROUND CONTEXT: Polyetheretherketone (PEEK) is an organic polymer thermoplastic with strong mechanical and chemical resistance properties. It has been used in industry to fabricate items for demanding applications such as bearings, piston parts, compressor plate valves, and cable insulation. Since the early 1980s, polyetheretherketone polymers have been increasingly used in orthopedic and spinal surgery applications. Numerous studies and years of clinical experience have confirmed the biocompatibility of this material. PURPOSE: The purpose of the study was to report a case of chronic systemic allergy after anterior cervical decompression and fusion (ACDF) and implantation of an intervertebral PEEK cage, with resolution of symptoms after removal of PEEK cage. STUDY DESIGN/SETTING: This study is a case report with clinical evidence for allergy to PEEK. METHODS: The methods involve clinical findings and review of current literature. RESULTS: After ACDF and implantation of an intervertebral PEEK cage, the patient had developed an angioedema-like picture marked by severe redness, itching, swelling of his tongue, and skin thickening. A skin patch test was positive for PEEK. Removal of the implant resulted in the resolution of his allergy symptoms shortly after surgery. CONCLUSIONS: Tissue reactions to PEEK are extremely rare. Herein, we present the first report of a chronic allergic response to interbody PEEK material.

Outpatient surgery in the cervical spine: is it safe?

Study Design Systematic review. Study Rationale As the length of stay after cervical spine surgery has decreased substantially, the feasibility and safety of outpatient cervical spine surgery come into question. Although minimal length of stay is a targeted metric for quality and costs for medical centers, the safety of outpatient cervical spine surgery has not been clearly defined. Objective The objective of this article is to evaluate the safety of inpatient versus outpatient surgery in the cervical spine for adult patients with symptomatic or asymptomatic degenerative disc disease. Methods A systematic review of the literature was undertaken for articles published through February 19, 2014. Electronic databases and the bibliographies of key articles were searched to identify comparative studies evaluating the safety of inpatient versus outpatient surgery in the cervical spine. Spinal cord stimulation, spinal injections, and diagnostic procedures were excluded. Two independent reviewers assessed the strength of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system, and disagreements were resolved by consensus. Results Five studies that met the inclusion criteria were identified. One study reported low risk of hematoma (0% of outpatients and 1.6% of inpatients). Two studies reported on mortality and both reported no deaths in either group following surgery. Dysphagia risks ranged from 0 to 10% of outpatients and 1.6 to 5% of inpatients, and infection risks ranged from 0 to 1% of outpatients and 2 to 2.8% of inpatients. One study reported that no (0) outpatients were readmitted to the hospital due to a complication, compared with four inpatients (7%). The overall strength of evidence was insufficient for all safety outcomes examined. Conclusion Though the studies in our systematic review did not suggest an increased risk of complication with outpatient cervical spine surgery, the strength of evidence to make a recommendation was insufficient. Further study is needed to more clearly define the role of outpatient cervical spine surgery.

Effects of crystalloid versus colloid and the α-2 agonist brimonidine versus placebo on intraocular pressure during prone spine surgery: a factorial randomized trial.

BACKGROUND: Volume replacement with colloid solution and topical α-2 agonists may each moderate the progressive increase in intraocular pressure (IOP) during prone surgery. The authors tested the hypotheses that during prolonged prone surgery, IOP increases less with goal-directed intravenous administration of 5% albumin than with goal-directed administration of lactated Ringer's solution, and with topical α-2 agonist brimonidine than with placebo eye drops. METHODS: Patients having complex prone spine surgery were factorially randomized to albumin and topical placebo (n = 15); albumin and topical brimonidine (n = 16); lactated Ringer's solution and topical placebo (n = 13); and lactated Ringer's solution and topical brimonidine (n = 16). IOP was measured with a pneumotonometer. The primary outcome was time-weighted average intraoperative IOP. RESULTS: Prone positioning increased IOP a mean ± SD of 12 ± 6 mmHg. IOP increased to 38 ± 10 mmHg at the end of anesthesia (approximately 5.5 h). Time- weighted average intraoperative IOP in the brimonidine group was 4 (95% CI: 1, 8) mmHg lower than in the placebo group (P = 0.023), but no different in the crystalloid and albumin groups (mean difference (95% CI) of -2 (-5, 2) mmHg (P = 0.34). There was no interaction between the two randomized factors. CONCLUSIONS: Brimonidine slightly reduced the primary outcome of intraoperative time-weighted average IOP, whereas there was no significant difference between goal-directed albumin or crystalloid administration. Brimonidine thus helps reduce IOP during spine surgery, but maintaining adequate blood pressure might play a more important role.

Iliac screw fixation using computer-assisted computer tomographic image guidance: technical note.

BACKGROUND: Iliac screw fixation is a powerful tool used by spine surgeons to achieve fusion across the lumbosacral junction for a number of indications, including deformity, tumor, and pseudarthrosis. Complications associated with screw placement are related to blind trajectory selection and excessive soft tissue dissection. OBJECTIVE: To describe the technique of iliac screw fixation using computed tomographic (CT)-based image guidance. METHODS: Intraoperative registration and verification of anatomic landmarks are performed with the use of a preoperatively acquired CT of the lumbosacral spine. With the navigation probe, the ideal starting point for screw placement is selected while visualizing the intended trajectory and target on a computer screen. Once the starting point is selected and marked with a burr, a drill guide is docked within this point and the navigation probe re-inserted, confirming the trajectory. The probe is then removed and the high-speed drill reinserted within the drill guide. Drilling is performed to a depth measured on the computer screen and a screw is placed. RESULTS: Confirmation of accurate placement of iliac screws can be performed with standard radiographs. CONCLUSION: CT-guided navigation allows for 3-dimensional visualization of the pelvis and minimizes complications associated with soft-tissue dissection and breach of the ilium during screw placement.

The role of adjuvant radiation therapy in the treatment of spinal myxopapillary ependymomas.

OBJECT: the goal in this study was to determine the role of radiation therapy (RT) in the treatment of spinal myxopapillary ependymomas (MPEs). METHODS: thirty-seven patients with histologically verified spinal MPEs were reviewed. Kaplan-Meier analyses and Cox proportional hazard regression were used to determine what patient and treatment factors influenced overall survival (OS) and recurrence. RESULTS: at the time of initial diagnosis, the median age was 33 years and the Karnofsky Performance Scale score was 80. In 86.5% of cases, the most common presenting symptom was pain. All patients received surgery as their initial treatment. Nine patients also received RT along with surgery, with a median total dose of 50.2 Gy. The mean survival time was 12.2 years; however, only 4 of 37 patients had died at the time of this study. None of the patient or treatment parameters significantly correlated with OS. Sixteen patients (43.2%) were found to have a recurrence, with a median time to recurrence of 7.7 years. None of the patient or treatment parameters correlated with recurrence-free survival for an initial recurrence. The median time to the second recurrence (recurrence following therapy for initial recurrence) was 1.6 years. Use of RT as salvage therapy after initial recurrence significantly correlated with longer times to a second recurrence. The median recurrence-free survival time before the second recurrence was 9.6 years for those who received RT versus 1.1 years for those who did not receive RT (p = 0.0093). None of the other parameters significantly correlated with a second recurrence. CONCLUSIONS: radiation therapy may have a role as salvage therapy in delaying recurrences of spinal MPEs.