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ABSTRACT: Retrospective radiographic analysis.
To retrospectively review a group of patients undergoing anterior cervical discectomy and fusion (ACDF) to determine the relative risk of adjacent level disc degeneration after incorrect needle localization.
The needle puncture technique is a well-established method to cause disc degeneration in experimental animal studies. The risk for accelerated degeneration because of needle puncture in humans is unknown.
A retrospective radiographic analysis of 87 consecutive patients after single or 2-level ACDF with anterior plate instrumentation was performed. Perioperative and follow-up radiographs were used to grade disc degeneration according to a previously described scale.
Eighty-seven patients were included in the study (36 underwent 1-level ACDF, and 51 underwent 2-level ACDF). Seventy-two had correct needle localization at the level of planned surgery; 15 had incorrect needle localization (1 level above the operative level). There were no differences between the 2 groups in age, sex and length of follow-up. Patients in the incorrectly marked group were statistically more likely to demonstrate progressive disc degeneration with an odds ratio of 3.2. There was no correlation between age and length of follow-up with development of disc degeneration.
There is a 3-fold increase in risk of developing adjacent level disc degeneration in incorrectly marked discs after ACDF at short-term follow-up. This may indicate that either needle related trauma or unnecessary surgical dissection contributes to accelerated adjacent segment degeneration.
Spine 02/2009; 34(2):189-92. · 2.08 Impact Factor
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ABSTRACT: Retrospective case-control study/economic analysis.
To determine the treatment times required for isolated lumbar decompressions and for combined decompression and instrumented fusion procedures to compare the relative reimbursements for each type of operation as a function of time expenditure by the surgeon.
Under current Medicare fee schedules, the payment for a fusion procedure is higher than of an isolated decompression. It has been recently suggested in the lay press that the greater reimbursement for a lumbar arthrodesis may inappropriately influence the manner in which surgeons elect to treat lumbar degenerative conditions, resulting in what they believe to be a substantial number of unnecessary spinal fusions.
A consecutive series of 50 single-level decompression cases performed by single surgeon were retrospectively analyzed and compared with an equivalent cohort of subjects who underwent single-level decompression and instrumented posterolateral fusion with autogenous iliac crest bone grafting. The operative reports, office charts, and billing records were reviewed to determine the total clinical time invested by the surgeon and the Medicare reimbursement for each surgery.
Relative to the corresponding values of the decompression group, combined decompression and fusion procedures were associated with a longer mean surgical time (134.6 min vs. 47.3 min, P<0.0001), a greater number of postoperative visits (1.0 vs. 3.2, P<0.0001), a higher mean total clinical time expenditure (186.6 min vs. 62.2 min, P<0.0001), and a lower mean dollars received per minute of surgeon time ($12.51 vs. $15.51, P<0.001).
These findings challenge the assertion that spine surgeons have an undue financial incentive to recommend a combined decompression and instrumented fusion procedure over an isolated decompression to patients with symptomatic lumbar degeneration, especially when considering the greater time, effort, and risk characteristic of this more complex operation.
Journal of spinal disorders & techniques 08/2008; 21(6):381-6. · 1.21 Impact Factor
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ABSTRACT: Patient survey.
To evaluate patient perspective on surgeons as consultants for industry and medical device manufacturers.
Relationships between surgeons and medical device manufacturers are becoming increasingly common. Little is known, however, about how patients perceive these relationships.
Patients in the waiting area of an orthopedic surgery clinic were given a simple 1-page, 8-question anonymous questionnaire. Their responses were tabulated and analyzed for 3 variables: gender, age, and education level.
A total of 245 patients completed the questionnaire. An overwhelming majority (94.3%) believed that surgeon-industry relationship is beneficial to patients, and a majority (66.5%) of patients thought that physicians should be compensated for this role. Women were more likely than men to want this relationship to be regulated by physicians instead of the government or hospitals. Patients older than 55 years were less likely to be in favor of physicians being compensated than younger patients. The more educated the patient, the less likely he/she was in favor of allowing physicians to regulate physician-industry relationship.
Patients support surgeons in the role of consultants for industry. Gender, age, and education level influence the way that patients perceive this issue.
Spine 12/2007; 32(23):2616-8; discussion 2619. · 2.08 Impact Factor
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ABSTRACT: Bioabsorbable polymers have been used in surgery for more than four decades. With increased reliability and decreased incidence of complications, their application has become widespread. Although their role in spinal surgery continues to evolve, the theoretic biomechanical and biologic advantages over contemporary metallic and composite implant materials make bioabsorbable interbody spacers an attractive alternative. The lack of artifact on postoperative imaging studies and the ability to load share across fusion sites in a time-dependent manner can lead to more accurate fusion assessment and increased fusion rates. The preliminary data from small, short-term studies are promising. However, larger studies with long-term follow-up are lacking. The theoretic advantages of bioabsorbable materials must be tempered by the lack of long-term clinical evidence of their benefit. Until the results of more studies in human spinal applications become available, the precise indications for the use of bioabsorbable interbody spacers will continue to evolve.
The Journal of the American Academy of Orthopaedic Surgeons 06/2007; 15(5):274-80. · 2.66 Impact Factor
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ABSTRACT: Distinguishing between the normal gait of the elderly and pathologic gaits is often difficult. Pathologic gaits with neurologic causes include frontal gait, spastic hemiparetic gait, parkinsonian gait, cerebellar ataxic gait, and sensory ataxic gait. Pathologic gaits with combined neurologic and musculoskeletal causes include myelopathic gait, stooped gait of lumbar spinal stenosis, and steppage gait. Pathologic gaits with musculoskeletal causes include antalgic gait, coxalgic gait, Trendelenburg gait, knee hyperextension gait, and other gaits caused by inadequate joint mobility. A working knowledge of the characteristics of these gaits and a systematic approach to observational gait examination can help identify the causes of abnormal gait. Patients with abnormal gait can benefit from the treatment of the primary cause of the disorder as well as by general fall-prevention interventions. Treatable causes of gait disturbance are found in a substantial proportion of patients and include normal-pressure hydrocephalus, vitamin B(12) deficiency, Parkinson's disease, alcoholism, medication toxicity, cervical spondylotic myelopathy, lumbar spinal stenosis, joint contractures, and painful disorders of the lower extremity.
The Journal of the American Academy of Orthopaedic Surgeons 03/2007; 15(2):107-17. · 2.66 Impact Factor
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ABSTRACT: Considerable variability exists in clinical approaches to thoracolumbar fractures. Controversy in evaluation and nomenclature contribute to this confusion, with significant differences found between physicians, between different specialties, and in different geographic regions. A new classification system for thoracolumbar injuries, the Thoracolumbar Injury Severity Score (TLISS), was recently described by Vaccaro. No assessment of regional differences has been described. We report regional variability in use of the TLISS system between United States and non-US surgeons.
Twenty-eight spine surgeons (8 neurosurgeons and 20 orthopedic surgeons) reviewed 56 clinical thoracolumbar injury case histories, which included pertinent imaging studies. Cases were classified and scored using the TLISS system. After a three month period, the case histories were re-ordered and the physicians repeated the exercise; 22 physicians completed both surveys and were used to assess intra-rater reliability. The reliability and treatment validity of the TLISS was assessed. Surgeons were grouped into US (n = 15) and non-US (n = 13) cohorts. Inter-rater (both within and between different geographic groups) and intra-rater reliability was assessed by percent agreement, Cohen's kappa, kappa with linear weighting, and Spearman's rank-order correlation.
Non-US surgeons were found to have greater inter-rater reliability in injury mechanism, while agreement on neurological status and posterior ligamentous complex integrity tended to be higher among US surgeons. Inter-rater agreement on management was moderate, although it tended to be higher in US-surgeons. Inter-rater agreement between US and non-US surgeons was similar to within group inter-rater agreement for all categories. While intra-rater agreement for mechanism tended to be higher among US surgeons, intra-rater reliability for neurological status and PLC was slightly higher among non-US surgeons. Intra-rater reliability for management was substantial in both US and non-US surgeons. The TLISS incorporates generally accepted features of spinal injury assessment into a simple patient evaluation tool. The management recommendation of the treatment algorithm component of the TLISS shows good inter-rater and substantial intra-rater reliability in both non-US and US based spine surgeons. The TLISS may improve communication between health providers and may contribute to more efficient management of thoracolumbar injuries.
World Journal of Emergency Surgery 02/2007; 2:24.
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ABSTRACT: A retrospective review of neurophysiologic alerts during anterior cervical surgery.
To examine incidence and types of neurophysiologic alerts and their correlation with new postoperative neurologic deficits after anterior cervical discectomy or corpectomy procedures.
Although multimodality neurophysiologic monitoring has been shown to predict iatrogenic neurologic injuries in scoliosis surgeries, their role in degenerative or trauma-related anterior cervical spine surgery is still unclear.
We retrospectively reviewed 1,445 patients who underwent anterior cervical discectomy or corpectomy and arthrodesis with neurophysiologic monitoring that included transcranial electrical motor-evoked potentials (tceMEP), somatosensory-evoked potentials (SSEP), and spontaneous electromyography (EMG). Intraoperative alerts were analyzed for type, perceived cause, actions taken to reverse or minimize the possible spinal cord injury, and any new postoperative neurologic deficits.
There were 267 (18.4%) procedures that had either minor (spontaneous, sustained EMG) or major (tceMEP/SSEP amplitude reduction) alerts. Patients who underwent corpectomies had 28% increased risk of having a major neurophysiologic alert compared with those who had discectomies. Diagnosis of cervical spondylotic myelopathy or trauma increased the risk of having a major neurophysiologic alert 30% and 76%, respectively, compared with cervical radiculopathy. Eight surgeries were aborted due to persistent tceMEP/SSEP amplitude loss, but none resulted in new postoperative neurologic deficits. Two patients had halo-vest applied due to early termination of surgery. One of these patients ultimately could not receive definitive surgical stabilization.
Diagnosis of cervical spondylotic myelopathy or trauma and cervical corpectomy procedures increase the risk for having major intraoperative alerts. In case of persistent tceMEP/SSEP amplitude loss, consider delaying potentially harmful interventions, such as premature termination of the procedure or methylprednisolone infusion, until a new neurologic deficit is verified with an awake-clinical examination.
Spine 09/2006; 31(17):1916-22. · 2.08 Impact Factor
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ABSTRACT: Prevertebral soft tissue swelling (PSTS) has been evaluated in the setting of traumatic cervical spine injuries. However, no study to date has quantified the PSTS following elective anterior cervical decompression and fusion or the time course to resolution of that swelling.
From May 2002 to May 2005 the senior author performed 193 elective 1- or 2-level anterior cervical decompression and fusions. Patients who underwent corpectomies and anterior cervical fusions for trauma or tumor were excluded. Preoperative, 2-week postoperative and 6-week postoperative radiographs were available on 100 patients. The prevertebral soft tissue stripe was measured on the neutral lateral radiographs for the 3 time points. The mean swelling (mm) for each time point was calculated and stratified by cervical level. Repeated measures analysis of variance with the Tukey-Kramer multiple comparisons test was used to compare the measured swelling at the various time points.
The average PSTS was calculated for each cervical level, for each of the 3 time points, preoperative, 2- and 6-week postoperative. There was a significant increase in PSTS between the preoperative and 2-week postoperative measurements at all levels. There is a significant decrease in PSTS between 2- and 6-week postoperatively at all cervical levels. There is no significant change in PSTS at C2, C3, and C5, when comparing the preoperative and 6-week postoperative measurements. There is significant PSTS at C4, C6, and C7, when comparing preoperative and 6-week postoperative measurements.
The "normal" range for PSTS at 2 weeks and at 6 weeks after elective 1- and 2- level anterior cervical decompression and fusions is described. Our data demonstrates that edema persists at the 2-week follow-up. By 6 weeks postoperative, the increased PSTS has greatly dissipated.
Journal of Spinal Disorders & Techniques 09/2006; 19(6):399-401. · 1.50 Impact Factor
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ABSTRACT: Retrospective review of radiographic parameters.
To identify preoperative radiographic parameters that may be quantitatively predictive of postoperative spinal cord drift after cervical laminectomy and arthrodesis.
Cervical laminectomy and arthrodesis can be an effective method to treat anterior compressions of the spinal cord if there is a sufficient posterior spinal cord drift after surgery. Preoperative cervical alignment has shown some correlations to the degree of spinal cord shift, but whether this and other preoperative radiographic parameters can be used to quantitatively predict the amount of spinal cord drift is unclear.
Preoperative and postoperative radiographs (radiographs, MRIs, and CT) of patients who had cervical laminectomy and arthrodesis were reviewed retrospectively. Various radiographic parameters, including sagittal alignment, longitudinal distance index, space available for the spinal cord at cephalad or caudad levels, and distance from apex of the lordosis to the C2-C7 vertical line were measured. In the first cohort of patients, these parameters were correlated with mean postoperative spinal cord shift to identify any relationships. In the second cohort of patients, the identified association was used on preoperative imaging studies to attempt quantitative prediction of the postoperative spinal cord shift.
Space available for the spinal cord at the level immediately cephalad to the laminectomized segments had high correlations (R = 0.94) to the postoperative spinal cord shift. This association was used to quantitatively predict postoperative spinal cord shift within 11% +/- 6% of the measured value. If 4 mm of mean postoperative spinal cord shift is desired, the ratio to the available space and anterior posterior diameter of the spinal cord should be approximately 2.0.
Relative stenosis at the level directly cephalad to the laminectomized level can affect the degree of postoperative spinal cord shift. Preoperative axial imaging studies should be closely scrutinized to ensure that adequate space is available at the cephalad adjacent level to allow sufficient cord shift after decompressive laminectomy and arthrodesis.
Spine 08/2006; 31(16):1795-8. · 2.08 Impact Factor
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ABSTRACT: A retrospective review of lumbar total disc replacement (TDR) radiographs.
To determine the error and variability in measuring TDR radiographic range of motion (ROM).
Motion preservation is the driving force behind lumbar TDR technology. In the recent literature, sagittal radiographic TDR ROM as low as 2 degrees has been reported. In these studies, ROM was determined by using the Cobb method to measure TDR sagittal alignment angles in flexion-extension lateral radiographs. However, previous studies in the spinal deformity literature have shown that the Cobb method is very susceptible to measurement error.
There were 5 observers, including 2 attending orthopedic spine surgeons, 1 spine fellow, 1 fifth-year resident, and 1 fourth-year resident, who measured the ROM of 50 ProDisc II (Synthes Spine Solutions, New York, NY) TDRs on standard flexion-extension lumbar spine radiograph sets. Repeated measurements were made on 2 occasions using the Cobb method. Measurement variability was calculated using 3 statistical methods.
The 3 statistical methods resulted in extremely similar values for TDR ROM observer variability. Overall, the intraobserver variability of TDR ROM measurement was +/-4.6 degrees, and interobserver variability was +/-5.2 degrees .
To be 95% certain that an implanted TDR prosthesis has any sagittal motion, a ROM of at least 4.6 degrees must be observed, which is the upper limit of intraobserver measurement variability for a TDR with a true ROM of 0 degrees. To be 95% certain that a change in TDR ROM has occurred between 2 measurements by the same observer, a change in ROM of at least 9.6 degrees must be observed (the entire range of +/-4.6 degrees intraobserver variability). ROM measurement variability should be considered when evaluating the success or failure of motion preservation in lumbar TDR.
Spine 06/2006; 31(10):E291-7. · 2.08 Impact Factor
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Alexander R Vaccaro,
Eli M Baron,
James Sanfilippo,
Sidney Jacoby,
Jacob Steuve,
Eric Grossman,
Matthew DiPaola,
Paul Ranier,
Luke Austin,
Ray Ropiak, [......], Moe R Lim,
Anthony Burns,
Ralph Marino,
Christian DiPaola,
Laura Zeiller,
Steven C Zeiler,
James Harrop,
D Greg Anderson,
Todd J Albert,
Alan S Hilibrand
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ABSTRACT: Prospective study of 5 spine surgeons rating 71 clinical cases of thoracolumbar spinal injuries using the Thoracolumbar Injury Severity Score (TLISS) and then re-rating the cases in a different order 1 month later.
To determine the reliability of the TLISS system.
The TLISS is a recently introduced classification system for thoracolumbar spinal column injures designed to simplify injury classification and facilitate treatment decision making. Before being widely adopted, the reliability of the TLISS must be studied.
A total of 71 cases of thoracolumbar spinal trauma were distributed on CD-ROM to 5 attending spine surgeons, including clinical/radiographic data, details of the TLISS, and a scoring sheet in which cases would be scored using the system. The surgeons were later assigned the task with the cases reordered. Intraobserver and interobserver reliability was calculated for TLISS components, total score, and surgeon's treatment decision using the Cohen unweighted kappa coefficients and Spearman rank-order correlation.
Interrater reliability assessed by generalized kappa coefficients was 0.33 +/- 0.03 for injury mechanism, 0.91 +/- 0.02 for neurologic status, 0.35 +/- 0.03 for posterior ligamentous complex status, 0.29 +/- 0.02 for TLISS total, and 0.52 +/- 0.03 for treatment recommendation. Respective results using the Spearman correlation were 0.35 +/- 0.04, 0.94 +/- 0.01, 0.48 +/- 0.04, 0.65 +/- 0.03, and 0.51 +/- 0.04. Surgeons agreed with the TLISS recommendation 96.4% of the time. Intrarater kappa coefficients were 0.57 +/- 0.04 for injury mechanism, 0.93 +/- 0.02 for neurologic status, 0.48 +/- 0.04 for posterior ligamentous complex status, 0.46 +/- 0.03 for TLISS total, and 0.62 +/- 0.04 for treatment recommendation. Respective results using the Spearman correlation were 0.70 +/- 0.04, 0.95 +/- 0.02, 0.59 +/- 0.05, 0.77 +/- 0.04, and 0.59 +/- 0.05.
The TLISS has good reliability and compares favorably to other contemporary thoracolumbar fracture classification systems.
Spine 06/2006; 31(11 Suppl):S62-9; discussion S104. · 2.08 Impact Factor
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ABSTRACT: Patients with acute spinal injury who require operative intervention may be at increased risk for postoperative surgical-site infection when compared with patients having elective spinal surgery. Various local, systemic, and iatrogenic factors predispose this unique population of patients to post-surgical infection. Nonmodifiable risk factors for surgical-site infection in spine trauma include age, medical comorbidities, and neurologic status. Modifiable risk factors include poor postoperative nutritional status, delay from time of injury to surgical intervention, posterior surgical approach, higher number of levels stabilized, length of postoperative stay in the intensive care unit, and treatment by a single specialty team (versus treatment by successive orthopaedic and neurosurgical teams). When treating patients with spine trauma, a high index of suspicion should be maintained for patients with multiple risk factors for infection and every effort should be made to minimize the modifiable risk factors. Level of Evidence: Level V (expert opinion). Please see the Guidelines for Authors for a complete description of levels of evidence.
Clinical Orthopaedics and Related Research 04/2006; 444:114-9. · 2.53 Impact Factor
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James S Harrop,
Alexander R Vaccaro,
R John Hurlbert,
Jared T Wilsey,
Eli M Baron,
Christopher I Shaffrey,
Charles G Fisher,
Marcel F Dvorak,
F C Oner,
Kirkham B Wood,
Neel Anand,
D Greg Anderson, Moe R Lim,
Joon Y Lee,
Christopher M Bono,
Paul M Arnold,
Y Raja Rampersaud,
Michael G Fehlings
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ABSTRACT: A new classification and treatment algorithm for thoracolumbar injuries was recently introduced by Vaccaro and colleagues in 2005. A thoracolumbar injury severity scale (TLISS) was proposed for grading and guiding treatment for these injuries. The scale is based on the following: 1) the mechanism of injury; 2) the integrity of the posterior ligamentous complex (PLC); and 3) the patient's neurological status. The reliability and validity of assessing injury mechanism and the integrity of the PLC was assessed.
Forty-eight spine surgeons, consisting of neurosurgeons and orthopedic surgeons, reviewed 56 clinical thoracolumbar injury case histories. Each was classified and scored to determine treatment recommendations according to a novel classification system. After 3 months the case histories were reordered and the physicians repeated the exercise. Validity of this classification was good among reviewers; the vast majority (> 90%) agreed with the system's treatment recommendations. Surgeons were unclear as to a cogent description of PLC disruption and fracture mechanism.
The TLISS demonstrated acceptable reliability in terms of intra- and interobserver agreement on the algorithm's treatment recommendations. Replacing injury mechanism with a description of injury morphology and better definition of PLC injury will improve inter- and intraobserver reliability of this injury classification system.
Journal of Neurosurgery Spine 03/2006; 4(2):118-22. · 1.53 Impact Factor
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Alexander R Vaccaro, Moe R Lim,
R John Hurlbert,
Ronald A Lehman,
James Harrop,
D Charles Fisher,
Marcel Dvorak,
D Greg Anderson,
Steven C Zeiller,
Joon Y Lee,
Michael G Fehlings,
F C Oner
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ABSTRACT: The optimal surgical approach and treatment of unstable thoracolumbar spine injuries are poorly defined owing to a lack of widely accepted level I clinical literature. This lack of evidence-based standards has led to varied practice patterns based on individual surgeon preferences. The purpose of this study was to survey the leaders in the field of spine trauma to define the major characteristics of thoracolumbar injuries that influence their surgical decision making. In the absence of good scientific data, expert consensus opinions may provide surgeons with a practical framework to guide therapy and to conduct future research.
A panel of 22 leading spinal surgeons from 20 level I trauma centers in seven countries met to discuss the indications for surgical approach selection in unstable thoracolumbar injuries. Injuries were presented to the surgeons in a case scenario survey format. Preferred surgical approaches to the clinical scenarios were tabulated and comments weighed.
All members of the panel agreed that three independent characteristics of thoracolumbar injuries carry primary importance in surgical decision making: the injury morphology, the neurologic status of the patient, and the integrity of the posterior ligaments. Six clinical scenarios based on the neurologic status of the patient (intact, incomplete, or complete) and on the status of the posterior ligamentous complex (intact or disrupted) were created, and consensus treatment approaches were described. Additional circumstances capable of altering the treatments were acknowledged.
Decision making for the surgical treatment of thoracolumbar injuries is largely dependent on three patient characteristics: injury morphology, neurologic status, and posterior ligament integrity. A logical and practical decision-making process based on these characteristics may guide treatment even for the most complicated fracture patterns.
Journal of Spinal Disorders & Techniques 03/2006; 19(1):1-10. · 1.50 Impact Factor
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Joon Y Lee,
Alexander R Vaccaro, Moe R Lim,
F C Oner,
R John Hulbert,
Rune Hedlund,
Michael G Fehlings,
Paul Arnold,
James Harrop,
Christopher M Bono,
Paul A Anderson,
D Greg Anderson,
Mitchel B Harris,
Andrew K Brown,
Gordon H Stock,
Eli M Baron
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ABSTRACT: Contemporary understanding of the biomechanics, natural history, and methods of treating thoracolumbar spine injuries continues to evolve. Current classification schemes of these injuries, however, can be either too simplified or overly complex for clinical use.
The Spine Trauma Group was given a survey to identify similarities in treatment algorithms for common thoracolumbar injuries, as well as to identify characteristics of injury that played a key role in the decision-making process.
Based on the survey, the Spine Trauma Group has developed a classification system and an injury severity score (thoracolumbar injury classification and severity score, or TLICS), which may facilitate communication between physicians and serve as a guideline for treating these injuries. The classification system is based on the morphology of the injury, integrity of the posterior ligamentous complex, and neurological status of the patient. Points are assigned for each category, and the final total points suggest a possible treatment option.
The usefulness of this new system will have to be proven in future studies investigating inter- and intraobserver reliability, as well as long-term outcome studies for operative and nonoperative treatment methods.
Journal of Orthopaedic Science 12/2005; 10(6):671-5. · 0.84 Impact Factor
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The Journal of Bone and Joint Surgery 11/2005; 87(10):2318-22. · 3.27 Impact Factor
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ABSTRACT: A critical review of available and emerging nucleus pulposus replacement implants.
To review the biomechanics, design, and clinical data of currently available and developing nucleus pulposus replacement technologies.
The interest in minimally invasive treatment of degenerative disc disease has grown as the technology for intervertebral motion-sparing devices continues to improve. Replacement of nucleus pulposus without anular obliteration represents a tempting alternative to spinal fusion procedures. The aim in nucleus pulposus replacement is to slow adjacent level degeneration, restore normal loads to the diseased level, and restore segmental spinal biomechanics.
A literature review of currently available biomaterials, biomechanics, and available preclinical and clinical data on nucleus pulposus replacement implants.
New synthetic biomaterials have recently been developed to closely mimic native biomechanics during compressive loading cycles of the intervertebral disc. This, in conjunction with improved understanding of global spine biomechanics, has allowed the development of novel nucleus replacement implants. These implants are currently at different stages of preclinical and clinical investigations.
Although some of the newly designed prosthesis have shown some promising results in preclinical studies, rigorous short- and long-term clinical evaluations will be critical in evaluating their true efficacy.
Spine 09/2005; 30(16 Suppl):S16-22. · 2.08 Impact Factor
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ABSTRACT: Occipito-cervical (OC) instrumentation and fusion is indicated in traumatic atlanto-occipital dissociation and type III Anderson-Montesano occipital condyle fractures. The goals of surgery are to stabilize the mechanically compromised OC junction, correct deformity or displacement, and decompress compromised neural structures. The goals of instrumentation are to provide immediate stability, improve fusion rate, diminish the need for postoperative external immobilization, and decrease rehabilitation time. To successfully instrument the occipito-cervical spine, a working knowledge of the anatomy of the occipital-cervical junction is imperative. A wide variety of stabilization techniques and instrumentation systems are currently available, each with its own advantages and disadvantages. With familiarity of the constraints and benefits of the available instrumentation systems, the individual fixation needs of a clinical situation can be fulfilled and successful patient outcomes can be achieved.
Injury 08/2005; 36 Suppl 2:B44-53. · 1.98 Impact Factor
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ABSTRACT: A retrospective chart and radiographic review of 122 pedicle screws placed with computerized stereotactic image-guidance into posterolateral fusion masses.
To determine the accuracy rate of computerized stereotactic image-guided pedicle screw placement in previously fused lumbar spines.
Placement of pedicle screws into a previously fused lumbar spine is challenging. The normal anatomic landmarks used to determine the starting point and trajectory of the screws have either been removed or are obscured by the fusion mass. Computerized frameless stereotaxis provides precise intraoperative real time multiplanar image-guidance and may be valuable in this clinical situation.
Computerized frameless stereotactic image-guidance was used to place pedicle screws into 78 consecutive patients with prior lumbar spine fusions. Postoperative computed tomography was available on 35 patients (231 screws). One hundred and twenty-two screws were placed into fusion masses. Pedicle cortical perforations were characterized by the direction (medial, inferior, lateral, or superior) and magnitude (in 2-mm increments) of perforation.
Five (4.1%) of the 122 pedicle screws placed into previously fused levels were found to have unintentional cortical violations. There were 1 superior (<2 mm), 1 medial (<2 mm), and 3 lateral perforations (<2, 4, and 6 mm). None of these perforations led to clinically apparent radicular pain or weakness. No pedicle screws required revision for malpositioning.
The accuracy rate of stereotactic image-guided pedicle screw placement into previously fused lumbar spine levels is 96%. Computerized stereotactic image-guidance may have particular application in situations in which posterior element anatomy is altered, such as in the presence of a prior fusion mass.
Spine 08/2005; 30(15):1793-8. · 2.08 Impact Factor
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ABSTRACT: Nonfusion technology in spine surgery may improve outcomes by reducing surgical morbidity and the incidence of adjacent level degeneration; however, new technologies also introduce new short- and long-term complications. There is currently no evidence that nonfusion implants are superior to fusion in mid- to long-term follow-up. Understanding the potential risks and benefits of nonfusion technology is essential for spine surgeons and their patients. This article reviews the current evidence relating to the potential risks and benefits of nonfusion technology in spine surgery.
Orthopedic Clinics of North America 08/2005; 36(3):263-9. · 1.25 Impact Factor
