Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis.

BACKGROUND CONTEXT: Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement may be asymptomatic but is also correlated with potential adverse events. Computer-assisted surgery (CAS) has been associated with improved screw placement accuracy rates. However, this technology has substantial acquisition and maintenance costs. Despite its increasing usage, no rigorous full economic evaluation comparing this technology to current standard of care has been reported. PURPOSE: Medical costs are exploding in an unsustainable way. Health economic theory requires that medical equipment costs be compared with expected benefits. To answer this question for computer-assisted spinal surgery, we present an economic evaluation looking specifically at symptomatic misplaced screws leading to reoperation secondary to neurologic deficits or biomechanical concerns. STUDY DESIGN/SETTING: The study design was an observational case-control study from prospectively collected data of consecutive patients treated with the aid of CAS (treatment group) compared with a matched historical cohort of patients treated with conventional fluoroscopy (control group). PATIENT SAMPLE: The patient sample consisted of consecutive patients treated surgically at a quaternary academic center. OUTCOME MEASURES: The primary effectiveness measure studied was the number of reoperations for misplaced screws within 1 year of the index surgery. Secondary outcome measures included were total adverse event rate and postoperative computed tomography usage for pedicle screw examination. METHODS: A patient-level data cost-effectiveness analysis from the hospital perspective was conducted to determine the value of a navigation system coupled with intraoperative 3-D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO, USA) in adult spinal surgery. The capital costs for both alternatives were reported as equivalent annual costs based on the annuitization of capital expenditures method using a 3% discount rate and a 7-year amortization period. Annual maintenance costs were also added. Finally, reoperation costs using a micro-costing approach were calculated for both groups. An incremental cost-effectiveness ratio was calculated and reported as cost per reoperation avoided. Based on reoperation costs in Canada and in the United States, a minimal caseload was calculated for the more expensive alternative to be cost saving. Sensitivity analyses were also conducted. RESULTS: A total of 5,132 pedicle screws were inserted in 502 patients during the study period: 2,682 screws in 253 patients in the treatment group and 2,450 screws in 249 patients in the control group. Overall accuracy rates were 95.2% for the treatment group and 86.9% for the control group. Within 1 year post treatment, two patients (0.8%) required a revision surgery in the treatment group compared with 15 patients (6%) in the control group. An incremental cost-effectiveness ratio of $15,961 per reoperation avoided was calculated for the CAS group. Based on a reoperation cost of $12,618, this new technology becomes cost saving for centers performing more than 254 instrumented spinal procedures per year. CONCLUSIONS: Computer-assisted spinal surgery has the potential to reduce reoperation rates and thus to have serious cost-effectiveness and policy implications. High acquisition and maintenance costs of this technology can be offset by equally high reoperation costs. Our cost-effectiveness analysis showed that for high-volume centers with a similar case complexity to the studied population, this technology is economically justified.

Perceptions of individuals living with spinal cord injury toward preference-based quality of life instruments: a qualitative exploration.

BACKGROUND: Generic preference-based health-related quality of life instruments are widely used to measure health benefit within economic evaluation. The availability of multiple instruments raises questions about their relative merits and recent studies have highlighted the paucity of evidence regarding measurement properties in the context of spinal cord injury (SCI). This qualitative study explores the views of individuals living with SCI towards six established instruments with the objective of identifying 'preferred' outcome measures (from the perspective of the study participants). METHODS: Individuals living with SCI were invited to participate in one of three focus groups. Eligible participants were identified from Vancouver General Hospital's Spine Program database; purposive sampling was used to ensure representation of different demographics and injury characteristics. Perceptions and opinions were solicited on the following questionnaires: 15D, Assessment of Quality of Life 8-dimension (AQoL-8D), EQ-5D-5L, Health Utilities Index (HUI), Quality of Well-Being Scale Self-Administered (QWB-SA), and the SF-36v2. Framework analysis was used to analyse the qualitative information gathered during discussion. Strengths and limitations of each questionnaire were thematically identified and managed using NVivo 9 software. RESULTS: Major emergent themes were (i) general perceptions, (ii) comprehensiveness, (iii) content, (iv) wording and (v) features. Two sub-themes pertinent to content were also identified; 'questions' and 'options'. All focus group participants (n = 15) perceived the AQoL-8D to be the most relevant instrument to administer within the SCI population. This measure was considered to be comprehensive, with relevant content (i.e. wheelchair inclusive) and applicable items. Participants had mixed perceptions about the other questionnaires, albeit to varying degrees. CONCLUSIONS: Despite a strong theoretical underpinning, the AQoL-8D (and other AQoL instruments) is infrequently used outside its country of origin (Australia). Empirical comparative analyses of the favoured instruments identified in this qualitative study are necessary within the context of spinal cord injury.

Surgeon-industry conflict of interest: survey of North Americans' opinions regarding surgeons consulting with industry.

BACKGROUND CONTEXT: Surgeon-industry conflict of interest (COI) has become a source of considerable interest. Professional medical societies, industry, and policy makers have attempted to regulate potential COI without consideration for public opinion. PURPOSE: The objective of this study was to report on the opinions of individuals representing the general public regarding surgeon-industry consulting relationships. STUDY DESIGN/SETTING: Web-based survey. METHODS: Survey was administered using a "spine Web site," and opinions are collected on surgeon-industry consulting and regulation. Associations among responses to similar questions were assessed to ensure validity and subgroup analysis performed for respondent age, sex, education, insurance, employment, and patient status. RESULTS: Six hundred ten of 642 surveys had complete data. The sample population comprised more females and was older and more educated than the American population. About 80% of respondents felt it was ethical and either beneficial or of no influence to the quality of health care if surgeons were consultants for surgical device companies. Most felt disclosure of an industry relationship was important and paying surgeons royalties for devices, other than those they directly implant, would not affect quality of care. Respondents support multidisciplinary surgeon-industry COI regulation and trust doctors and their professional societies to head this effort. CONCLUSIONS: Despite the known potential negative impact of surgeon-industry COI on patient care, this study revealed that this does not seem to be reflected in the opinion of the general public. The respondents felt that disclosure is deemed one of the most important means of self-regulation and COI management, which is in agreement with current trends of most spine societies and journals that are increasing the stringency of disclosure policies.

Physician-industry conflict of interest: public opinion regarding industry-sponsored research.

OBJECT: The nature of physician-industry conflict of interest (COI) has become a source of considerable concern, but is often not discussed in the research setting. With reduced funding available from government and nonprofit sources, industry support has enthusiastically grown, but along with this comes the potential for COI that must be regulated. In this era of shared decision making in health care, society must have input into this regulation. The purpose of this study was to assess the opinions of a North American population sample on COI regarding industry-funded research and to analyze population subgroups for trends. METHODS: A survey was developed for face and content validity, underwent focus group evaluation for clarity and bias reduction, and was administered via the World Wide Web. Demographic and general survey results were summarized as a percentage for each answer, and subgroup analysis was done using logistic regression. Generalizability of the sample to the US population was also assessed. RESULTS: Of 541 surveys, 40 were excluded due to missing information, leaving 501 surveys for analysis. The sample population was composed of more females, was older, and was more educated than a representative cross-section of the American population. Respondents support multidisciplinary surgeon-industry COI regulation and trust doctors and their professional societies the most to head this effort. Respondents trust government officials and company representatives the least with respect to regulation of COI. Most respondents feel that industry-sponsored research can involve physicians and be both objective and beneficial to patients. CONCLUSIONS: Most respondents in this study felt that surgeons should be involved in industry-sponsored research and that more research, regardless of funding source, will ultimately benefit patients. The majority of respondents distrust government or industry to regulate COI. The development of evidence-based treatment recommendations requires the inclusion of patient preference. The authors encourage regulatory bodies to follow suit and include society's perspective on regulation of COI in research.

Postoperative infection treatment score for the spine (PITSS): construction and validation of a predictive model to define need for single versus multiple irrigation and debridement for spinal surgical site infection.

BACKGROUND CONTEXT: There is very little evidence to guide treatment of patients with spinal surgical site infection (SSI) who require irrigation and debridement (I&D) in deciding need for single or multiple I&Ds or more complex wound management such as vacuum-assisted closure dressing or soft-tissue flaps. PURPOSE: The purpose of this study was to build a predictive model that stratifies patients with spinal SSI, allowing us to determine which patients will need single versus multiple I&D. The model will be validated and will serve as evidence to support a scoring system to guide treatment. STUDY DESIGN: A consecutive series of 128 patients from a tertiary spine center (collected from 1999 to 2005) who required I&D for spinal SSI were studied based on data from a prospectively collected outcomes database. METHODS: More than 30 variables were identified by extensive literature review as possible risk factors for SSI and tested as possible predictors of risk for multiple I&D. Logistic regression was conducted to assess each variable's predictability by a "bootstrap" statistical method. A prediction model was built in which single or multiple I&D was treated as the "response" and risk factors as "predictors." Next, a second series of 34 different patients meeting the same criteria as the first population were studied. External validation of the predictive model was performed by applying the model to the second data set, and predicted probabilities were generated for each patient. Receiver operating characteristic curves were constructed, and the area under the curve (AUC) was calculated. RESULTS: Twenty-four of one hundred twenty-eight patients with spinal SSI required multiple I&D. Six predictors: anatomical location, medical comorbidities, specific microbiology of the SSI, the presence of distant site infection (ie, urinary tract infection or bacteremia), the presence of instrumentation, and the bone graft type proved to be the most reliable predictors of need for multiple I&D. Internal validation of the predictive model yielded an AUC of 0.84. External validation analysis yielded AUC of 0.70 and 95% confidence interval of 0.51 to 0.89. By setting a probability cutoff of .24, the negative predictive value (NPV) for multiple I&D was 0.77 and positive predictive value (PPV) was 0.57. A probability cutoff of .53 yielded a PPV of 0.85 and NPV of 0.46. CONCLUSIONS: Patients with positive methicillin-resistant Staphylococcus aureus culture or those with distant site infection such as bacteremia were strong predictors of need for multiple I&D. Presence of instrumentation, location of surgery in the posterior lumbar spine, and use of nonautograft bone graft material predicted multiple I&D. Diabetes also proved to be the most significant medical comorbidity for multiple I&D. The validation of this predictive model revealed excellent PPV and good NPV with appropriately chosen probability cutoff points. This study forms the basis for an evidence-based classification system, the Postoperative Infection Treatment Score for the Spine that stratifies patients who require surgery for SSI, based on specific spine, patient, infection, and surgical factors to assess a low, indeterminate, and high risk for the need for multiple I&D.

Morbidity and mortality of major adult spinal surgery. A prospective cohort analysis of 942 consecutive patients.

BACKGROUND CONTEXT: To date, most reports on the incidence of adverse events (AEs) in spine surgery have been retrospective and dependent on data abstraction from hospital-based administrative databases. To our knowledge, there have been no previous rigorously performed prospective analysis of all AEs occurring in the entire population of patients presenting to an academic quaternary referral center. PURPOSE: To determine the mortality and true incidence and severity of morbidity (major and minor, medical and surgical) in adults undergoing complex spinal surgery, both trauma and elective, in a quaternary referral center. To examine the influence of the introduction of a dedicated weekly multidisciplinary rounds, and a formal abstraction tool, on the recording of this prospective perioperative morbidity data. To examine the validity and inter- and intraobserver reliability of a dedicated Spine AdVerse Events Severity system, version 2 (SAVES V2) AE abstraction tool. STUDY DESIGN: Ours is an academic quaternary referral center serving a population of 4.5 million people. Beginning in April 2008, a spine-specific AE-recording instrument, entitled SAVES V2, was introduced at our center for reporting, categorization, and classification of AEs. The use of this system remains an ongoing prospective study. PATIENT SAMPLE: All adult patients admitted to the spine service of a quaternary referral center for a 12-month period. OUTCOME MEASURES: A validity and an inter- and intraobserver reliability examination of the SAVES V2 system, as used at our institution. Morbidity and inhospital deaths, unplanned second surgeries during index admission, wound infections requiring reoperation, and readmissions during the same calendar year. We also examined in detail all intraoperative and nonsurgical postoperative AEs, as well as hospital length of stay (LOS). METHODS: Data on all patients undergoing surgery over a 12-month period were prospectively collected using a perioperative morbidity abstraction tool at weekly dedicated mortality and morbidity rounds. This tool allows identification of each specific AE and grades the severity. Before the introduction of this system, and using the hospital inpatient database, our documented perioperative morbidity rate (major and minor, medical and surgical) was 23%. Diagnosis, operative data, hospital data, major and minor complications both medical and surgical, and deaths were recorded. RESULTS: One hundred percent of all patients discharged from the unit had complete data available for analysis. Nine hundred forty-two patients with an age range of 16 to 90 years (mean, 54 years; mode, 38 years) were identified. There were 552 males and 390 females. Around 58.5% of patients had undergone elective surgery. Thirty percent of patients were American Spinal Injury Association class D or worse on admission. The average LOS was 13.5 days (range, 1-221 days). Eight hundred twenty-two (87%) patients had at least one documented complication. Thirty-nine percent of these adversely affected hospital LOS. There were 14 mortalities during the study period. The rate of intraoperative surgical complication was 10.5% (4.5% incidental durotomy and 1.9% hardware malposition requiring revision and 2.2% blood loss >2 L). The incidence of postoperative complication was 73.5% (wound complications, 13.5%; delerium, 8%; pneumonia, 7%; neuropathic pain, 5%; dysphagia, 4.5%; and neurological deterioration, 3%). CONCLUSIONS: Major spinal surgery in the adult is associated with a high incidence of intra- and postoperative complications. We identified a very high rate of previously unrecognized postoperative complications, which adversely affect LOS. Without strict adherence to a prospective data collection system, the true complexity of this surgery may be greatly underestimated.

Postoperative improvement in health-related quality of life: a national comparison of surgical treatment for focal (one- to two-level) lumbar spinal stenosis compared with total joint arthroplasty for osteoarthritis.

BACKGROUND CONTEXT: The results of single-center studies have shown that surgical intervention for lumbar spinal stenosis yielded comparable health-related quality of life (HRQoL) improvement to total joint arthroplasty (TJA). Whether these results are generalizable to routine clinical practice in Canada is unknown. PURPOSE: The primary purpose of this equivalence study was to compare the relative improvement in physical HRQoL after surgery for focal lumbar spinal stenosis (FLSS) compared with TJA for hip and knee osteoarthritis (OA) across six Canadian centers. STUDY DESIGN/SETTING: A Canadian multicenter ambispective cohort study. PATIENT SAMPLE: A cohort of 371 primary one- to two-level spinal decompression (n=214 with instrumented fusion) for FLSS (n=179 with degenerative lumbar spondylolisthesis [DLS]) was compared with a cohort of primary total hip (n=156) and knee (n=208) arthroplasty for OA. OUTCOME MEASURES: The primary outcome was the change in preoperative to 2-year postoperative 36-Item Short Form Health Survey Physical Component Summary (PCS) score as reflected by the number of patients reaching minimal clinically important difference (MCID) and substantial clinical benefit (SCB). METHODS: Univariate analyses were conducted to identify baseline differences and factors that were significantly related to outcomes at 2 years. Multivariable regression modeling was used as our primary analysis to compare outcomes between groups. RESULTS: The mean age (years) and percent females for the spine, hip, and knee groups were 63.3/58.5, 66.0/46.9, and 65.8/64.3, respectively. All three groups experienced significant improvement of baseline PCS (p<.001). Multivariate analyses, adjusting for baseline differences (age, gender, baseline Mental Component Summary score, baseline PCS), demonstrated no significant differences in PCS outcome between spinal surgery and arthroplasty (combined hip and knee cohorts) patients with an odds ratio of 0.80 (95% confidence interval [CI], 0.57-1.11; p=.17) and 0.79 (95% CI, 0.58-1.09; p=.15) for achieving MCID or SCB, respectively. In subgroup analysis, spine and knee outcomes were not significantly different, with hip arthroplasty superior to both (p<.0001). CONCLUSIONS: Significant improvement in physical HRQoL after surgical treatment of FLSS (including DLS) is consistently achieved nationally. Our overall results demonstrate that a comparable number of patients can expect to achieve MCID and SCB 2 years after surgical intervention for FLSS and total knee arthroplasty.

The Chiropractic Hospital-based Interventions Research Outcomes (CHIRO) study: a randomized controlled trial on the effectiveness of clinical practice guidelines in the medical and chiropractic management of patients with acute mechanical low back pain.

BACKGROUND CONTEXT: Evidence-based clinical practice guidelines (CPGs) for the management of patients with acute mechanical low back pain (AM-LBP) have been defined on an international scale. Multicenter clinical trials have demonstrated that most AM-LBP patients do not receive CPG-based treatments. To date, the value of implementing full and exclusively CPG-based treatment remains unclear. PURPOSE: To determine if full CPGs-based study care (SC) results in greater improvement in functional outcomes than family physician-directed usual care (UC) in the treatment of AM-LBP. STUDY DESIGN/SETTING: A two-arm, parallel design, prospective, randomized controlled clinical trial using blinded outcome assessment. Treatment was administered in a hospital-based spine program outpatient clinic. PATIENT SAMPLE: Inclusion criteria included patients aged 19 to 59 years with Quebec Task Force Categories 1 and 2 AM-LBP of 2 to 4 weeks' duration. Exclusion criteria included "red flag" conditions and comorbidities contraindicating chiropractic spinal manipulative therapy (CSMT). PRIMARY OUTCOME: improvement from baseline in Roland-Morris Disability Questionnaire (RDQ) scores at 16 weeks. SECONDARY OUTCOMES: improvements in RDQ scores at 8 and 24 weeks; and in Short Form-36 (SF-36) bodily pain (BP) and physical functioning (PF) scale scores at 8, 16, and 24 weeks. METHODS: Patients were assessed by a spine physician, then randomized to SC (reassurance and avoidance of passive treatments, acetaminophen, 4 weeks of lumbar CSMT, and return to work within 8 weeks), or family physician-directed UC, the components of which were recorded. RESULTS: Ninety-two patients were recruited, with 36 SC and 35 UC patients completing all follow-up visits. Baseline prognostic variables were evenly distributed between groups. The primary outcome, the unadjusted mean improvement in RDQ scores, was significantly greater in the SC group than in the UC group (p=.003). Regarding unadjusted mean changes in secondary outcomes, improvements in RDQ scores were also greater in the SC group at other time points, particularly at 24 weeks (p=.004). Similarly, improvements in SF-36 PF scores favored the SC group at all time points; however, these differences were not statistically significant. Improvements in SF-36 BP scores were similar between groups. In repeated-measures analyses, global adjusted mean improvement was significantly greater in the SC group in terms of RDQ (p=.0002), nearly significantly greater in terms of SF-36 PF (p=.08), but similar between groups in terms of SF-36 BP (p=.27). CONCLUSIONS: This is the first reported randomized controlled trial comparing full CPG-based treatment, including spinal manipulative therapy administered by chiropractors, to family physician-directed UC in the treatment of patients with AM-LBP. Compared to family physician-directed UC, full CPG-based treatment including CSMT is associated with significantly greater improvement in condition-specific functioning.

Differences between neurosurgeons and orthopedic surgeons in classifying cervical dislocation injuries and making assessment and treatment decisions: a multicenter reliability study.

Variability exists in the management of cervical spinal injuries. The goal of this study was to assess the effect of training specialty (orthopedic surgery vs neurosurgery) on management of cervical dislocations. Twenty-nine spine surgeons reviewed 10 cases of cervical dislocation injuries. For each of the 10 cases, the surgeons evaluated 3 clinical scenarios, which included a neurologically intact patient, a patient with an incomplete spinal cord injury (SCI), and a patient with complete SCI. Surgeons determined whether a unilateral or bilateral facet dislocation was present and whether pretreatment magnetic resonance imaging (MRI) or immediate closed reduction was indicated. Management decisions were re-assessed after review of MRIs. While spine surgeons may agree on what they see on MRI and how they classify certain cervical injuries irrespective of training, significant differences of opinion continue to exist regarding the therapeutic implications of this information, specifically, whether to order a pretreatment MRI and how to manage the injury.

Injury of the posterior ligamentous complex of the thoracolumbar spine: a prospective evaluation of the diagnostic accuracy of magnetic resonance imaging.

STUDY DESIGN: Prospective diagnostic imaging study. OBJECTIVE: To determine the accuracy of magnetic resonance imaging (MRI) in diagnosing injury of the posterior ligamentous complex (PLC) in patients with thoracolumbar trauma. SUMMARY OF BACKGROUND DATA: Treatment decisions in thoracolumbar injury patients are currently based on the status of the PLC. It is, therefore, important to understand the accuracy of MRI in diagnosing varying degrees of PLC injury. Prior studies report that MRI is up to 100% sensitive for diagnosing PCL injury. METHODS: Patients with an acute injury from T1 to L3 who required posterior surgery were prospectively studied. A musculoskeletal radiologist, based on the preoperative MRI findings, characterized each of the 6 components of the PLC as intact, incompletely disrupted, or disrupted. During the surgical procedure, the surgeon identified each component of the PLC as intact, incompletely disrupted, or disrupted. The radiologist's interpretation and surgical findings were compared. RESULTS: Forty-two patients with 62 levels of injury were studied. There were 33 males (78.6%) and 9 females (21.4%), and the average age was 35.7 years. According to the kappa score, there was a moderate level of agreement between the radiologist's interpretation and the intraoperative findings for all PLC components except the thoracolumbar fascia, for which there was slight agreement. The sensitivity for the various PLC components ranged from 79% (left facet capsule) to 90% (interspinous ligament). The specificity ranged from 53% (thoracolumbar fascia) to 65% (ligamentum flavum). There was less agreement between the radiologist and surgeon for the patients with less severe neurologic compromise, i.e., those patients with an AIS grade of either D or E. CONCLUSION: The sensitivity and specificity of MRI for diagnosing injury of the PLC are lower than previously reported in the literature. The integrity of the PLC as determined by MRI should not be used in isolation to determine treatment.

Ex vivo measurement of lumbar intervertebral disc pressure using fibre-Bragg gratings.

Methods were developed to measure intervertebral disc pressure using optical fibre-Bragg gratings (FBGs). The FBG sensor was calibrated for hydrostatic pressure in a purpose-built apparatus and the average sensitivity was determined to be -5.7 +/- 0.085 pm/MPa (mean +/- SD). The average coefficient of determination (r(2)) for the calibration data was 0.99, and the average hysteresis of the sensor was 2.13% of full scale. The FBG was used to measure intradiscal pressure response to compressive load in five lumbar functional spine units. The pressure measured by the FBG sensor varied linearly with applied compressive load with coefficients of determination ranging from 0.84 to 0.97. The FBG sensor's sensitivity to compressive load ranged from 0.702 +/- 0.043 kPa/N (mean +/- SD) in a L1-L2 specimen, to 1.07 +/- 0.069 kPa/N in a L4-L5 specimen. These measurements agree with those of previous studies in lumbar spines. Two strain gauge pressure sensors were also used to measure intradiscal pressure response to compressive load. The measured pressure sensitivity to load ranged from 0.251 kPa/N (L4-L5) to 0.850 kPa/N (L2-L3). The average difference in pressure sensitivity to load between Sensors 1 and 2 was 12.9% of the value for Sensor 1, with a range from 1.1% to 20.4%, which suggests that disc pressure was not purely hydrostatic. This may have contributed to the difference between the responses of the FBG and strain gauge sensors.

En bloc marginal excision of a multilevel cervical chordoma. Case report.

The purpose of this case report is to demonstrate that an en bloc resection with negative surgical margins can be successfully achieved in a case of a seemingly unresectable C-2 chordoma if appropriate preoperative staging and planning are performed. The management of chordomas is controversial and challenging because of their location and often large size at presentation. Because chordomas are malignant and will aggressively recur locally if intralesional resection is conducted, wide or true en bloc resection is generally recommended. The literature indicates, however, that surgeons are reluctant to perform wide or even marginal resections because of the lesion's complex surrounding anatomy and the risk of significant neurological compromise when a tumor abuts the dura mater or neural tissues. In this report the authors outline the successful en bloc resection of a large C1-3 chordoma and discuss the importance of preoperative staging and planning.

Similarities and differences in the treatment of spine trauma between surgical specialties and location of practice.

STUDY DESIGN: Questionnaires administered to practicing orthopedic and neurosurgical spine surgeons from various regions of the United States and abroad. OBJECTIVES: To determine similarities and differences in the treatment of spinal trauma. SUMMARY OF BACKGROUND DATA: Spinal trauma is generally referred to subspecialists of orthopedic or neurosurgical training. Prior studies have suggested that there is significant variability in the management of such injuries. METHODS: Questionnaires based on eight clinical scenarios of commonly encountered cervical, thoracic, and lumbar injuries were administered to 35 experienced spinal surgeons. Surgeons completed profile information and answered approximately one dozen questions for each case. Data were analyzed with SPSS software to determine the levels of agreement and characteristics of respondents that might account for a lack of agreement on particular aspects of management. RESULTS: Of the 35 surgeons completing the questionnaire, 63% were orthopedists, 37% were neurosurgeons, and 80% had been in practice for more than 5 years. Considerable agreement was found in the majority of clinical decisions, including whether or not to operate and the timing of surgery. Of the differences noted, neurosurgeons were more likely to obtain a MRI, and orthopedists were more likely to use autograft as a sole graft material. Physicians from abroad were, in general, more likely to operate and to use an anterior approach during surgery than physicians from the northeastern United States. CONCLUSIONS: More commonalities were identified in the management of spinal trauma than previously reported. When found, variability in opinion was related to professional and regional differences.

Anterior occiput to axis screw fixation: part II: a biomechanical comparison with posterior fixation techniques.

STUDY DESIGN: This biomechanical study used flexibility testing on fresh-frozen human cadaveric specimens (occiput to C3) and compared the range of motion and neutral zone for three occipitocervical fixation techniques. OBJECTIVES: To contrast the stabilization provided by a new technique of anterior occipitocervical screw fixation with two other commonly used posterior occipitocervical fixation techniques. SUMMARY OF BACKGROUND DATA: There are no published reports describing this novel technique of anterior occipitocervical screw fixation. METHODS: Six human occipitocervical spine specimens were mounted in a custom-designed, spine-testing machine that applied a pure moment in flexion-extension, lateral bending, and axial rotation. The specimens were tested intact, after an odontoid osteotomy with capsular injury, and after each of three fixation methods: posterior wiring, posterior plate fixation with C1-C2 transarticular screws, and finally with anterior occipitocervical screws. Intervertebral motion was measured with an optoelectronic measurement system, and the range of motion and neutral zone were the kinematic variables measured and used for analysis. RESULTS: In flexion and extension testing, the posterior plate with transarticular screws provided greater stabilization than posterior wiring or anterior occipitocervical screws. In lateral bending and rotation, the anterior screws were similarly effective to the posterior plate, both of which were more effective than posterior wiring. CONCLUSION: The anterior screw fixation technique was as effective as a posterior plate with transarticular screws in stabilizing between the occiput and C2 in axial rotation and lateral bending. In extension and flexion, the anterior screw technique was not as effective as a posterior plate with transarticular screws in providing stability.

Anterior occiput-to-axis screw fixation: part I: a case report, description of a new technique, and anatomical feasibility analysis.

STUDY DESIGN: A case report of anterior screw fixation from the axis to the occiput is described, as is the surgical technique. The pertinent anatomy is described with a radiographic assessment of the feasibility, safety, and general applicability of this technique. OBJECTIVES: To describe a novel technique of anterior occipitocervical fixation and the pertinent anatomy. SUMMARY OF BACKGROUND DATA: In unique clinical situations where posterior fixation techniques may not be possible or may have already failed, an anterior screw fixation technique may add stability to further attempts at obtaining a posterior arthrodesis. METHODS: A case report is presented, followed by a detailed description of the surgical technique. Ten normal cervical spines had radiographs and computed tomography scans with reformats reviewed to determine screw entry points, target points, and proposed screw trajectories. Following screw insertion in eight fresh frozen human cadaver spine specimens, dissection verified screw location relative to structures at risk. RESULTS: The ideal entry point is located caudal to the C2 superior facet joint in line with the medial third of the C2 superior facet. The screw is directed 25 degrees posteriorly in the sagittal plane and 15 degrees laterally in the coronal plane. The screw tip is located in the posterolateral third of the occipital condyle. Anatomic variation is considerable and makes this technique inadvisable in up to 20% of cases. Structures at risk include the vertebral artery and the hypoglossal nerve. CONCLUSIONS: This new technique of anterior fixation of the atlas to the occiput is feasible and safe if meticulous surgical planning is performed.

Comparison of outcomes for unstable lower cervical flexion teardrop fractures managed with halo thoracic vest versus anterior corpectomy and plating.

STUDY DESIGN: A retrospective cohort study with cross-sectional outcome analysis was conducted. OBJECTIVES: To compare the outcome for two groups of patients with unstable cervical flexion teardrop fractures: those treated with halo thoracic vests and those treated with anterior corpectomy and plating. SUMMARY OF BACKGROUND DATA: With the evolution of safe and effective anterior cervical plates, the treatment of unstable cervical flexion teardrop fractures has shifted from halo immobilization to surgical stabilization. Although outcomes for these treatment alternatives have been reported, the literature reflects the inherent bias of retrospective studies without standardized health-related quality-of-life outcomes and without a control or comparative group. Furthermore, study populations have lacked homogeneity with respect to fracture patterns. METHODS: For this study, 45 patients with cervical flexion teardrop fractures and at least 2 years of follow-up evaluation were identified. Of these patients, 24 were treated with a halo thoracic vest and 21 with anterior corpectomy and plating. Unstable cervical flexion teardrop fractures were defined as those exhibiting failure of the anterior spine under compression and the posterior spine in tension. The primary outcome was radiographic kyphosis at follow-up assessment. Secondary outcomes included the MOS 36-Item Short-Form Health Survey and the Cervical Spine Research Society Long-Term Follow-Up questionnaire. RESULTS: The halo thoracic vest group and the anterior corpectomy and plating group were comparable for baseline demographic and clinical data, except for neurologic deficit (67% of the halo thoracic vest group and 96% of the anterior corpectomy and plating group had neurologic deficit). Most of the injuries occurred at C5. All 45 patients had radiographic follow-up evaluation, but only 17 of the 24 patients in the halo thoracic vest group and 13 of the 21 patients in the anterior corpectomy and plating group (30 of 45 in all) completed the health-related quality-of-life outcome instruments. The mean kyphosis was 11.4 degrees in the halo thoracic vest group and 3.5 degrees in the anterior corpectomy and plating group (P < 0.001). The difference remained significant, with control used for the baseline variables. The halo thoracic vest group had five failures, four of which were subsequently managed operatively. No major intra- or postoperative complications occurred in the anterior corpectomy and plating group. There were no significant differences in the MOS 36-Item Short-Form Health Survey mental component score and the Cervical Spine Research Society subscales even after adjustment for neurologic deficit. CONCLUSIONS: The results of this study indicate that anterior cervical plating is a safe and effective treatment for cervical teardrop fractures, and that it is superior to the halo thoracic vest for restoring and maintaining sagittal alignment and for minimizing treatment failures. There does not appear to be a relation between residual kyphosis and health-related quality-of-life outcomes. Although this raises questions about the relevance of restoring sagittal alignment in the treatment and outcome of cervical flexion teardrop fractures, the study was underpowered for secondary outcomes. Therefore, the secondary outcome results must be interpreted with caution.