Comparison of Outcomes in Percutaneous Fixation of Traumatic Fractures between Ankylosing Spondylitis and Diffuse Idiopathic Skeletal Hyperostosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

This study aims to analyze outcomes and complications of patients with thoracic and lumbar fractures in the setting of ankylosing spinal disorders (ASD) treated with minimally invasive surgery (MIS).

METHODS

The operative logs from 2012 to 2019 from one academic, Level I trauma center were reviewed for cases of thoracic and lumbar spinal fractures in patients with ASD treated with a MIS approach. Variables were compared between patients with ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis (DISH), and advanced spondylosis.

RESULTS

A total of 48 patients with ASD and concomitant thoracic or lumbar spinal fracture managed with an MIS approach were identified. A total of 11 patients were identified with AS, 21 with DISH, and 16 with advanced spondylosis. A total of 27 (56.3%) patients experienced complications. Complications differed between groups; DISH patients experienced a greater number of post-operative complications compared to AS and advanced spondylosis patients (P = .009). There was no significant difference in length of surgery, estimated blood loss, length of stay, readmission, and reoperation rates between AS and DISH patients. There were 3 mortalities unrelated to the surgery.

CONCLUSION

Percutaneous stabilization of patients with ankylosing spinal disorder fractures remains a viable management method. Operative characteristics were similar between AS, DISH, and advanced spondylosis patients; however, DISH patients experienced a greater number of post-operative complications.

Retrospective Analysis of Causes and Risk Factors of 30-Day Readmission After Spine Surgery for Thoracolumbar Trauma

STUDY DESIGN

Retrospective Case Series.

OBJECTIVE

This study aims to evaluate readmission rates, risk factors, and reason for unplanned 30-day readmissions after thoracolumbar spine trauma surgery.

METHODS

A retrospective chart review was conducted for patients undergoing operative treatment for thoracic or lumbar trauma with open or minimally invasive surgical approach at a Level 1 urban trauma center. Patients were divided into two groups based on 30-day readmission status. Reason for readmission, reoperation rates, injury type, trauma severity, and incidence of polytrauma were compared between the two groups.

RESULTS

A total of 312 patients, 69.9% male with an average age of 47 ± 19 years were included. The readmitted group included 16 patients (5.1%) of which 9 (56%) were readmitted for medical complications and 7 for surgical complications. Wound complications (31.3% of readmissions) were the most common cause of readmission, followed by non-wound related sepsis (18.9% of readmissions). A total of 6 patients (37.5%) required reoperation; 2 instrumentation failures underwent revision surgery, and 4 wound complications underwent irrigation and debridement. Patients with higher Injury Severity Scale (ISS) were more likely to be readmitted (27.8% vs 22.1%, P = .045). Concomitant lower limb surgery increased odds of readmission (OR, 4.40; 95% CI, 1.10-17.83; P = .037).

CONCLUSION

Spine trauma 30-day readmission rate was 5.1%, comparable to those reported in the elective spine surgery literature. Readmitted patients were more likely to sustain concomitant operative lower limb trauma. Wound complications were the most common cause of readmission, and almost half of the patients were readmitted due to surgery-related complications.

Catastrophic acute failure of pelvic fixation in adult spinal deformity requiring revision surgery: a multicenter review of incidence, failure mechanisms, and risk factors

OBJECTIVE

There are few prior reports of acute pelvic instrumentation failure in spinal deformity surgery. The objective of this study was to determine if a previously identified mechanism and rate of pelvic fixation failure were present across multiple institutions, and to determine risk factors for these types of failures.

METHODS

Thirteen academic medical centers performed a retrospective review of 18 months of consecutive adult spinal fusions extending 3 or more levels, which included new pelvic screws at the time of surgery. Acute pelvic fixation failure was defined as occurring within 6 months of the index surgery and requiring surgical revision.

RESULTS

Failure occurred in 37 (5%) of 779 cases and consisted of either slippage of the rods or displacement of the set screws from the screw tulip head (17 cases), screw shaft fracture (9 cases), screw loosening (9 cases), and/or resultant kyphotic fracture of the sacrum (6 cases). Revision strategies involved new pelvic fixation and/or multiple rod constructs. Six patients (16%) who underwent revision with fewer than 4 rods to the pelvis sustained a second acute failure, but no secondary failures occurred when at least 4 rods were used. In the univariate analysis, the magnitude of surgical correction was higher in the failure cohort (higher preoperative T1-pelvic angle [T1PA], presence of a 3-column osteotomy; p < 0.05). Uncorrected postoperative deformity increased failure risk (pelvic incidence-lumbar lordosis mismatch > 10°, higher postoperative T1PA; p < 0.05). Use of pelvic screws less than 8.5 mm in diameter also increased the likelihood of failure (p < 0.05). In the multivariate analysis, a larger preoperative global deformity as measured by T1PA was associated with failure, male patients were more likely to experience failure than female patients, and there was a strong association with implant manufacturer (p < 0.05). Anterior column support with an L5-S1 interbody fusion was protective against failure (p < 0.05).

CONCLUSIONS

Acute catastrophic failures involved large-magnitude surgical corrections and likely resulted from high mechanical strain on the pelvic instrumentation. Patients with large corrections may benefit from anterior structural support placed at the most caudal motion segment and multiple rods connecting to more than 2 pelvic fixation points. If failure occurs, salvage with a minimum of 4 rods and 4 pelvic fixation points can be successful.

Open vs Percutaneous Pedicle Instrumentation for Kyphosis Correction in Traumatic Thoracic and Thoracolumbar Spine Injuries

OBJECTIVES

Percutaneous pedicle instrumentation (PPI) has been used for the treatment of thoracic and thoracolumbar (TL) trauma. However, the ability of PPI to correct significant post-traumatic kyphosis requires further investigation. The objective of this study is to compare the amount of kyphosis correction achieved by PPI vs the traditional open posterior approach in patients presenting with significant kyphotic deformity following traumatic thoracic and TL spine injuries.

METHODS

Following Institutional Review Board approval, patients who underwent surgery for thoracic (T1-T9) or TL (T10-L2) fractures with at least 15° of focal kyphosis in a 5-year period were included in this study. Patients were separated into 2 cohorts based on surgical technique: traditional open posterior approach and minimally invasive PPI. Kyphosis correction was measured using Cobb angle 1 vertebrae above and 1 below the level of injury on sagittal preoperative computed tomography image, immediate and follow-up postoperative upright lateral radiographs. Initial degree of correction and loss of correction at the final follow-up were compared.

RESULTS

Of 91 patients included, 65 (71%) underwent open surgery and 26 (29%) underwent PPI. Open patients had 11° (95% CI, 9°-13°) of immediate correction compared with 11° (95% CI, 6°-15°) for PPI (P = 0.81). Follow-up data were available for 70 patients with a median of 105.5 days. Both groups had 1° (95% CI, 0°-2°) of loss of correction at follow-up (P = 0.82). Regardless of surgical technique, obesity (>30 kg/m²) and AO type-A compression fractures had significantly less correction. For each unit of body mass index, there was a 0.75° decrease in correction achieved (P < 0.0001). Other factors did not influence the degree of correction.

CONCLUSIONS

PPI techniques provide equivalent postoperative angular correction and maintenance of correction compared with open surgery in thoracic and TL trauma patients.

CLINICAL RELEVANCE

This study provides evidence for spine surgeons to utilize either technique for treating significant traumatic kyphotic deformity.

LEVEL OF EVIDENCE

Therapeutic 3.

Predicting Length of Stay After Thoracolumbar Trauma: A Single-Center, Retrospective Analysis

BACKGROUND

Length of stay (LOS) is a meaningful outcome measure for more efficient and effective quality of care. However, algorithms to predict LOS have yet to be created for patients who undergo surgical management for traumatic spinal fractures.

OBJECTIVES

The objectives of this study were to (1) identify preoperative, perioperative, and postoperative factors associated with increased LOS and (2) create predictive formulas to estimate LOS in thoracolumbar trauma patients who undergo surgical correction.

METHODS

This is a retrospective case series of 196 patients operated for thoracolumbar spine trauma from January 2012 to December 2017 at a level 1 trauma and academic institution. Bivariate analysis between LOS and various preoperative, perioperative, and postoperative factors was conducted to identify significant associations. Multivariate analysis was conducted to create models capable of predicting LOS.

RESULTS

LOS was significantly associated with various preoperative (eg, Charlson Comorbidity Index, Glasgow Coma Scale [GCS], injury severity score), operative (eg, length of surgery, number of instrumented segments, surgical technique), and postoperative variables (eg, complications, discharge location). Multivariate analysis of preoperative variables identified 5 significant independent predictors that could predict LOS with strong correlation with observed LOS (ρ = 0.63). With all variables considered, multivariate analysis identified 8 variables (GCS, American Society of Anesthesiologists score, neurological status, polytrauma, packed red blood cell transfusion, number of unique postoperative complications, skin complications, and discharge facility) that could predict LOS with strong correlation (ρ = 0.80).

CONCLUSIONS

Various preoperative, perioperative, and postoperative factors are significantly associated with LOS in traumatic thoracolumbar spine patients. We developed models with good predictive capacity for LOS. If validated, these models should help in risk stratifying patients for increased LOS and consequently improve perioperative patient counseling.

CLINICAL RELEVANCE

This article contributes to identifying and predicting patients who are high risk for extended LOS after traumatic thoracolumbar injuries.

LEVEL OF EVIDENCE: 4

Developing a National Trauma Research Action Plan: Results from the Neurotrauma Research Panel Delphi Survey

BACKGROUND

In 2016, the National Academies of Science, Engineering and Medicine called for the development of a National Trauma Research Action Plan. The Department of Defense funded the Coalition for National Trauma Research to generate a comprehensive research agenda spanning the continuum of trauma and burn care. Given the public health burden of injuries to the central nervous system, neurotrauma was one of 11 panels formed to address this recommendation with a gap analysis and generation of high-priority research questions.

METHODS

We recruited interdisciplinary experts to identify gaps in the neurotrauma literature, generate research questions, and prioritize those questions using a consensus-driven Delphi survey approach. We conducted four Delphi rounds in which participants generated key research questions and then prioritized the importance of the questions on a 9-point Likert scale. Consensus was defined as 60% or greater of panelists agreeing on the priority category. We then coded research questions using an National Trauma Research Action Plan taxonomy of 118 research concepts, which were consistent across all 11 panels.

RESULTS

Twenty-eight neurotrauma experts generated 675 research questions. Of these, 364 (53.9%) reached consensus, and 56 were determined to be high priority (15.4%), 303 were deemed to be medium priority (83.2%), and 5 were low priority (1.4%). The research topics were stratified into three groups-severe traumatic brain injury (TBI), mild TBI (mTBI), and spinal cord injury. The number of high-priority questions for each subtopic was 46 for severe TBI (19.7%), 3 for mTBI (4.3%) and 7 for SCI (11.7%).

CONCLUSION

This Delphi gap analysis of neurotrauma research identified 56 high-priority research questions. There are clear areas of focus for severe TBI, mTBI, and spinal cord injury that will help guide investigators in future neurotrauma research. Funding agencies should consider these gaps when they prioritize future research.

LEVEL OF EVIDENCE

Diagnostic Test or Criteria, Level IV.

Postoperative outcomes of minimally invasive pedicle screw fixation for treatment of unstable pathologic neoplastic fractures

STUDY DESIGN

Retrospective Case Series.

OBJECTIVES

Minimally invasive techniques have emerged as a useful tool in the treatment of neoplastic spine pathology due to decrease in surgical morbidity and earlier adjuvant treatment. The objective of this study was to analyze outcomes and complications in a cohort of unstable, symptomatic pathologic fractures treated with percutaneous pedicle screw fixation (PPSF).

METHODS

A retrospective review was performed on consecutive patients with spinal stabilization for unstable pathologic neoplastic fractures between 2007 and 2017. Patients who underwent PPSF through a minimally invasive approach were included. Surgical indications included intractable pain, mechanical instability, and neurologic compromise with radiologic visualization of the lesion.

RESULTS

20 patients with mean Tomita Score of 6.3 ± 2.1 points [95% CI, 5.3-7.2] were treated with constructs that spanned a mean of 4.7 ± 1.4 [95% CI, 4.0-5.3] instrumented levels. 10 (50%) patients were augmented with vertebroplasty. Majority of patients (65%) had no complications during their hospital stay and were discharged home (60%). Four patients received reoperation: two extracavitary corpectomies, one pathologic fracture at a different level, and one adjacent segment disease.

CONCLUSION

Minimally invasive PPSF is a safe and effective option when treating unstable neoplastic fractures and may be a viable alternative to the traditional open approach in select cases.

LEVEL OF EVIDENCE

4.

An updated management algorithm for incorporating minimally invasive techniques to treat thoracolumbar trauma

OBJECTIVE

Minimally invasive surgery (MIS) techniques can effectively stabilize and decompress many thoracolumbar injuries with decreased morbidity and tissue destruction compared with open approaches. Nonetheless, there is limited direction regarding the breadth and limitations of MIS techniques for thoracolumbar injuries. Consequently, the objectives of this study were to 1) identify the range of current practice patterns for thoracolumbar trauma and 2) integrate expert opinion and literature review to develop an updated treatment algorithm.

METHODS

A survey describing 10 clinical cases with a range of thoracolumbar injuries was sent to 12 surgeons with expertise in spine trauma. The survey results were summarized using descriptive statistics, along with the Fleiss kappa statistic of interrater agreement. To develop an updated treatment algorithm, the authors used a modified Delphi technique that incorporated a literature review, the survey results, and iterative feedback from a group of 14 spine trauma experts. The final algorithm represented the consensus opinion of that expert group.

RESULTS

Eleven of 12 surgeons contacted completed the case survey, including 8 (73%) neurosurgeons and 3 (27%) orthopedic surgeons. For the 4 cases involving patients with neurological deficits, nearly all respondents recommended decompression and fusion, and the proportion recommending open surgery ranged from 55% to 100% by case. Recommendations for the remaining cases were heterogeneous. Among the neurologically intact patients, MIS techniques were typically recommended more often than open techniques. The overall interrater agreement in recommendations was 0.23, indicating fair agreement. Considering both literature review and expert opinion, the updated algorithm indicated that MIS techniques could be used to treat most thoracolumbar injuries. Among neurologically intact patients, percutaneous instrumentation without arthrodesis was recommended for those with AO Spine Thoracolumbar Classification System subtype A3/A4 (Thoracolumbar Injury Classification and Severity Score [TLICS] 4) injuries, but MIS posterior arthrodesis was recommended for most patients with AO Spine subtype B2/B3 (TLICS > 4) injuries. Depending on vertebral body integrity, anterolateral corpectomy or mini-open decompression could be used for patients with neurological deficits.

CONCLUSIONS

Spine trauma experts endorsed a range of strategies for treating thoracolumbar injuries but felt that MIS techniques were an option for most patients. The updated treatment algorithm may provide a foundation for surgeons interested in safe approaches for using MIS techniques to treat thoracolumbar trauma.

Effect of Surgical Setting on Cost and Hospital Reported Outcomes for Single-Level Anterior Cervical Discectomy and Fusion

BACKGROUND

Hospitals seek to reduce costs and improve patient outcomes by decreasing length of stay (LOS), 30-day all-cause readmissions, and preventable complications. We evaluated hospital-reported outcome measures for elective single-level anterior cervical discectomy and fusions (ACDFs) between tertiary (TH) and community hospitals (CH) to determine location-based differences in complications, LOS, and overall costs.

METHODS

Patients undergoing elective single-level ACDF in a 1-year period were retrospectively reviewed from a physician-driven database from a single medical system consisting of 1 TH and 4 CHs. Adult patients who underwent elective single-level ACDF were included. Patients with trauma, tumor, prior cervical surgery, and infection were excluded. Outcomes measures included all-cause 30-day readmissions, preventable complications, LOS, and hospital costs.

RESULTS

A total of 301 patients (60 TH, 241 CH) were included. CHs had longer LOS (1.25 ± 0.50 versus 1.08 ± 0.28 days, P = .01). There were no differences in complication and readmission rates between hospital settings. CH, orthopaedic subspecialty, female sex, and myelopathy were predictors for longer LOS. Overall, costs at the TH were significantly higher than at CHs ($17 171 versus $11 737; Δ$ = 5434 ± 3996; P < .0001). For CHs, the total costs of drugs, rooms, supplies, and therapy were significantly higher than at the TH. TH status, orthopaedic subspecialty, and myelopathy were associated with higher costs.

CONCLUSION

Patients undergoing single-level ACDFs at CHs had longer LOS, but similar complications and readmission rates as those at the TH. However, cost of ACDF was 1.5 times greater in the TH. To improve patient outcomes, optimize value, and reduce hospital costs, modifiable factors for elective ACDFs should be evaluated.

LEVEL OF EVIDENCE

3.

Evaluation of Risk Factors for Postoperative Urinary Retention in Elective Thoracolumbar Spinal Fusion Patients

STUDY DESIGN

Retrospective case series.

OBJECTIVES

Postoperative urinary retention (POUR) represents a common postoperative complication of all elective surgeries. The aim of this study was to identify demographic, comorbid, and surgical factors risk factors for POUR in patients who underwent elective thoracolumbar spine fusion.

METHODS

Following institutional review board approval, patients who underwent elective primary or revision thoracic and lumbar instrumented spinal fusion in a 2-year period in tertiary and academic institution were reviewed. Sex, age, BMI, preoperative diagnosis, comorbid conditions, benign prostatic hyperplasia, diabetes, primary or revision surgery status, narcotic use, and operative factors were collected and analyzed between patients with and without POUR.

RESULTS

Of the 217 patients reviewed, 54 (24.9%) developed POUR. The average age for a patient with POUR was 67 ± 9, as opposed to 59 ± 10 for those without (P < .0001). Single-level fusions were associated with a 0% incidence of POUR, compared with 54.5% in 6 or more levels. The average hospital stay was increased by 1 day for those who had POUR (5.8 ± 3.3 vs 4.9 ± 3.9 days). There was no significant association with other demographic variables, comorbid conditions, or surgical factors.

CONCLUSIONS

POUR was a common complication in our patient cohort, with an incidence of 24.9%. Our findings demonstrate that patients who developed POUR are significantly older and have larger constructs. Patients who developed POUR also had longer in-hospital stays. Although our study supports other findings in the spine literature, more prospective data is needed to define diagnostic criteria of POUR as well as its management.

The Prevalence of Bacterial Infection in Patients Undergoing Elective ACDF for Degenerative Cervical Spine Conditions: A Prospective Cohort Study With Contaminant Control

STUDY DESIGN

Prospective cohort study.

OBJECTIVES

To determine the prevalence of bacterial infection, with the use of a contaminant control, in patients undergoing anterior cervical discectomy and fusion (ACDF).

METHODS

After institutional review board approval, patients undergoing elective ACDF were prospectively enrolled. Samples of the longus colli muscle and disc tissue were obtained. The tissue was then homogenized, gram stained, and cultured in both aerobic and anaerobic medium. Patients were classified into 4 groups depending on culture results. Demographic, preoperative, and postoperative factors were evaluated.

RESULTS

Ninety-six patients were enrolled, 41.7% were males with an average age of 54 ± 11 years and a body mass index of 29.7 ± 5.9 kg/m². Seventeen patients (17.7%) were considered true positives, having a negative control and positive disc culture. Otherwise, no significant differences in culture positivity was found between groups of patients. However, our results show that patients were more likely to have both control and disc negative than being a true positive (odds ratio = 6.2, 95% confidence interval = 2.5-14.6). Propionibacterium acnes was the most commonly identified bacteria. Two patients with disc positive cultures returned to the operating room secondary to pseudarthrosis; however, age, body mass index, prior spine surgery or injection, postoperative infection, and reoperations were not associated with culture results.

CONCLUSION

In our cohort, the prevalence of subclinical bacterial infection in patients undergoing ACDF was 17.7%. While our rates exclude patients with positive contaminant control, the possibility of contamination of disc cultures could not be entirely rejected. Overall, culture results did not have any influence on postoperative outcomes.

Effect of Surgical Setting on Hospital-Reported Outcomes for Elective Lumbar Spinal Procedures: Tertiary Versus Community Hospitals

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

As hospital compensation becomes increasingly dependent on pay-for-performance and bundled payment compensation models, hospitals seek to reduce costs and increase quality. To our knowledge, no reported data compare these measures between hospital settings for elective lumbar procedures. The study compares hospital-reported outcomes and costs for elective lumbar procedures performed at a tertiary hospital (TH) versus community hospitals (CH) within a single health care system.

METHODS

Retrospective review of a physician-maintained, prospectively collected database consisting of 1 TH and 4 CH for 3 common lumbar surgeries from 2015 to 2016. Patients undergoing primary elective microdiscectomy for disc herniation, laminectomy for spinal stenosis, and laminectomy with fusion for degenerative spondylolisthesis were included. Patients were excluded for traumatic, infectious, or malignant pathology. Comparing hospital settings, outcomes included length of stay (LOS), rates of 30-day readmissions, potentially preventable complications (PPC), and discharge to rehabilitation facility, and hospital costs.

RESULTS

A total of 892 patients (n = 217 microdiscectomies, n = 302 laminectomies, and n = 373 laminectomy fusions) were included. The TH served a younger patient population with fewer comorbid conditions and a higher proportion of African Americans. The TH performed more decompressions (P < .001) per level fused; the CH performed more interbody fusions (P = .007). Cost of performing microdiscectomy (P < .001) and laminectomy (P = .014) was significantly higher at the TH, but there was no significant difference for laminectomy with fusion. In a multivariable stepwise linear regression analysis, the TH was significantly more expensive for single-level microdiscectomy (P < .001) and laminectomy with single-level fusion (P < .001), but trended toward significance for laminectomy without fusion (P = .052). No difference existed for PPC or readmissions rate. Patients undergoing laminectomy without fusion were discharged to a facility more often at the TH (P = .019).

CONCLUSIONS

We provide hospital-reported outcomes between a TH and CH. Significant differences in patient characteristics and surgical practices exist between surgical settings. Despite minimal differences in hospital-reported outcomes, the TH was significantly more expensive.

Radiographic Evaluation of Minimally Invasive Instrumentation and Fusion for Treating Unstable Spinal Column Injuries

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Facet fusion in minimally invasive spine surgery (MISS) may reduce morbidity and promote long-term construct stability. The study compares the maintenance of correction of thoracolumbar (TL) trauma patients who underwent MISS with facet fusion (FF) and without facet fusion (WOFF) and evaluates instrumentation loosening and failure.

METHODS

TL trauma patients who underwent MISS between 2006 and 2013 were identified and stratified into FF and WOFF groups. To evaluate progressive kyphosis and loss of correction, Cobb angles were measured at immediate postoperative, short-term, and long-term follow-up. Evidence of >2 mm of radiolucency on radiographs indicated screw loosening. If instrumentation was removed, postremoval kyphosis angle was obtained.

RESULTS

Of the 80 patients, 24 were in FF and 56 were in WOFF group. Between immediate postoperative and short-term follow-up, kyphosis angle changed by 4.0° (standard error [SE] 1.3°) in the FF and by 3.0° (SE 0.4°) in the WOFF group. The change between immediate postoperative and long-term follow-up kyphosis angles was 3.4° (S.E 1.1°) and 5.2° (S.E 1.6°) degrees in the FF and WOFF groups, respectively. Facet fusion had no impact on the change in kyphosis at short term (P = .49) or long term (P = .39). The screw loosening rate was 20.5% for the 80 patients with short-term follow-up and 68.8% for the 16 patients with long-term follow-up. There was no difference in screw loosening rate. Fifteen patients underwent instrumentation removal-all from the FF group.

CONCLUSION

FF in MISS does not impact the correction achieved and maintenance of correction in patients with traumatic spine injuries.

Minimizing Blood Loss in Spine Surgery

STUDY DESIGN

Broad narrative review.

OBJECTIVE

To review and summarize the current literature on guidelines, outcomes, techniques and indications surrounding multiple modalities of minimizing blood loss in spine surgery.

METHODS

A thorough review of peer-reviewed literature was performed on the guidelines, outcomes, techniques, and indications for multiple modalities of minimizing blood loss in spine surgery.

RESULTS

There is a large body of literature that provides a consensus on guidelines regarding the appropriate timing of discontinuation of anticoagulation, aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and herbal supplements prior to surgery. Additionally, there is a more heterogenous discussion the utility of preoperative autologous blood donation facilitated by erythropoietin and iron supplementation for healthy patients slated for procedures with high anticipated blood loss and for whom allogeneic transfusion is likely. Intraoperative maneuvers available to minimize blood loss include positioning and maintaining normothermia. Tranexamic acid (TXA), bipolar sealer electrocautery, and topical hemostatic agents, and hypotensive anesthesia (mean arterial pressure (MAP) <65 mm Hg) should be strongly considered in cases with larger exposures and higher anticipated blood loss. There is strong level 1 evidence for the use of TXA in spine surgery as it reduces the overall blood loss and transfusion requirements.

CONCLUSION

As the volume and complexity of spinal procedures rise, intraoperative blood loss management has become a pivotal topic of research within the field. There are many tools for minimizing blood loss in patients undergoing spine surgery. The current literature supports combining techniques to use a cost- effective multimodal approach to minimize blood loss in the perioperative period.

Comparison of percutaneous minimally invasive versus open posterior spine surgery for fixation of thoracolumbar fractures: A retrospective matched cohort analysis

Introduction

Percutaneous minimally invasive spine surgery (MISS) is a treatment option for thoracolumbar fractures and we aim to evaluate its outcomes.

Methods

A retrospective matched cohort study of all patients with thoracolumbar fractures treated with MISS or open posterior approach.

Results

We included 100 MISS and 155 open patients. After controlling for patient characteristics, our results statistically favor MISS in mean operative time, mean intraoperative blood loss, and number of patients requiring postoperative blood transfusions within 48 h.

Conclusions

Advantages of using MISS for treatment of thoracolumbar fractures are decreased operative time, decreased blood loss, and fewer patients requiring transfusions.

Decompression Versus Fusion for Grade I Degenerative Spondylolisthesis: A Meta-Analysis

STUDY DESIGN

Meta-analysis of evidence level I to IV studies.

OBJECTIVE

To compare decompression alone versus decompression plus fusion in the treatment of grade I degenerative spondylolisthesis (DS).

METHODS

Following established guidelines, we systematically reviewed 3 electronic databases to assess studies evaluating patients with grade I DS. We stratified all patients into 2 cohorts; the first cohort underwent a decompression-type surgery, and the second cohort underwent decompression plus fusion. We noted clinical outcomes, complications, reoperations, and surgical details such as blood loss. Descriptive statistics and random-effects models were used to determine the specified outcome metrics with 95% confidence intervals (CIs).

RESULTS

In both cohorts, the pain (legs and lower back) significantly decreased and the physical component of the Short Form 36 showed better patient clinical outcomes. The decompression cohort had a 5.8% complication rate (95% CI = 1.7-2.1), and the decompression plus fusion cohort had an 8.3% complication rate (95% CI = 5.5-11.6). The reoperation rate was higher in the decompression-only cohort (8.5%; 95% CI = 2.9-17.0) compared with the decompression plus fusion cohort (4.9%; 95% CI = 2.5-7.9).

CONCLUSIONS

There does not appear to be any advantage of one procedure over the other. Patients undergoing decompression alone tended to be older with a higher percentage of leg pain, whereas patients additionally undergoing fusion tended to be younger with more lower back pain. The decompression-only cohort had fewer complications but a higher revision rate.

Biomechanical evaluation of lumbar lateral interbody fusion for the treatment of adjacent segment disease

BACKGROUND CONTEXT

Adjacent segment disease (ASD) is a well-known complication after lumbar fusion. Lumbar lateral interbody fusion (LLIF) may provide an alternative method of treatment for ASD while avoiding the morbidity associated with revision surgery through a traditional posterior approach. This is the first biomechanical study to evaluate the stability of lateral-based constructs for treating ASD in existing multilevel fusion model.

PURPOSE

We aimed to evaluate the biomechanical stability of anterior column reconstruction through the less invasive lateral-based interbody techniques compared with traditional posterior spinal fusion for the treatment of ASD in existing multilevel fusion.

STUDY DESIGN/SETTING

Cadaveric biomechanical study of laterally based interbody strategies for treating ASD.

METHODS

Eighteen fresh-frozen cadaveric specimens were nondestructively loaded in flexion, extension, and lateral bending. The specimens were randomized into three different groups according to planned posterior spinal instrumented fusion (PSF): group 1: L5-S1, group 2: L4-S1, and group 3: L3-S1. In each group, ASD was considered the level cranial to the upper-instrumented vertebrae (UIV). After testing the intact spine, each specimen underwent PSF representing prior fusion in the ASD model. The adjacent segment for each specimen then underwent (1) Stand-alone LLIF, (2) LLIF + plate, (3) LLIF + single screw rod (SSR) anterior instrumentation, and (4) LLIF + traditional posterior extension of PSF. In all conditions, three-dimensional kinematics were tracked, and range of motion (ROM) was calculated for the comparisons.

RESULTS

ROM results were expressed as a percentage of the intact spine ROM. LLIF effectively reduces ROM in all planes of ROM. Supplementation of LLIF with plate or SSR provides further stability as compared with stand-alone LLIF. Expansion of posterior instrumentation provides the most substantial stability in all planes of ROM (p <.05). All constructs demonstrated a consistent trend of reduction in ROM between all the groups in all bending motions.

CONCLUSIONS

This biomechanical study suggests potential promise in exploring LLIF as an alternative treatment of ASD but reinforces previous studies' findings that traditional expansion of posterior instrumentation provides the most biomechanically stable construct.

Outcomes of multilevel vertebrectomy for spondylodiscitis

BACKGROUND CONTEXT

The incidence of pyogenic vertebral osteomyelitis (PVO) continues to increase in the United States, highlighting the need to recognize unique challenges presented by these cases and develop effective methods of surgical management. To date, no prior research has focused on the outcomes of PVO requiring two or more contiguous corpectomies.

PURPOSE

To describe our experience in the operative management of PVO in 56 consecutive patients who underwent multilevel corpectomies (≥2 vertebral bodies) via a combined approach.

STUDY DESIGN/SETTING

Single institution retrospective cohort review between January 2002 and December 2015. All patients had been treated at an academic tertiary referral center by one of two fellowship-trained orthopedic spine surgeons.

PATIENT SAMPLE

Patient records were cross-referenced with International Classification of Diseases osteomyelitis codes and paravertebral abscess code. Inclusion criteria for the study were patients within the cohort who had adequate medical records for review, a minimum patient age of 18 years, active vertebral osteomyelitis as an indication for surgical intervention, a minimum of 1-year radiographic follow-up, and surgical intervention that included at least two complete vertebral corpectomies. Subsequently, 56 patients met the inclusion criteria and were reviewed for this retrospective analysis.

OUTCOME MEASURES

Outcomes of interest were readmission and reoperation rates related to treatment of PVO, 30-day and 1-year mortality rates, radiographic outcomes, perioperative complications, infection control, and length of stay.

METHODS

After obtaining approval from the Institutional Review Board, retrospective review was performed on records of all adults with PVO refractory to standard nonoperative treatment who underwent complete corpectomy of two or more contiguous vertebrae at a single institution between January 2002 and December 2015. This study was not funded, and no potential conflict of interest-associated biases were present.

RESULTS

Fifty-six patients were identified (63% men; mean age 56.8 years; mean radiographic follow-up 2.8 years). Median length of stay was 13 days with nearly half readmitted (47%) after a median of 222.5 days after surgery. Twelve (22%) posterior revisions were required after a median 54 days for infection, painful or failed hardware, proximal junction kyphosis, adjacent level disease, or extension of the fusion. Thirty-day and 1-year mortality rates were 7.14% and 19.6%, respectively, with an infectious etiology as the most common cause of death.

CONCLUSIONS

Multilevel vertebral corpectomy for treatment of refractory vertebral osteomyelitis is associated with relatively high rates of complications and mortality compared with historical controls for 1 or 2 level procedures. We found clinical resolution and absence of complications requiring return to the operating room in 75% of patients when complete extirpation of the involved vertebrae is achieved. Our findings suggest multilevel anterior corpectomies with posterior stabilization may be a reasonable surgical option when approaching patients with complicated spondylodiscitis.

Low-Density Pedicle Screw Constructs for Adolescent Idiopathic Scoliosis: Evaluation of Effectiveness and Cost

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine whether a low-density (LD) screw construct can achieve curve correction similar to a high-density (HD) construct in adolescent scoliosis.

METHODS

Patients treated operatively for idiopathic scoliosis between 2007 and 2011 were identified through a database review. A consistent LD screw construct was used. Radiographic assessment included percent correction of major and fractional lumbar curves, T5-T12 kyphosis, and angle of lowest instrumented vertebra (LIV). Costs were compared with HD constructs.

RESULTS

Thirty-five patients were included in the analysis. Ages ranged from 12 to 19 years (mean = 14.9 years). Average screw density was 1.2 screws per level (range = 1.07-1.5 screws). Mean percent curve correction at latest follow-up: major curve, 66.9%; fractional lumbar curve, 63%. Average postoperative thoracic kyphosis: 29.5°. Mean LIV angle: 5.6°. Average construct cost was $14 871 per case compared with $23 840 per case if all levels had been instrumented with 2 screws, amounting to an average savings of $9000.

CONCLUSIONS

Our LD screw construct is among the lowest density constructs reported and achieves curve correction comparable to HD constructs at substantially lower cost.

Biomechanical comparison of the pullout strengths of C1 lateral mass screws and C1 posterior arch screws

BACKGROUND CONTEXT

Conditions of the atlantoaxial complex requiring internal stabilization can result from trauma, malignancy, inflammatory diseases, and congenital malformation. Several techniques have been used for stabilization and fusion. Posterior wiring is biomechanically inferior to screw fixation. C1 lateral mass screws and C1 posterior arch screws are used for instrumentation of the atlas. Previous studies have shown that unicortical C1 lateral mass screws are biomechanically stable for fixation. No study has evaluated the biomechanical stability of C1 posterior arch screws or compared the two techniques.

PURPOSE

The purpose of the study was to assess the differences in the pullout strength between C1 lateral mass screws and C1 posterior arch screws.

STUDY DESIGN

Biomechanical testing of pullout strengths of the two atlantal screw fixation techniques.

METHODS

Thirteen fresh human cadaveric C1 vertebrae were harvested, stripped of soft tissues, evaluated with computed tomography for anomalies, and instrumented with unicortical C1 lateral mass screws on one side and unicortical C1 posterior arch screws on the other. Screw placement was confirmed with postinstrumentation fluoroscopy. Specimens were divided in the sagittal plane and potted in polymethylmethacrylate. Axial load to failure was applied with a material testing device. Load displacement curves were obtained, and the results were compared with Student t test. DePuy Spine, Inc. (Raynham, MA, USA) provided the hardware used in this study.

RESULTS

Mean pullout strength of the C1 lateral mass screws was 821 N (range 387-1,645 N ± standard deviation [SD] 364). Mean pullout strength of the posterior arch screws was 1,403 N (range 483-2,200 N ± SD 609 N). The difference was significant (p=.009). Five samples (38%) in the posterior arch group experienced bone failure before screw pullout.

CONCLUSIONS

Both unicortical lateral mass screws and unicortical posterior arch screws are viable options for fixation in the atlas. Unicortical posterior arch screws have superior resistance to pullout via axial load compared with unicortical lateral mass screws in the atlas.

A novel radiographic targeting guide for percutaneous placement of transfacet screws in the cervical spine with limited fluoroscopy: A cadaveric feasibility study

Background

We describe a technique for percutaneous transfacet screw placement in the cervical spine without the need for lateral-view fluoroscopy.

Methods

Previously established articular pillar morphometry was used to define the ideal trajectory for transfacet screw placement in the subaxial cervical spine. A unique targeting guide was developed to allow placement of Kirschner wires across the facet joint at 90° without the guidance of lateral-view fluoroscopy. Kirschner wires and cannulated screws were placed percutaneously in 7 cadaveric specimens. Placement of instrumentation was performed entirely under modified anteroposterior-view fluoroscopy. All specimens were assessed for acceptable screw placement by 2 fellowship-trained orthopaedic spine surgeons using computed tomography. Open dissection was used to confirm radiographic interpretation. Acceptable placement was defined as a screw crossing the facet joint, achieving purchase in the inferior and superior articular processes, and not violating critical structures. Malposition was defined as a violation of the transverse foramen, spinal canal, or nerve root or inadequate fixation.

Results

A total of 48 screws were placed. Placement of 45 screws was acceptable. The 3 instances of screw malposition included a facet fracture, a facet distraction, and a C6-7 screw contacting the C7 nerve root in a specimen with a small C7 superior articular process.

Conclusions

Our data show that with the appropriate radiographic technique and a targeting guide, percutaneous transfacet screws can be safely placed at C3-7 without the need for lateral-view fluoroscopy during the targeting phase. Because of the variable morphometry of the C7 lateral mass, however, care must be taken when placing a transfacet screw at C6-7.

Clinical Relevance

This study describes a technique that has the potential to provide a less invasive strategy for posterior instrumentation of the cervical spine. Further investigation is needed before this technique can be applied clinically.

Neurologic deficit following percutaneous vertebral stabilization

STUDY DESIGN

A retrospective review.

OBJECTIVE

The purpose of this study is to document a series of cases of neurologic deficit following percutaneous vertebral stabilization, to identify patterns of neurologic injury, and to describe potential methods for avoiding these injuries.

SUMMARY OF BACKGROUND DATA

Percutaneous vertebral stabilization procedures, including vertebroplasty and kyphoplasty, have become a widely used for the treatment of osteoporotic vertebral compression fractures, primary and metastatic vertebral tumors, and traumatic burst fractures. Despite an increasing array of indications, there have been few reports of adverse events. Neurologic complications associated with vertebroplasty and kyphoplasty have been described previously as case reports and have generally been considered as infrequent and minor in severity.

METHODS

The clinical course of 14 patients with documented loss of neurologic function following percutaneous vertebral cement augmentation was retrospectively reviewed.

RESULTS

The average patient age was 74.9 years (range, 46-88 years) with 3 male and 11 female patients. Four patients underwent a vertebroplasty procedure while 10 were treated with kyphoplasty. Six patients developed neurologic deficits acutely (<24 hours of procedure). The remaining 8 patients developed neurologic symptoms at an average of 37.1 days (range, 3-112 days) postprocedure. Neurologic deficits were recorded as ASIA A in 4 patients, ASIA B in 2 patients, ASIA C in 1 patient, and ASIA D in 7 patients. Twelve of 14 patients (85.7%) required revision open surgical intervention for treatment of their neurologic injury.

CONCLUSION

Percutaneous vertebroplasty and kyphoplasty have been reported to be safe options for the treatment of painful osteoporotic vertebral fractures. Although complications are infrequent, there remains the potential for catastrophic neurologic injury. Physicians performing these procedures need to be aware of these potential complications and be prepared to respond in an emergent manner (surgically) if a need arises.

A biomechanical comparison of sacral pedicle screw salvage techniques

STUDY DESIGN

Biomechanical cadaver study.

OBJECTIVES

The purpose of our study was to compare the pullout strength of standard, expandable, and cement-augmented pedicle screws.

SUMMARY OF BACKGROUND DATA

Salvage procedures are needed to restore the stability of lumbosacral arthrodesis when pedicle screw fixation in the sacrum fails.

METHODS

Thirteen pairs of sacral (S1) pedicles were implanted initially with 7-mm tapped monoaxial stainless steel pedicle screws (Moss Miami, Depuy Spine, Raynham, MA) inserted under fluoroscopy with bicortical purchase. The screws were distracted axially at a rate of 6 mm/min to measure pullout strength. One pedicle of each pair was assigned randomly to be revised with an expandable pedicle screw (omega-21 Spinal Fixation System, EBI Medical Systems, Parsippany, NJ); the contralateral pedicle was revised with a screw augmented with polymethylmethacrylate (Simplex P, Howmedica, Mahwah, NJ). The screws then were retested as before to measure pullout strength.

RESULTS

Expandable screws (391 +/- 28 N) and polymethylmethacrylate-augmented screws (599 +/- 28 N) exhibited significantly greater pullout strength than their respective initial standard pedicle screws (145 +/- 28 N and 156 +/- 28 N).

CONCLUSIONS

Our results suggest that expandable pedicle screws may provide sufficient fixation, but these results need clinical verification.

Accuracy of computed tomography in assessing thoracic pedicle screw malposition

OBJECTIVE

Transpedicular instrumentation of the thoracic spine is potentially dangerous because of the close proximity of vital structures and the morphologic variability seen. Computed tomography has become the gold standard in evaluating the position of thoracic pedicle screws in vivo. Unfortunately, despite its common use, the accuracy of computed tomography has not been adequately investigated. The objective of this work was to evaluate the accuracy of computed tomography in evaluating the position of thoracic pedicle screws.

METHODS

One hundred ninety-four thoracic pedicles in nine cadaveric specimens were instrumented and evaluated postoperatively with computed tomography and open dissection. Computed tomography films were assessed by three blinded observers who noted the position of each pedicle screw on two separate occasions. These data were subsequently compared with the open dissection data.

RESULTS

Computed tomography was found to be 76 +/- 16% sensitive and 75 +/- 13% specific when compared with open dissection. Overall accuracy was 76 +/- 8%. Intraobserver accuracy was 79 +/- 5% in assessing thoracic pedicle screws by computed tomography. Fair to moderate degree of agreement was demonstrated for both interobserver and intraobserver data using kappa values.

CONCLUSIONS

Computed tomography was found to be relatively insensitive in assessing thoracic pedicle screw position. In the face of postoperative complications, surgical exploration and hardware removal may still be necessary despite negative computed tomography.

Radiographic predictors of outcome after long fusion to L5 in adult scoliosis

Radiographic factors that correlate with outcome following long posterior fusion to L5 for adult scoliosis were investigated. Measurement of thoracic, lumbar, and fractional lumbosacral curves, L5 obliquity, lumbar and L5-S1 lordosis, coronal balance, sagittal balance, and L5-S1 disc height were performed on preoperative, postoperative, and follow-up 36-in posteroanterior/lateral radiographs. Of 16 patients, 14 were female (88%) and 2 male (12%). Average follow-up was 32 months (8-78 months). Scoliotic curves demonstrated stable corrections; however, lumbar and L5-S1 lordosis decreased and sagittal decompensation worsened. Ten patients (62%) had no evidence of transitional degeneration. Six patients (38%) had radiographic evidence of L5-S1 degeneration, and three (19%) underwent revision. Patients with good preoperative sagittal balance, preserved lumbar lordosis, good postoperative fractional curve correction, and L5-S1 disc height preservation are most likely to benefit from posterior fusion to L5, avoiding sacral fusion, for adult scoliosis.

Preliminary results of staged anterior debridement and reconstruction using titanium mesh cages in the treatment of thoracolumbar vertebral osteomyelitis

BACKGROUND CONTEXT

Vertebral osteomyelitis can be successfully treated with spinal immobilization and parenteral antibiotics. Failure of medical therapy may necessitate surgical treatment consisting of anterior debridement and structural anterior column reconstruction. Autologous structural bone graft has traditionally been the gold standard in anterior column reconstruction. Because of the morbidity related to graft harvest, vertebral body replacement cages have emerged as a viable option for reconstructing a deficient anterior column.

PURPOSE

To evaluate the efficacy of titanium mesh cages in the reconstruction of anterior column defects in the presence of active pyogenic infection.

STUDY DESIGN

Prospective case series.

METHODS

Eleven patients underwent operative treatment for osteomyelitis of the thoracolumbar spine using staged anterior debridement and reconstruction with cylindrical titanium mesh cages followed by delayed posterior spinal fusion with pedicle screw instrumentation during a 2-year period. Patients were postoperatively evaluated clinically and radiographically.

RESULTS

Follow-up averaged 17+/-9 months. Average increase in kyphosis of 10+/-6 degrees corresponding to 4+/-4 mm loss in the height (subsidence) of the anterior construct. One patient died during revision surgery for hardware failure. Seven of the remaining 10 patients have not required antibiotics after the initial postoperative course of treatment. Three patients are maintained on chronic suppressive therapy as a precaution. There has been no evidence of recurrence or residual infection in any patient. Seven of the 10 patients were pain free at latest follow-up. There has been one case of pseudarthrosis.

CONCLUSION

Cylindrical titanium mesh can be used with consistently good results for large anterior column defect reconstructions even in the face of active pyogenic infection. In our cohort of patients with pyogenic vertebral osteomyelitis, the use of titanium mesh cages has not been associated with early recurrence of infection.

Rheumatoid arthritis of the cervical spine

BACKGROUND CONTEXT

Rheumatoid arthritis affects over 2 million patients in the United States. It is the most common inflammatory disorder of the cervical spine. The natural history is variable. Women tend to be more commonly involved than men. Atlantoaxial instability is the most common form of cervical involvement and may occur either independently or concomitantly with cranial settling and subaxial instability. Cervical spine involvement can be seen in up to 86% of patients and neurologic involvement in up to 58%. Myelopathy is rare but when present portends a poor prognosis. What is frustrating for clinicians treating these patients is that pain cannot be equated with instability or instability with neurologic symptoms. The goal is to identify patients at risk before the development of neurologic symptoms. Both radiographic and nonradiographic risk factors play an important role in the surgical decision-making process.

PURPOSE

We will describe the current concepts in rheumatoid arthritis of the cervical spine. Emphasis is placed on the natural history, anatomy, pathophysiology and decision-making process.

STUDY DESIGN

A review of the current concepts of rheumatoid arthritis of the cervical spine.

METHODS

MEDLINE search of all English literature published on rheumatoid arthritis of the cervical spine.

RESULTS

Rheumatoid arthritis of the cervical spine was first described by Garrod in 1890. The prevalence has been estimated to be 1% to 2% of the world's adult population. Despite its prevalence, the etiology of rheumatoid arthritis remains unknown. Because of its potentially debilitating and life-threatening sequelae in advanced disease, rheumatoid arthritis in the cervical spine today remains a high priority to diagnose and treat.

CONCLUSIONS

Many aspects of the natural history and pathophysiology of the rheumatoid spine remain unclear. The timing of operative intervention in patients with radiographic instability and no evidence of neurologic deficit is an area of considerable controversy. Continued surveillance into the natural history of the rheumatoid spine is required.