Spinal infections have historically been associated with significant morbidity and mortality. Current treatment protocols have improved patient outcomes through prompt and accurate infection identification, medical treatment, and surgical interventions. Medical and surgical management, however, remains controversial because of a paucity of high-level evidence to guide decision making. Despite this, an awareness of presenting symptoms, pertinent risk factors, and common imaging findings are critical for treating spine infections. The purpose of this article is to review the recent literature and present the latest evidence-based recommendations for the most commonly encountered primary spinal infections: vertebral osteomyelitis and epidural abscess.

Study Design: This is a retrospective study. Objective: The objective of this study was to evaluate lumbar spine synovial cyst recurrence rates of decompression-alone versus decompression/fusion procedures. Background: Improvements in imaging modalities allow for increased diagnosis and surgical treatment of symptomatic spinal juxtafacet synovial cysts. Conservative management may be used as a first-line management strategy, however rarely provides durable, effective relief of symptoms. Surgical treatment of spinal synovial cysts ranges from decompression and cyst excision to decompression with fusion procedures. Decompression procedures alone have a higher risk of recurrence of spinal synovial cysts. Methods: We retrospectively reviewed 87 patients undergoing surgical treatment of lumbar spinal juxtafacet synovial cysts as a single institution over 20 years. Surgical treatment consisted of either decompression versus decompression/fusion procedures. Preoperative symptoms included back pain, radiculopathy, motor deficits, or sensory deficits. The incidence of recurrence of spinal synovial cysts at the same-site or differing sites was compared between 2 categories of surgical treatment. Revision surgical procedure rates were also evaluated. Results: A total of 55 (63%) patients were treated with an index decompression-only procedure for the lumbar spinal synovial cyst compared with 32 (37%) patients treated with an index decompression and fusion procedure. Fifty-eight (68%) of the lumbar spinal cysts occurred at the L4–L5 level. There were 10 (11.5%) spinal synovial cyst recurrences in the decompression-only group, and 0 recurrences in the decompression/fusion group. Revision decompression procedures were performed in 4 of the 10 (4.6%) recurrences, and 6 of 10 (6.9%) recurrences had subsequent decompression and fusion surgery. The mean time to recurrence was 23.9±17.3 months. The mean length of follow-up was 65.1±48.6 months. Both recurrence and nonrecurrence cohorts had significant symptomatic improvement using Odom criteria. Conclusions: Decompression and cyst excision was the more common surgical treatment of lumbar spinal synovial cysts compared with decompression/fusion procedure in our study. The rate of synovial cyst recurrence and revision surgery in patients undergoing index decompression was relatively low and comparable to current literature. Symptomatic improvement of patients undergoing decompression versus decompression/fusion was similar in our study. Although the fusion may be required for the extent of pathology or coexisting instability, decompression and excision of spinal synovial cysts provide durable, effective treatment with a known, appropriate risk of recurrence and subsequent revision surgery.

Study Design: Systematic literature review. Objectives: Many studies have provided evidence that short-segment posterior fixation (SSPF—1 level above and 1 below) with screws at the fracture level (SFL) are enough to achieve stability in some injury patterns, such as burst fractures, avoiding the need for circumferential reconstruction and long-segment instrumented fusion (LSIF—at least 2 levels above and 2 below). Given the potential benefits of avoiding unnecessary fusion in mobile healthy spinal segments, we performed a systematic review of biomechanical studies comparing different spinal reconstruction techniques for fractures of the thoracolumbar spine. Methods: A systematic literature review was performed in the PubMed and OVID databases of biomechanical studies comparing biomechanical differences between techniques of spine reconstructions. Results: Eight studies were included and evaluated. Five of 6 studies reported stiffness improvement with SSPF and SFL, even comparable to circumferential fusion for a burst fracture. Two studies reported that LSPF has higher stiffness and restricts range of motion better than SSPF, but inclusion of screws in the fracture level is similar to LSPF (1 study). Finally, although SSPF is less stiff than anterior reconstruction, adding a SFL in SSPF results in similar stiffness than circumferential fusion for unstable burst fractures. Conclusions: Biomechanical studies analyzed generally suggested that SFL in SSPF may improve construction stiffness, and can even be compared with long-segment fixation or circumferential reconstruction in some scenarios. This construct option may be used to enhance stiffness in selected injury patterns, avoiding the needs of an additional anterior approach.

Mini It is unclear whether the ACS NSQIP Surgical Risk Calculator can predict 30-day complications after lumbar and cervical spinal fusions. This study shows that the Risk Calculator is only of marginal benefit in predicting outcomes in cervical fusion and unlikely to be of benefit in lumbar fusions. Study Design. Retrospective cohort study. Objective. The aim of this study was to assess the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Risk Calculator's ability to predict 30-day complications after spine surgery. Summary of Background Data. Surgical risk calculators may identify patients at increased risk for complications, improve outcomes, enhance the informed consent process, and help modify risk factors. The ACS NSQIP Risk Calculator was developed from a cohort of >1.4 million patients, using 2805 unique CPT codes. It uses 21 patient predictors and the planned procedure to predict the risk of 12 different outcomes within 30 days following surgery. Methods. A retrospective chart review was performed on patients who underwent primary lumbar and cervical fusions with at least 30-day postoperative follow-up between 2009 and 2015 at a single-institution. Descriptive statistics were calculated for the overall sample, anterior versus posterior fusion (cervical only), and single versus multilevel fusion. Logistic regression models were fit with actual complication occurrence as the dependent variable in each model and ACS estimated risk as the independent variable. The c-statistic was used as the measure of concordance for each model. Receiver-operating charateristic curves depicted the predictive ability of the estimated risks. Acceptable concordance was set at c >0.80. Results. A total of 237 lumbar and 404 cervical patients were included in the study. The Risk Calculator risk estimates significantly predicted (P < 0.001) “any complication” and “discharge to skilled nursing facility” among the cervical cohort and demonstrated no significant outcome prediction the lumbar cohort. Conclusion. The ACS Risk-Calculator accurately predicted complications in the categories of “any complication” and “discharge to skilled nursing facility” for our cervical cohort and failed to demonstrate benefit for our lumbar cohort. Although the ACS Risk-Calculator may be useful in general surgery, our findings demonstrate that it does not necessarily provide accurate information for patients undergoing spinal surgery. Level of Evidence: 3

Objective: This study evaluates the disease burden of sciatica on the US Medicare cohort. Background Data: Sciatica is a common disability that has important physical, mental, and economic effects. The Medicare Health Outcomes Survey (HOS) is a demographic and outcomes survey used to monitor the performance of Medicare Advantage health plans in the United States. The HOS includes data on demographics, chronic medical conditions, and patient-reported outcomes. Methods: Medicare HOS data for cohorts from 2007 to 2013 were obtained. Patients were placed into two categories based on the survey results: with or without a history of sciatica. Baseline demographics, chronic medical conditions, and physical health symptoms were aggregated. In addition, average VR-12 physical component summary and mental component summary scores were calculated for each group at baseline and at 2-year follow-up. A Fisher exact test was used to assess significance for categorical variables, and a t-test was used for continuous variables. VR-12 changes as small as 1 to 2 units have been found to be clinically and socially relevant. Results: The baseline cohort data of 1,000,952 patients yielded 250,869 patients (25%) who reported the diagnosis of sciatica, compared with 750,083 patients (75%) without sciatica. Patients with a history of sciatica tended to be younger, less educated, and notably with more medical comorbidities. Physical component summary outcomes were approximately 8 units lower in the sciatica group at baseline and 7 units lower at 2-year follow-up. Mental component summary outcomes were 6 units lower in the sciatica group at baseline and 5 units lower at 2-year follow-up. Conclusion: A large percentage of the US Medicare cohort suffers from symptomatic sciatica. Our study identified a 25% prevalence in the Medicare cohort. In addition, sciatica is associated with an increased incidence of comorbid medical conditions and poor health-related quality of life. Level of Evidence: Level III Study Design: Observational-Cohort Study

Study Design: This was a retrospective cohort study. Objective: The objective of this study was to assess the American College of Surgeons (ACS) Risk Calculator’s ability to accurately predict complications after cervical spine surgery. Summary of Background Data: Surgical risk calculators exist in many fields and may assist in the identification of patients at increased risk for complications and readmissions. Risk calculators may allow for improved outcomes, an enhanced informed consent process, and management of modifiable risk factors. The American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Risk Calculator was developed from a cohort of over 1.4 million patients, using 2805 unique Current Procedural Terminology (CPT) codes. The risk calculator uses 21 patient predictors (eg, age, American Society of Anesthesiologists class, body mass index, hypertension) and the planned procedure (CPT code) to predict the chance that patients will have any of 12 different outcomes (eg, death, any complication, serious complication, reoperation) within 30 days following surgery. The purpose of this study is to determine if the ACS NISQIP risk calculator can predict 30-day complications after cervical fusion. Methods: A retrospective chart review was performed on patients that underwent primary cervical fusions between January 2009 and 2015 at a single institution, utilizing cervical fusion CPT codes. Patients without 30 days of postoperative follow-up were excluded. Descriptive statistics were calculated for the overall sample, anterior versus posterior fusion, and single versus multilevel fusion. Logistic regression models were fit with actual complication occurrence as the dependent variable in each model and ACS estimated risk as the independent variable. The c-statistic was used as the measure of concordance for each model. Receiver operating characteristic curves were plotted to visually depict the predictive ability of the estimated risks. Acceptable concordance was set at c>0.80. All analyses were conducted using SAS, v9.4. Results: A total of 404 patients met the inclusion criteria for this study. Age, body mass index, sex, and a number of levels of fusion were gathered as input data the ACS NSQIP Risk Calculator. Results of Risk Calculator were compared with observed complication rates. Descriptive statistics of the Risk Calculator risk estimates showed a significant prediction of “any complication” and “discharge to skilled nursing facility” among the cohort. Because there were no deaths or urinary tract infections, no models were fit for these outcomes. Conclusions: The ACS Risk Calculator accurately predicted complications in the categories of “any complication” (P<0.0001) and “discharge to the skilled nursing facility” (P<0.001) for our cohort. We conclude that the ACS Risk Calculator was unable to accurately predict specific complications on a more granular basis for the patients of this study. Although the ACS risk calculator may be useful in the field of general surgery and in the development of new institutional strategies for risk mitigation, our findings demonstrate that it does not necessarily provide accurate information for patients undergoing cervical spinal surgery.

Study designBiomechanical cadaveric study ObjectiveTo compare biomechanical properties of a single stand-alone interbody fusion and a single-level pedicle screw construct above a previous lumbar pedicle fusion.Summary of background dataAdjacent segment disease (ASD) is spondylosis of adjacent vertebral segments after previous spinal fusion. Despite the consensus that ASD is clinically significant, the surgical treatment of ASD is controversial.MethodsLateral lumbar interbody fusion (LLIF) and posterior spinal fusion (PSF) with pedicle screws were analyzed within a validated cadaveric lumbar fusion model. L3-4 vertebral segment motion was analyzed within the following simulations: without implants (intact), L3-4 LLIF-only, L3-4 LLIF with previous L4-S1 PSF, L3-4 PSF with previous L4-S1 PSF, and L4-S1 PSF alone. L3-4 motion values were measured during flexion/extension with and without axial load, side bending, and axial rotation.ResultsL3-4 motion in the intact model was found to be 4.7 ± 1.2 degrees. L3-4 LLIF-only decreased motion to 1.9 ± 1.1 degrees. L3-4 LLIF with previous L4-S1 fusion demonstrated less motion in all planes with and without loading (p < 0.05) compared to an intact spine. However, L3-4 motion with flexion/extension and lateral bending was noted to be greater compared to the L3-S1 construct (p < 0.5). The L3-S1 PSF construct decreased motion to less than 1° in all planes of motion with or without loading (p < 0.05). The L3-4 PSF with previous L4-S1 PSF constructs decreased the flexion/extension motion by 92.4% compared to the intact spine, whereas the L3-4 LLIF with previous L4-S1 PSF constructs decreased motion by 61.2%.ConclusionsStand-alone LLIF above a previous posterolateral fusion significantly decreases motion at the adjacent segment, demonstrating its utility in treating ASD without necessitating revision. The stand-alone LLIF is a biomechanically sound option in the treatment of ASD and is advantageous in patient populations who may benefit from less invasive surgical options.

Study Design:Prospective randomized study.Objectives:To define the impact of an inexpensive, user-friendly, and reproducible lumbar pedicle screw instrumentation bioskills training module and evaluation protocol.Methods:Participants were randomized to control (n = 9) or intervention (n = 10) groups controlling for level of experience (medical students, junior resident, or senior resident). The intervention group underwent a 20-minute bioskills training module while the control group spent the same time with self-directed study. Pre- and posttest performance was self-reported (Physician Performance Diagnostic Inventory Scale [PPDIS]). Objective outcome scores were obtained from a blinded fellowship-trained attending orthopedic spine surgeon using Objective Structured Assessment of Technical Skills (OSATS) and Objective Pedicle Instrumentation Score metrics. In addition, identification of pedicle breach and breach anatomic location was measured pre- and posttest in lumbar spine models.Results:The intervention group showed a 30.8% improvement in PPDIS scores, compared with 13.4% for the control group (P = .01). The intervention group demonstrated statistically significant 66% decrease in breaches (P = .001) compared with 28% decrease in the control group (P = .06). Breach identification demonstrated no change in accuracy of the control group (incorrect identification from 32.2% pre- to posttest 35%; P = .71), whereas the intervention group’s improvement was statistically significant (42% pre- to posttest 36.5%; P = .0047).Conclusions:We conclude that a concise lumbar pedicle screw instrumentation bioskills training session can be a useful educational tool to augment clinical education.